The Scientific Basis of National Progress/II

It is not highly necessary after what has been already said in these pages, to adduce much evidence to show that scientific discoveries, either directly or through the medium of the inventions based upon them, have been a great cause of mental and moral progress. As however there are many persons who do not perceive the dependence of such progress, and especially of moral advance, upon science, a few of the chief relations of those subjects to each other may be pointed out.

The dependence of mental progress upon science may be rendered manifest in several ways:—1st. By showing that new scientific knowledge is continually extending and modifying our views of existing things. 2nd. That inventions based upon scientific discoveries have aided and extended our mental powers:—3rd. That mental phenomena may be made the subject of experiment, observation, analysis, and inference:—4th. That the criteria of truth, and the mental powers and processes employed for discovering and detecting truth, are the same in mental as in physical science, and, 5th. That mental action is subject to the great principles and laws of science. And moral progress may be proved to have a scientific basis:—1st. By shewing that moral actions are a class of mental actions, and therefore subject to the same fundamental laws and influences:—2nd. That the discovery of new scientific knowledge, and the use of inventions based upon it, often conduce to morality:—3rd. That moral phenomena may be made the subject of experiment, observation, analysis, and inference:—4th. That the criteria of truth, and the mental faculties and processes employed, in discovering truth, are the same in moral as in physical science:—5th. That the fundamental rules of morality are subject to the great principles of science:—6th. That moral improvement follows in the wake of scientific advance:—and 7th. By showing the moral influence of experimental research in imparting "the scientific spirit;" promoting a love of truth; dispelling ignorance and superstition; detecting error; imparting certainty and accuracy to our knowledge; inculcating obedience to law; producing uniformity of belief; aiding economy and cleanliness, promoting humanity, &c, &c. Each of these will be treated with extreme brevity.

The chief object of this chapter is only to shew that mental action is largely consistent with the great principles of science; not that in our present state of knowledge, mental phenomena can be entirely explained by them, or that mental actions involve nothing more than physical and chemical processes.

That mental progress is advanced by scientific discovery is a common circumstance. Our ideas of facts, our knowledge of general principles, our views of man, of nature, and of the Universe; and even our modes of thought, have been gradually and profoundly changed by the new knowledge acquired by means of scientific research. This truth is capable of being most extensively illustrated by a multitude of facts in the whole of the sciences, and in the arts, manufactures, and other subjects dependent upon science. For example, in astronomy, great changes, produced by the results of scientific discovery have taken place in our ideas respecting the magnitude of Space and of the Heavenly bodies, the constitution, form, and motion of the Earth, the functions of the Sun and Moon, the distances of the Sun and fixed Stars, the nature of eclipses and comets; and a great many other matters. In terrestrial physics, the mental advances have been equally great in our ideas respecting the causes of tides and of winds, the pressure of the atmosphere, the existence and course of the Gulf Stream, the physical conditions of the Equator and Poles, the conditions upon which day and night, summer and winter depend, the depth of the ocean, the height of the atmosphere, the cause of rainbows, of rain, hail, snow, mist and dew, of thunder and lightning, the composition of air, water, mineral, and organic substances, and other most numerous and varied phenomena. In the subjects of heat, light, electricity, magnetism, chemistry, vegetable and animal physiology, psychology and morality, and the more concrete subjects depending upon them, such as politics, trade, commerce, government, &c., our ideas have equally advanced, in consequence of scientific research; and to fully describe the mental progress resulting from discovery in nearly all branches of human knowledge would require a series of books to be written on the History of all the Sciences.

Other causes also, which I need hardly mention, besides scientific discovery, have of course contributed to the mental progress of mankind. We arrive at true ideas, not only by the more certain and systematic process employed in scientific research, but largely also by the uncertain method of trusting to instinct and habit, by adopting dogmatic opinions, and by the semi-scientific plan of following empirical rules.

Dogma and empiricism, in nearly all subjects, has rendered immense service to mankind. Contemporaneously with the progress produced by new knowledge, the mental condition of man has been maintained and prevented from receding, by the combined influence of hereditary mental proclivity, acquired habit, promulgation of dogmatic opinions and empirical rules, and by previously known verified truth. Religious belief has thus been the forerunner of Science. Dogma and empiricism are indispensable agents of civilization; they cannot be dispensed with by the great mass of mankind, who have not the time at command, nor possess the other means, necessary for acquiring verified knowledge. They afford rough and ready guides and useful "rule of thumb" methods, though less certain and less accurate than those afforded by verified and definite science.

That various inventions, based upon scientific discoveries, have greatly aided and extended our mental powers is quite certain. The discovery of the properties of a mixture of solution of nutgalls and green vitriol, has, through the invention of ink, exercised an immense influence in promoting the mental developement of mankind; and the discovery of the properties of esparto grass and other materials for making paper has contributed to this result. Every discovery also resulting in inventions which facilitated the transmission of intelligence has had a similar effect. Amongst these are magnetism, which, in the mariner's compass greatly assisted navigation and the conveyance of letters by sea; and the steam engine which facilitated the transmission of letters by land and by water; the electric telegraph, the telephone, and other contrivances for transmitting ideas, have also greatly promoted mental advance. The steam engine, by largely abolishing physical drudgery, gave time for study and mental and moral improvement. It has been said that "it is impossible to lay down a railway without creating an improved intellectual influence. It is probable that Watt and Stephenson will eventually modify the opinions of mankind, almost as profoundly as Luther and Voltaire." Photography has exercised an immense intellectual influence of an improved kind, by making common to all mankind views of the beautiful scenery of all parts of our globe, and portraits of individuals of all nations and of all classes of society. Processes of printing from electrotype plates, pictures and letter-press, upon the paper wrappers used by grocers and other tradesmen, have also carried into the homes of millions of poor persons truthful ideas and an improved intellectual influence. The invention of steel pens, of which a thousand millions are made yearly in Birmingham alone, must also have considerably aided intellectual progress. The various calculating machines used by merchants, the copying presses, papyrographs, and the numerous inventions for copying and multiplying letters and circulars and for domestic printing, have saved intellectual toil, and promoted the diffusion of intelligence. These are only a few of the numerous ways in which inventions based upon scientific discoveries, have resulted in mental progress.

Less perhaps has been done in the way of actual definite scientific experiments upon mental actions and processes than in almost any other department of science, and this is partly accounted for by the fact that the other sciences require to be largely advanced before we can use them to examine mental action, and partly also because (as occasionally happens) the latter has been a neglected subject of research. During the past few years however, various experimental investigations have been made, especially by Donders in Holland, and Mosso in Turin, for the purpose of elucidating the physical conditions of mental action; and it has been found that instead of an act of thought being instantaneous, as was formerly believed, it requires a variable time. Numerous desultory experiments made upon dreamers, and with drugs, alcohol, &c., upon persons in the waking state, also prove that mental phenomena are amenable to scientific research. F. Galton has even proposed experiments and methods for measuring the mental faculties of different persons. The effects of exciting different parts of the brain of animals by means of electric currents, and the localization of the functions of the brain effected by the experiments of Ferrier, Hirtzig and others, also tend to throw further light upon mental phenomena. The fact alone that mental actions and conditions may be made the subject of experiment, and consequently of observation, comparison, analysis and inference, proves that they may be rendered sources of new facts and principles, and are therefore within the domain of science. As the dependence of mental phenomena upon physical conditions has been clearly demonstrated, an extensive reduction of them to scientific laws is only a question of time and labour.

The principles of nature and the modes of mental action are the same for all men. It necessarily follows from the essential nature of truth and the invariability of the chief methods of detecting it, that the criteria of truth in mental science, and the mental powers and processes by which truth is arrived at and detected in that science, are essentially the same as in the physiological, chemical, and physical ones. In each of these subjects, we first, either with or without the aid of experiment, make observations, record facts, compare them, and draw conclusions from our comparisons; we also group the facts, and the conclusions, in every possible way, and then draw other conclusions; we also analyse, combine, and permutate the various truths arrived at, and cross examine the evidence in every possible manner in order to extract from it the greatest amount of new knowledge. And in each case we employ as the criteria of truth, the test of consistency with the whole of the evidence bearing upon the case, and especially with the great principles of science. We determine what is true, chiefly by comparison with those principles, because they are the most firmly established true ones and the most universal. There is no royal road to truth, and no special mental faculty for detecting it in any subject; and it is in consequence of our mental faculties being so very finite that we have no easier way of arriving at truth.

No dogmatic teaching can ever, except by accident, fully explain to man the true nature of mind; and only in proportion as man becomes enlightened by extension of new scientific knowledge, especially in physiology, will he be able to view himself in a true aspect apart from his consciousness. Science penetrates deeper than metaphysical speculation, into the nature of mental action, chiefly because metaphysics deals only with old ideas, whilst science furnishes us with new experience and therefore with new conceptions and wider evidence.

Fallacies are very prevalent, every subject of human study is liable to a very large class of errors arising from the extremely imperfect state of our knowledge, and in very few subjects is our ignorance as great as in that of mental and moral phenomena. Every different subject of study also, has, in consequence of its special peculiarities, its own peculiar class of fallacies, into which the student of it is likely to be led, unless he is previously guarded against them. In accordance with this truth, the study of man's nature, especially the mental and moral portions, is particularly liable to a class of errors arising from the circumstance, that the phenomena to be observed and the observing power are intimately connected together, each influencing and disturbing the other. The obstacles to our arriving at truth in the study of mental and moral actions, are greater and more frequent, the more nearly and intimately related the phenomena to be observed and contemplated, are to the observing and contemplating faculty, or rather to the contemplative action. When the two mental actions are extremely intimate, as when attention is directed to the action of will (which is itself a conscious act of attention) undisturbed thought becomes very difficult; and when further, the contemplative faculty attempts to contemplate itself, as when consciousness attempts to observe consciousness, in order to define it, the attempt results in almost complete failure, probably because the two actions (observing and being observed) being opposite in kind, cannot coexist at the same time in the same structure. Knowledge of the exact nature of consciousness therefore, will probably only be arrived at by indirect means, when physiological and other knowledge is sufficiently advanced.

Consciousness, when uncorrected by sufficient knowledge and inference, is a great source of error. That which we feel, we think exists whether it does or not, until the subject is correctly explained to us. The incessant and irresistible obtrusion of consciousness exercises dominion over every mind, even of our greatest thinkers, and causes disturbance and interruption in nearly every train of thought. It is largely the cause of some of our most general ideas and emotions and insensibly influences our views of man and nature. It produces true impressions as well as erroneous ones. It is a cause of the feeling that an occult spirit exists within us independent of our material structure. Combined with the almost equally persistent impression of the uniformity of nature, it largely produces the idea that the spirit within us, will live and be active for ever. And by uniting with the frequent impressions of failure of our efforts and desire for more perfect enjoyment, it largely originates the idea of everlasting happiness.

It is in accordance with modern scientific knowledge, to view the mind, not as a collection of distinct faculties, but rather as a single kind of power, like each of the physical forces, having several different modes of action; and as that which perceives, thinks, and wills. Its oneness is shewn by its inability to be simultaneously occupied by several diverse feelings, thoughts, or volitions, and by our incapacity to think of many varied ideas at once; the more ideas also or objects we attempt to perceive at once, the less we realize of each. In proportion as the mind is engaged upon one idea, so is it also unable to be occupied with another. Strong feelings exclude intellectual action. The mind can only execute several actions at a time, provided they have been rendered more or less automatic by habit, &c., but as all mental acts are in different degrees imperfectly automatic, and require more or less attention, and each individual mind is limited in its power, every such act withdraws a portion of attention from the more engrossing ideas. Power of mind and power of maintaining attention are nearly synonymous.

The recognised fundamental elements of mind are Receptivity and Perception of impression: Retentiveness of impression: Perception of agreement (or similarity) of impression: and Perception of difference of impression. All purely mental acts appear to be resolvable into these.

Many persons still entertain the idea that mental actions are largely independent of the natural conditions to which physiological, chemical, and physical phenomena are subject. The unscientific mind is readily beguiled by easy schemes of mental action, or simple systems of mental and moral philosophy, unaware that great abstract truths often require deep thought to discover them, or even to perceive them when discovered and published. "A false notion, which is clear and precise, will always meet a greater number of adherents in the world than a true principle which is obscure." It is not until unscientific persons have become used to advanced scientific ideas and nomenclature, and knowledge as so far progressed as to enable thinking men to illustrate those ideas freely in familiar language, that great abstract truths are believed by the public. The ordinary and simple theory of the operations of the human mind is, that they often arise without any cause, and are frequently not obedient to ordinary influences, and this idea is still entertained and promulgated even by some of our most popular ministers of truth. It is therefore necessary in order to further prove that new scientific knowledge is really a basis of mental progress, to point out a few of the chief ways in which mental action essentially depends on scientific principles, and to adduce a few instances in which other substances than brain exhibit essentially similar phenomena. To shew this however in a more satisfactory manner would require a large treatise to be written upon the subject.

The human brain and mind are evidently subject to the ordinary laws of matter and energy. Receptivity and retentiveness of impression is not only a property of brain, but of all solid matter without exception. Moser's pictures, and Chinese mirrors, the impressions on each being reproducible by warm breath, are examples of this. And as these two properties are fundamental elements of mind, they must be present in and essential to, every mental action.

All phenomena require time and all matter occupies space; thought and brain are no exception to this. Whilst all persons say "I must have time to think," many believe that thought is instantaneous. Time is a necessary condition of all thought, and therefore of all comparison, inference, imagination, and mental analysis; it takes time even to form an idea, or draw an inference from it, and the two cannot be formed simultaneously. Professor Donders, of Utrecht, has invented what he terms a Noëmatachograph for registering the amount of time occupied in mental processes, and by the aid of that instrument has ascertained that the time required by a man of middle age to perform a single act of simple thought is about one twenty-fifth part of a second. It has also been ascertained that the time required is longer in some persons than in others; and longer if the subject of thought is one with which the thinker is not familiar. Mosso, by means of an instrument which he calls a Plethysmograph, has shewn, that during mental action, either in the waking state, or in dreaming, there is a greater amount of blood determined to the brain, and more during difficult than during easy mental action. These are instances of scientific research casting a light upon mental processes.

Coexistence of matter and energy is another great truth which appears to be applicable to all nature; wherever there is matter, there is either active or stored up power; and as particular forms of energy are in some cases most exhibited by particular kinds of substance, (as magnetism by iron), so mind is associated with living brain. As also we never see the physical powers exhibited except by material substance, so have we never yet observed mental action in a space devoid of material. The most perfect vacuum yet produced contains many millions of particles of substance in each cubic inch. Of all the countless number of scientific phenomena observed since men have been able to reliably investigate, not one has afforded us conclusive evidence of mental action entirely independent of these conditions. In accordance also with the usual truth in science, that complicated action requires complex structures; mind, being the most intricate action, is manifested by the most complicated body.

Mind, like each of the physical forces may be viewed as a mode of energy; it is essentially dynamic; activity or change, within or without us, appears to be the original source of all our mental impressions, and the cause of their re-excitement in an act of memory. A man's mind, being continually excited by circumstances, must be active whether he will or no, and if it does not possess sufficient truthful ideas entirely to occupy it, it must be more or less occupied with erroneous ones. "We can neither feel, nor know, without a transition or change of state—and every cognition, must be viewed as in relation to some other feeling, or cognition," (Bain. Mental and Moral Science, p. 83); i.e. the mental effect of impressions upon us depends upon our immediately previous mental state; consciousness and perception appear to be based upon cerebral change or activity; after strong excitement of consciousness an increased amount of acid products is found in the secretions. "It is a general law of the mental constitution, more or less recognised by inquirers into the human mind, that change of impression is essential to consciousness in every form," (Bain. Emotions and Will, 3rd edi. p. 550). A sufficient degree also of such change is a necessary condition of conscious perception; it is the stronger or more rapid only of mental changes that excite our consciousness.

We perceive nearly all things by means of a difference of impression which they make upon us; by contrast. That which makes no such difference of impression, such as the great uniformities of time and space, makes no immediate impression upon us. We only know of the existence of those uniformities by inference from our perceptions of sequences or of relative difference. Although the Earth moves at the rate of 62,000 miles an hour in its orbit, consciousness does not perceive it. If also there was no error, we should be less immediately able to discern truth, without pain we should lose much of the enjoyment of pleasure. Without the contrast of imperfection we could not directly appreciate perfection.

This principle of "relativity," or of change of impression, operates both in the phenomena of dead and living matter and in those of mind; the selenium in a photophone is kept in a state of motion or activity, not by a beam of uniform light, but only by one which changes; electrical action is excited by a relative difference of friction, of temperature, of chemical action, &c.; chemical action also often results from a relative difference of property of two bodies. That the most inscrutable phenomenon of mind, viz., consciousness, is largely dependent upon relative physical and chemical conditions, is proved by the powerful influence which alcohol, chloroform, opium, haschish, and other substances, have in exciting or depressing it. These facts prove that excitement of consciousness or mental action depends upon precisely the same general condition, viz.: change of impression, as the excitement of some of the physical forces; and that mind possesses a similar property to the physical forces of being changed by inequality of impression. Whilst copious evidence is available to shew that the mind is excitable by physical causes, no more conclusive proof exists that a mental impression arises without a natural cause, than that a physical one, such as a photographic impression, arises in that way. Abundant evidence of non-creation of ideas out of nothing might be adduced; even imagination and invention are subject to this limit, because an unlimited number of new conceptions cannot be formed from a limited number of previous ideas.

The dependence of the mind (like any other mode of energy) upon physical conditions, is further proved by the fact that the mental and moral states of a man are largely governed by sensation; if the latter is unhealthy it makes the mind so, and it makes some difference what the part of the body is in which the sensation exists; most commonly it is the viscera. The mind is also intimately dependent upon the physical condition of the brain, and is largely affected by the quantity and quality of the blood in that organ.

The most fundamental principle which pervades every one of the sciences, and agrees with the actions of every natural form of energy without exception, including mind, is, that of consistency or non-contradiction. No machine or scientific apparatus of any kind can perform two contradictory acts at the same time. It is both a physiological and psychological fact, that we cannot experience two contradictory sensations, nor perceive two contradictory ideas at the same instant. We can neither feel, perceive, nor observe, one thing, whilst we are feeling, perceiving, or observing, one of a contradictory nature; nor can we perform any two contradictory acts of comparison, inference, imagination, or volition, simultaneously. As also two mental actions are often not exactly alike, or entirely harmonious, they must so far as they are really contradictory, be mutually exclusive; and one of them must partly prevent the other, the strongest one prevailing, and this general truth is commonly though not explicitly, recognised in the maxim, that to do anything well, we must do only one thing at a time. In accordance with the universal truth, that contradictions cannot co-exist, it is well-known that one disease frequently expels another from our frame, and the action of counter-irritants is based upon the same principle. The fortitude of martyrs may probably be explained by this power of one set of ideas and feelings to exclude another, and the facts of mental physiology afford plenty of other examples.

It is probably because we cannot simultaneously perform two contradictory actions, that we cannot contemplate consciousness, or think of an idea and at the same time think of that act of thought. In accordance with this, even Newton, and other great geniuses, have been unable to accurately describe the mental processes by means of which they arrived at their most difficult results. In consequence also of this, we cannot define consciousness, and are often unable to directly observe or analyse our mental actions, especially those of a very abstruse or complex kind. Much of the knowledge of the operations of our mind, we are therefore obliged to obtain by indirect means; by analogies, and inferences from the phenomena of nature, &c., and in this way our knowledge of mental action largely depends upon our acquaintance with physical and chemical science, and can only advance as it advances. To clearly understand one subject we are often obliged to study several others. Ignorance of science in general, and of cerebral physiology in particular, is the chief obstacle to our acquiring a more accurate knowledge of mind.

Next to consistency, the great principle of causation constitutes the most essential part of all natural truth, and to deny the operation of this principle in particular cases of mental action, simply because we, with our very finite powers, cannot in the extremely imperfect state of our knowledge, yet fully explain some of the most difficult, complex, transient, and ever-changing phenomena of will and consciousness, is contrary to the most weighty evidence. "The Will" is a conscious mental effort to effect an object, the idea of which is already in the mind, and being a mental "effort" it absorbs the mind and thereby incapacitates it at the moment from observing its own action.

If any phenomenon (such as mental action) is essentially dependent upon another, it must be connected with it in a never-failing or indissoluble manner, so that when the one occurs the other is always present, otherwise it would not be essentially dependent. The only known connections of this kind are those causation and continuity of phenomena, according to which every phenomenon has a cause, and all phenomena are indissolubly connected in endless series. The evidence of the truth of these principles is so vast, that even all mankind thinking through all ages, and after having made an almost infinite number of definite experiments and observations, have never yet met with a single well verified instance of their failure; and we are therefore justified in inferring that they are universal. There are however instances in the physical and chemical sciences, as well as in mental action, where the dependence of phenomena upon those principles is not very apparent, and has not yet been sufficiently proved, but it is probably in consequence of our imperfect knowledge and limited faculties, that we are unable as yet to fully trace such dependence. The history of science, abundantly proves that we should not assume that a phenomenon arises without a natural cause, simply for the reason that it is very difficult to trace its origin, but wait patiently for more knowledge respecting it. It is unphilosophic and contrary to reason to attribute to occult agencies, effects which may be explicable by ordinary causes, or to refuse to believe in more abstruse causes where the assumption of simple ones is contradicted by some of the evidence.

The principle of causation forms the basis of many minor ones, such as selection, evolution, differentiation, &c. Plurality of causes also is a very common circumstance in all the sciences, and especially in concrete phenomena, and in the complex ones of animal life; the arrival of a ship for example at a distant port, is a result of many conditions. Similarly with most of our mental actions, they are compounds of feeling and intellect, and produced by many causes, such as hereditary tendency, acquired habit, internal and external mental excitants, dogmatic belief, knowledge of empirical rules, and occasionally of verified principles. Several of these causes also frequently conspire to produce a single idea or decision.

Various general principles of lesser magnitude arise from the combined action of two or more of the greater ones, and these also appear to operate in mental actions as well as in physical ones. Thus by the combined influence of causation and of the principle that every phenomenon occupies time, "effects often lag behind their causes;" and in some cases during a long period. The greatest heat of summer for example usually occurs several weeks after mid-summer. The mental effects of early mistakes are often not fully experienced until old age. The decline of a nation also follows a long time behind the period of action of the chief causes which produce it.

Although effects are indissolubly connected with their causes, they frequently do not occur in an active form until a long period after them. In such cases they are stored up in what is termed a potential or latent state, ready for liberation at a future occasion, when the suitable conditions are present; the storage of chemical power in gunpowder, of solar heat in coal, and its subsequent liberation in our fires, are suitable examples. The principle of deferred activity and storing up of power, occurs also in vital and mental phenomena; potential heat is stored up in our food, and is afterwards evolved by oxidation in our tissues. Muscular power is stored up during sleep, ready to be evolved during labour. The storage also of cerebral impressions, and cerebral energy, ready to call forth ideas, and thereby powerful emotions, by the exciting action of memory, may also be viewed as an instance of similar kind belonging to mental phenomena. A new and striking instance of the storage of energy has been shewn in Faure's improved form of secondary voltaic battery, in which the most powerful voltaic current may be (at least practically) stored up (in a box containing lead plates immersed in dilute sulphuric acid) and conveyed to a distance with little loss, and then liberated.

Exciting causes operate very extensively in mental actions as well as in physical ones, a mere look or word from an eloquent speaker will excite the passions and liberate the muscular power of a multitude. Every part of the human body, especially the muscles and nerve centres, is a store-house of power always ready to be set free by the slightest suitable causes; this is strongly illustrated in the irrepressible activity of children, and in the excitable passions of young men and women. The more immediate cause of this power is the oxidation of assimilated food; and the source of power in the food is the heat of the Sun stored up in the plants and animals they have eaten.

The subsequent liberation of power under the influence, often of very slight causes, long after the original cause has ceased to act, has led us to conclude erroneously that causes are not always proportional to effects. Proportionality of effect to cause appears to be universal; it probably operates in mental as well as in physical actions, our faith in education as a means of intelligence is based upon this; the more complete the education of a particular individual, the greater usually is his degree of intelligence. Proportionality of cause to effect is apparently disobeyed not only in physical but also in mental phenomena. Throughout the whole realm of nature, minute circumstances often act as exciting, deflecting, and guiding causes, and contribute to the production of apparently disproportionate effects. Thus a spark will discharge the largest cannon; a touch determine the most distant electric signal; a word or look, excite the strongest emotions; the little change of position of a railway point will direct a train either to distant North or South; the minute change of contact of the telegraph switch, will determine the signal to places wide asunder; one false idea also at a critical moment will often lead a man or woman to ruin; and in all these classes of cases, whilst trifling causes appear to produce great effects; the real causes are the stored up latent powers set free or directed. It is astonishing how small a circumstance will excite an idea, and deflect the entire current of our thoughts; and it is equally surprising what great physical and chemical effects are often started by most minute exciting or deflecting conditions; the explosion of seven tons of dynamite at Hell-gate, near New York, by the pressure of a child's finger closing an electric circuit is a suitable example.

Every phenomenon therefore whether physical or mental, is probably connected in an indissoluble manner with some preceding phenomenon, either immediately in point of time, or remotely through some static condition, usually that of stored up power. In this sense the great principle of continuity of phenomena appears to be universal, and the present state of the Universe is said to implicitly or potentially contain all the future states of the Universe. Mind also in this way, like each of the physical forces, often acts as a link in an endless chain of causes and effects, and is connected with non-mental phenomena in accordance with the great principles of science.

Science has demonstrated what has been termed the "Convertibility of Forces," or, that when one form of energy disappears, another form (or forms) of energy, and in precisely equivalent amount, is produced in its stead, either in a latent or active state. The equivalent quantities of the various forms of energy have also been discovered by actual experiment and measurement. A pound weight falling through 772 feet gives forth as much energy as would (in the form of heat) raise the temperature of one pound of water one Fahrenheit degree. We know that so much mechanical power is equal also to so much electric current, chemical action, &c., and a large amount of evidence exists to show that these transformations of energy occur in all the organs of living creatures, and in obedience to the law of their equivalents. How far mental power is a "mode of energy" transformable, and obedient to the laws of equivalence, are interesting questions for future research.

The mechanical principle of action and reaction is another which can be traced in mental as well as in physical phenomena. Mental excitement is often succeeded by mental depression, "after pleasure follows pain." The power of mental self-guidance and self-education is largely dependent upon the two well known scientific principles of latent energy, and action and reaction. We are able to liberate energy, not only in cases where it will influence inanimate matter but also ourselves. The principle of self-guidance is not restricted to living creatures, nor is self-regulation limited to mental power. The principle of self-regulation operates in clocks, watches, musical boxes, the governors of steam engines, water regulators, gas regulators, &c., &c., and upon an immense scale in the movements of the heavenly bodies. With the electric locomotive, the greater the load it has to draw, or the steeper the incline it has to ascend, the more strongly does it exert its strength, up to the full limits of its power. Neither in physical nor in mental actions can a body or force usually act directly upon itself to change its state whether of activity or rest. In both classes of cases however we meet with plenty of instances where, a body by an almost imperceptible expenditure of energy on its own part either alters some surrounding conditions, or excites a powerful liberation of energy in another body which then reacts upon it to change its state. In this way the action of clock-work in the self-exploding apparatus of a torpedo liberates at a particular moment a spring, and causes an explosion which destroys the apparatus. Similarly, whilst a man, in many cases, is unable to directly alter his mental state, to increase or diminish his mental activity, to cause sleep, &c., he is able indirectly to change his mental condition by drinking stimulants or by adopting means of self-education; and to induce sleep by means of opium, suitable exercise, &c.

The principles of indestructibility or conservation of matter and energy, flow from the preceding ones, and are exhibited in mental actions as well as in physical ones. Whilst the universal experience of mankind has not yet afforded us a single well verified instance of actual creation or destruction of matter or energy, it has supplied us with plenty of examples of apparent destruction and creation of each of them. But scientific knowledge corrects the uncertain testimony of consciousness; whilst we see coal burn and be apparently destroyed, science proves to us that the elements composing it remain undiminished. We observe also that the heat of the fire dissipates and is apparently lost for ever; but science again proves that it is either stored up in the latent state, ready to be again liberated at a future time, or else converted into other forms of energy. A given atom of matter or a portion of energy, therefore, to the best of our knowledge, continues and persists for ever. As we cannot either create or destroy matter so also can we not create or annihilate energy, and this truth probably holds good with regard to mental as well as to physical and chemical power. Great changes of state in bodies (as in the combustion of wood &c.) have led us to erroneously think that the substances are destroyed; and great apparent differences of property, such as those of diamond and charcoal, have led us similarly to conclude that they are entirely distinct and independent of each other when they are not.

As the cerebrum of man is composed of matter, and during excitement, its parts are active, we might confidently predict that its particles obey the First law of Motion, viz.: that a body in a state of rest or motion will continue in that state of rest or motion until some cause arise to prevent it. So it has been found that the action of the vital and mental forces have a degree of persistence, like the physical ones. It has been experimentally found that portions of living bone transplanted to fleshy parts of animals where there was no bone, continued to grow for a time by a life of their own, and increased by formation of additional bone, like a crystal grows in its medium; but after a time they diminished and disappeared. In a similar manner we are all of us aware of the persistency of ideas, even in opposition to the will, after the cause of them has been removed. Sometimes we cannot retain an idea because of the persistence of others; and at other times we cannot get rid of one, for a similar reason. Our mental habits also have often very great persistence.

The principle of heredity may be viewed as a result of the First law of Motion, and appears as Persistency of state, either of structure, form, or mode of action. It appears both in inanimate bodies, living structures, and in mental phenomena; in the latter, as hereditary mental peculiarities. The principle of Persistency of structure and Heredity of form and property, during repeated or even continual dissolution and aggregation of a material substance, is more or less manifest nearly throughout the whole of nature. In the formation of crystals it is clearly seen; each crystallizable substance will only grow into its own shape or shapes; each particle of common salt, during an endless series of successive solutions and aggregations into the solid state, always forms a more or less perfect cube; that of silica a hexagon; and so on throughout the entire series of thousands of different crystalline bodies. As each form of crystal only produces crystals of like form and property (or at most in certain cases a limited number of modified forms, as in the instance of calcic carbonate, &c.) so also each seed, both of animals and vegetables, only produces its own particular essential shape and collection of functions. The same principle shews itself in the transmission of particular types of disease, and of eccentricities of organization, from one generation to another of animals. Peculiar malformations of body and characteristics of mind often persist in families from generation to generation. This persistency or heredity of structure and of property is not limited to solid bodies, but exists also in liquids: "The effect of vaccine virus upon the liquid blood, in producing a permanent and organic change in its constitution and character, which continues to exercise a protective influence against small-pox, in the great mass of cases, through a long life, during which time the blood must have undergone, many thousands, if not millions of changes and modifications." (F. Winslow. "Obscure diseases of Brain and Mind," page 432). The same persistency of structure and property of structure, has even been detected in vapours; the vapour of red iodide of mercury for example, deposits only crystals of red iodide, whilst that of the yellow deposits only yellow (see Gmelin's Handbook of Chemistry, vol. 1, p. 100.)

We often appear to mentally select when we only yield to causes acting upon us, i.e., to the strongest influence or motive. That "self-preservation is the first law of nature," is not only true of living creatures, but largely also of dead substances. Inanimate as well as animate matter, appears to usually select what is good for itself. Apparent selection, which is manifested in the phenomena of instinct, is exhibited not only by brain, but by all material substances. Acids appear to select bases, North magnetism rejects North and prefers South magnetism. Also if a piece of zinc is put into a mixed solution of the nitrates of silver, magnesium, calcium, strontium, barium, lithium, sodium, potassium, and rubidium, it will select the silver only with which to form a "metallic tree," and reject all the other metals. Everything which aggregates or grows to a definite shape, appears to select its material; if a crystal of a particular salt is placed in a mixture of saturated solutions of different salts, it will only select and assimilate to itself suitable material, either particles of the same composition as itself, or those which are isomorphous with it, i.e. belonging to the same crystalline system. In living bodies also, the same principle operates; Living tissues, whether of animals or vegetables, usually select from their nutrient fluids, and assimilate, particles only of those kinds of matter which are suitable for their structure; in this way, a bone assimilates lime and phosphoric acid from the multitude of different substances conveyed to it by the blood. And in all these cases, the selecting material appears to act as if it possessed the powers of instinct, perception, comparison, judgment, and volition. The act of self-repair is clearly connected with this, and is not limited to living structures; Sir David Brewster observed that if a portion of the surface of a perfect crystal of alum is very slightly abraded by dissolving a film from it, and the crystal be then immersed during a very brief period in a saturated solution of alum, the abraded portion repairs itself. The subjects of "malformation of crystals," and "diseases of crystals" have been scientifically investigated. The power of selection (or rather of apparent selection) is no doubt a result of the combined action of causation and of the inherent properties of bodies, and depends, like consciousness, upon difference of impression, the strongest suitable influence determining. If apparent selection can thus be performed by inanimate matter, we should not, except for a very sufficient reason, assume the existence in living creatures, of a special occult power to perform the same function. In the selection of ideas also the intellect acts according to the purely scientific method.

We frequently appear to mentally adapt ourselves to particular circumstances when we are really determined by causes; and this apparent adaptation is also seen in ordinary physical and chemical phenomena. The course of a river for instance, adapts itself to the configuration of the country through which it flows, and if it cannot pass wholly by one channel, as in seasons of flood, or on occasions of accidental obstruction, it travels through several; and a similar result occurs with the flow of the blood when an artery is tied or becomes obstructed. A plant when growing in a dark recess, bends itself towards the light as if it preferred light; and its roots adapt themselves to the forms of existing obstacles. A decapitated frog jumps away from a source of irritation, as if he still possessed sensation, volition, and choice. A man seeking his way through a crowd avoids the course in which the throng is densest. The human mind also, chooses as it were, the easiest way of solving a problem, and usually adapts itself to altered circumstances.

The principle of evolution also operates both in physical and mental actions, and is a result of that of causation. Complexity of structure and function is evolved out of simplicity of composition and property by plurality of causes and conditions. For instance, many complex forms of crystals of ice are produced from water. Calcspar crystallizes in more than one hundred varieties of form, (all derived from an obtuse rhombohedron) under the influence of a number of slightly different conditions of temperature, impurities in the solution, &c. The most complex bodies are evolved out of the simplest, the bodily frame of man himself (and that of other animals) is constructed of less than twenty of the elementary substances. The same simple substances are capable of yielding very different and more complex bodies under different conditions; thousands of different chemical compounds are composed of hydrogen, oxygen, and carbon only. In the development of living forms from ova, the ultimate form produced does not exist in the germ, any more than a crystal exists in its solution, but is a natural consequence of the forces acting in and upon the germ, like the cubical form of a crystal of common salt is a result of the forces acting in its constituents under the conditions of its environment, especially those of pressure and temperature. The extent to, and manner in which, the force and principle operate, depend upon the material substance, and its conditions internal and external.

It is a common circumstance, both in physical, mental, and moral subjects, for the apparent to be the very opposite of the real. This general truth has been repeatedly illustrated in an incidental manner in this book, and need not be much further elucidated. Phenomena are none the less real, however, because they are not readily manifest; our earth is as much tied to the sun by the invisible power of gravity, as if it was attached to it by visible material chains. Mistaking the apparent for the real, largely explains the persistency of certain beliefs, and why it is that persons unacquainted with science, cling to self-deception, and resist some of the most firmly established truths. The more evident but untrue explanation is believed, whilst the less apparent but true one is rejected. It is the chief cause of the belief that "the will is a supernatural power." To a scientific man however, apparent contradictions are not unfrequently a sign of truth; too accurate results sometimes indicate that they have been artificially made to appear correct.

Sympathetic action or propagation of similar influence by immediate impulse, is a property of all the natural forms of energy, as well as of mind. Similar actions are propagated thus in all kinds of dead substances, as well as in the living brain. Matter is sympathetic to sound in the phenomena of singing-flames, and a vibrating string responds to a particular note in obedience to well-known laws. Iodide of nitrogen may be caused to explode by the influence of a particular note from a fiddle. In the phenomena of light, with a spectroscope, a luminous gas is sympathetic with, and emits and absorbs, only particular kinds of luminous rays. In chemical action also, combustion excites combustion, ferment excites ferment, infection communicates infection, and the similar chemical change is transmitted from molecule to molecule. Mental excitement and disease in one person, often excite similar phenomena in another, as is seen in "religious revivals," and well-known epidemics, such as the "dancing mania," "preaching epidemics," the "leaping ague," the "mewing contagion," etc., etc., (See "Epidemics of the Middle Ages," by Hecker; Sydenham Society publications; also Carpenter's Mental Physiology, p. 312.) Like excites like in the actions of each of the forces of nature; both in physical, chemical, and mental action, the kind of impulse transmitted is similar, unless conditions exist which transmute it. Dynamite, started into combustion by a flame, burns slowly away; but when started by a detonating substance, detonates violently. Guthrie has also discovered that if a melted cryohydrate (e. g. a chilled saturated aqueous solution of a solid salt) is cooled to a certain greater extent, it will not solidify—nothing separates out, although the solution is four or five degrees below its proper solidifying point. If a little crystal of ice be then thrown into it, nothing separates but ice, which comes to the surface. If we throw in a little anhydrous salt, nothing but the anhydrous salt separates out, and that sinks to the bottom. But if we throw into it a crystal of a previous crop of cryohydrate, then nothing but the cryohydrate separates. In this case also, like evidently excites like only, in obedience to physical laws. (Addresses, Science Conferences; South Kensington Museum, 1876; Vol. 2, p. 108). Even two clocks, when hung near each other, against a board or surface which readily transmits vibrations, have been known to exhibit, by synchronous action, an apparent sympathy, which changed their rate of going.

Periodical phenomena, also, brought about by definite causes, occur in mental, as well as in physical phenomena. In the former we have the phenomena of sleep, and in the latter, definite causes produce summer and winter, day and night, the tides, cycles of solar spots, maxima and minima of magnetic intensity, etc., etc.

Conversely to the manifestation of the principles of inanimate matter by living bodies and in mental action, so have modern inventions demonstrated the possibility of the performance by inanimate substances and apparatuses, of the functions, not only of our bodily organs, (as of locomotion by the steam engine,) but also of our senses and intellect, and in some cases, to a degree far surpassing unaided human power. Apparatus, sensitive to sound, have been constructed, as in the microphone and singing-flames; others capable of reproducing articulate speech, as in the phonograph, telephone, etc.; others again sensitive to light, as in the production of visible images by photography, and reproducing them at a distance through wires by means of the photophone; the power of indicating or foretelling future events has also been embodied in instruments called "tide predictors," and that of evolving inferences has been shewn in Jevon's "Logical machine."

The various facts mentioned in this chapter prove that mind agrees with the various forms of physical energy in many essential points, and obeys many of the same laws or principles. Examine whatever general phenomena of the mind we may, we can always detect some apparent or real connection of them with the great principles of inorganic nature; and in order to prove the dependence of them upon the great principles of science it is not necessary to show that all such actions are subject to those principles. Until the whole is explained however, there will always remain mysterious phenomena to cavil about.

At the present time few competent persons have largely investigated the fundamental relations of morality to Physical Science, consequently moral actions are usually considered not to have a scientific basis, and the doctrine is still extensively taught that some moral phenomena are essentially supernatural.

As new scientific knowledge has increased, belief in witchcraft, sorcery, demonology, exorcism, evil influences and omens, unseen spirits, a God of evil, supernatural and occult powers, supernatural sources of strange diseases, evil presages from comets and eclipses, fetishism, worship of images and of the Sun, a belief that the Earth is the chief body in the Universe, that man is the "Lord of Creation," &c, &c. have largely passed away, and beliefs more consistent with facts and with true inferences drawn from them, have taken their place. Belief in the supernatural nature of the human will however is still largely retained. A writer on morality, says—"In every genuine volition we have a phenomenon not law-determined, law-regulated, and law-explained." A popular expositor of religion says—"The phenomena of the human soul are essentially different from the phenomena with which the student of science is most familiar, and must be investigated on other principles and by other methods." "The voluntary activity of man lies beyond the limits of science." "Every language man has ever spoken—no matter how perfect or how rude—the literature of the ancient and the modern world, the indestructible instincts of the human soul, the testimony of consciousness, unite to affirm that the human will is independent of natural law." "The will is a supernatural power." "I myself am not under the dominion of natural law;" "my moral life is essentially a supernatural thing." "As soon as you approach the intellectual and moral life of man, you enter a region in which you have to do with a new order of facts." &c.

Morality, the subject of duty, or of right and wrong-doing in conscious creatures, is usually considered to relate only to those actions over which a man has or might have had control, and which it was his duty either to perform or avoid, and not to those which are entirely beyond his influence, it is therefore essentially dependent upon the power of selection or choosing. As then all moral actions require voluntary choice between right and wrong, and every act of choice is a mental one of comparison of two or more things, all moral actions are mental ones. We cannot compare things which have not made any mental impression upon us. We know further, and the evidence already given proves, that mental actions are intimately dependent upon the principles of nature operating within and around us. If then all acts of morality (or immorality) are mental ones, and if all mental actions are intimately dependent upon the great principles of nature; then all acts of morality are dependent upon those principles. Morality also cannot be properly understood without a knowledge of various sciences, especially biology, because it relates to human creatures, all of whom are morally affected by the various forces and substances belonging to the physical and chemical sciences.

Having shown that moral actions are mental ones, and adduced evidence to prove that mental actions are largely subject to scientific principles;—it follows as a necessary consequence, that moral actions also largely obey those principles, and I need not repeat that evidence.

The extension of scientific knowledge conduces in a very general way to moral progress, by diffusing the "scientific spirit," increasing our love of truth, facilitating the attainment of greater certainty and accuracy, enabling us to more perfectly avoid error, reducing our ignorance, dispelling superstition, inculcating obedience to law, diminishing difference of opinion and thereby lessening strife, conducing to humility, to greater economy of means, to increased cleanliness, &c, &c. Scientific research also, by disclosing to man his true position in nature, enables him to act in harmony therewith, and thus increase his morality and general happiness.

Knowledge is as free as the air, once diffused it becomes impressed upon the brains of men and cannot be easily destroyed or restrained; and the greatest moral effects of science are cosmopolitan ones. Inventions based upon new scientific truths are gradually breaking down the barriers between the various nations of the Earth, and infusing common interests amongst all mankind. Nothing is uniting the sympathies of different nations, increasing the friendly feelings between them, and diminishing the probability of war, more than the increasing facilities of communication brought about in a great measure by the developments of science and art; more particularly by ocean steam navigation, rapid postal communication and the telegraph, (see p. 51). At the present time there are about six Atlantic telegraph cables in use, and an almost daily service of passenger steam ships across that ocean. The use of inventions based upon scientific discovery has aided moral progress in various ways. All inventions are made with the object of supplying some real or supposed want, and nearly everything which supplies a common want, conduces to contentment and happiness and the general progress of mankind. No one can possibly measure or estimate the advantage of the inventions of writing and printing, in helping men to avoid quarrels, to settle differences of opinion, to sympathise with suffering, to give advice: &c. Similar moral functions are also performed by the electric telegraph, and a few specimens of some of the messages sent through the wire would clearly illustrate this fact. Great moral progress has also resulted from cheap daily intelligence, collected largely with the aid of the telegraph; and of cheap books produced by means of the steam engine. It is estimated that 250 millions of copies of newspapers are yearly published in Great Britain. The Bible and Religious Tract Societies could hardly have existed had not the properties of the ingredients of ink been discovered. The present multiplicity of testaments, prayer-books, hymn-books, &c., has also been rendered possible by the invention of printing. As darkness is favourable to crime, so the invention of gaslight has conduced to morality. The numerous sources of intellectual and moral enjoyment, developed by inventions based upon scientific discovery, have attracted mankind from more sensual and less moral amusements, and the invention of the piano-forte has operated largely in a similar manner.

In many respects, the poor man of to-day can command social comforts, conveniences, and pleasures, which an emperor could not in former times. Who can estimate the amount of beneficial moral influences of an indirect kind obtained by means of modern science? The relief from pain by chloroform and other new medicines, the diminution of domestic toil by the sewing machine; the increased health and pleasure obtained by access to the country and seaside by means of railways; the diminution of anxiety resulting from more speedy conveyance of letters, and especially of messages by telegraphs, the increased pleasure of life resulting from being surrounded by objects of beauty multiplied cheaply by means of scientific processes, such as photography?

The human mind cannot greatly resist impression, the various effects of scientific research necessarily produce an influence upon it. Whilst great deep-seated truths make a powerful impression on the minds of philosophers, the great practical effects of science in inventions, &c., profoundly impress the mass of mankind. One of the chief influences of the discovery of important scientific truths and of their practical application in some wonderful way, such as in the telescope and microscope, phosphorus matches, photography, electro-plating, the electric light, the spectroscope, microphone, telephone, &c., is to produce a profound and wide-spread impression of the existence of a great and mysterious influence, which produces (or enables us to produce) such striking effects.

Whilst also the novelty of the practical effects of new scientific truths in inventions, astonish persons in general; the definiteness of scientific phenomena, and the certainty with which they may be reproduced convince all competent persons who examine them, that they are rigidly subject to definite laws. In this way the antique belief that natural phenomena are produced by supernatural agencies, is gradually being abandoned, and the more moral conviction of the omnipresence and universality of law has been largely established in its stead. Every new scientific fact and invention thus becomes a new proof of the universality of law. Belief in the supernatural has diminished in proportion as scientific knowledge has advanced; instead of natural phenomena being erroneously ascribed to demons, spirits, supernatural powers, and occult causes, they have been proved to be results of natural powers, acting in accordance with known principles. Assertions which have been made, that "the will is a supernatural power, independent of natural law" &c., are not supported by evidence at all equal in cogency to that in proof of the statement, that our mental and moral powers as a whole act in accordance with the great principles of science.

That moral phenomena, like those of the physical sciences, are capable of being made the subject of experiment, observation, comparison, analysis, and inference, is very manifest. Every case of bribery may be viewed as an experiment in morality. The very common case where an employer tests the honesty of a servant by some contrivance, is also a trial of a similar kind. The dependence of the moral powers upon scientific conditions, is clearly seen in the influences of intoxicating drinks. A mere natural substance could not possibly overcome the influence of a power which exists entirely independent of it; i.e., a "supernatural" one. Even the greatest believer in the "supernatural" power of the human will, deplores the serious injury which the abuse of alcoholic liquors produces upon mankind, rendering the will powerless, and debasing the moral sentiments. The effects of opium, haschisch, &c., are other examples. A vast number of experiments remain to be made of the effects of drugs and organic compounds, both solid, liquid and gaseous, upon moral actions; which will probably prove a still greater degree of dependence of those actions upon purely physical and chemical conditions.

The "order of facts" in the subject of morality requires precisely similar mental treatment to those to which scientific investigation has been already applied with such great success, and which include all phenomena admitting of observation, comparison, analysis and inference; and not only those in which we are able, but also those in which we are not able to produce by means of experiment, the phenomena to be observed, such as those of astronomy and geology. Different subjects also are experimental in different degrees, physical science is more experimental, physiology is more observational; morality is partly experimental, and therefore capable of reduction to scientific system by means of our intellectual powers.

In consequence of the essential nature of truth being the same in all subjects, and of the fundamental processes of mental action in the determination of truth being also alike in all, the essential modes of arriving at and detecting moral truth are the same as those employed in research in the physical sciences. We possess therefore no special faculty, call it "conscience," or what we may, by which we are enabled to infallibly arrive at truth in moral questions. What is right and good, and what is wrong and evil, are determined by precisely the same general means as what is true; our much vaunted consciousness alone does not infallibly tell us; reason alone, acting upon the evidence, is the final arbiter in any doubtful or disputed case. The truth of moral questions must be examined and tested by precisely the same mental faculties and processes as those employed in physical science, viz:—by the faculties of perception, observation, comparison, and inference, acting upon the whole of the evidence; and by the processes of observing facts, comparing them, inferring conclusions; by analysing and cross-examining the evidence in every possible way, and extracting from it the largest amount of consistent knowledge.

Although we cannot detect moral truth by any other than intellectual processes, we may however arrive at correct moral conduct in two ways, viz:—either blindly or intelligently. We arrive at it blindly or automatically by the process of trusting to our inherited and acquire tendencies and dogmatic beliefs; and intelligently by the conscious use of our knowledge and intellectual powers; and each of these methods has its advantages. The former process being an empirical one, is very uncertain and cannot be employed for the judicial detection of truth, or the certain discrimination of it from error, it has however to be trusted to in all cases where we are deficient in knowledge, or have not time for investigation. Truthful ideas and correct conduct also, which at first require the exercise of considerable intellect and much self-discipline, in order to arrive at them, become by habit so completely converted into acquired tendencies as to be automatic. It is not improbable that many of our truthful ideas and correct tendencies were originally arrived at by intellectual processes; and have become incorporated into our mental and physical structure by habit, education, and inheritance.

The scientific basis of morality is further shewn and essentially proved by the fact that the fundamental rules of morality are dependent upon scientific principles. According to Dr. Clarke, the two fundamental "rules of righteousness" which regulate our moral conduct are, first, that we should do unto another what we would, under like circumstances, have him do unto us; and second, that we should constantly endeavour to promote to the utmost of our power, the welfare and happiness of all men (to the latter might well be added, the welfare of all sentient creatures). The first of these rules is essentially dependent upon the scientific principle of causation, viz:—that the same cause, acting under the same circumstances, always produces the same effect, if what we did for another person under like circumstances might produce a different effect to what it would when done for ourself, the rule could not be depended upon and would be of no use. The second also agrees with the great principles of science, for the more we obey those principles, the more do we really "promote the happiness and welfare of all men." The first of these rules however in the form usually stated, is incomplete, because it does not provide for the circumstance, that many persons desire to have done unto themselves, not that which is most right, and really most for their welfare and that of mankind in general, but that which would most please them. The desire of immediate pleasure or consolation is greater than the love of truth in nearly all men, and this is connected with another fact, viz:—that persons unacquainted with the great principles of science, have not the advantage of the moral sustaining power of those principles, and are compelled in circumstances of trial to seek extraneous mental relief.

The desire to do right is not the primary source of morality; there must be a cause for that desire, and this fact also shews that moral phenomena are dependent upon the scientific principle of causation. We can also much better understand a subject, especially a complex one like that of morals, when we can co ordinate its facts in a scientific manner, by referring them to some general principle which governs or includes them. Referring moral actions to a verified scientific principle, is more satisfactory than referring them to a less definite source such as "conscience"; the "testimony of consciousness"; or "the indestructible instincts of the human soul," because a principle affords a more consistent explanation than a dogmatic idea. The fact also that the discoveries of science usually precede the developments of the moral advantages of science to mankind, is in harmony with the general truth that effects follow their causes, and with the conclusion that moral rules and moral progress have a scientific basis.

In a general way, the influence of science upon moral progress is connected with what has been termed, "the scientific spirit." This characteristic consists mainly of an intense love of truth, a desire to acquire new knowledge, to arrive at certainty and accuracy; also an obedience to law in general, and a consequent philosophic resignation to inevitable ills. Science inculcates these qualities, and it is well known that scientific discoverers have usually been highly moral persons, truthful, accurate, law abiding, patient, persevering, temperate, &c. On the other hand, the most lawless persons are usually those who are most ignorant of the great laws which govern their actions, who over-estimate human power and ability, and are impelled by ill-regulated enthusiasm or feeling.

Belief in and obedience to law, being a fundamental moral quality, is in its turn the source of other moral qualities of less importance; for instance, it tends to produce calmness, resignation, contentment, patience, submission to the inevitable, &c. No man can be highly moral who disobeys the great principles of nature. We may however obey those laws either intelligently, by acquiring a scientific knowledge of them; empirically, by obeying rules framed in accordance with them; or blindly, by obeying dogmas which happen to agree with them. Those who do not understand laws cannot of course intelligently obey them, and those who most disobey them, consist nearly wholly of those who do not understand them. Superstition, ignorance of natural law, and a belief in occult powers, encourages lawlessness, injures the moral sentiments, and is often attended by bigotry, associated with strife, schism, and sectarian dispute.

Probably the greatest influence which scientific discovery has had upon the moral progress of mankind, has been by inculcating an intelligent love of truth on account of its own intrinsic goodness; in this respect it stands pre-eminent. Love of truth is a fundamental virtue because it is the basis of many smaller ones. It is more virtuous, also, to pursue truth on account of its own intrinsic and unqualified goodness in all respects, than for any narrow extrinsic quality, such as the personal pleasure or utility it may afford, or on account of any personal gain or loss, reward or punishment, which may result from pursuing or neglecting it. In the present imperfect state of civilization however, the great bulk of mankind unavoidably employ less noble, as well as the noblest motives, as a means of improvement. Most men can only be moved to do right by means of inferior motives, one of the most effectual of which in a commercial nation is "small investments, large profits, and quick returns;" an expectation of great reward in return for small self-sacrifice.

The discovery and dissemination of verified scientific knowledge is a purer kind of occupation than the promulgation of any kind of dogma, because the statements of verified science are usually capable of demonstration, whilst those of doctrine, being often contradictory, may, or may not be true; mere affirmation also, when not based upon proof, is often dangerous to morality. In dogmatic subjects a man may tell untruths with impunity, because no one can disprove or convict him; but in demonstrable ones, a man dare not utter falsehoods, because others will prove his statements to be erroneous. It is demonstration rather than doctrine that is of divine origin. A man also who practises scientific research is largely compelled to adopt the most truthful views of nature, in order to enable him to make discoveries.

Real science is largely independent of opinion or faith. Whether we believe or not that a piece of clean iron immersed in a mixture of oil of vitriol and water, evolves hydrogen gas, the fact itself remains unaltered. It is a great and glorious circumstance for mankind, that human progress depends essentially upon a knowledge of new verified truth. As verified experimental knowledge can only come from the great source of all that is good, to doubt the value of new demonstrable truth, is practical atheism. Those also who systematically investigate sources of verifiable truth, are much more likely to ultimately arrive at the fountain of all truth, than those who employ unsystematic methods, or prefer unproved beliefs to verified knowledge.

Another of the most powerful ways in which scientific discovery has promoted moral progress has been an indirect one, viz., by diminishing ignorance. Deficiency of knowledge is the parent of a vast amount of evil and failure. "There is no instance on record of an active ignorant man, who, having good intentions, and supreme power to enforce them, has not done far more evil than good." (Buckle, "History of Civilization," vol. 1, p. 167). Ignorance largely precludes happiness, and intelligence is an indispensable condition of the highest morality. There are plenty of difficult positions in life in which the desire to do right is not alone sufficient, we must intelligently know what is the right course to pursue. We are all of us ignorant in different degrees, and must be content in many matters to walk by faith until we can walk by sight, and to act according to rule and precept until we have discovered general principles to guide us:—blind dogmatic morality and "rule of thumb" method is vastly better than none, and has rendered great services to mankind. Whether comforting doctrines are true or not, the great bulk of mankind prefer them because they afford immediate relief; and whether they be erroneous or truthful, men will be benefited by them and continue to believe in them, until their minds are sufficiently advanced to receive a knowledge of verified principles. Rules of morality however, when presented to us with a basis of demonstrable truth, come with a degree of divine authority, and possess greater claim to our observance, than the same rules presented to us as empirical or dogmatic statements only.

In proportion to our ignorance the more we dislike to be apprised of our defects and the more inclined are we to continue uninformed; because the less intelligent we are the less are we able to perceive the evil effects of our blindness or the advantages of knowledge. As also the present state of civilization is very imperfect, and unsolved problems exist in all directions, ignorance and all its evil consequences are extremely prevalent. It causes the great mass of mankind to neglect better objects for the sake of money. It indirectly constrains lawyers to neglect moral evidence. It induces medical men to withhold truth from ignorant patients. It causes ministers of religion to prefer doctrine to demonstration. It would therefore be comparatively easy to compose lists of our moral deficiencies, and of improvements urgently needed in morality, far more extensive than the very incomplete ones of our material shortcomings already given (see pp. 68 to 78). To enumerate however the imperfections in the moral conduct of mankind, the frauds in trades, the undue advantage taken of the defenceless, the deceit and empiricism in professions, the professional trading on human weakness, the cruelty of field sports, the hollow motives of social, political, and religious life, the propagating as infallible truth, doctrines which may be fallacious, is not the object of this Chapter; but rather to make clear the fact, that the extension of the domain of verified truth by means of scientific research is highly conducive to moral progress.

The extension of new scientific knowledge is influencing morality and gradually reducing the selfishness of mankind, by proving that there exist no royal roads to happiness, and that the greatest amount of individual and national success can only be secured by a genuine pursuit of truth, as an individual and cosmopolitan duty. Increased knowledge is gradually proving to mankind that the purest happiness is to be obtained by intelligent and virtuous conduct. By shewing Man the unreasonable character of some of his fears and hopes, and substituting for them a greater variety and extent of intellectual pleasures, science is slowly making him more satisfied with his lot on this Earth. Meanwhile the great mass of mankind are still pursuing the ever retreating phantom of an easy way to happiness; the great laws of nature however cannot be evaded, the avoidance of evil and the attainment of good can only be secured by obeying all the great laws which govern our nature.

Progress in morality is largely dependent upon the diffusion of belief in the universality of scientific laws. When men understand those laws, know that their action is irresistible, and that they have no alternative but to obey them or suffer, they acquire a habit of obeying them. Universality of law in moral actions is often considered to be incompatible with the existence of freedom of the will in selecting ideas, and choosing courses of conduct; but we are free or not, according to circumstances, both to think and to act. All things are free to be active or not, in accordance with their properties and surrounding conditions, but not in contradiction to them; and the human will is no exception to this statement. The "will" is only free within certain limits; it cannot act in opposition to its strongest motives or causes of action. We believe ourselves to be much more free than we are, because we often do not know the causes which determine us, and we frequently fail to detect those influences, because we cannot think, and at the same time clearly observe our act of thought and its motives. Freedom of the will does not enable us to set aside laws: entire freedom from law in any instance is probably only apparent. This limited degree of freedom of the will indicates the dependence of volition upon scientific laws, because a supernatural power, being entirely independent of natural law, could not be limited by it. To affirm without proof that the human will is a "supernatural power" is to implicitly deny the universality and constancy of natural laws. New knowledge developed by Science, imparts to us liberty, but not license; and, so far from diminishing the freedom of the will, increases it by showing us what conditions we must fulfil and obey in order to effect our objects. We acquire power by being first obedient; and this is in accordance with the principles and facts of science; we must obey nature before we can make nature obey us; the elementary bodies, also, usually acquire the free state, latent power, and the ability to evolve heat and electric energy, only by being first subjected in their crude state to a process of reduction and purification.

Few circumstances connected with the discovery of new truths of science, have had a greater moral effect, than the very high degree of certainty of such truths. The moral result of this is a corresponding degree of confidence in the statements of science. Trustworthiness is a great moral quality. Uncertainty is a continual hindrance to action and enjoyment; and many persons are driven to believe in error, and hence to commit sin, rather than remain in suspense. Contradictions of doctrine, and the consequent uncertainty of belief, in any subject, are fertile sources of strife. Science consists, not merely of opinions and words, but also of the tangible realities which those opinions and words represent, the forces, substances and phenomena of the material Universe. Some persons however fancy that the results of science are as uncertain as those of the undemonstrable subjects with which they are familiar.

Another way in which science has contributed to moral progress, has been by requiring greater accuracy in nearly all human actions, and thereby diffusing greater exactitude of language and of conduct, which has spread itself throughout all civilised society. Previous to the use of watches and clocks, persons were no doubt much less exact in fulfilling their appointments; the establishment also in our chief towns, of electric time-keepers regulated from Greenwich Observatory, is increasing exactitude in our large communities. Since the introduction of railways, millions of persons have been compelled to be more exact in their movements, by the risk they incur of missing their train. Numerous inventions and processes based upon scientific discoveries could not be worked at all unless men possessed habits of greater accuracy than formerly. Workmen now require higher moral and intellectual education, and their duties require more intelligence and involve greater responsibility.

Science diminishes error, and the avoidance of error is a large step towards the attainment of truth. There is no tyranny equal to that of false ideas. Error often produces immoral acts, and every act of immorality is a mental error. "The ignorant justice-loving man, enamoured of the right, is blinded by the speciousness of wrong." "Inaccuracy of thought is the cause not only of the errors we meet with in the sciences, but also of the majority of the offences which are committed in civil life,—of unjust quarrels, unfounded law suits, rash counsel, and ill-arranged undertakings. There are few of those which have not their origin in some error, and in some fault of judgment, so that there is no defect which it more concerns us to correct."

Our senses and consciousness are often great deceivers, and unless corrected by sufficient knowledge, are frequently as great a source of error in moral questions as in mental ones. Their incessant influence is a cause of selfishness, and of the fallacious tendency existing in nearly every man, to exaggerate the importance of himself and of everything relating to him. It has led man to consider himself "the Lord of Creation";—to believe that his volitions are not subject to natural laws &c.:—and has given rise to the comparatively narrow-minded idea "the study of mankind is man." The fact that consciousness frequently misleads men of energetic temperament who feel their energy, indicates its connection with a physical basis.

Consciousness is also an essential condition of what we term evil. If we define evil as that which produces pain or discomfort in sentient creatures, then evil is that influence only which unpleasantly affects consciousness. And if we admit this, then all evil is relative, and there is no absolute evil; because, if there were no sentient creatures, there would be no evil. It is manifest also, that if the existence of evil is dependent upon that of sentient creatures, and if the existence of such creatures depends upon physical conditions, and upon the operations of the great principles of science, then the existence of evil must itself depend to that extent upon those conditions and principles. What we term Evil, is caused, not only by the actions of man, but also on a large scale by the operation of the simplest forces of matter, in earth-quakes, storms, volcanic outbursts, droughts and famines, pestilences, etc. Evil (as well as good) may therefore be viewed as a result, to some extent, of the operation of the laws of the Universe; and here again we are compelled to recognise a scientific basis of morality.

That the same causes, acting under different conditions, produce different and even opposite effects, is a well-known scientific truth. The same heat of summer which causes our foods to decay, promotes the growth of plants in the soil; the same cold of winter which increases the pain of bronchial affections, and cuts short the lives of aged and infirm persons, acts as a stimulant and a source of pleasure to the young and healthy. We need not therefore be surprised, that the same physical conditions and principles of nature, act as causes or conditions both of what we term evil and what we term good. If, also the theory of relativity in physical and mental action is true, that change of impression is a necessary cause or condition of consciousness, and that previous experience of pain increases the perception of pleasure, we possess in that theory, as one of the general ideas of science, a partial basis of morality. All these remarks tend to shew, that in order to obtain a truly scientific view of the nature of man, and of man's position and duties in the Universe, we must avoid the errors caused by uncorrected consciousness.

Another great moral effect of the continual discovery of new truth in science, is the gradual production and diffusion of uniformity of belief, first amongst scientific men, and then amongst the mass of mankind. This uniformity of belief is a necessary result of the invariability of fact and law; it does not extend to scientific opinions, hypotheses or theories, because they are not necessarily facts, and may be erroneous. A knowledge of science tends to remove differences of opinion between man and man, because it enables every honest examiner to obtain essentially similar results. Scientific research will gradually disclose what is true and what is untrue in doctrine and empirical rules; and what is true will be retained. A universal religion or a scientific philosophy which is composed of contradictory creeds cannot be wholly true. Science is gradually superseding unreasonable beliefs, and inaugurating a true universal gospel in which all men will eventually think alike in fundamental matters. The continued discovery of new truth must of necessity sooner or later lead mankind to the source of all truth and to universal satisfaction and happiness. It has been frequently stated that science is antagonistic to religion; it is evident however that as science is so conducive to morality, it cannot be opposed to true religion, but only to false or unfounded beliefs. Nothing shews more plainly a weakness of moral confidence and a deficiency of faith in an over-ruling power, than a fear that the pursuit of scientific truth will lead to results injurious to mankind. What we most need to fear is, not that our most cherished doctrinal beliefs may be proved to be mistakes, but that we through deficiency of knowledge may be led to do wrong.

There are plenty of questions, especially in matters of theory and doctrine in concrete subjects, which science cannot directly and absolutely decide either one way or the other, but respecting which, by the aid of new knowledge and of inference based upon it, science gradually accumulates so large a preponderence of evidence as conclusively settles them to the conviction of every unprejudiced and reasonable person. Many of the most deeply interesting questions in mental science and morality are of this kind; and will probably be settled in this manner. It is well-known also to scientific men that the indirect conclusions of the intellect and reasoning power are often more certain than the direct evidence of the senses and consciousness; we are more certain for instance that the Earth is a sphere than that it is a plane, although the former conclusion is arrived at largely by inference, whilst the latter is the direct testimony of uneducated consciousness. Whilst our senses and consciousness inform us that the Earth is a fixed body, inference proves to us that it is rushing through space at an immense velocity. Sense and consciousness are not intellect, although they are often treated as such. Their functions are to perceive and observe, to act as witnesses, to supply evidence to the judgment, and not to usurp the reasoning power. Even the universal consciousness of all mankind is insufficient to overthrow the final decisions of the intellect, or to decide what is true or false, because the senses and consciousness cannot compare or infer. As it is the force and repitition, and not the truthfulness of mental impressions, which largely determines belief, we are capable of believing error as well as truth, and we believe much that is erroneous until the corrections of the intellect are applied to the evidence of the senses and feelings. The correctness or otherwise of our present beliefs will be tested in the future as others have been in the past, and the new experiences requisite for the purpose will probably be obtained by means of original research. It is a great mistake to suppose that the warrantable inferences deduced from scientific knowledge will not sooner or later profoundly influence questions relating to the highest hopes and aspirations of the human race, such as the independent existence and immortality of the human soul; that of a personal Ruler of the Universe; freedom of the will; the origin of evil; future reward and punishment; &c. By extension of knowledge a scientific system of morality will be formed. The great principles which govern the phenomena of all bodies are gradually being discovered, and when found we deductively apply them to ourselves, and thus arrive at a knowledge of our true position in nature, our duties, our proper course of conduct, &c. Science also by disclosing to us the true relations of matter to mind in the human brain, will probably not only make known to us the true limits of our mental powers and of the knowable, but also help to solve the problems of the relations of the Universe and of Man to an intelligent Creator. It will decide such questions, largely by shewing us whether or not the ideas we entertain respecting them are consistent with the more extensive knowledge evolved by research. A part of the data from which we may safely predict that science will in the future exercise so great a moral influence over mankind, is the fact that its chief principles are fundamental guides and regulators of human action.

Probably nothing has a greater effect in making a man humble and reverent than a thorough knowledge of science. By the inventions of the telescope, microscope, spectroscope, telegraph, microphone, telephone, &c., the extremely finite extent of all our faculties has been abundantly demonstrated. Whilst the wonders of the telescope have developed an intelligent sentiment of reverence, by revealing to us a portion of the vast amount of the Universe of matter and energy, those of the microscope have strengthened that sentiment by affording us an insight into the almost endless complexity of minute creatures, substances and actions. Whilst also these and other scientific instruments and appliances have proved the excessively limited extent of our senses; the inscrutable character and immense number and variety of problems of nature yet unsolved, equally demonstrate the extreme feebleness of our mental powers. To obtain an accurate acquaintance with science also, and especially to discover new scientific truths, it is absolutely necessary to set aside human pride, and approach the subject like a little child; no other course is possible.

A knowledge of geology and astronomy also makes a man humble and reverent. The fact that this globe must have existed myriads of years; and is always moving at the immense velocity of more than 62,000 miles an hour in its orbit, is sufficient to convince any unprejudiced person of his own transient physical existence and his comparative physical feebleness and insignificance. Hitherto, man has largely been accustomed, through the influence of uncorrected impressions and other causes, to view all nature as having been expressly provided for him, but science informs us that whilst this Earth is suitable for his abode, and Nature ministers to his necessities and pleasures, it is only on condition that he first obeys the great laws of matter and energy, and adapts himself to their requirements. The operation of those laws often ruthlessly destroys thousands of men by pestilence, famine, drought, and other great calamities, and man can do nothing which is incompatible with them without suffering a penalty. Science shews that man is but one out of at least 320,000 different species of animals; it also discloses the fact that the entire human population of this globe constitute only about one 50,575,785 millionth part of the Earth, and proves to us that the Earth itself is but a speck in the Universe, one out of at least 75 millions of worlds; and that not only is it merely a planet revolving round the Sun, but that the Sun is only one of a multitude of Suns, and is itself, with all its planets, revolving round a still more distant centre in space.

There is scarcely a faculty man possesses, which is not immeasurably limited in comparison with the powers and capabilities of inanimate nature. His physical energy, when compared with that of the momentum of this Earth, is so exceedingly small that it can hardly be conveyed to our minds by means of figures; even the steam engine, excessively wasteful as it is of power, far surpasses him in strength. The duration of his existence is to that of the world he inhabits, as nothing to infinity. His power and speed of locomotion are also very limited; the globe to which he is fixed by gravity, moves in one hour through a distance greater than he could walk in twenty years. Practically, by circumstances, he is almost rooted like a vegetable to the locality where he exists; comparatively few men have walked even a hundred miles from their homes, or have been conveyed round this little globe by the aid of all our improved means of transport. A balloon can ascend in the air, but a man cannot; without the aid of that apparatus he is absolutely fixed to the surface of the Earth, and with the assistance of all the appliances of science, he cannot yet ascend even ten miles into the atmosphere, nor dive more than a few fathoms into the sea. His senses are equally contracted; his perceptions of touch and sound are far less delicate than that of the microphone; a photographic surface will detect vibrations of light which he cannot at all perceive, and record images more quickly than his brain; and for the detection of magnetism and the chemical rays of light he possesses no sense whatever:—electrometers and galvanometers can detect thousands of times smaller quantities of electricity than he can perceive:—whilst a bolometer renders manifest a one hundred-thousandth of a Centigrade degree change of temperature, he can hardly detect a difference of an entire degree; and whilst carbon and platinum may be heated to whiteness without material change, a rise or fall of about five Fahrenheit degrees in his temperature endangers his life. His mental and intellectual powers are as limited as his senses; he can hardly reckon without making an error even a single million, nor can he conceive an adequate idea of a billion; a million miles or a millionth of an inch are each quite beyond his immediate perception; an extremely minute circumstance also is capable of disturbing and entirely diverting his train of thought. He cannot create or destroy even a particle of dust, nor form out of nothing a single idea. The velocity of transmission of his nervous power, and the speed of his execution of will, are also extremely slow in comparison with that of an electric current in a copper wire. Every person is aware that he can only very slowly receive and understand a new idea. His mental advance is as tardy as his locomotion, a sixth part of his life is spent in acquiring the merest rudiments of universal knowledge. Whilst his reasoning power, when applied to actual and truthfully stated experience, is truly "the great guide" of his life, it only renders explicit what was already contained in that experience; for when he draws an inference, he usually only states in one form of words, what he has already implicitly included in the propositions; and if the inference contains more than this it is unwarranted. His mental helplessness in the absence of knowledge, is equal to his physical incapacity in the absence of light. Nearly every problem of nature also is so complex, and affected by so many conditions, that his reasoning power only enables him to advance a very minute step at a time in the discovery of new knowledge; he is then obliged to halt, and have recourse to new experiences obtained either by means of experiment and observation, or by the latter alone.

Man's moral actions are largely the effect of circumstances; his thoughts and actions are probably the whole of them limited by law. He is never free from the influence of causation. His mental and moral freedom are limited by the epoch in which he lives, by the customs of his nation, by the individuals by whom he is immediately surrounded, by the alcoholic stimulants of which he partakes, and by his own physical and mental constitution, his degree of intelligence, &c., &c. Whether he is willing or not, he is incessantly compelled to receive sensuous and mental impressions, and be influenced by an almost infinite number and variety of agencies acting upon him both from within and without:—To be mentally and physically active, and perform all the bodily functions and acts necessary to his existence:—To live on this globe in presence of all its phenomena, and be carried through space at an immense velocity:—To undergo through a long series of generations a progressive existence and development of civilization, &c., &c. He is more subject to the laws of the Universe than those laws are subject to him; and he can only exercise his will successfully and become their master by first obeying them.

Under the influence of the light and heat of the Sun, the entire population of this planet (about fifteen hundred millions) are renewed out of the crust of the Earth every few years, by breathing the air, drinking the water, feeding upon plants which take their constituents from the Earth, water and air; or by eating animals which have lived upon plants; and if that heat and light, or that supply of food and air, were to cease, all those human beings would die, and all the moral phenomena of man on this globe would terminate. Whilst man cannot exist without the support of inanimate nature and the operation of its laws, inanimate nature and its laws can exist without him. That also which is naturally ordained by Creative power to be dependent, cannot be essentially more important than that upon which it depends for its existence. The essential importance of man in relation to the Universe, exists only in his own imagination.

These facts shew that the principles of science, and the physical and chemical properties of substances, lie at the very basis of man's existence and activity and it would therefore be incorrect to say that the physical system of the Universe is unimportant in comparison with the moral phenomena of mankind.

That science conduces to humanity by preventing and alleviating animal suffering has been already alluded to (p. 80-81). True humanity consists not in the abolition of experiments upon living creatures, but in the judicious employment of them. Instead of barbarously treating our suffering fellow creatures by indolently and ignorantly allowing causes of disease and pain to continually occur and take their course, it urgently enforces upon us the duty of extending our knowledge of physiology by means of new experiments, observations and study. It would be untruthful to say that experiments purposely made upon men and other animals do not yield new and valuable information;—Pharmacopœias and Materia-Medicæs are full of descriptions of the properties of curative agents discovered by these and other scientific methods.

Amongst the lesser virtues which have been greatly promoted by means of scientific research is that of cleanliness. The origin of soap was the discovery of the detergent properties of a boiled mixture of fat and alkali. The numerous inventions which have cheapened the most important soap-producing material, viz., washing soda, and those which have cheapened oil of vitriol, the chief substance consumed in making washing-soda, have all contributed to the cleanliness of mankind; and it has been stated that the degree of civilization of a nation might be ascertained by the amounts consumed of those substances.

Even the minor virtue of economy has been greatly promoted by the results of scientific research. New scientific truth has through inventions taught us how to obtain greater effects with less expenditure of space, of time, of materials, and forces. It has enabled us to effect our objects quicker and with a diminution of waste. In the sugar manufacture for example, by means of the centrifugal machine, the sugar is deprived as perfectly of molasses in three minutes, as it was previously in three days, and the necessary manufacturing apparatus has been so much reduced in magnitude as not to require more than one half the space. The process of bleaching linen, which formerly required weeks, has by the discovery of chlorine been reduced to hours. Journeys which at one time occupied weeks now only require days. Messages are now transmitted in hours which formerly required months. Multitudes of instances might be adduced of the diminished cost of the comforts and conveniences of life, resulting in consequence of discovery of new scientific knowledge. Ultramarine for example, which at one time cost from ten to twenty pounds an ounce, has by means of chemical research been reduced in price to a few pence per pound; phosphorus, which formerly cost several guineas an ounce, now costs only as many pence.

Numerous substances which were formerly thrown away, destroyed, or neglected, are now utilized. Coal tar and gas-water, which were at one time waste products in the making of gas, and which when thrown away were the causes of costly litigation to gas-companies, by polluting streams and wells, &c., are now sources of very large income to those companies. Those substances yield great quantities of salts of ammonia, the beautiful aniline dyes, paraffin, benzene, napthaline, alizarine, and other valuable products. Glycerine also, which formerly was a most offensive waste product in soap-making, is now purified and used, to an extent of twenty millions of pounds annually, for a great number of purposes; as an emollient for the skin; as a source of nitro-glycerine and dynamite, used in blasting rocks, in warfare, &c. The immense beds of native sulphide of iron also, notably those of Tharsis and Rio Tinto in Spain, and of many other places, are now utilized, literally in millions of tons, for the production of sulphur, copper, oxide of iron, &c. A long list of instances of this class might be adduced if it were necessary, some of them of very great importance.

The promotion of morality by enabling us to detect crime, is one of the smaller influences of scientific research, and may be referred to as a set-off against the bad uses sometimes made of scientific knowledge. The telegraph is very commonly employed to assist in tracking and capturing criminals. Photography is also largely used in our gaols as a means of recognising offenders.

Knowledge of science conduces also to self-discipline and self-mastery, it tends to bridle our vicious passions by making known to us the penalties which must be paid for their indulgence; it limits our self-will by shewing us that we must respect and obey the laws of nature whether we are willing or not, no man can improperly manipulate dangerous substances or forces with impunity; it moderates our bigotry by exhibiting to us the great uncertainty of unproved opinions; it restrains undue credulity in men's assertions, by shewing us their frequent fallacy; it gives us confidence in the laws of nature, by proving to us their uniformity; it withdraws us from self-deception by compelling us to accept the truths of nature as they exist ready made for us, whether they harmonise with our preconceived ideas or not; men cannot argue with nature, as they can with their fellow-men, but must submit to the influence of verified truth. It supplies us with principles instead of empirical "rule of thumb" methods as guides of morality. Whilst it liberates us from the terror of irrational fears, it cautions us against entertaining unreasonable hopes. It substitutes for ignorant wonder and awe, an intelligent appreciation of created things; and when fully developed it will probably satisfy all the reasonable instincts and desires of men.

Whilst law, medicine and divinity, direct man's attention almost exclusively to matters concerning himself, and thus tend to limit his sphere of perception and knowledge, and unconsciously impress him with the idea that all other existences are less important than himself, science not only enlightens him respecting all the departments of his own nature, but extends his mental vision in all directions by exciting his mind to observe and reflect upon all other bodies and actions throughout the Universe. Whilst also music, painting, sculpture, poetry and the drama, afford excitement and pleasure to his senses, feelings and sentiments, and are largely personal; science not only constitutes the basis of those arts, but shews the relations of them to Man and to the external Universe, and thus more largely cultivates the intellect and corrects and refines the senses, feelings and sentiments.

New scientific knowledge affords advantages to all classes of men; to the minister of religion, by supplying him with new illustrations of Creative power, in the greatness, smallness, and vast variety of nature; to the physician, by explaining to him more perfectly the structure and phenomena of the human body, and by providing him with new remedies; to the statesman and politician, by making known to him the great and increasing relations of science to national progress, by its influence upon wages, capital, the employment of workmen, the art of war, the means of communication with foreign countries, &c.; to the philanthropist, as an endless source of employment for poor persons, by the development of new discoveries, inventions, and improvements in arts and manufactories; to the military man, by affording him new engines and materials for warfare and defence; to the inventor, by supplying him with new discoveries upon which to found inventions; to the merchant and man of trade, by the influence of new products and processes upon the prices of his commodities; to the manufacturer, as a means of improving his materials, apparatus, and processes; and to the investor of money, by assisting him to judge what new technical schemes are likely to succeed.

As the domain of rational enjoyment afforded by means of science gradually enlarges, that derivable from less intellectual sources will probably be modified; indeed this change is already progressing, and is manifested in the alterations occurring in theological views, and in the extensive adoption of scientific entertainments by religious bodies. The recognition of science by professors of religion is also shewn by the already extensive use of railways on Sundays as a means of conveyance to churches and chapels; also by the publication by the Society for Promoting Christian Knowledge, of Manuals of Electricity, Astronomy, Botany, Chemistry, Crystallography, Geology, Physiology, Zoology, Matter and Motion, the Spectroscope, &c.

Having shewn some of the chief modes in which new scientific truth is a basis of mental and moral progress, it is not necessary to say much respecting the evil uses sometimes made of science, because every good thing is liable to be abused by ignorant or ill-intentioned persons. The abuses of scientific knowledge do not arise from the true spirit of research, viz., a desire for new knowledge on account of its intrinsic goodness and value to man, but from an absence of that sentiment. The Bremerhaven explosion, the assassination of the Czar, the uses of photography to forge letters of credit, and of the telegraph in swindling operations, the employment of electro-gilding and silvering in coining base money, &c., &c., are all attributable to motives other than a love of science.

All the facts mentioned in this chapter, and the various points of essential similarity between physical, physiological, and mental phenomena, justify the conclusion that both moral and other mental actions, like physical and chemical ones, are obedient to the great principles of science. And from the evidence here adduced and alluded to, it is certain that those principles influence human progress, not only in a few conspicuous direct ways, but in a multitude of varied, deep-seated, and indirect ones.

If the statements made in this Chapter are true, that the innate properties of matter really are motive powers of the human organism, and the principles of science are regulators of mental and moral action; that Man is a feeble epitome of the principles and powers of inorganic matter; that the laws of Nature operate in utter disregard of his erroneous beliefs; that nearly all man's sins and sufferings are traceable to his ignorance and limited powers; that in proportion to his ignorance of science so is he unable to foresee the more remote consequences of his thoughts and acts; and if new knowledge does correct erroneous beliefs and purify human thought and action, it behoves teachers of morality to make themselves adequately acquainted with the principles and newest developments of science.

12 —The whole of this chapter, especially the Moral Section, is capable of great amplification and much more copious illustration.

13 —See also p. 95.

14 —Athenæum, Aug. 3, 1877. p. 242.

15 "Wish and Will," by L. Turner, M.A.

16 "The Mutual Relations of Physical Science and Religious Faith."

17 Port Royal Logic, Discourse 1.

18 See p. 91-92.

19 See "Waste Products and Undeveloped Substances," by P. W. Simmonds.