10. Distrust of the Senses. The senses, they say, cannot be regarded as criteria of truth and falsehood; for many things the senses cannot see at all, either because the objects are so fine, or because they are far away. In other cases the senses are deceptive, as when the large appears small at a distance, the small appears great in the water, and the straight appears broken when partly in water and partly without. So a man with the jaundice sees everything yellow, and one with red bile on his tongue tastes everything bitter. There is method in their madness. The motive for this sceptical principle is to evade criticism. If the senses testify in opposition to their theories, they reply that the senses cannot be trusted, as they did in their explanation of motion and in their theory of the succession of created accidents. These are all ancient theories of the Sophists, as is clear from Galen.[265]
Having given an outline of the fundamental principles of the Mutakallimun and criticised them, Maimonides next gives their arguments based upon these principles in favor of creation in time and against eternity. It will not be worth our while to reproduce them here as they are not adopted by Maimonides, and we have already met some of them though in a somewhat modified form before (cf. above, p. [29 ff.]).[266]
The Kalamistic proofs for the unity of God are similarly identical for the most part with those found in Saadia, Bahya and others, and we need only mention Maimonides's criticism that they are inadequate unless we assume with the Mutakallimun that all atoms in the universe are of the same kind. If, however, we adopt Aristotle's theory, which is more plausible, that the matter of the heavenly bodies is different from that of the sublunar world, we may defend dualism by supposing that one God controls the heavens and the other the earth. The inability of the one to govern the domain of the other would not necessarily argue imperfection, any more than we who believe in the unity of God regard it as a defect in God that he cannot make a thing both be and not be. This belongs to the category of the impossible; and we should likewise class in the same category the control of a sphere that is independent of one and belongs to another. This is purely an argumentum ad hominem, for Maimonides does not regard the sublunar and superlunar worlds as independent of each other. He recognizes the unity of the universe.[267]
Maimonides closes his discussion of the Kalamistic system by citing their arguments for incorporeality, which he likewise finds inadequate, both because they are based upon God's unity, which they did not succeed in proving (Saadia, in so far as he relates the two, bases unity upon incorporeality), and because of inherent weakness.[268]
Having disposed of the arguments of the Mutakallimun, Maimonides proceeds to prove the existence, unity and incorporeality of God by the methods of the philosophers, i. e., those who, like Alfarabi and Avicenna, take their arguments from Aristotle. The chief proof[269] is based upon the Aristotelian principles of motion and is found in the eighth book of Aristotle's Physics. We have already met this proof in Ibn Daud (cf. above, p. [217]), and the method in Maimonides differs only in form and completeness, but not in essence. There is, however, this very important difference that Ibn Daud fights shy of Aristotle's theory of the eternity of motion and time, thus losing his strongest argument for God's infinite power and incorporeality (cf. p. [218]); whereas Maimonides frankly bases his entire argument from motion (provisionally to be sure) upon the Aristotelian theory, including eternity of motion. With this important deviation there is not much in this part of the Maimonidean discussion which is not already contained, though less completely, in the "Emunah Ramah" of Abraham Ibn Daud. We should be tempted to omit these technical arguments entirely if it were not for the fact that it is in the form which Maimonides gave them that they became classic in Jewish philosophy, and not in that of Ibn Daud.
The second proof of God's existence, unity and incorporeality, that based upon the distinction between "possible" and "necessary" existent,[270] which has its origin in Alfarabi and Avicenna, is also found in Ibn Daud.[271] The other two proofs[272] are Maimonides's own, i. e., they are not found in the works of his Jewish predecessors.
As in the exposition of the theory of the Mutakallimun Maimonides began with their fundamental principles, so here he lays down twenty-six propositions culled from the Physics and Metaphysics of Aristotle and his Arabian commentators, and applies them later to prove his points. He does not attempt to demonstrate them, expecting the reader to take them for granted, or to be familiar with them from a study of the philosophical sources. Ibn Daud presupposed less from his readers, having written as he said, for beginners; hence he proves many of the propositions which Maimonides lays down dogmatically. Possibly Maimonides expected his readers to be familiar with the work of his immediate Jewish predecessor.
The twenty-six propositions of the philosophers are as follows:
1. There can be no infinite object possessing magnitude.
2. There cannot be an infinite number of bodies possessing magnitude, all at the same time.