Is God Personal? Aquinas’s Arguments for the Divine Intellect

Most adherents of monotheistic faiths hold that God — whatever else this name may designate — is a reality that is in some sense “personal.” Consider the opening verses of the first chapter of Genesis, a text which has had significant influence on the understanding of God for at least three major world religions: Judaism, Christianity, and Islam. “In the beginning God created the heavens and the earth . . . . And God said, ‘Let there be light’; and there was light. And God saw that the light was good; and God separated the light from the darkness. God called the light day, and the darkness he called night” [1]. In these few sentences we are told that God is a creative agent who can speak, can “see”, and can recognize/appreciate goodness. These are all more or less unique characteristics of “personal” realities [2]. Later in the same chapter, we read: “Then God said, ‘Let us make man in our image, after our likeness” [3]. Now we are told that the human person, seemingly alone out of all created reality described thus far, is made “in the image” and “likeness” of God. In other words, at the very least, something about the nature of human persons reflects God in a way that no other kind of thing in the cosmos does.

This understanding of God is only further developed throughout the entire course of the Hebrew scriptures; and it is confirmed and even radically deepened in the texts of the Christian New Testament, where we find, among other things, the simple assertion that “God is love” [4]. All across both Jewish and Christian writings we find ascribed to God a range of characteristically “human” qualities/actions: emotions, decision-making, conversation, planning etc. We also find God depicted in terms of human relationships, especially as father and husband.

Now compare these descriptions with some of the typical terms/expressions used to denote God from the classical philosophical tradition: ground/source of being, the ultimate, the infinite, first cause, prime mover, pure act, being itself (among others). These terms are of a decidedly less personal kind than the former. This fact, along with other considerations, has led to the well-known distinction/problem of the “God of the Bible” as opposed to the “God of the philosophers.” Pascal famously distinguished between the “God of Abraham, God of Isaac, God of Jacob” and the God “of the philosophers and the learned”; it was the former, and not the latter, which was the object of his profound religious experience and his devout faith [5].

More recently, philosopher of religion Brian Davies has distinguished between two genera of theism: classical theism, and what he calls “theistic personalism.” The latter has gone by different titles, some of its own adherents preferring “neo-classical theism.” Davies used “theistic personalism” because, on his view, the central and defining trait of this brand of theism is its emphasis precisely on the personhood of God. Such a theist will insist that God, fundamentally, is a person. Davies, on the other hand, contends that, from a classical theistic perspective, it is entirely improper to refer to God as “a person,” even if it can be said that God is in some sense personal [6].

In this post, I do not wish to pick up either of these debates (i.e. that between the God of the Bible and God of the philosophers, or that between classical theists and neo-classical theists). Here I simply wish to ask whether, from a philosophical stand-point, it can be shown that God is in any way “personal.” More specifically, in this post I am examining the position of St. Thomas on this question, who holds 1) that God is indeed personal, and 2) that the personal nature of God can be demonstrated philosophically, without recourse to revelation.

Of course, St. Thomas holds that the existence itself of God can be philosophically demonstrated. In the Summa Theologiae, he provides his famous quinque via or “five ways,” which are five ways by which Deum esse . . . probari potest (“the existence of God is able to be proved”) [7]. The prima via (first way) is that from motion, and it concludes ad aliquod primum movens (to some first mover). The secunda via is that from efficient causality, and it concludes to aliquam causaum efficientem primam (some first efficient cause). The tertia via is that from possibility and necessity, and it concludes to aliquid quod sit per se necessarium (something which is necessary in itself). The quarta via is that from gradation, and it concludes to aliquid quod omnibus entibus est causa esse, et bonitatis, et cuiuslibet perfectionis (something which is for all beings the cause of existence, and goodness, and whatever perfection). Finally, the quinta via is that from final causality, and it concludes to aliquid intelligens, a quo omnes res naturales ordinantur ad finem (some intellect, by which all natural things are ordered to an end).

It’s worth noting that the quinta via alone, without any other consideration, arrives at an intellect above the order of nature which directs all of nature. But let’s set the fifth way aside for now, as well as the third and fourth, and focus on the first two, which arrive at a “first cause” (either of motion or efficient causality). If we had just these arguments, and just this prima causa as their conclusion, could we know that the entity in question is personal?

Notice that so far, all Saint Thomas has concluded is that there is some first cause, and that people generally call this “God”. But the Doctor does not stop here. In the first article of the third question of the Summa Theologiae (the very next article in order after that which contains the quinque viae), he argues that “it is necessary that that which is the first being is in act and is in no way in potency,” i.e. that God is purus actus (pure act). He goes on to argue that God is immaterial, existence itself, absolutely simply, infinite, immutable, and eternal [8]. Finally, in question fourteen, Aquinas asks “whether there is knowledge in God?” Here is the body of his answer:

“In God there is knowledge most perfectly. For evidence of which, it must be considered that knowing things [cognoscentia] are distinguished from non-knowing things by this, that non-knowing things have nothing except their own form only; but a knowing thing is born to have the form of another thing, for the species of the known [cogniti] is in the knower [cognoscente]. Hence it is manifest that the nature of a not-knowing thing is more narrow and limited; however the nature of knowing things has more fullness [amplitudinem] and extension. On account of which the Philosopher says (De Anima III), that the soul is in a certain way all things. However the contraction of form is through matter. Hence, and [as] we said above that forms, according as they are more immaterial, according to this they approach more to a certain infinity. It is evident therefore that the immateriality of something is the reason that it is cognitive [cognoscitiva]; and according to the mode of immateriality is the mode of cognition. Hence in De Anima II it is said that plants do not know, on account of their materiality. Sense however is cognitive, because it is receptive of species without matter; and intellect is still more cognitive, because it is more separated from matter and unmixed, as is said in De Anima III. Hence, since God is in the highest [mode] of immateriality, as is clear from the above, it follows that he himself is in the highest [mode] of cognition [9].

The argument here is relatively straightforward, even though it contains many premises which will seem doubtful or unfounded to contemporary readers. It can be outlined as follows:

  1. Every type of thing is cognitive to the same degree as it is immaterial
  2. God is immaterial to the highest degree
  3. Therefore, God is cognitive to the highest degree

The second premise is one St. Thomas defended prior to the present article (in 1.3.2). The first premise will be the most contentious. The insight it is derived from is founded upon a consideration of the very nature of knowledge itself. To know, for Saint Thomas, is in a certain sense to become united with that which is known. The known, the object of knowledge, must come to exist in some manner in the knower himself. In an act of knowing, the idea (the species, essence, form) of the known object exists in the knower. However, the forms of material things, precisely qua material, are limited and restricted. The form of “lion” in itself is not limited to any particular lion, but this lion is limited to being this lion, precisely because its form is received and limited by this matter, by these flesh and bones. It is a basic Thomistic principle that potency limits act, and hence that matter limits form [10].

But if matter is that which limits form, then it follows that the less limited something is, the less material it is (and conversely, the less material, the less limited). A stone has only its own single form, that of a stone. Similarly, a plant has only the form of a plant. But when we reach conscious animals, things are different. Sense perception is the receiving of another form, if only a sensible form. E.g., when a cat sees a dog, it is, in a manner, taking in the dog’s visible image, which image now exists in the cat itself. A rational creature attains, not simply to the sensible form, but to the intelligible form itself of things, their very essence. A human not only sees the dog but knows what the dog is. In both cases, but especially in intellection, the cognition of the creature stretches beyond the limits of its own material constitution to a form outside itself.

Can we formalize this argument for the first premise? Perhaps it would look something like this:

  1. Whatever has extension to forms distinct from itself, has cognition
  2. To the degree that something is immaterial, it is not restricted by its matter to its own form
  3. Whatever is not restricted by its matter to its own form, has an extension to forms distinct from itself
  4. Therefore, whatever is not restricted by its matter to its own form, has cognition
  5. Therefore, to the degree that something is immaterial, it has cognition [11]

The conclusion of this argument is in essence equivalent to the first premise in the previous argument. As a whole, the central idea is that an immaterial thing, qua immaterial, just is a cognitive thing, a knowing thing. Insofar as God, the prima causa, is absolutely immaterial, God is therefore absolutely knowing.

The metaphysical presuppositions here are, once again, going to be extremely contentious for most contemporary readers. But the above is not the only argument Aquinas gives for God’s personal nature. In the Summa contra Gentiles Book I, caput 44, Saint Thomas argues quod deus est intelligens (that God is intelligent, i.e., has intellect). Here he gives at least seven philosophical arguments for the relevant conclusion. We will consider now only some.

The first is an argument which to understand requires a level of familiarity with Aristotelian physics. The second is brief and can be outlined thus:

  1. God is the absolute first mover
  2. The absolute first mover is the universal source of all motion (universale principium motus)
  3. Every mover moves through some form which it intends in that which is to be moved
  4. The universal source of all motion moves through a universal form which it intends in that which is to be moved
  5. A form is not found in a universal mode except in the intellect
  6. Therefore God is intelligent

There are some implicit premises which would need to be brought out in a fuller treatment, but the basic idea is fairly simple to grasp: the first mover is a cause of a universal effect (all motion). Every cause intends its effect [12]. Therefore, the first mover intends a universal effect. However, what is universal as such exists only in an intellect. Hence the first mover, in order to intend a universal effect, must have an intellect which can perceive the universality of that effect. Therefore, the first mover has an intellect.

The third argument I find quite intriguing, and will perhaps give it fuller treatment elsewhere. In effect, it contends that no intelligent agent, qua intelligent, can be an instrumental cause of a non-intelligent agent. Since human beings are intelligent agents, and since (like all creatures) human beings are also instrumental causes of the prima causa, the latter must itself be an intelligent agent.

The fourth argument is in essence the same as the argument from the Summa Theologiae considered in more detail above. I will not comment on it again, but will quote the text of it from the contra Gentiles:

“Something is intelligent from this, that it is without matter. A sign of which is that forms are made understood in act through abstraction from matter. And hence understanding is of universals and not of singulars: since matter is the principle of individuation. However forms understood in act are made one with the intellect understanding in act. Hence if forms are understood in act from this, that they are without matter, it is necessary that something is intelligent from this, that it is without matter. It has been shown however that God is entirely immaterial. Therefore he is intelligent [13].

The fifth argument is based upon Saint Thomas’s prior conclusion that God is universaliter ens perfectum, a “universally perfect being”, which follows from the fact that God is suum esse, “his own being” [14] (or, as the Doctor puts it elsewhere, God is ipsum esse per se subsistens, “existence itself subsisting through itself” [15]). Insofar as God is being itself, God must “contain in himself the whole perfection of being” [16]. God “has existence according to the whole power of existence itself” [17]. Hence for God there is “not lacking the excellence of any genus,” he “is not able to be without any excellence which should convene to any thing” [18]. “Nothing of the perfection of being is able to be lacking for him”, and “the perfection of not any thing is lacking in God” [19].

On this foundation, Saint Thomas builds the following argument:

  1. God has every perfection of being
  2. Intelligence is a perfection of being
  3. Therefore God has intelligence

The central question which will be raised here is what exactly is meant by a “perfection of being”. Very roughly and simplistically, we can think of a “perfection” of something as a quality (understanding “quality” in a very wide and loose sense) it has which constitutes it in some way in act. For instance, if an apple is actually red, “redness” will be a perfection of the apple. Similarly, every power that a thing has can be thought of as a perfection of it. Living things have the perfection “life,” sensing things have the perfection “sensation,” and intelligent things have the perfection “intelligence.”

Immediately the objection will be raised: if this is what we understand by perfections, then obviously there are a whole host of perfections which most theists will not wish to attribute to God. For example, most theists will not wish to say that “God is red,” and yet we have said above that redness is a type of perfection. This is correct, and Saint Thomas’s answer to this issue is somewhat complex. Very simplistically, we can distinguish between absolute perfections (or perfections simpliciter), and relative perfections [20] A relative perfection, we might say, is one which in itself contains or implies or entails some imperfection. Redness, for example, is only a relative perfection, for redness as such entails that its subject is material, and materiality, according to Aquinas, is imperfection [21]. Or, again, sensation is a perfection of animals, but sensation can only be a relative perfection, since sensation properly depends upon corporeal organs. Pure or absolute perfections, however, those unmixed with any sort of imperfection whatsoever, would be such qualities as existence, life, goodness, wisdom, knowledge, love. These can be attributed to God (albeit, still, only analogously).

So we can alter our previous syllogism:

  1. God has every absolute perfection of being
  2. Intelligence is an absolute perfection of being
  3. Therefore God has intelligence.

The sixth argument is along the same lines as the fifth way. It can be sketched:

  1. Everything that tends determinately to some end either set that end for itself, or the end was set for it by something else.
  2. Natural things tend determinately to some end.
  3. Therefore, natural things either set their ends for themselves, or their ends were set for them by something else.
  4. Anything that does not have knowledge of an end cannot set an end for itself.
  5. Natural things do not have knowledge of an end.
  6. Therefore, natural things cannot set their ends for themselves.
  7. Therefore, the ends of natural things were set for them by something else.
  8. That which sets the ends for natural things must be the creator of their natures.
  9. [The creator of the natures of natural things is the prima causa].
  10. Therefore, the ends of natural things were set for them by the prima causa.
  11. Only that which is intelligent can set the end for something.
  12. Therefore, the prima causa is intelligent.

This argument, of course, depends upon the Thomistic understanding of final causality or natural teleology. Once it is granted that things have natural ends towards which they are ordered, the question then becomes how they are ordered to those ends, if they cannot conceive of those ends themselves. Aquinas’s answer is that they must be ordered to their ends by some agent which can conceive of the ends, i.e. by some intelligent agent. Now, natural things tend towards their ends by their very natures, so whatever directs them to their ends must be that which gave them their natures, which can only be the prima causa. To put it another way: the prima causa is the cause of the being and natures of things. Now the natures of things have natural ends. So the prima cause must have given things their natural ends. But something can only give something else an end if it first knows those ends. Therefore, the prima causa must have knowledge of ends, and hence must be intelligent.

There are other arguments Saint Thomas presents throughout his extensive corpus, but the ones we’ve considered here are a good sampling of the major themes. If successful, these arguments would establish that God at least has an intellect. Is having an intellect, however, sufficient for being personal? That is a question I will address in a future post.


[1]. Genesis 1:1, 3-5. RSV-2CE. I have no knowledge of Hebrew, so I can only here draw from the English text. But, so far as I am aware, none of my remarks here are falsified by the original language.

[2]. I refer here to “personal realities” rather than more simply “persons”, for reasons which I shall make clear shortly.

[3]. Genesis 1:

[4]. See 1 John 4:10.

[5]. See here:

[6]. Thus above I spoke of “personal realities” rather than “persons.” For more on this, see Davies’s Introduction to the Philosophy of Religion.

[7]. ST I.2.3

[8]. There are other names/attributes that I don’t mention here. In particular, Aquinas up to this point argues that God is perfect and good, which some might thing presuppose personhood. But the attributes of “goodness” and “perfection,” as Aquinas understands them, are different from the “moral” goodness and perfection which many contemporary analytic philosophers apply to God. It might be useful to think of “goodness” and “perfection” here as ontological goodness and perfection. One might think of the former in terms of desirability, and latter in terms of completion.

[9]. ST 1.14.1

[10]. Recall this statement from the second of the Twenty-four Thomistic Theses: “Act, in as much as it is perfection, is not limited except by potency, which is capacity of perfection.” See my explanation and defense of the second thesis here:

[11]. This is a bit rough and imprecise. My aim here is not to defend the argument so much as to present it and give a general explanation.

[12]. A basic principle of Thomistic philosophy, the principle of finality (or final causation).

[13]. SCG 1.44.5

[14]. See SCG 1.28.1

[15]. See ST 1.4.2

[16]. Ibid.

[17]. SCG 1.28.1

[18]. Ibid.

[19]. ST 1.4.2

[20]. This distinction is not, so far as I am aware, exactly made by Aquinas. He does however say something similar: “Certain names signify perfections of this kind proceeding from God into created things, in this way that that the imperfect mode itself by which a divine perfection is participated in by a creature, is included in the signification itself of the name, as “stone” signifies something materially being, and names of this kind are not able to be attributed to God except metaphorically. Certain names however signify the perfections themselves absolutely, apart from this that any mode of participation be confined [claudatur] in their signification, as ‘being’, ‘good’, ‘living’, and [others] of this kind; and such are properly said of God” (ST 1.13.3).

[21]. This should not be taken as even an implicit or slight gnosticism or Manichaeism. It is not the position of Saint Thomas that matter is intrinsically evil or bad. Imperfection is not equivalent to badness. Badness or evil is the lack of a perfection which something ought to have by nature, while imperfection is the mere absence of a perfection. A rock is imperfect insofar as (among other reasons) it lacks the power of sight, but a rock is not evil or bad or even defective for lacking sight, since it is not the nature of a rock to have sight. On the other hand, a dog which lacks sight is to this extent defective, since a dog by nature ought to have sight.

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