Page:Theory of Mind of Roger Bacon.djvu/19

 identical effect which is first called Species and afterwards complete Effect. For, the only difference is that of degree; the kind of difference that exists between embryo and boy, and boy and man.

The principal effect. Principal is here opposed to accidental; the Species is the only effect of the Agent’s essence, as we have seen, whereas the other effects of the Agent are effects per accidens. The former is produced by the Agent itself, whereas the latter are produced by the Species. The principal effect, once generated, is the means through which all other effects are generated. In part they are effects which perfectly resemble their cause, but for the most part they are not; indeed Nature seeks chiefly the latter. The principal action is that which is straight-ahead, so to speak, and the accidental is rather by the way. While the Agent is at work operating its principal effect through the Species, the Species in turn is sending out its Species in all directions and producing the accidental effects. In sense-perception the accidental as well as the principal propagation of Species is operative. But Bacon is not conscious of the serious implications in this admission.

The immediate or first effect. By immediate, or first, effect is meant that effect of the Agent which is produced without the intermediation of any third factor between Agent and Effect. The Species alone is that effect for which such immediacy is demanded; and this is taken simply as an ultimate. But in addition to this primary effect, other or secondary effects are produced; and indeed through the medium of the Species. These mediate or secondary effects are, in the nature of things, further removed from the Agent than the immediate or primary effect. This is obvious, for instance, in the case of light. Its effects are the Species, heat, putrefaction, and death, in the order as they occur in an object deleted. The first is by nature “nearest” the Agent in essence; while the other effects are different in essence from the Agent. For this