II. To the Principal Arguments

33. To the arguments.

To the first [n.2] I say that Augustine takes light there for a subtle body (to wit, for fire, which is the more subtle body in a mixed body, or for some subtle body very much agreeing with fire in nature), just as Scripture too says that light was made on the first day; not because then an accident came to be without a subject, but a luminous body then came to be whose more known form was light; and so the subject is described through a more known term.

34. To the second [n.3] I say that the altering agent, and not the quality by which it generates, generates at the end of the alteration.

35. To the third [n.4] I say that those things are said metaphorically of light, as is plain from Avicenna On the Soul p.3 ch.2.“For as to our saying that a ray descends or goes out or enters, these words are taken transumptively, because a ray has nothing of this... But that a ray shines back is also transumptively taken; for when a body is illumined and is polished, another body opposite to it is said to be illumined by it, in such a way that the first body is not moved toward the second by local motion.” ³⁰ For no same illuming proceeds in a direct line as by local motion, and yet it is sometimes turned obliquely (by bending or refracting), but when the active power is not totally used up (that is, has not caused as much as it can cause), then, if it cannot then further act in a straight line (in which direction nature acts most of all, because a straight line is shortest and most effective for acting in), it acts in another line nearer to it if it cannot do anything further (and this a refracted or reflex line [n.19]), by reacting on the same thing it acted on before, causing there however, along with what was first caused, something simply more imperfect.

36. And if you object that a later more imperfect caused thing cannot stand together with a prior more perfect caused thing, and so there cannot be light along with a whole medium illumined by the primary ray, nor even can a reflex ray exist along with a medium illumined by a direct ray - I say that the falsity of the conclusion is manifest to sense. For it is plain that if a ray of the sun falls on water and is reflected into some dark place where there is no direct ray, the sense says that a reflection comes to be in that dark place; for it would not come to be there if the reflex ray was not first in the medium illumined by the direct ray. In the same way the sense says that a secondary illuming (or the species of a primary illuming) is diffused by the primary illuming (in contact with some opaque body) up to the eye; otherwise the primary illuming would not be seen, and yet the primary illuming is there through the whole medium. So then this proposition must be denied, ‘where there is a more perfect form, a more imperfect form (or a species, which is a more imperfect form) cannot be multiplied there’.

37. To the other arguments that are against the species or against the intention [nn.5-7].

I say to the first [n.5] that every accident could, perhaps, denominate its subject in which it is, if it were an imposed denominating term which would signify a denomination agreeing with such a form in respect of such a subject; in this way a denominative term is not imposed by the species of colors, because the denominatives imposed by colors denominate the subject that is possessed of the colors in its real being. But if a denominative were imposed that would denominate that a subject has a form in intentional being (not in real being), the medium could well be denominated by such a name as ‘white’; such a name is imposed by the illuming, and perhaps more here than in the case of colors, because of the greater perfection and evidence of this sort of intention than of other visible intentions.

38. As to what is added secondly about the opposite [darkness, n.6], I say that one illuming does not exclude another illuming of a different idea, as the illuming of the sun does not exclude the illuming of the moon in the same part of the medium, or of another star - just as neither does the species of black exclude the species of white (or conversely) in the same part of the medium; but just as any illuming excludes darkness from the medium, which darkness is a privation of illuming (not the contrary or the disparate of it), so the species of any color excludes the privation of that color in the medium.

39. To the third [n.7] I say that illuming is a thing and can have a real effect; but it is not a thing in such a way that it cannot be an intention, because along with its idea stands that it is per se the reason for tending to the object, and this suffices for the idea of intention.