ST. THOMAS D'AQUINO (1225–1274)
SCG I, I, xx: THAT GOD IS NOT A BODY (Quod Deus non est corpus)
 From the preceding remarks [in SCG I, I, xix, i.e. that in God is nothing violent or unnatural] it is also shown that God is not a body.
 Every body, being a continuum, is composite and has parts. But, as we have shown, God is not composite, and is, therefore, not a body.
 Again, everything possessed of quantity is in a certain manner in potency. For a continuum is potentially divisible to infinity, while numbers can be increased to infinity. But every body has quantity and is therefore in potency. But God is not in potency, being pure act…. Therefore, God is not a body
[Ergo Deus non est corpus].
 Furthermore, if God is a body, He must be some natural body, since, as the Philosopher proves, a mathematical body is not something self-existing, since dimensions are accidents. But God is not a natural body, being immobile, as we have shown, whereas every natural body is movable. God is, therefore, not a body.
 Again, every body is finite
[Omne corpus finitum est],
as is proved in De caelo I [I, 5]…. Now, we can transcend any given finite body by means of the intellect and the imagination. If, then, God is a body, our intellect and imagination can think of something greater than God. God is thus not greater than our intellect—which is awkward
[Quodlibet autem corpus finitum intellectu et imaginatione transcendere possumus. Si igitur Deus est corpus, intellectus et imaginatio nostra aliquid maius Deo cogitare possunt. Et sic Deus non est maior intellectu nostro. Quod est inconveniens].
God is, therefore, not a body.
 Intellectual knowledge, moreover, is more certain than sensitive knowledge. In nature we find an object for the sense and therefore for the intellect as well. But the order and distinction of powers is according to the order of objects
[Sed secundum ordinem obiectorum est ordo potentiarum, sicut et distinctio].
Therefore, above all sensible things there is something intelligible among things … [and] we can find something nobler above all bodies. Hence, if God is a body, He will not be the first and greatest being.
[That "the order and distinction of [cognitive] powers is according to the order of objects" [secundum ordinem obiectorum est ordo potentiarum, sicut et distinctio], is a cornerstone of Thomistic epistemology. In Kantianism, by contrast, the order of objects––i.e. the knowable world––is according to the order and distinction of our cognitive structure.]
 A living thing, likewise, is nobler than any non-living body, and the life of a living body is nobler than it
[Quolibet autem corpore vivente sua vita est nobilior],
since it is this life that gives to the living body its nobility above other bodies. Therefore, that than which nothing is nobler is not a body. …
[God is the life of all things––the pure form of the world––and therefore distinct from all things by His very immanence.]
 Then, too, there are the arguments of the philosophers to the same effect, based on the eternity of motion
[ostendendum procedentes ex aeternitate motus].
They are as follows. In every everlasting motion, the first mover cannot be moved either through Himself or by accident…. Now, the body of the heavens is moved in a circle with an everlasting motion. Therefore, its first mover is not moved either through Himself or by accident. … Now, that to which the motion of the heavens is ultimately reduced as to its first unmoved mover is God. God is, therefore, not a body.
[This is interesting. Thomas grants ex hypothesi the eternity of celestial motion––the analogue of which might, say, be "strings" in modern parlance––and argues further that, given the nature of local motion, God could not be a (local) body. So, even allowing for celestial eternity, Thomas notes how it would still depend on God as its First Unmoved Mover.]
 Again, no infinite power is a power in a magnitude. But the power of the prime mover is an infinite power. Therefore, it is not in any magnitude
[Nulla potentia infinita est potentia in magnitudine. Potentia primi motoris est potentia infinita. Ergo non est in aliqua magnitudine. Et sic Deus, qui est primus motor, neque est corpus neque est virtus in corpore.].
Therefore, God, Who is the prime mover, is neither a body nor a power in a body.
[I love this argument. I have argued at least twice before––here and here––that an infinite quantity is incoherent, and therefore that a key premise of naturalism (i.e. that the universe, being uncaused, is eternal, and therefore also spatiotemporally infinite), either renders the universe an object outside of scientific knowledge, thus making naturalism ultimately non-scientific; or, given the obvious measurability of the universe, scientifically refutes naturalism. Were the universe in itself of infinite power, and thus not dependent on God's infinite creative power, it would not be a magnitude, and thus would not be a body. But clearly the world is a body of a certain magnitude,ergo….
A further point I take from this argument is that, were the universe in se infinitely powerful, it would have actualized all possibilities within it, since nothing in it would be subject to (finite) potentiality. If that were the case, however, there would be no such thing as possibility per se in the world. But it's clear that this is only possibly the case and therefore possibility exists; ergo….
Additionally––and this is only a dim hunch––I think St Thomas' argument here also sheds light on the famous dispute between him and St Bonaventure (inter alii) on the possibility of the eternity of the world, i.e. on the feasibility of an actual infinitude in nature. (Cf. this page and this page for details.) St Thomas argued that we know the world is not eternal only by Divine Revelation, whereas St Bonaventure argued that it could be demonstrated an eternal world was impossible. St Thomas' De aeternitate mundi is actually (and ironically!) quite short, if you care to read it.
What strikes from this argument in SCG is that, perhaps a premise in Aquinas' argument (cf. articula v and vii, immediately above] is that the possible celestial eternity of the world does not impinge on the actual, empirical finitude of the world, whereas St Bonaventure was focusing on the temporal finitude of the world as a sensible reality. In other words, perhaps the cosmos Thomas granted could be eternal was not of the same order as the cosmos which Bonaventure insisted could only be temporal finite. They may, in other words, have been arguing equivocally about two subtly different conceptions of "the world." Might the aeviternality of the angels as cosmic powers somehow allow for a reconciliation of these views, if the former is linked to St Thomas' hypothetical conception of celestial as opposed to terrestrial eternity? Insofar, in other words, as the celestial world is beyond magnitude, it is not subject to finite (de)composition, and therefore could exist in an idealized timelessness. The terrestrial world, by contrast, is subject to magnitude and quantitative (de)composition, and therefore cannot be eternal. On the latter point I think St Thomas and St Bonaventure would agree.]
 The first proposition is proved thus. If the power of some magnitude is infinite, it will be the power either of a finite magnitude or an infinite one. But there is no infinite magnitude, as is proved in Physics III  and De caelo I . But a finite magnitude cannot have an infinite power. Therefore, an infinite power cannot reside in any magnitude
[Magnitudo infinita nulla est, ut probatur in III Physic. et in I caeli et mundi. Magnitudinis autem finitae non est possibile esse potentiam infinitam. Et sic in nulla magnitudine potest esse potentia infinita.].
That an infinite power cannot reside in a finite magnitude is proved thus. A greater power produces an equal effect in a shorter time than a lesser power does in a longer time. … Therefore, by moving more swiftly, it should produce its effect in a shorter time than any finite power. Nor can it be in something lesser that still is in time. Therefore, this will be in an indivisible point of time. And thus to move, to be moved, and motion will take place in an instant—of which the contrary has been proved in Physics VI 
[Et sic movere et moveri et motus erunt in instanti. Cuius contrarium demonstratum est in VI physicorum.]. …
[Interesting. An infinite power would produce its effect in an infinitely small time, but this would mean motion occurs in literally no time at all, which is impossible. Thus, if the world were produced by a body of some (even, say, 'infinitely large') magnitude, its causing motion would never occur. Consequently, the cause of the motion of the world is not only not a body of any magnitude but also, for that reason, not subject to time, which allows for it to generate an infinitely powerful effect without the limitations of magnitude in time.]
 That the power of the first mover is infinite is proved thus. No finite power can move in an infinite time. But the power of the first mover moves in an infinite time because the first motion is endless. Therefore, the power of the prime mover is infinite.
[Now St Thomas addresses the other side of the coin, as it were. Just as no allegedly infinitely powerful finite magnitude can effect anything in a real amount of finite time, so no magnitude can effect an infinite effect in infinite time.]
… If the finite power of some body moves in an infinite time, a part of that body, having a part of the power, will move in a shorter time; for the greater the power of a mover, the more it will be able to keep up its motion in a longer time
[quia quanto aliquid est maioris potentiae, tanto in maiori tempore motum continuare poterit].
… Thus, as we add to the power of the mover, we shall always add to the time according to the same proportion
[Et sic semper, secundum quod addetur ad potentiam motoris, addetur ad tempus secundum eandem proportionem].
But after a certain addition has been made, the addition will reach the quantity of the whole or even exceed it. So, too, an addition of time will reach the quantity of time in which it moves the whole. But the time in which it moved the whole was said to be infinite. Therefore, a finite time will measure an infinite time—which is impossible.
[Ergo tempus finitum metietur tempus infinitum. Quod est impossibile.]
 But against this reasoning there are several objections.
[Sed contra hunc processum plures sunt obiectiones.]
 One objection is this. It can be assumed that the body that moves the first moved is not divisible, as is the case with a heavenly body. But the preceding proof is based on the division of the first body.
[This objection says that the foregoing argument simply begs the question about the divisibility of a first mover as a body.]
 The reply to this objection is as follows. There can be a true conditional proposition whose antecedent is impossible. If there is something that destroys the truth of this conditional proposition, it is then impossible.
[Sed ad hoc dicendum quod conditionalis potest esse vera cuius antecedens est impossibile. Et si quid est quod destruat veritatem talis conditionalis, est impossibile].
For example, if someone destroys the truth of the conditional proposition, "If man flies, he has wings," it would be impossible. It is in this manner that the above proof is to be understood. For the following conditional proposition is true: "If a heavenly body is divided, a part of it will have less power than the whole." Now, the truth of this conditional proposition is taken away if it be posited that the first mover is a body; and the reason is the impossibilities that follow from it. Therefore, to posit this is impossible. A similar reply can be given if objection is made concerning the increase of finite powers. We cannot assume powers in nature according to all proportions of time to any given time. Nevertheless, the proposition required in the above proof is a true conditional proposition.
[Thomas is here saying that, were the first premise true––i.e. "the first body is indivisible"––, the objection against his argument in this chapter would stand. However, given the impossibilities that follow from such a claim, the first premise is false, and therefore the objection fails. I fear I am misconstruing something here, though.]
 The second objection is this. Although a body is divided, it is possible to find in a given body a power that is not divided when the body is divided
[…etsi corpus dividitur, aliqua virtus potest esse alicuius corporis quae non dividitur diviso corpore].
For example, the rational soul is not divided if the body is divided.
 The reply is as follows. The above argument does not prove that God is not joined to a body as the rational soul is joined to the human body; it proves that He is not a power in a body in the manner of a material power, which is divided upon the division of the body. So, too, it is said of the human intellect that it is not a body or a power in a body. However, that God is not joined to a body as the soul is, this is another issue
[Et ad hoc est dicendum quod per processum praedictum non probatur quod non sit Deus coniunctus corpori sicut anima rationalis corpori humano: sed quod non est virtus in corpore sicut virtus materialis, quae dividitur ad divisionem corporis. Unde etiam dicitur de intellectu humano quod non est corpus neque virtus in corpore. Quod autem Deus, non sit unitus corpori sicut anima, alterius rationis est.].
[This is a very fecund rebutall and, from what I can gather, is the basic shape of Charles Taliaferro's Consciousness and the Mind of God, a book I have wanted to read for about a decade, and which I finally have in my possession. The key point is that, even if we grant that there is some level of division at which we find a power not subject to the objections against infinite power in (finite) magnitude, this would only show that that power is not a body, which confirms the thrust of this chapter.]
 The third objection is this. If some given body has a finite power, as the above argument shows, and if through a finite power nothing can endure through an infinite time, it will follow that no body can endure through an infinite time. Thus, a heavenly body will of necessity be corrupted.
[See what I mean about Thomas' emphasis on celestial incorruptibility vis-à-vis the eternity of the world?]
 To this objection some reply that, as far as its own power is concerned, a heavenly body can fail, but it acquires an eternal duration from another being of an infinite power. Plato [Timaeus] seems to speak for this solution when he introduces God addressing the heavenly bodies as follows: “By your natures you are dissoluble, but through my will you are indissoluble; for my will is greater than your bond.”
 The Commentator attacks this position in Metaphysics XI. According to him, it is impossible that what can of itself not-be should acquire a perpetuity of being from another. This would mean that something corruptible becomes incorruptible, which according to him is impossible. Hence, Averroes answers the objection as follows. All the potency that is in a heavenly body is finite, but there is no reason why a heavenly body should have every potency. For, according to Aristotle in Metaphysics VIII, there is in a heavenly body potency with respect to place, but not with respect to being. Hence, a heavenly body need not have a potency to non-being.
 This reply of the Commentator, however, is not sufficient. Even if we should grant that in a heavenly body there is no sort of a passive potency to being, which is the potency of matter, yet there is in it a potency of an active kind, which is the power of being
[Quia, etsi detur quod in corpore caelesti non sit potentia quasi passiva ad esse, quae est potentia materiae, est tamen in eo potentia quasi activa, quae est virtus essendi].
For Aristotle expressly says in De caelo I [I, 3] that "the heavens have the power to be forever.”
 Hence, it is better to reply as follows
[Et ideo melius dicendum est quod,…].
Since potency is said relatively to act, we must judge of potency according to the mode of the act. Now, according to its nature, motion has quantity and extension, and hence its infinite duration requires that the potency moving it be infinite. But being does not have any quantitative extension
[…cum potentia dicatur ad actum, oportet iudicare de potentia secundum modum actus. Motus autem de sui ratione quantitatem habet et extensionem: unde duratio eius infinita requirit quod potentia movens sit infinita. Esse autem non habet aliquam extensionem quantitatis],
especially in the case of a thing, such as the heavens, whose being is without change. Hence, the power of being need not be infinite in a finite body, even though it will endure to infinity. For it is one and the same whether through that power something will endure for an instant or for an infinite time, since its changeless being is not touched by time except by accident.
 The fourth objection is this. In those beings that in moving are not themselves altered, it does not seem necessary that what moves in an infinite time should have an infinite power. For such a motion consumes nothing of their power, so that after they have moved for a time they are able to move for no less a time than before. Thus, the power of the sun is finite, and because its active power is not lessened by acting, it is able, according to its nature, to act on the sublunary world during an infinite time.
 To this the reply is, as we have proved, that a body does not move unless it be moved. If, then, it should happen that a certain body is not moved, that body will consequently not move. But in everything that is moved there is a potency towards opposites, since the termini of motion are opposites. Therefore, of itself, every body that is moved can also not-be-moved. But what can not-be-moved is not of itself able to be moved through endless time, and hence neither to move through endless time
[Et ideo, quantum est de se, omne corpus quod movetur possibile est non moveri. Et quod possibile est non moveri, non habet de se ut perpetuo tempore moveatur. Et sic nec quod in perpetuo tempore moveat.].
[Being in motion entails being-moved. But since motion is radically subject to potency––i.e. in opposite directions––, any moving object is subject to potency as a moving object and therefore its motion lacks the necessity of an endlessly powerful mover. If it's not clear, the reason motion is radically subject to potency, is that, if a moving object were not possibly able to be moved in any other way, it would not actually be in motion, but would necessarily be in stasis, since, again, it would not be subject to any possible motion from its current (necessary) state of being. Conversely, any moving object cannot have been moving as it is from eternity, and thus cannot be an eternal mover.]
 The above demonstration, consequently, holds of the finite power of a finite body, which power of itself cannot move in an infinite time. But a body that of itself can be moved and not-moved, move and not-move, can acquire perpetuity of motion from another. This must be incorporeal. The first mover must, therefore, be incorporeal [Procedit ergo praedicta demonstratio de potentia finita corporis finiti, quae non potest de se movere tempore infinito. Sed corpus quod de se possibile est moveri et non moveri, movere et non movere, acquirere potest perpetuitatem motus ab aliquo. Quod oportet esse incorporeum. Et ideo oportet primum movens esse incorporeum.].
[I take this to be the linch pin of this chapter's argument.]
Thus, according to its nature, nothing prevents a finite body, which acquires from another a perpetuity in being moved, from likewise having a perpetuity in moving. For the first heavenly body itself, according to its nature, can revolve the lower heavenly bodies with a perpetual motion, according as sphere moves sphere.
[And this I take to be the linch pin to the distinction between celestial and terrestrial motion as it figures into the debate about the eternity of the world, discussed above.]
Nor, according to the Commentator, is it impossible (as it was impossible in the of perpetuity of being) that what of itself can be moved and not-moved should acquire perpetuity of motion from another. For motion is a certain flow out of the mover to the thing moved, and hence something moved can acquire from another a perpetuity of motion that it does not have of itself. To be, on the other hand, is something fixed and at rest in being, and, therefore, that which of itself is in potency to non-being cannot, as Averroes himself says [In XII Metaphysicorum], following the course of nature acquire from another a perpetuity of being [Esse autem est aliquid fixum et quietum in ente: et ideo quod de se est in potentia ad non esse, non potest, ut ipse dicit, secundum viam naturae acquirere ab alio perpetuitatem essendi].
[This is a very important point, but I don't have the time right now to exegete it at great length–not the least because it is a bit over my head! The basic point I take to be that, while motion can be granted perpetually from one mover to another, no such perpetuity can be given in the order of being as such, since the potency of a thing's actus essendi precludes it from receiving perpetual being. The heavenly bodies might, therefore, be able to move perpetually, but they can not have existed perpetually in and of themselves, since their perpetual motion depends on their being, and their being, in turn, radically depends on their reception of being from a necessary being.]
 The fifth objection is that, following the above reasoning, there does not seem to be a greater reason why an infinite power is not in a magnitude rather than outside a magnitude. For in either case it will follow that it moves in null time.
 To this the reply is that, in magnitude, time, and motion, finite and infinite are found according to one and the same notion, as is proved in Physics III  and VI [2, 7]. Therefore, the infinite in one of them removes a finite proportion in the others. But in beings without magnitude there is no finite or infinite except equivocally
[Et ad hoc dicendum quod finitum et infinitum in magnitudine et tempore et motu inveniuntur secundum unam rationem, sicut probatur in III et in VI Physic.: et ideo infinitum in uno eorum aufert proportionem finitam in aliis. In his autem quae carent magnitudine, non est finitum et infinitum nisi aequivoce.].
Hence, the aforementioned method of demonstration is not applicable among such potencies.
[I understand the objection to be that, if a body cannot possess an infinite power by virtue of its having a magnitude, as was argued above, there is no probative reason to say that an infinite power is outside the order of magnitude either (viz., is not a body), since in either case, the infinite power will act in zero. Yet, the temporal nullity of an infinite effect by a body of some magnitude was argued as a disproof of infinite power being found in any body. Thomas' rejoinder seems to be, however, that insofar as magnitude, time, and motion are all linked under one metaphysical heading, a being without magnitude will not be subject to limitations by the other two categories. There is an inverse proportion between motion, time, and magnitude. An infinitely large body will have 'no where else' to go, and therefore will not move, and thus will not move at any time. By contrast, a being outside the order of magnitude altogether will not face these problems, since its infinite power is not proportionally limited by time. As such, the objection is a category mistake.
I admit this point is not totally clear to me.]
 There is, however, another and better answer [Aliter autem respondetur et melius]. The heavens have two movers, a proximate one with a finite power, which is responsible for the fact that they have a finite velocity, and a remote mover with an infinite power, which is responsible for the fact that their motion can be of an infinite duration. And thus it is evident that an infinite power that is not in a magnitude can move a body in time, but not immediately
[non immediate in tempore].
But a power that is in a magnitude must move immediately, since no body moves except by being moved. Hence, if it did move, it would follow that it would move in null time
[Sed potentia quae est in magnitudine oportet quod moveat immediate: cum nullum corpus moveat nisi motum. Unde, si moveret, sequeretur quod moveret in non tempore].
 An even better reply is this.
[Potest adhuc melius dici quod…].
A power that is not in a magnitude is an intellect, and moves by will
[…potentia quae non est in magnitudine est intellectus, et movet per voluntatem].
For we have proved that the intellect is not a corporeal power. Therefore, it moves according to the needs of the movable body and not the proportion of its power; whereas a power that is in a magnitude can move only through the necessity of nature.
[Potentia autem quae est in magnitudine non potest movere nisi per necessitatem naturae: quia probatum est quod intellectus non est virtus corporea.]
Thus, of necessity, it moves according to the proportion of its quantity. Hence, if it moves, it moves in an instant.
 Thus, with the removal of the preceding objections, we see that the argumentation of Aristotle stands
[Secundum hoc ergo, remotis praedictis obiectionibus, procedit demonstratio Aristotelis.].
 No motion, furthermore, which is from a corporeal mover can be continuous and regular, because in local motion a corporeal mover moves by pulling and pushing. Now, what is pulled or pushed is not uniformly disposed towards its mover from the beginning to the end of the motion, since at times it will be nearer and at other times farther away. Thus, no body can move with a continuous and regular motion. But the first motion is continuous and regular, as is proved in Physics VIII . Therefore, the mover of the first motion is not a body.
 Again, no motion to an end that passes from potency to act can be endless, since when it reaches act the motion comes to rest. If, then, the first motion is endless, it must aim at an end that is always and in all ways in act. But such an end is not a body or a power in a body, since all such things are movable either through themselves or by accident. Therefore, the end of the first motion is neither a body nor a power in a body. But the end of the first motion is the first mover, which moves as something desired. This, however, is God. God, therefore, is neither a body nor a power in a body.
 However, although according to our faith it is false that the motion of the heavens is perpetual
[Quamvis autem falsum sit, secundum fidem nostram, quod motus caeli sit perpetuus],
… yet it is true that it will not fail either through a failure of power in the mover or through the corruption of the substance in the moved; for there is no evidence that the passing of time has slowed down the motion of the heavens. Hence, the above demonstrations do not lose their force.
 With this demonstrated truth divine authority stands in agreement. For it is said in John (4:24): “God is a spirit, and they that adore Him must adore Him in spirit and in truth.” It is likewise said: “To the King of ages: immortal, invisible, the only God” (1 Tim. 1:17). Again: “The invisible things of God... are clearly seen, being understood by the things that are made” (Rom. 1:20); for what is seen, not by sight, but by the intellect, is incorporeal
[quae enim non visu sed intellectu conspiciuntur, incorporea sunt].
 Thereby is destroyed the error of the early natural philosophers, who posited only material causes
[Per hoc autem destruitur error primorum philosophorum naturalium, qui non ponebant nisi causas materiales],
such as fire or water or the like, and who thus said that the first principles of things were bodies and called them gods. Among them there were some who further posited friendship and strife as moving causes. (They, too, were refuted through the above arguments.) For since, according to them, strife and friendship are in bodies, it will follow that the first moving principles are bodily powers. They also held that God is composed of the four elements and friendship, which would give us to understand that for them God was a heavenly body. Among the early thinkers, Anaxagoras alone approached the truth by positing that an intellect moved all things
[Inter antiquos autem solus Anaxagoras ad veritatem accessit, ponens intellectum moventem omnia].
 By this truth, too, are refuted the Gentiles, who, taking their beginning in the errors of the philosophers we have listed, posited that the elements of the world and the powers in them are gods; for example, the sun, the moon, the earth, water, and the like.
 By the same arguments, moreover, are set aside the wild fantasies of the simple Jews, Tertullian, the Vodiani or Anthropomorphite heretics, [as well as Mormons,] who endowed God with a bodily figure; and also of the Manicheans, who thought that God was a certain infinite substance of light, stretched out through an infinite space.
 The occasion of all these errors was that, in thinking of divine things, men were made the victims of their imagination, through which it is not possible to receive anything except the likeness of a body. This is why, in meditating on what is incorporeal, we must stop following the imagination.
[Quorum omnium errorum fuit occasio quod de divinis cogitantes ad imaginationem deducebantur, per quam non potest accipi nisi corporis similitudo. Et ideo eam in incorporeis meditandis derelinquere oportet.]
[This is a lapidary distillation of proper method in dogmatic theology! Skeptics want a 'model' or a 'picture' or a perfect 'analogy' for God, but to ask for that is to beg the question in favor of a God beneath the incoporeal, immortal, omnipotent God of classical theism.]