Throughout the Guide, Maimonides considers four accounts of creation: that of the kalam, Moses, Plato, and Aristotle. He rejects the kalam account (GP 1. 71–73) according which one demonstrates that the universe must have been created and then reasons that if it was created, it must have a creator. Like Thomas Aquinas, Maimonides believes it is impossible to show by logical considerations alone either that the universe was created or that it is eternal. Though Maimonides says he believes in creation, he admits one can do no more than tip the scales in this direction. As of Guide 2.13, he limits his discussion to the theories of Moses, Plato, and Aristotle.
Unfortunately Maimonides' characterizations of these alternatives are neither precise nor historically accurate [Seeskin, 2005]. Suffice it to say that his treatment of them is mainly thematic. Briefly stated, they are:
Moses: | the world was created de novo and entirely ex nihilo. |
Plato: | the world was created de novo from a preexisting material substrate. |
Aristotle: | the world is eternal and its existence is best understood as eternal information of matter. |
Based on his explicit remarks, Maimonides prefers the theory of Moses but allows one to hold that of Plato as a reasonable alternative. But there has always been a school of thought that maintains that he is secretly committed to the view of Aristotle [Harvey 1981]. My own position is with those who argue that Maimonides' explicit remarks are an accurate account of his view and that all the arguments he offers point in that direction [Davidson 1979; Feldman 1990; Hyman 1988; Wolfson 1973).
The historical Aristotle did argue that the world is eternal and that whatever is eternal is necessary [On Generation and Corruption 338a1–4, Physics 203b 29, Metaphysics 1050b8–15]. His medieval followers took this to mean that while the world is ontologically dependent on God, there is no moment when it first comes to be and therefore does not owe its existence to a decision to create. As we might say, it exists not because of anything God does but simply because of what God is. Because God's nature does not change, according to this position, neither does the existence or fundamental structure of the world. The most important consequence of this view is that God does not exercise free choice, which is to say that according to the Aristotelian alternative, the world is governed by necessity.
The standard arguments in favor of this position take one of two approaches: either they show that there is something inherent in the nature of the world that makes creation impossible or that there is something inherent in the nature of God that does. An example of the former is that change always proceeds from something to something else, as when a chicken springs from an egg or an acorn develops into a full grown oak tree. If this is true, it is impossible for something to come to be from nothing (ex nihilo). An example of the latter is that if God is perfect, it makes no sense to suppose that God could ever do anything new such as bring the world into being.
Maimonides' answer to the first argument (GP 2.17) is that given the world as we know it, change does proceed from one thing to something else. But why should we assume the creation of the world has to follow the same pattern? An account of creation is a theory of origin, how a thing comes to be initially. By contrast, an account of change is a theory of development or alteration, how one existing thing emerges into another. For all we know, the origin of a thing may be completely different from its development later on. Thus it is presumptuous to suppose that we can extrapolate from our experience of the world as it is at present to the moment of its creation. It follows that the first argument against creation is not decisive, which means that creation remains a possibility.
Maimonides' answer to the second argument (GP 2.18) is that in a perfect being, willing something new need not imply change. If I will today to take a trip tomorrow and events intercede to spoil my plans, I may have to change my mind, but to suppose that something analogous happens to God is absurd. Assume I will today to do something tomorrow independent of external circumstances — to think about the numerical characteristics of pi. And assume that when tomorrow comes, I do exactly as planned. While I would be undertaking something new, to the degree that I had intended to do it all along, it would be misleading to say that I underwent a change. Certainly I did not undergo a change of mind.
Maimonides takes this to mean that it is possible for a being not affected by external circumstances to will something new as long as it is part of his original intention. This is sometimes expressed by saying that changing one's will is not the same as willing change. So once again, the argument against creation is not decisive.
Maimonides is aware that all his arguments establish is the possibility of creation, not its actuality. To go further, and argue for the actuality of creation, he returns to the claim that everything that is eternal is necessary. If it could be shown that there are features of the world that are not necessary, it would follow that the world must have been created. Here Maimonides challenges Aristotle and his followers on the issue of astronomy.
Medieval Aristotelians believed as follows. God thinks and manifests self-awareness. Because God is one and simple, what emerges from God must be one and simple as well. In this way, God generates the first heavenly intelligence. According to Alfarabi, because the first intelligence is aware of two things — itself and God — it is capable of generating two things: the second heavenly intelligence and the outermost sphere of the universe. By contrast, Avicenna held that because the first intelligence is aware of God and duality in itself, it generates three things. The difference need not concern us here. The important point is that God's production of the outermost sphere is indirect; the immediate cause is the activity of the first intelligence. The process continues until we get the ten intelligences and nine primary spheres that make up the standard picture of medieval cosmology.
Maimonides criticizes this account in two ways. First if the originator of a causal sequence is one and simple, there is no way for complexity to arise, and everything else in the sequence should be one and simple as well (GP 2.22). Even if the sequence contains thousands of members, there is no way to account for the complexity of a celestial sphere, which is a composite of matter and form. When we get to the inner spheres, we have to account for even more because not only is there the sphere itself but the stars or planets attached to it. They too are composites of matter and form. How can we have such complexity if we start with something that is radically one?
Second, there are features of the heavenly bodies that defy scientific explanation and thus appear to be contingent in the sense that they were chosen rather than necessitated (GP 2.19–24). If the outer spheres impart motion to the inner ones, we would expect spherical motion to slow as we move closer to the earth. But this is hardly the case. As Maimonides points out (GP 2.19):
We see that in case of some spheres, the swifter of motion is above the slower; that in the case of others, the slower of motion is above the swifter; and that, again in another case, the motions of the spheres are of equal velocity though one be above the other. There are also other very grave matters if regarded from the point of view these things are as they are in virtue of necessity.
If there is no explanation for why the spheres behave in this fashion, or why some stars and planets emit more light than others, or why some regions of the heavens are relatively crowded while others are empty, there is no reason to think the phenomena in question are what they are by virtue of necessity. If there is no necessity, there are no grounds for eternity. The alternative is to say that God created the world as a result of a free choice and fashioned it in a particular way.
Maimonides recognizes (GP 2.24) that his argument does not constitute a demonstration. Just because science cannot explain something now, it does not follow that it will never be able to explain it. As he himself admits, science can and does make progress. But in the case of the heavenly bodies, he thought progress very unlikely. Because they too far away to make close observations, and too high in rank, we can only rely on inferences based on accidental qualities size, speed, and direction. As long as this is true, we will never know their essential natures and will never be able to support claims of necessity. As long as this is true, creation, though not demonstrated, will always be preferable to eternity.
Maimonides (GP 2.25) also offers a practical reason for believing in creation: How can a God without free will issue commandments? Beyond this there is a textual reason: belief in creation does less violence to scripture than belief in eternity. He concludes that the theory of Moses offers the best alternative, while that of Plato, which retains the idea of creation de novo, is acceptable. Though some people fault Maimonides for not coming up with a stronger argument on behalf of Moses, he would reply by saying that given the limits of our knowledge, this is the strongest argument we can expect. Although Maimonides is often seen as part of the Aristotelian tradition, and often expresses praise for Aristotle, his account of creation indicate that he is willing to depart from Aristotle when he thinks the arguments lead in that direction.