2. The Physics, De Coelo, De Generatione et Corruptione, Meteorologica.
3. Historia Animalium, De Anima, Parva Naturalia, De Partibus Animalium, De Animalium Incessu, De Generatione Animalium.
4. Ethics and Politics.
5. Poetics and Rhetoric.
6. Metaphysics (unfinished).
But Zeller does not give enough weight either to the evidence of early composition contained in the Politics and Meteorology, or to the evidence of subsequent contemporaneous composition contained in the cross-references, e.g. between the Physics and the Metaphysics. On the other hand he gives too much weight to the references from one book to another, which Aristotle could have entered into his manuscripts at any time before his death. Moreover, the arrangement sometimes breaks down: for example, though on the whole the logical books are quoted without quoting the rest, the De Interpretatione (chap. 1) quotes the De Anima, and therefore is falsely taken by Zeller against its own internal evidence to be subsequent to it and consequently to the other logical books. Again, the Meteorologica (iii. 2, 372 b 9) quotes the De Sensu (c. 3), and therefore, on Zeller’s arguments, ought to follow one of the Parva Naturalia. Lastly, though the Metaphysics often quotes the Physics, and is therefore regarded as being subsequent, it is itself quoted in the Physics (i. 8, 191 b 29), and therefore ought to be regarded as antecedent. Zeller tries to get over this difficulty of cross-reference by detaching Metaphysics, Book Δ, from the rest and placing it before the Physics. But this violent and arbitrary remedy is only partial. The truth is that the Metaphysics both precedes and follows the Physics, because it had been all along occupying Aristotle ever since he began to differ from Plato’s metaphysical views and indeed forms a kind of presupposed basis of his whole system. So generally, the references backwards and forwards, and the cross-references, are really evidences that Aristotle mainly wrote his works not successively but simultaneously, and entered references as and when he pleased, because he had not published them.
There are two kinds of quotations in Aristotle’s extant works, the quotation of another book, and the quotation of a historical fact. While the former is useless to determine the sequence of books written simultaneously, the latter is insufficient to determine a complete chronological order. When Aristotle, e.g. in the Politics, quotes an event as now (νῦν), he was writing about it at that time; and when he quotes another event as lately (νεωστί) he was writing about it shortly after that time; but he might have been writing the rest of the Politics both before and after either event. When he quotes the last event mentioned in the book, e.g. in the Rhetoric (ii. 23, 1399 b 12) the “common peace” of Greece under Alexander in 336, he was writing as late as that date, but he might also have been writing the Rhetoric both before it and after it. When he quotes what persons used to say in the past, e.g. Plato and Speusippus in the Ethics, Eudoxus and Callippus in the Metaphysics, he was writing these passages after the deaths of these persons; but he might have been also writing the Ethics and the Metaphysics both beforehand and afterwards. Lastly, when he is silent about a historical fact, the argument from silence is evidence only when he could not have failed to mention it; as, for example, in the Constitution of Athens, when he could not have failed to mention quinqueremes and other facts after 325-324. But this is in a historical work; whereas the argument from silence about historical facts in a philosophical work can seldom apply.
The chronological order therefore is not sufficiently detailed to be the real order of Aristotelian writings. Secondly, the traditional order, which for nearly 2000 years has descended from the edition of Andronicus to the Berlin edition, is satisfactory in details, but unsatisfactory in system. It gives too much weight to Aristotle’s logic, and too little to his metaphysics, on account of two prejudices of the commentators which led them to place both logic and physics before metaphysics. Aristotle rightly used all the sciences of his day, and especially his own physics, as a basis of his metaphysics. For example, at the very outset he refers to the Physics (ii. 2)for his use of the four causes, material, efficient, formal and final, in the Metaphysics (Α 2). This and other applications of the science of nature to the science of all being induced the commentators to adopt this order, and entitle the science of being the Sequel to the Physics (τὰ μετὰ τὰ φυσικά). But Aristotle knew nothing of this title, the first known use of which was by Nicolaus Damascenus, a younger contemporary of Andronicus, the editor of the Aristotelian writings, and Andronicus was probably the originator of the title, and of the order. On the other hand, Aristotle entitles the science of all being “Primary Philosophy” (πρώτη φιλοσοφία), and the science of physical being “Secondary Philosophy” (δεύτερα φιλοσοφία), which suggests that his order is from Metaphysics to Physics, the reverse of his editor’s order from Physics to Metaphysics. Thus the traditional order puts Physics before Metaphysics without Aristotle’s authority. With some more show of authority it puts Logic before Metaphysics. Aristotle, on introducing the principle of contradiction (Met. Γ 3), which belongs to Metaphysics as an axiom of being, says that those who attempt to discuss the question of accepting this axiom, do so on account of their ignorance of Analytics, which they ought to know beforehand (προεπισταμένους). He means that the logical analysis of demonstration in the Analytics would teach them beforehand that there cannot be demonstration, though there must be induction, of an axiom, or any other principle; whereas, if they are not logically prepared for metaphysics, they will expect a demonstration of the axiom, as Heraclitus, the Heraclitean Cratylus and the Sophist Protagoras actually did,—and in vain. Acting on this hint, not Aristotle but the Peripatetics inferred that all logic is an instrument (ὄργανον) of all sciences; and by the time of Andronicus, who was one of them and sometimes called “the eleventh from Aristotle,” the order, Logic-Physics-Metaphysics, had become established pretty much as we have it now. It is, however, not the real order for studying the philosophy of Aristotle, because there is more Metaphysics in his Physics than Physics in his Metaphysics, and more Metaphysics in his Logic than Logic in his Metaphysics. The commentators themselves were doubtful about the order: Boethus proposed to begin with Physics, and some of the Platonists with Ethics or Mathematics; while Andronicus preferred to put Logic first as Organon (Scholia, 25 b 34 seq.). None of the parties to the dispute had the authority of Aristotle. What do we find in his works? Primary philosophy, Metaphysics, the science of being, is the solid foundation of all parts of his philosophical system; not only in the Physics, but also in the De Coelo (i. 8, 277 b 10), in the De Generatione (i. 3, 318 a 6; ii. 10, 336 b 29), in the De Anima (i. 1, 403 a 28, cf. b 16), in the De Partibus Animalium (i. 1, 641 a 35), in the Nicomachean Ethics (i. 6, 1096 b 30), in the De Interpretatione (5, 17 a 14); and in short throughout his extant works. The reason is that Aristotle was primarily a metaphysician half for and half against Plato, occupied himself with metaphysics all his philosophical life, made the science of things the universal basis of all sciences without destroying their independence, and so gradually brought round philosophy from universal forms to individual substances. The traditional order of the Aristotelian writings, still continued in the Berlin edition, beginning with the logical writings on page 1, proceeding to the physical writings on page 184, and postponing the Metaphysics to page 980, is not the real order of Aristotle’s philosophy.
The real order of Aristotle’s philosophy is that of Aristotle’s mind, revealed in his writings, and by the general view of thinking, science, philosophy and all learning therein contained. He classified thinking (Met. Ε 1) and science (Topics, vi. 6) by the three operations of speculation (θεωρία), practice (πρᾶξις) and production (ποίησις), and made the following subdivisions:—
I. Speculative: about things; subdivided (Met. Ε 1; De An. i. 1) into:—