Editorial note — B. — Aristotle’s Doctrine.

The remaining books are known as α, Δ, I, K, M, N. The short Book α is entirely unconnected with any of the others, and most probably is not the work of Aristotle. Book Δ (περὶ τῶν ποσαχῶς λεγομένων) — a vocabulary of philosophical terms — is Aristotelian beyond question, being referred to occasionally in the chief books; but it lies quite apart from the exposition proper. Book I — dealing with Unity and Opposites — though it also has no place in the actual line of treatment, is truly ontological in character, and probably was intended to fall within some larger scheme of metaphysical doctrine; the like, as far as can be judged, being true of Books M and N, containing together a criticism of Pythagorean and Platonic theories. Finally, Book K, consisting in part of an epitomized excerpt from the Physica — hardly from the hand of Aristotle, gives otherwise only a sketch in outline of the argument of Books B, Γ, E, and thus, although Aristotelian, is to be discounted.