But not merely the plan and arrangement of his work give evidence of the influence upon Saadia of Islamic schools, many of his arguments, those for example on the existence of God and the creation of the world, are taken directly from them. Maimonides, who was a strong opponent of the Mutakallimun, gives an outline of their fundamental principles and their arguments for the existence, unity and incorporeality of God.[38] Some of these are identical with those of Saadia. Saadia, however, is not interested in pure metaphysics as such. His purpose is decidedly apologetic in the defence of Judaism and Jewish dogma. Hence we look in vain in his book for definite views on the constitution of existing substances, on the nature of motion, on the meaning of cause, and so on. We get a glimpse of his attitude to some of these questions in an incidental way.
The Mutakallimun were opposed to the Aristotelian theory of matter and form, and substituted for it the atomic theory. God created atoms without magnitude or quality, and he likewise created qualities to inhere in groups of atoms. These qualities they called accidents, and one of their important discussions was whether an accident can last more than a moment of time. The opinions were various and the accidents were classified according to their powers of duration. That is, there were some accidents which once created continued to exist of their own accord some length of time, and there were others which had to be re-created anew every moment in order to continue to exist. Saadia does not speak of matter and form as constituting the essence of existing things; he does speak of substance and accident,[39] which might lead us to believe that he held to the atomic theory, since he speaks of the accidents as coming and going one after the other, which suggests the constant creation spoken of by the Mutakallimun. On the other hand, when he answers an objection against motion, which is as old as Zeno, namely, how can we traverse an infinitely divisible distance, since it is necessary to pass an infinite number of parts, he tells us that it is not necessary to have recourse to the atomic theory or other theories adopted by some Muʿtazilites to meet this objection. We may believe in the continuity and infinite divisibility of matter, but as long as this divisibility is only potentially infinite, actually always finite, our ability to traverse the space offers no difficulty.[40] Finally, in refuting the second theory of creation, which combines Platonism with atomism, he argues against an atomic theory primarily because of its implications of eternity of the atoms, but partly also on other grounds, which would also affect the Kalamistic conceptions of the atoms.[41] These points are not treated by Saadia expressly but are only mentioned incidentally in the elucidation of other problems dealing with the creation of the world and the existence of God.