only be one proposition which is certain before the connection with others. For if there were many such propositions, they would either be not at all connected with the former, and then they would not belong with it to the same whole; or they would be thus connected; but since they are only to be connected by one and the same certainty—that is, if the one theorem is true, then the other must be true—they can not have independent certainty; for in that case one proposition might have independent certainty, although others had no certainty, and hence they would not be connected through common certainty.
Such a proposition, which has certainty before and independent of all connection, is a fundamental principle. Every science must have a fundamental principle; nay, it might consist of simply such one principle, which in that case could not be called fundamental, however, since it would not be the foundation of others. But a science also can not have more than one fundamental principle, for else it would result in many sciences.
The other propositions which a science may contain get certainty only through their connection with the fundamental principle; and the connection, as we have shown, is this: If the proposition A is true, then the proposition B is also true ; and if B is true, then must C be true, etc. This connection is called the systematic form of the whole, which results from the several component parts. Wherefore this connection? Surely not to produce