VII.

We have endeavoured to show that Aristotle’s account of the syllogism is redundant on the one side and defective on the other, both errors being due to a false analysis of the reasoning process itself, combined with a false metaphysical philosophy. The same evil influences tell with much greater effect on his theory of applied reasoning. Here the fundamental division, corresponding to that between heaven and earth in the cosmos, is between demonstration and dialectic or experimental reasoning. The one starts with first principles of unquestionable validity, the other with principles the validity of which is to be tested by their consequences. Stated in its most abstract form, the distinction is sound, and very nearly prefigures the modern division between deduction and induction, the process by which general laws are applied, and the process by which they are established. Aristotle, however, committed two great mistakes; he thought that each method corresponded to an entirely different order of phenomena: and he thought that both were concerned for the most part with definitions. The _Posterior Analytics_, which contains his theory of demonstration, answers to the astronomical portion of his physics; it is the doctrine of eternal and necessary truth. And just as his ontology distinguishes between the Prime Mover himself unmoved and the eternal movement produced by his influence, so also his logic distinguishes between infallible first principles and the truths derived from them, the latter being, in his opinion, of inferior value. Now, according to Aristotle, these first principles are definitions, and it is to this fact that their self-evident certainty is due. At the same time they are not verbal but real definitions—that is to say, the universal forms of things in themselves as made manifest to the eye of reason, or rather, stamped upon it like the impression of a signet-ring on wax. And, by a further refinement, he seems to distinguish between the concept as a whole and the separate marks which make it up, these last being the ultimate elements of all existence, and as much beyond its complex forms as Nous is beyond reasoned truth.

Such a view was essentially unfavourable to the progress of science, assigning, as it did, a higher dignity to meagre and very questionable abstractions than to the far-reaching combinations by which alone we are enabled to unravel the inmost texture of visible phenomena. Instead of using reason to supplement sense, Aristotle turned it into a more subtle and universal kind of sense; and if this disastrous assimilation was to a certain extent imposed upon him by the traditions of Athenian thought, it harmonised admirably with the descriptive and superficial character of his own intelligence. Much was also due to the method of geometry, which in his time had already assumed the form made familiar to us by Euclid’s _Elements_. The employment of axioms side by side with definitions, might, indeed, have drawn his attention to the existence and importance of judgments which, in Kantian terminology, are not analytic but synthetic—that is, which add to the content of a notion instead of simply analysing it. But although he mentions axioms, and states that mathematical theorems are deduced from them, no suspicion of their essential difference from definitions, or of the typical significance which they were destined to assume in the theory of reasoning, seems ever to have crossed his mind; otherwise he could hardly have failed to ask how we come by our knowledge of them, and to what they correspond in Nature. On the whole, it seems likely that he looked on them as an analysis of our ideas, differing only from definition proper by the generality of its application; for he names the law of contradiction as the most important of all axioms, and that from which the others proceed;[277] next to it he places the law of excluded middle, which is also analytical; and his only other example is, that if equals be taken from equals the remainders are equal, a judgment the synthetic character of which is by no means clear, and has occasionally been disputed.[278]

We cannot, then, agree with those critics who attribute to Aristotle a recognition of such things as ‘laws of nature,’ in the sense of uniform co-existences and sequences.[279] Such an idea implies a certain balance and equality between subject and predicate which he would never have admitted. It would, in his own language, be making relation, instead of substance, the leading category. It must be remembered also that he did not acknowledge the existence of those constant conjunctions in Nature which we call laws. He did not admit that all matter was heavy, or that fluidity implied the presence of heat. The possession of constant properties, or rather of a single constant property—circular rotation—is reserved for the aether. Nor is this a common property of different and indefinitely multipliable phenomena; it characterises a single body, measurable in extent and unique in kind. Moreover, we have something better than indirect evidence on this point; we have the plain statement of Aristotle himself, that all science depends on first principles, about which it is impossible to be mistaken, precisely because they are universal abstractions not presented to the mind by any combination,[280]—a view quite inconsistent with the priority now given to general laws.

Answering to the first principles of demonstration in logic, if not absolutely identical with them, are what Aristotle calls causes in the nature of things. We have seen what an important part the middle term plays in Aristotle’s theory of the syllogism. It is the vital principle of demonstration, the connecting link by which the two extreme terms are attached to one another. In the theory of applied logic, whose object is to bring the order of thought into complete parallelism with the order of things, the middle term through which a fact is demonstrated answers to the cause through which it exists. According to our notions, only two terms, antecedent and consequent, are involved in the idea of causation; and causation only becomes a matter for reasoning when we perceive that the sequence is repeated in a uniform manner. But Aristotle was very far from having reached, or even suspected, this point of view. A cause is with him not a determining antecedent, but a secret nexus by which the co-existence of two phenomena is explained. Instead of preceding it intercedes; and this is why he finds its subjective counterpart in the middle term of the syllogism. Some of his own examples will make the matter clearer. Why is the moon eclipsed? Because the earth intervenes between her and the sun. Why is the bright side of the moon always turned towards the sun? Because she shines by his reflected light (here light is the middle term). Why is that person talking to the rich man? Because he wants to borrow money of him. Why are those two men friends? Because they have the same enemy.[281]

Aristotle even goes so far as to eliminate the notion of sequence from causation altogether. He tells us that the causes of events are contemporary with the events themselves; those of past events being past; of present events, present; and of future events, future. ‘This thing will not be because that other thing has happened, for the middle term must be homogeneous with the extremes.’[282] It is obvious that such a limitation abolishes the power of scientific prediction, which, if not the only test of knowledge, is at any rate its most valuable verification. The Stagirite has been charged with trusting too much to deductive reasoning; it now appears that, on the contrary, he had no conception of its most important function. Here, as everywhere, he follows not the synthetic method of the mathematician, but the analytic method of the naturalist. Finally, instead of combining the notions of cause and kind, he systematically confuses them. It will be remembered how his excellent division of causes into material, formal, efficient, and final, was rendered nugatory by the continued influence of Plato’s ideas. The formal cause always tended to absorb the other three; and it is by their complete assimilation that he attempts to harmonise the order of demonstration with the order of existence. For the formal cause of a phenomenon simply meant those properties which it shared with others of the same kind, and it was by virtue of those properties that it became a subject for general reasoning, which was interpreted as a methodical arrangement of concepts one within another, answering to the concentric disposition of the cosmic spheres.

Owing to the slight importance which Aristotle attaches to judgments as compared with concepts, he does not go very deeply into the question, how do we obtain our premises? He says, in remarkably emphatic language, that all knowledge is acquired either by demonstration or by induction; or rather, we may add, in the last resort by the latter only, since demonstration rests on generals which are discovered inductively; but his generals mean definitions and abstract predicates or subjects, rather than synthetic propositions. If, however, his attention had been called to the distinction, we cannot suppose that he would, on his own principles, have adopted conclusions essentially different from those of the modern experiential school. Mr. Wallace does, indeed, claim him as a supporter of the theory that no inference can be made from particulars to particulars without the aid of a general proposition, and as having refuted, by anticipation, Mill’s assertion to the contrary. We quote the analysis which is supposed to prove this in Mr. Wallace’s own words:—

We reason that because the war between Thebes and Phocis was a war between neighbours and an evil, therefore the war between Athens and Thebes, being also a war between neighbours, will in all probability be also an evil. Thus, out of the one parallel case—the war between Thebes and Phocis—we form the _general_ proposition, All wars between neighbours are evils; to this we add the minor, the war between Athens and Thebes is a war between neighbours—and thence arrive at the conclusion that the war between Athens and Thebes will be likewise an evil.[283]

On the strength of this Mr. Wallace elsewhere observes:—

His [Aristotle’s] theory of syllogism is simply an explicit statement of the fact that all knowledge, all thought, rests on universal truths or general propositions—that all knowledge, whether ‘deductive’ or ‘inductive,’ is arrived at by the aid, the indispensable aid, of general propositions. We in England have been almost charmed into the belief that reasoning is perpetually from particular to particular, and a ‘village matron’ and her ‘Lucy’ have been used to express the truth for us in the concrete form adapted to our weaker comprehension (Mill’s _Logic_, bk. ii. ch. 3). We shall next be told, forsooth, that oxygen and hydrogen do not enter into the composition of water, because our village matron ‘perpetually’ drinks it without ‘passing through’ either element, and the analysis of the chemist will be proved as great a fiction as the analysis of the logician. Aristotle has supplied the links which at once upset all such superficial analysis. He has shown that even in analogy or example, which _apparently_ proceeds in this way from one particular instance to another particular instance, we are only justified in so proceeding in so far as we have transformed the particular instance into a general proposition.[284]

Now, there is this great difference between Aristotle and Mill, that the former is only showing how reasoning from examples can be set forth in syllogistic form, while the latter is investigating the psychological process which underlies all reasoning, and the real foundation on which a valid inference rests—questions which had never presented themselves clearly to the mind of the Greek philosopher at all. Mill argues, in the first instance, that when any particular proposition is deduced from a general proposition, it is proved by the same evidence as that on which the general itself rests, namely, on other particulars; and, so far, he is in perfect agreement with Aristotle. He then argues that inferences from particulars to

## particulars are perpetually made without passing through a general

proposition: and, to illustrate his meaning, he quotes the example of a ‘village matron and her Lucy,’ to which Mr. Wallace refers with a very gratuitous sneer.[285]

However, as we have seen, he is not above turning it against Mill. The drift of his own illustration is not very clear, but we suppose it implies that the matron unconsciously frames the general proposition: My remedy is good for all children suffering from the same disease as Lucy; and with equal unconsciousness reasons down from this to the case of her neighbour’s child. Now, it is quite unjustifiable to call Mill’s analysis superficial because it leaves out of account a hypothesis incompatible with the nominalism which Mill professed. It is still more unjustifiable to quote against it the authority of a philosopher who perfectly agreed with those who disbelieve in the possibility of unconscious knowledge,[286] and contemptuously rejected Plato’s opinion to the contrary. Nor is this all. The doctrine that reasoning is from particulars to particulars, even when it passes through general propositions, may be rigorously deduced from Aristotle’s own admissions. If nothing exists but particulars, and if knowledge is of what exists, then all knowledge is of particulars. Therefore, if the propositions entering into a chain of reasoning are knowledge, they must deal with particulars exclusively. And, quite apart from the later developments of Aristotle’s philosophy, we have his express assertion, that all generals are derived from particulars, which is absolutely incompatible with the alleged fact, that ‘all knowledge, all thought, rests on universal truths, on general propositions; that all knowledge, whether “deductive” or “inductive,” is arrived at by the aid, the indispensable aid, of general propositions.’ To Aristotle the basis of knowledge was not ‘truths’ of any kind, but concepts; and in the last chapter of the _Posterior Analytics_ he has explained how these concepts are derived from sense-perceptions without the aid of any ‘propositions’ whatever.

We are here confronted with an important and much disputed question, Was Aristotle an empiricist? We hold most decidedly that he was, if by empiricist is meant, what alone should be meant—one who believes that the mind neither anticipates anything in the content, nor contributes anything to the form of experience; in other words, who believes knowledge to be the agreement of thought with things imposed by things on thought. We have already shown, when discussing Sir A. Grant’s view to the contrary, that Aristotle was in no sense a transcendental idealist. The other half of our position is proved by the chapter in the _Posterior Analytics_ already referred to, the language of which is _primâ facie_ so much in favour of our view that the burden of proof rests on those who give it another interpretation. Among these, the latest with whom we are acquainted is Zeller. The eminent German historian, after asserting in former editions of his work that Aristotle derived his first principles from the self-contemplation of the Nous, has now, probably in deference to the unanswerable arguments of Kampe, abandoned this position. He still, however, assumes the existence of a rather indefinable _à priori_ element in the Aristotelian noology, on the strength of the following considerations:—In the first place, according to Aristotle, even sense-perception is not a purely passive process, and therefore intellectual cognition can still less be so (p. 190). But the passages quoted only amount to this, that the passivity of a thing which is raised from possibility to actuality differs from the passivity implied in the destruction of its proper nature; and that the objects of abstract thought come from within, not from without, in the sense that they are presented by the imagination to the reason. The pure empiricist need not deny either position. He would freely admit that to lose one’s reason through drunkenness or disease is a quite different sort of operation from being impressed with a new truth; and he would also admit that we generalise not directly from outward experience, but from that highly-abridged and representative experience which memory supplies. Neither process, however, constitutes an anticipation of outward experience or an addition to it. It is from the materialist, not from the empiricist, that Aristotle differs. He believes that the forms under which matter appears are separable from every particular portion of matter, though not from all matter, in the external world; and he believes that a complete separation between them is effected in the single instance of self-conscious reason, which again, in cognising any particular thing is identified with that thing _minus_ its matter. Zeller’s next argument is that the cognition of ideas by the Nous is immediate, whereas the process of generalisation from experience described by Aristotle is extremely indirect. Here Zeller seems to misunderstand the word ἄμεσος. Aristotle never applies it to knowledge, but only to the objective relations of ideas with one another. Two terms constitute an ‘immediate’ premise when they are not connected by another term, quite irrespective of the steps by which we come to recognise their conjunction. So with the terms themselves. They are ‘immediate’ when they cannot be derived from any ulterior principle; when, in short, they are simple and uncaused. Finally, the objection that first principles, being the most certain and necessary of any, cannot be derived from sensible experience, which, dealing only with material objects, must inherit the uncertainty and contingency of matter,—is an objection, not to the empiricist interpretation of Aristotle’s philosophy, but to empiricism itself; and it is not allowable to explain away the plain words of an ancient writer in order to reconcile them with assumptions which he nowhere admits. That universality and necessity involve an _à priori_ cognition or an intellectual intuition, is a modern theory unsupported by a single sentence in Aristotle.[287] We quite agree with Zeller when he goes on to say that in Aristotle’s psychology ‘certain thoughts and notions arise through the action of the object thought about on the thinking mind, just as perception arises through the action of the perceived object on the percipient’ (p. 195); but how this differs from the purest empiricism is more than we are able to understand.

It is remarkable that Aristotle, after repeatedly speaking of induction as an ascent from particulars to generals, when he comes to trace the process by which we arrive at the most general notions of any, does not admit the possibility of such a movement in one direction only. The universal and the individual are, according to him, combined in our most elementary sense-impressions, and the business of scientific experience is to separate them. Starting from a middle point, we work up to indivisible predicates on the one hand and down to indivisible subjects on the other, the final apprehension of both extremes being the office, not of science, but of Nous. This theory is equally true and acute. The perception of individual facts is just as difficult and just as slowly acquired as the conception of ultimate abstractions. Moreover, the two processes are carried on _pari passu_, each being only made possible by and through the other. No true notion can be framed without a firm grasp of the particulars from which it is abstracted; no individual object can be studied without analysing it into a group of common predicates, the idiosyncrasy of which—that is, their special combination—differentiates it from every other object. What, however, we wish to remark is the illustration incidentally afforded by this striking aperçu of Aristotle’s analytical method, which is also the essentially Greek method of thought. We saw that, for our philosopher, syllogism was not the subsumption of a particular case under a general law, but the interpolation of a mean between two extremes; we now see that his induction is not the finding of a law for the particular phenomenon, but its analysis into two elements—one universal and the other individual—a solution of the mean into the extremes. And the distinctive originality of his whole system was to fix two such extremes for the universe—a self-thinking thought in absolute self-identity at one end of the scale, and an absolutely indeterminate matter at the other; by combining which in various proportions he then re-constructed the whole intermediate phenomenal reality. In studying each particular class of facts, he follows the same method. The genus is marked by some characteristic attribute which one species—the prerogative species, so to speak—exhibits in its greatest purity, while the others form a graduated scale by variously combining this attribute with its opposite or privation. Hence his theory, since revived by Goethe, that the colours are so many different mixtures of light and darkness.

It has, until lately, been customary to speak as if all that Aristotle knew about induction was contained in a few scattered passages where it is mentioned under that name in the _Analytics_. This, no doubt, is true, if by induction we mean simple generalisation. But if we understand by it the philosophy of experimental evidence—the analysis of those means by which, in the absence of direct observation, we decide between two conflicting hypotheses—then the _Topics_ must be pronounced as good a discussion on the subject as was compatible with his general theory of knowledge. For he supposes that there are large classes of phenomena, including, among other things, the whole range of human life, which, not being bound by any fixed order, lie outside the scope of scientific demonstration, although capable of being determined with various degrees of probability; and here also what he has in view is not the discovery of laws, but the construction of definitions. These being a matter of opinion, could always be attacked as well as maintained. Thus the constant conflict and balancing of opposite forces, which we have learned to associate with the sublunary sphere, has its logical representative no less than the kindred ideas of uncertainty and vicissitude. And, in connexion with this side of applied logic, Aristotle has also to consider the requirements of those who took part in the public debates on disputed questions, then very common among educated Athenians, and frequently turning on verbal definitions. Hence, while we find many varieties of reasoning suggested, such as Reasoning by Analogy, Disjunctive Reasoning, Hypothetical Reasoning (though without a generalised expression for all its varieties), and, what is most remarkable, three out of Mill’s four Experimental Methods,[288] we do not find that any interesting or useful application is made of them. Even considered as a handbook for debaters, the _Topics_ is not successful. With the practical incompetence of a mere naturalist, Aristotle has supplied heads for arguments in such profusion and such utter carelessness of their relative importance that no memory could sustain the burden, except in the probably rare instances when a lifetime was devoted to their study.