commandment implies the very thing which the commandment expresses. The existence of God therefore as the basis of all commandments cannot itself be a commandment. Besides only those things can form the objects of a command which can be controlled by the will. But a matter of belief like the existence of God is not subject to will, it is a matter of fact and of proof.387
Maimonides, as we know, based his proofs of the existence, unity and incorporeality of God upon twenty-six philosophical propositions taken from the works of Aristotle and his Arabian interpreters. As he was not writing a book on general philosophy, Maimonides simply enumerates twenty-five propositions, which he accepts as proved by Aristotle and his followers. To these he adds provisionally another proposition, number twenty-six, concerning the eternity of motion, upon which he bases his proof of the existence of God in order to be safe from all criticism. In the sequel he discusses this last proposition and shows that unlike the other twenty-five, it is not susceptible of rigid demonstration, and the arguments in favor of the origin of motion and the world in time are more plausible.
Crescas goes further than Maimonides, and controverts most of the other propositions as well, maintaining in particular against Aristotle and Maimonides that an infinite magnitude is possible and exists actually; that there is an infinite fullness or void outside of this world, and hence there may be many worlds, and it need not follow that the elements would pour in from one world into the next, so that all earth should be together in the centre, all fire together in the outer circumference, and the intermediate elements, air and water, between these two. The elements may stay in their respective worlds in the places assigned to them. It will not be worth our while to wade through all the technical and hair-splitting discussions of these points. The results will be sufficient for our purpose.
The proof of the existence of an unmoved mover in Aristotle and Maimonides is based upon the impossibility of a regress to infinity. If Hasdai Crescas admits the infinite, the Aristotehan proof fails. Similarly God's unity in Maimonides is among other things based upon the finiteness of the world and its unity. If infinite space is possible outside of this world, and there may be many worlds, this proof fails for God's unity. So Crescas takes up in detail all the Mai-
