cloud. Let C be a cloud, A thunder, B the extinction of fire, hence B is present with C, that is, with the cloud, for fire is extinguished in it, but A, sound, is present with this, and B is the definition of A, the first extreme; if there be again another medium of this it will be from the remaining definitions.
We have shown therefore thus, how what a thing is, is assumed, and becomes known, wherefore there is neither syllogism nor demonstration of what a thing is, still it will become evident through syllogism, and through demonstration; and hence without demonstration it is neither possible to know what a thing is, of which there is another cause, nor is there demonstration of it, as we have already observed in the doubts.
Chapter 9
Of some things indeed there is a certain other cause, but of others there is not, so that it is plain that some of them are immediate, and principles, whose existence and what they are, we must suppose, or make manifest after another manner, which indeed the arithmetician does, for he both supposes what unity is, and that it is. Of those however which have a medium, and of whose essence there is another cause, it is possible, as we have said, to produce a manifestation through demonstration, yet not by demonstrating what they are.
