In this triple division of speculative philosophy into Physics, Mathematics, and Metaphysics, it will naturally occur to one to ask: Did Aristotle distinguish between what he called Physics and what we nowadays call the special physical sciences? He did. These special _analytic_ studies of the various departments of the physical universe, animate and inanimate, Aristotle described indiscriminately as “partial” sciences: αἱ ἐν μέρει ἐπιστημάι—ἐπιστημαὶ ἐν μέρει λεγόμεναι. These descriptive, inductive, comparative studies, proceeding _a posteriori_ from effects to causes, he conceived rather as a preparation for scientific knowledge proper; this latter he conceived to be a _synthetic_, deductive explanation of things, in the light of some common aspect detected in them as principle or cause of all their concrete characteristics.(18) Such synthetic knowledge of things, in the light of some such common aspect as change, is what he regarded as scientific knowledge, meaning thereby what we mean by philosophical knowledge.(19) What he called _Physics_, therefore, is what we nowadays understand as _Cosmology_ and _Psychology_.(20) Mathematical science Aristotle likewise regarded as science in the full and perfect sense, _i.e._ as philosophical. But just as we distinguish nowadays between the special physical and human sciences on the one hand, and the philosophy of external nature and man on the other, so we may distinguish between the special mathematical sciences and a Philosophy of Mathematics: with this difference, that while the former groups of special sciences are mainly inductive the mathematical group is mainly deductive. Furthermore, the Philosophy of Mathematics—which investigates questions regarding the ultimate significance of mathematical concepts, axioms and assumptions: unity, multitude, magnitude, quantity, space, time, etc.—does not usually form a separate department in the philosophical curriculum: its problems are dealt with as they arise in the other departments of Metaphysics.