Page:Theory of Mind of Roger Bacon.djvu/16

 elsewhere guilty of serious ambiguity, for which his reader must be prepared.

3. DESCRIPTION OF THE SPECIES.

We are now in a position to enter into a detailed study of the theory. And to this end we shall examine in order the following: first, the nature of the Species; second, its genesis; third, its limitations.

What then, precisely, is the Species? This question presses for an answer so soon as one touches his theory at any point. In and for itself it is nothing; it is described always by reference to something else. And from the very nature of his theory we should expect it to be so. He describes it chiefly by reference to the Agent, but briefly too by reference to the Patient and the Effect. We shall follow the description in this order.

—Everything, Bacon tells us, has some essential nature, which must be either a definite substance or an accident. And such a nature is active (agens) because it is possessed of some particular virtue; that it has this virtue means that it can do something. Indeed, this operating virtue is only another name for the essence of the thing; from the standpoint, namely, of the operation itself. Moreover, essence and nature and virtue are but different aspects of the same thing; and the same is true of substance, potentiality and force. While each of the others refers to one or another aspect, virtue refers to the operation; that is, the potentiality in all Agents of calling out the action, as distinguished from that in the Patients of finishing this action.

Now, Bacon frequently uses Species as convertible with virtue. Is then the virtue just described the Species? It is not. There is yet a second sense of the word virtue, namely, the first effect of the virtue just described. This is the Species. And it is like the virtue, whose effect it is, both in essence and in action. The Species, then, is not exactly the virtue or essence of a given Agent; but similar only to it. And yet it is as nearly like this virtue as it can be, short of absolute identity with it. It is, as it were, a representative of the Agent, with full power to stand for its principal because of its likeness to it.