having sensation; for sensation has to do with particulars." It is easy to show that Aristotle uses the term _Induction_, as we use it, to express the process of collecting a general proposition from particular cases in which it is exemplified. Thus in a passage which we have already quoted[15], he says, "Induction, and Syllogism from Induction, is when we attribute one extreme term to the middle by means of the other." The import of this technical phraseology will further appear by the example which he gives: "We find that several animals which are deficient in bile are long-lived, as man, the horse, the mule; hence we infer that _all_ animals which are deficient in bile are long-lived." We may observe, however, that both Aristotle's notion of induction, and many other parts of his philosophy, are obscure and imperfect, in consequence of his refusing to contemplate ideas as something distinct from sensation. It thus happens that he always assumes the ideas which enter into his proposition as _given_; and considers it as the philosopher's business to determine whether such propositions are true or not: whereas the most important feature in induction is, as we have said, the _introduction_ of a new idea, and not its employment when once introduced. That the mind in this manner gives unity to that which is manifold,--that we are thus led to speculative principles which have an evidence higher than any others,--and that a peculiar sagacity in some men seizes upon the conceptions by which the facts may be bound into true propositions,--are doctrines which form no essential part of the philosophy of the Stagirite, although such views are sometimes recognized, more or less clearly, in his expressions. Thus he says[16], "There can be no knowledge when the sensation does not continue in the mind. For this purpose, it is necessary both to perceive, and to have some _unity_ in the mind (αἰσθανομένοις εχειν ἔν τι[17] ἐν τῇ ψυχῇ); and many such perceptions having taken place, some difference is then perceived: and from the remembrance of these arises Reason. Thus from Sensation comes Memory, and from Memory of the same thing often repeated comes Experience: for many acts of Memory make up one Experience. And from Experience, or from any Universal Notion which takes a permanent place in the mind,--from the _unity in the manifold_, the same some one thing being found in many facts,--springs the first principle of Art and of Science; of Art, if it be employed about production; of Science, if about existence."