Page:Encyclopædia Britannica, Ninth Edition, v. 2.djvu/576

516 gical and physiobgical writings. Granting that the work On Soul was written later than most of the other works of Aristotle, it seems to us safest to say that, in all probability, many of his works were simultaneously " on the stocks " up to the time of his death, and this makes their precise order difficult to assign.

We shall now proceed briefly to indicate, we cannot attempt more, the leading features of the contents of Aristotle's undoubted works, as they have come down to us. The books of the Oryanon (see note 10, p. 5 14) form together a connected whole. Of these the Topics appear to have been written first, but the sequence of thought between the books is that the Prior Analytics stand first, as containing the theory of the syllogism, a necessary preliminary to reasoning of all kinds; and then growing out of this root we have two divergent treatises: the Posterior Analytics, on demonstrative reasoning, or the logic of science; and the Topics, on dialectic, or the art of discussing subjects in which demonstration is impossible. For the details contained in these treatises we must refer the reader to Grote's (see note 3, p. 511) generally 1 excellent account. The matter of the Prior Analytics has become the common property of all modern books on logic. And scarcely anything 3 has had to be detracted from or added to what Aristotle wrote upon the syllogism. His was the proud distinction of having discovered and fully drawn out the laws under which the mind acts in deductive reasoning. That in deduction the mind proceeds from some universal proposition, and how it proceeds these were the first things which Aristotle had to tell the world. The modern attempts to impugn these principles, and to show that the mind does not reason from universals, are a failure. They confuse inductive with deductive reasoning, and ignore both the case of a science like geometry, which is all deduction, and also the numerous cases where the mind, having unduly assumed a universal principle, rests in it afterwards and makes deductive applications of it. Grant ing that there is such a thing as deductive reasoning (and surely life is full of it), it is a great matter to have the laws of this so clearly ascertained, that about the process itself there can no longer be doubt, and any flaw in the process can instantly be detected. This was the service that Aristotle rendered in drawing out the laws of the syllogism. Men, of course, reasoned deductively by means of "the syllogism " before Aristotle had appropriated this name 3 to indicate the formula for deductive reasoning, and before he had discovered and stated the laws under which the mind acts in deductive reasoning. They did so, how ever, unconsciously and by instinct, just as men wrote and talked grammatically before any idea of a science or an art of grammar existed. In Aristotle deductive reasoning became conscious of itself. Unfortunately for his reputation, this merely preliminary part of his labours, in which the principles and rules of syllogistic inference were drawn out, occupied almost exclusively the minds of thinkers in the Middle Ages. The errors of modern Aristotelians were imputed to Aristotle, and hence arose the notion that Aristotle explained nature by means of the syllogism. Nothing could be further from the truth; Aristotle was not only one of the most inquiring and encyclopaedical, but also one of the most thoroughly sensible, of all writers, and no one would have repudiated more strongly than himself the idea that the formula of the syllogism can be used to test or explain anything beyond the process of reasoning from certain premisses possessed or assumed, and he is never tired of telling us that the only means of obtaining premisses is by experience and observation of facts. While discussing the syllogism itself, he says, 4 " This is the case in astronomy, which is based on the observation of astronomical phenomena, and it is the case with every branch of science or art. When the facts in each branch are brought together, it will be the province of the logician to set out the demonstrations in a manner clear and fit for use." It is true that Aristotle did nothing towards the logic of Induction, that is to say, towards elucidating the methods by which the mind legitimately arrives at general facts or laws of nature. This was left to be worked out by the moderns,, by Galileo, and Bacon, and Whewell, and J. S. Mill. Aristotle, indeed, made a cursory attempt 5 to put the inductive process into syllogistic form, thus: "A, B, and C draw iron; A, B, and C are (or represent) all magnets; therefore all magnets draw iron." It is clear that this syllogism does not explain the inductive process, it only records in the minor premiss a previous induction. The real question is, do A, B, and C here properly represent all magnets 1 To answer this, verification would be required. The syllogism, then, does not explain the inductive process, but only calls attention to what is implied in it. Leaving unattempted the question how [the minor premiss in the Inductive syllogism is to be obtained, and how tested, what Aristotle really works out is the logic of Deductive Science (in the Post. Analytics) and the logic of Deductive Probability (in the Topics). Under the former head he draws the ideal of a perfect science, and recounts the conditions necessary to its existence. Interesting discussions 6 are introduced by him on Causation, Hypotheses, Axioms,. Ultimate Laws, Definition, and the Apprehension of Primary Truths. In all this there is little which might not be accepted by a man of science of the present day. The Topics, on the other hand, treat of a subject which possesses rather an antiquarian than a living interest, namely, the conduct and regulation of Dialectic as practised in Athenian society. In the Middle Ages men made a business 7 of propounding, attacking, and defending theses, but this was a lame imitation of the spontaneous disputations of lively Athens, and from its utter profitlessness has long fallen into desuetude. The Dialogues of Plato may serve to give us an idea of a society possessed with an insatiate appetite for discussion and controversy, and always delighted to take part in, or assist at, an intellectual game or fencing match between two opponents. And it is the object of the Topics of Aristotle to lay down the rules for the game of Dialectic, and to establish it as a highly salubrious and necessary intellectual art. Dialectic, properly speaking, is discussion with a view to probable truth, and so far is worthy of the attention of a philosopher. But it may easily emerge into Eristic, which is discussion with a view to victory. Even under this aspect Aristotle does not think it ought to be neglected. Drawing on his vast and methodised observation of life, he gives rules and hints for the conduct of Eristic. The name Topics means " On Common-places;" the chief contents of this treatise consist of "heads" useful in arguing for or against a proposition. All this is wearisome to read in eight books. Much more readable are the Sophistical Refutations, which form a conclusion to the