Page:Enneads (IA enneads05plot).pdf/110
antecedents, must necessarily be a distinct species; for the event and process of becoming cannot be identified with merely passive alteration, like turning hot or white: it is possible for the antecedents to take place without becoming as such being accomplished, except in so far as the actual alteration (implied in the antecedents) has "come to be"; where, however, an animal or a vegetal life is concerned, becoming (or birth) takes place only upon its acquisition of a Form.
The contrary might be maintained: that change is more plausibly ranked as a species than is Motion, because change signifies merely the substitution of one thing for another, whereas Motion involves also the removal of a thing from the place to which it belongs, as is shown by locomotion. Even rejecting this distinction, we must accept as types of Motion knowledge and musical performance—in short, changes of condition: thus, alteration will come to be regarded as a species of Motion—namely, motion displacing.
22.
But suppose that we identify alteration with Motion on the ground that Motion itself results in difference: how then do we proceed to define Motion?
It may roughly be characterised as the passage from the potentiality to its realisation. That is potential which can either pass into a Form—for example, the potential statue—or else pass into actuality—such as the ability to walk: whenever progress is made towards the statue, this progress is Motion; and when the ability to walk is actualised in walking, this walking is itself Motion: dancing is, similarly, the motion produced by the potential dancer taking his steps.
In the one type of Motion a new Form comes into existence created by the motion; the other constitutes, as it were, the pure Form of the potentiality, and leaves nothing behind it when once the motion has ceased. Accordingly, the view would not be unreasonable which, taking some Forms to be active, others inactive, regarded Motion as a dynamic Form in opposition to the other Forms which are static, and further as the cause of whatever new Form ensues upon it. To proceed to identify