Page:Theory of Mind of Roger Bacon.djvu/14

 As for Aristotle so too for Bacon the essential feature in the process is assimilation. The change is always for the production of a “like.” The Agent assimilates the Patient to itself; the Patient is potentially that which the Agent actually is. For example, in the case of sense-perception, the sense of sight is assimilated to the quality to be perceived, and this is effected through the Species. The details of this process, omitted by Aristotle, it is Bacon’s intention to fill in. The conditions presupposed for the assimilation are the same for Bacon as for Aristotle, as we shall see.

We may now summarize. Within the general concept of motion, that which is formal as opposed to spatial, gives the field within which this theory of Species is to be applied. Within the formal, that change which is qualitative as opposed to quantitative engages his attention; and the qualitative is taken to include the change of generation-dissolution as well as that of alteration, though meant more particularly for the latter. Finally, the change is always such as makes for the assimilation of the Patient to the Agent.

We may now get clearly before us our Author’s description of the process of assimilation through the Species. As we should expect, his general description of the process begins always with the broad notion of Agent and Patient, or Efficient and Material Cause. And the problem takes this form: How is any natural phenomenon brought into being? The answer in simple terms is this: When an Efficient Cause acts upon a Material Principle, the “virtue” of the former works the change in the latter—the Virtue of the Agent is infused into the Matter of the Patient, and transforms it until the Effect is produced. We have, then, three factors; the Efficient Cause or Agent, the Material Cause or Patient, and the Effect.

As a first condition for this process it is necessary that the Agent and Patient should come together. And by this is meant, that they must exist not only simultaneously, but also in actual contact; the Agent must touch some part of the Patient, and through this contact work the change. But while “approximation” is a necessary condition, none other than that described is required. It is a surface-contact, and that suffices. For, the Agent-as-a-whole is active, and changes the depths of the Patient part by part through the Species. As a second condition, the Agent and Patient must belong