on this part of Aristotle's philosophy. The logic of Aristotle is usually termed formal or deductive, to distinguish it from the inductive logic, for which Bacon usually gets the credit. It was at one time, and not very long ago, supposed that the inductive logic, which studied real nature, was much more valuable than the deductive logic, which merely scrutinised mental processes; but it is now generally acknowledged that both sciences are equally worthy of our attention. In point of technical precision, the logic of Aristotle, and in particular his doctrine of the syllogism, is unrivalled; and it is not a little remarkable that it should have sprung at once into perfection. The industry and ingenuity of more than two thousand years have added little or nothing to the symmetrical beauty, the finished excellence, of the logical system of the mighty Stagirite. Aristotle's logical treatises have been collected together under the general title of the Organon. The Organon comprises treatises on the Categories (κατηγορίαι), and on the interpretation or expression of thought, περὶ ἑρμηνείας (as (the genuineness of these writings, however, has been doubted). It contains a treatise called the Prior Analytics (ἀναλυτικὰ προτέρα), which deals with propositions, and another entitled ἀναλυτικὰ ὕστερα, which deals with proof, definition, and division. It also contains τοπικά, or topics, a treatise on probable reasoning, and a treatise on sophistical fallacies and their solution (περὶ σοφιστικῶν ἐλέγχων). These are the logical writings of Aristotle. They deal with the method of science, and are therefore
