Page:The New International Encyclopædia 1st ed. v. 04.djvu/422

* CAUSALITY. 360 CAUSALITY. cause is the end or motive for the sake of which the work is produced, e.g. the j)leasure of the owner. Aristotle mentions the case of a pliysician curing himself, as exemplifying all the causes in one and the same subject. Important as this classification has proved itself to be in the subsequent develoimient of thought on the subject, it does not touch upon the prohleiii of causality as it presents itself to the modern mind. This was due to the naivete that in so many ways characterized the Greek thinkers. He nssHBies that there are causes and that they produce etTects; but he does not help us to con- ceive the nature of the power — if power there be — exercised by the cause in the production of the effect. Sextus Kmpirieus, probably following .Ene- sidenius, raised some of the problems that have ever since busied the thoughts of philosophers. First of all he pointed out the relativity of the notion of cause, since cause has no meaning ajjart from effect. But, he argued, the relation has no real existence, but is merely a thought-product. We think causality into things which are themselves free from any such relation. Furthermore, there is a dilliculty about the temporal relation of cause and effect. Cause cannot be prior to the effect, for it is not cause till the effect arises. It cannot be simultaneous with, nor subsequent to, the effect, for in either case it would not be what we mean by cause. This is evidently a sophism to be discussed further on; but it is a subtle one that has puzzled many thinkers even to the present day, and has con- duced much to a clearer understanding of the time relation involved in causality. In early modern philosophy there were two rival notions of cause. Descartes and his school made cause identical with substance, while the physical scientists reduced cause to a motion or change followed by other motion or change with a mathemq,tical equality between measures of motion. I5ut it was Hume who first in modern times took up the problem of causal- ity where the skeptics had laid it down. He carried out to its logical conclusion the con- tention of Sextus Empiricus that causality is not a real relation, but a fiction of the mind, and he used the doctrine of association to ac- count for the origin of the fiction. Any tie binding cause and effect, he pointed out, is undiscoverable by the senses; and as ideas are merely copies of sense-impressions, we have no idea of casuality. . But we have a fiction of the imagination in regard to causality, and the fic- tion arises from the ease with which we pass from one perception to another perception, which in past experience has been constantly and un- varyingly associated with it. "We have no other notion of cause and effect, but that of certain objects, which have been always conjoined to- gether, and which in all past instances have been found inseparable. We cannot penetrate into the reason of the conjunction. We only observe the thing itself, and always find that from the constant conjunction the objects acquire a union in the imagination." Hence "a cause is an object precedent and contiguous to another, and so united with it, that the idea of the one deter- mines the mind to form the idea of the other, and the impression of the one to form a more lively idea of the other." Hume's ex-planation of cause as a fiction which has no discoverable objective correlate led Kant to the position that the only knowable objective world is, so faj as all the relations obtaining with- in it go, the product of mind's creative activity. Kant accepted Hume's skeptical result as far as it concerned itself with the world of tliings- in- themselves; but not being satisfied that ex- perience is only a succession of perceptions without any discoverable coherence, jie made causality one of the principles of coherence ob- taining in the world of phenomena, and uni- versallj' present there because always put there by thought as a part of its contribution to the nature of that world. (See K.>T, and Cate- gory.) Thus both Hume and Kant agree in denying absolute objectivity to causality: they disagree in that the former denies also a relative objectivity to causality, while the latter asserts such objectivity. The difference is due to the fact that for Hume the ideal world ( the bundle of perceptions) is comparatively unorganized and chaotic; for Kant it is so thoroughly or- ganized that it is regarded as a universe with relative objectivity and the relations obtain- ing therein as thoroughly knowable, inasmuch as they are contributions by the knower. Hegel, denying outright a transcendent world beyond experience, and recognizing, as Kant did. the uni- versal prevalence of causality witliin experience, made causality thoroughly objective. But the question arises. How is it known that causality is universal within the world of experience? We have not always experienced a cause for every experienced effect ; in fact, the whole problem of physical science is to discover causes for known events. How do we know they have any causes at all ? Kant, as we have already seen, answers : We know, because we have made our world in such a way that everything has a cause. Hegel's answer to this question cannot be given here, as it would require too minute a discussion. J. S. Jlill took up the problem here; den-ing the fundamental postulate of Kant's transcendental- ism, viz. that the order of this world is thought- made, he seeks to justify our belief in universal causation by tracing it back to an induction (q.v.) which rests upon a larger experience than any other induction can have. The difficulty with this view is that for Mill all induction rests upon the principle of causality, and it is a circular procedure to make causality rest on induction. But circularity is the last resort in- evitable in all reasoning. (See Knowledge, The- ory OF; and Logic.) But the difference be- tween valid logical circularity and vicious cir- cularity is the difference between a systematic support given to each part of experience by all other parts, and an attemi)t to make two judg- ments support each other while neglecting the concrete experience upon which all judgments must rest. Mill's circularity in the present in- stance is fundamentally sound, but the form in which he presents his reasoning is inadequate, and hence has led to severe criticism. Perhaps it would answer all purposes concerned to say that the tendency to make induction from ob- served fact is natural to a thinker. But whether any particular induction is valid is another ques- tion, to be answered only by carefully studying all the inductiims that have reached satisfactory re- sults and finding what characteristics they have in common and wherein they differ from induc- tions admittedly erroneous. Such a study shows that satisfactory inductions, i.e. inductions upon