Page:Encyclopædia Britannica, Ninth Edition, v. 14.djvu/815

 LOGIC 791 temporal significance, but he also notes that in universal judgments there is no reference to any specific time, and also that the copula, the verb is, has no existential meaning. He is thus driven to the enunciation of a view, common among recent logicians, that the judgment is a reflective or critical act, pronouncing on the truth or falsity of a contemplated separation or conjunction of facts, while, on the other hand, the very contemplation of conjunction or separa tion has appeared as the essence of the judgment. So, in dealing with opposition, he distinguishes contradictories from contraries, and is inclined to refer the second to the given nature of facts, wherein extreme oppositions of members falling under the same genus are presented. Modality, likewise, he treats confusedly, for the assignment of the modal relations to the predicate does not sufficiently determine their place in a theory of judgment, nor explain the relation in which they stand to the judgment as the simplest activity of thought. Further, in dealing with the quantity of judgments, Aristotle is perplexed by his own theory of what constitutes generality. He is compelled to throw together universal judgments of a totally distinct kind, empirical and rational, as one may call them, and though the underlying view that empirical universality is the expression of, and is dependent on, rational connexion is made sufficiently clear in the doctrine of proof, it is not carried out to its consequences in the doctrine of judgment. Finally, to note only the crowning difficulty, the theory of proof and of definition turns upon the nature of the essential connexion of attributes in a subject, but the explanation of essence is precisely the lacuna in the system. Indications of a theory of essence are not wanting, but it does not seem possible so to unite them as to form a consistent whole. The greatest obscurity still hangs over the fundamental part of the system, the nature of the irpura. which are apprehended by vovs, of the specific relation of attributes Ka.tfa.v-ra to their subjects, and of the iStai apx^i from which particular sciences start. That the irpuTOLfftis &/j.f&amp;lt;roi, so frequently adduced as integral parts of proof, are analytical judgments 1 cannot be accepted without such qualifications as to render the use of such a term misleading ; but what their precise nature is remains in the Aristotelian system undetermined. Logic from Aristotle to Bacon and Descartes. 20. The long history of philosophic thought from Aristotle to the beginning of the modern period furnishes no new conception of logic so complete and methodical as to require detailed treatment, but exhibits alterations in special doctrines, additions, and new points of view numerous enough to account for a certain radical change in the mode of regarding logic which is, for our present purpose, the only interesting feature. This change may perhaps be expressed not inaccurately as the tendency towards formalizing logic. Gradually logical researches came to have their boundaries extended in one way by the introduction of new matter, and narrowed in another by restriction of logical consideration to one special aspect of knowledge. Much in the history of this movement still remains in obscurity, but the general result is sufficiently clear. The periods into which the historical development of logic through out this long interval may be naturally divided, with their main characteristics, are the following.! (1) The Peripatetic School, represented by Theophrastus and Eudemus, following in the main the Aristotelian tradition, but deviating in certain fundamental respects, and on the whole treating the matter of logical research as though it were separate from and independent of the theory of knowledge as a whole. To this school is due the distinct recognition of the hypothetical and disjunctive proposition and syllogism, and the more complete enumeration of the possible valid modes of CcXtegorical reasoning. In both cases the additions are made to turn upon purely formal considerations. The hypothetical and disjunctive judgments are treated as given varieties, to be discerned in ordinary language and expression, not as resting upon any fundamentally distinct principle or activity of thought. 2 The addition of five indirect moods to those recognized by Aristotle as belonging to the first figure proceeds on the purely formal ground of ditl erence in position of the middle term in the two premisses. (2) The Epicurean and Stoic Logics. Of these the Epicurean pre sents no points of interest. The Stoic logic, on the other hand, is the first example of a purely formal doctrine based on and associated with a thoroughly empirical theory of cognition. In essence the Stoic doctrine is identical with that of Antisthenes, above noted, and it is interesting to observe that, under the purely nominalist theory, logic becomes almost identical with the doctrine of expression, or rhetoric. The theory of naming, and that of the i As Zeller will have it ; see Ph. d. Gr., II. 2, 191, n. Doubtless Aristotle does define an essential attribute as being one contained in the subject or one of which the subject notion is an integral part, but this relation of entering into the definition is not to be identified rashly with the modern view of the analytical relation of subject and predicate. 3 The nature of hypothetical inference and its law are recognized with the greatest distinctness by Aristotle. From his theory of essence as causal nexus, any distinction of kind between an apodictic (categorical) syllogism and a hypo thetical of the type contemplated by later logicians was impossible and needles?. conjunction of names in propositions, are the fundamental portions of the body of logic, Naturally the Stoic logicians tended to increase the bulk of logic by introducing numerous distinctions of language, and by signalizing varieties of judgment dependent on varieties of verbal expression. (3) The acceptation of Logic among the Romans. Here there must be distinguished the quasi-rhetorical logic, such as is found in Cicero, which is altogether Stoic in character, and the Aristotelian logic, as developed by Boetius with the additions of the later commentators. In Boetius one notes specially the technical or formal character of the treatment, which was of special importance historically, from the fact that the earlier scholastic writers derived their main knowledge of logic from certain of the treatises of Boetius. (4) The ScJwlastic Logic. On the details of the scholastic logic it is not necessary to enter, but there must be noted the following points as of interest in determining what may well be called the current conception of the Aristotelian logic in modern times. The earlier scholastics, in possession of but few of Aristotle s writings, added nothing of importance to the body of logical researches, and the permanent subject of discussion, the nature of universals, did not, through any of its solutions, affect the treatment of logical doctrines. The introduction of the body of the Aristotelian writings was contemporaneous with the introduction of the Arab writings and commentaries into western Europe, and there grew up therewith a more developed treatment of what may be called the psychological element of logic. The logic of the later scholastics is characterized by two points of interest, historically unconnected, but having a natural affinity, the one, the introduc tion of an immense mass of subtle distinctions, mainly verbal, making up the body of the Parva Logicalia, the other, the influence of the nominalist conception of thought. 3 The peculiarity of the nominalist view is the severance of immediate apprehension from discursive thought, the assignment of all matter of knowledge to the one, and of all form to the other. But form, under this con ception of discursive thought, can be found only in the generalizing I function of signs or names ; accordingly the fundamental processes of logical thought are regarded as so many modes of application of names. The later nominalist logicians were thus naturally led to the expenditure of immense subtlety and diligence on the thorny problems of the Parva Logicalia, while at the same time the peculiar inner difficulty of the theory became apparent as its con sequences were worked out. (5) The Reaction against AristoteUanism and the Humanist Modification of Logic. Little of positive value for logical theory is offered by the numerous works representing this stage of historical development. Valla, Agricola, and Yives, with much good criticism in general spirit and detail, present a rhetorico-gram- matical logic that resembles most closely Cicero s eclectic reproduc tion of Stoicism. Ramus, the only logician of the period with historic renown, contributes really nothing to the history of logic, his innovations consisting mainly in the omission of the most valuable portions of the genuine Aristotelic logic, the insertion of practical and interesting examples, and finally rearrangement or redistribution of the heads under which logical doctrine was ex pounded. The Ramist school, most numerous and flourishing, produced no logical work of the first importance. 4 The net result of this whole period was the severance of a cer tain body of doctrine, formal in character (the theory of second intentions), from theory of knowledge generally, and from all the concrete sciences. The boundaries and even the functions of this doctrine remained unfixed, for difference regarding fundamental points of extra-logical theory led to difference in mode of treat ment, as well as to difference in conceptions of the end and value of logic. Logic of Bacon and Descartes. 21. Modern reform of logic, by which may be understood the attempt to place logical theory in a more close and living relation to actual scientific method, begins with Bacon and Descartes. To both the scholastic logic presented itself as the essence of a thoroughly false and futile method of knowledge. Neither had the acquaintance with the genuine Aristotelian system requisite in order to distinguish the elements of permanent value from the worthless accretions under which these had been buried, and, as a natural consequence, the views of both have a far closer resemblance to the Aristotelian doctrine than might be imagined from the attitude of opposition common to them. Both thinkers were animated by the spirit of reformation in science, and both em phasize the practical end of all speculation. For both, therefore, logic, which to neither is of high value, appeared to be a species of practical science, a generalized statement of the mode in which intellect acquires new knowledge, in which the mind proceeds from known to unknown. 5 But such a conception of logic is, if the expression be permitted, formal ; that is to say, the actual province of logic is not determined thereby, but awaits determination from 3 The first of these is no doubt, as Prantl has laboured to prove, Byzantine in origin, but it still remains doubtful whence the Eastern logicians draw. The most probable source is the Stoic writings. 5 Comp. Prineip. Phil., Pref. De Aug. Sc., bk. v. chap. 1, 2.
 * See note C, p. 803.