tain privation of light, and a man, because it is a certain animal, and soul, because it moves itself. As regards then whatever we know accidentally that they are, it is by no means necessary that we should possess any thing by which to know what they are, for neither do we (really) know that they are, and to inquire what a thing is, when we do not know that it is, is to inquire about nothing. In those things however of which we know something, it is easy (to inquire) what they are; hence as we know that a thing is, so also are we disposed to know what it is, now of those things, of whose essential nature we know something, let this be first an example, an eclipse A, the moon C, the opposition of the earth B. To inquire then whether there is an eclipse or not, is to inquire whether B is or not, but this does not at all differ from the inquiry if there is a reason of it, and if this is, we say that that also is. Or we (inquire) of which contradiction there is a reason, whether of possessing, or of not possessing, two right angles, but when we have discovered, we know at the same time, that it is, and why it is, if it is inferred through media; but if it is not so inferred, we know the that, but not the why. Let C be the moon, A an eclipse, not to be able to produce a shadow when the moon is full and nothing is seen interposed between us, B, if then B, that is, not to be able to produce a shadow when there is nothing between us, be present with C, and A, to be eclipsed, present with this, that there is an eclipse, is indeed evident, but why is not yet so, and that there is an eclipse, we indeed know, but what it is we do not know. Yet as it is clear that A is with C, (to inquire) why it is, is to investigate what B is, whether it is the opposition (of the earth), or the turn of the moon, or the extinction of light, but this is the definition of the other extreme, as in those (examples) of A, since an eclipse is the interposition of the earth. What is thunder? the extinction of fire in a cloud: why does it thunder? because fire is extinguished in a
