In this chapter, Maimonides pokes holes in the Aristotelian cosmology, which he believes cannot be satisfactorily explained merely by the laws of nature. The specifics of his critique are not too important, because they have to do with a view of the Universe that is not really intelligible to the modern reader (read: me). After mounting his attack, he clarifies that his criticism is not about the entire Aristotelian system, and is only about his theories of the heavenly spheres.

I hold that the theory of Aristotle is undoubtedly correct as far as the things are concerned which exist between the sphere of the moon and the centre of the earth. Only an ignorant person rejects it … But what Aristotle says concerning things above the sphere of the moon is, with few exceptions, mere imagination and opinion.

However, Maimonides acknowledges that the holes he is poking do not amount to a clear and unambiguous refutation, which can only be accomplished by proof. Rather than overstate his case, he acknolwedges that doubts in one theory do not prove the opposite theory. However, since the question of creation vs. eternity cannot be established by proof — as he established earlier — then one will have to settle for the theory which has the least doubt associated with it. To this, Maimonides the believer adds that his theory is to be preferred also on the authority of Abraham and Moses.

It may perhaps be asked … whether by mere doubts a theory can be overthrown, or its opposite established? This is certainly not the case. But we treat this philosopher exactly as his followers tell us to do. For Alexander stated that when a theory cannot be established by proof, the two most opposite views should be compared as to the doubts entertained concerning each of them, and that view which admits of fewer doubts should be accepted. Alexander further says that this rule applies to all those opinions of Aristotle in Metaphysics for which he offered no proof. For those that followed Aristotle believed that his opinions are far less subject to doubt than any other opinion. We follow the same rule. Being convinced that the question whether the heavens are eternal or not cannot be decided by proof, neither in the affirmative nor in the negative, we have enumerated the objections raised to either view, and shown how the theory of the Eternity of the Universe is subject to stronger objections … Another argument can be drawn from the fact that the theory of the Creation was held by our Father Abraham, and by our Teacher Moses.