Connected in fine with the empirical character of the Aristotelian philosophizing, is the fragmentary form of his writings, and their want of a systematic division and arrangement. Proceeding always in the line of that which is given, from individual to individual, he considers every province of the actual by itself, and makes it the subject of a separate treatise; but he, for the most part, fails to indicate the lines by which the different parts hang together, and are comprehended in a systematic whole. Thus he holds up a number of co-ordinate sciences, each one of which has an independent basis, but he fails to give us the highest science which embraces them all. The principle is sometimes affirmed that all the writings follow the idea of a whole; but in their procedure there is such a want of all systematic connection, and every one of his writings is a monograph so thoroughly independent and complete in itself, that we are sometimes puzzled to know what Aristotle himself received as a part of philosophy, and what he excluded. We are never furnished with an independent scheme or outline, we rarely find definite results or summary explanations, and even the different divisions of philosophy which he gives, vary essentially from one another. At one time he divides science into theoretical and practical, at another, he adds to these two a poetical creative science, while still again he speaks of the three parts of science, ethics, physics, and logic. At one time he divides the theoretical philosophy into logic and physics, and at another into theology, mathematics, and physics. But no one of these divisions has he expressly given as the basis on which to represent his system; he himself places no value upon this method of division, and, indeed, openly declares himself opposed to it. It is, therefore, only for the sake of uniformity that we can give the preference here to the threefold division of philosophy as already adopted by Plato.