Page:Philosophical Review Volume 13.djvu/15

Volume XII. Number 1.

LIKE other works of Aristotle, the Posterior Analytics has had an influence upon the history of human thought out of all proportion to its length. Within a comparatively short compass the author succeeds in giving a tolerably complete and systematic statement of the processes by which scientific truth is reached. The main object of the treatise, it is true, is to explain the conditions under which the necessary conclusions of science may be drawn, a fact which naturally gave countenance to the doctrine that truth is reached by a deductive process. A careful examination, however, shows that the preëminence assigned to deduction cannot be justified by the contents of the work itself, in which the necessity of induction as an indispensable preparation for the deductions of sciences is everywhere kept in view, and indeed expressly stated. The treatise is so interesting in itself, and so valuable for the light it throws upon the philosophy of Aristotle in general, and especially upon his Metaphysic, that it may not be superfluous to give a summary of its main con- tents, and to attempt some estimate of their value.

"All teaching and all learning of a reflective character," Aristotle tells us, "start from knowledge that we already have." As we learn from a passage in the Ethics, the "teaching and learning" here referred to proceed either by induction or by syllogism; for, it is by induction, as Aristotle goes on to explain, that we obtain universal propositions, and it is from these