In the sixth book Aristotle comes to the consideration of the dialectic of this motion and change as advanced by Zeno, that is, to the endless divisibility which we have already (Vol. I. pp. 266-277) considered. Aristotle solves it through the universal. He says that they are the contradiction of the universal turned against itself; the unity in which its moments dissolve is not a nothing, so that motion and change are nothing, but a negative universal, where the negative is itself again posited as positive, and that is the essence of divisibility.
Of the further details into which Aristotle enters, I shall only give the following. As against atoms and their motion, he remarks (Phys. VI. 10) that the indivisible has no motion and mutation, which is the direct opposite of the proposition of Zeno that only simple indivisible Being and no motion exists. For as Zeno argues from the indivisibility of atoms against motion, Aristotle argues from motion against atoms. “Everything which moves or changes is in the first division of this time partly here and partly there. The atom, as simple indivisible Being, can, however, not have any part of it in both points in space, because it then would be divisible. The indivisible could thus only move if time consisted of the Now; this is, however, impossible, as we proved before.” Because atoms thus neither have change in themselves, nor can this come to them from without through impulse, &c., they are really without truth.
The determination of the pure ideality of change is important. Aristotle says of this (Phys. VII. 3), “That which is changed is alone the sensuous and perceptible (αἰσθητόν); and forms and figures, as also capacities, are not changed, they arise and disappear in a thing only, without being themselves changed.” In other words: the content of change is unchangeable; change as such belongs to mere form. “Virtues or vices belong, for example, to habits acquired. Virtue is the perfection (τελείωσις) in which something has reached the end of its nature. Vice, however, is the corruption and non-attainment of this. They are not changes, for they only arise and pass away while another alters.” Or the difference becomes a difference of Being and non-being, _i.e._ a merely sensuous difference.