In the Question immediately following the Five Ways (Question 3), Thomas turns to establishing the simplicity of the First Cause. This simplicity consists of eight characteristics, corresponding to the eight articles of Question 3:
- God is not a body, and so has no material parts.
- God is wholly immaterial, not composed of form and matter.
- God is identical to His own nature or essence.
- God’s essence, in turn, is identical to His act of existence.
- God has no genus or differentia.
- God has no accidents.
- God has no proper parts of any kind.
- God is not a proper part of any other whole.
Of these eight, it is characteristics 3 and 4 that are most central to Thomas’s natural theology, and most controversial.
God and His “Properties”
The Thomistic doctrine of divine simplicity has often be described as one in which God is identical to each of His own properties. This seems to lead to a number of absurdities. Take, for example, the property of being self-identical or being such that 2 + 2 = 4. These are properties that everything has. If God were identical to properties like these, He would be an abstract object, something exemplified by all concrete objects. Or take contingent properties like being the creator of the world or being the one who called Abraham out of Ur. If God is identical to these properties, then He is necessarily identical to them, which would seem to mean that God necessarily created the world and necessarily called Abraham out of Ur. As a result, we would be denying God’s free will and the contingency of anything in creation.
Finally, if God is identical to each of His properties, then each of His properties is identical to any other property He has. The four properties we mentioned above would be identical to each other. Since I have the property of being self-identical, it would follow that I also have the property of having created the world!
In contemporary philosophy, the category of property plays a central role. We distinguish, for example, between a thing, like an apple, and its properties, like being red, being round, being an apple, lying on a table, belonging to me, and so on. There is no word in Thomas’s philosophical Latin that corresponds perfectly with this modern concept of property. Instead, we find a variety of property-like terms: essence (essentia, quidditas), accident (accidens), proper accident (proprium), form (forma), genus, species, differentia, common being (esse commune), predicate (predicatum), universal. None of these correspond closely in meaning to the modern word ‘property’. Therefore, it is not illuminating to express Thomas’s notion of divine simplicity by means of the formula: God is identical to each of His properties.
There’s another contemporary distinction that is very hard to apply to Thomas’s intellectual world: the distinction between the concrete and the abstract. Concrete objects are supposed to have causal power, especially active power. Abstract objects, like sets, numbers, and other mathematical objects, are causally inert and immutable, existing (if they exist at all) only as objects of thought, proof, and calculation.
In the Aristotelian tradition, the word ‘abstract’ carries quite a different connotation. A thing is abstract if it has been abstracted from something else, by omitting or deleting some aspects of the more complete original. Abstract things in this sense would include form and matter, essences and accidents (including qualities and quantities). Some things that count as abstract in Aristotelian terms might be concrete in modern terms, since form, matter, essences, and accidents are all causally relevant factors.
Most contemporary metaphysicians are nominalistic, in the sense of denying both Plato’s theory of Forms and the Aristotelian theory of particular forms and accidents. Somewhat confusingly, many modern nominalists are called “platonists” simply because they believe in properties and other “abstract” objects (in the modern sense). Such abstract properties are post rem entities: they can be truthfully predicated of real things, but they don’t ground the characters of those things. An ante rem Form (as in the systems of Plato or Aristotle) is something by which some real thing is a certain way. For Plato, beautiful things are beautiful by virtue of participating in Beauty itself. For Aristotle, dogs are canine by virtue of being informed by a canine form. In contrast, post rem properties do no such heavy metaphysical lifting. The post rem property of beauty applies to beautiful because they are beautiful, not vice versa.
Hence, it would make no sense to suppose that God is identical to any of His post rem properties. Such an absurdity should not be attributed to Thomas.
Post rem properties are abstract in the modern sense. Thomas has a distinction that comes close to the modern concrete/abstract distinction: the distinction between real beings and logical beings (De Ente et Essentia I, In Metaphysica V, Lect. 9 par 895). Absences and privations (like darkness or blindness) are typical examples of logical being. Something has logical being if it can be referred to in a true proposition. Real beings (substances and accidents) have existence in a more robust sense, one that necessarily involves causal power of some kind. Since God is certainly a real being, He cannot be identical to any post rem property. Universals also seem to count for Thomas as logical beings, since universals exist only “in the intellect,” and so God cannot be identical to any universal.
Thomas does not claim that God identical to the universal of wisdom, or the universal of power, etc. Instead, the claim is that God is identical to God’s wisdom, to God’s power. As we have shall argue below, God is identical to His own nature. God’s wisdom, power, goodness, and so on are identical to His nature. Geach and Anscombe point out that we must avoid attributing any form of Platonism to Thomas:
By the “individualization of the form” Geach and Anscombe mean that particular entity by which a substance belongs to the relevant kind. In creatures, there are particular individual forms by which a substance is powerful or wise. The individual accident by which Socrates is wise is distinct from the individual substance by which he is powerful. But in God’s case, it is God himself by which God is wise, good, and powerful.
…if we do think on these lines, Aquinas will appear to be saying that wisdom and power are different, but God possesses them both, and in him they are not different but identical—which is sheer self-contradiction. The analogy of mathematical functions, which I used before, proves valuable here too. ‘The square of —’ and ‘the double of —’ signify two quite different functions, but for the argument 2 these two functions both take the number 4 as their value. Similarly, ‘the wisdom of —-’ and ‘the power of —-’ signify different forms, but the individualization of these forms in God’s case are not distinct from one another; nor is either distinct from God, just as the number 1 is in no way distinct from its own square.” (Geach and Anscombe 1961, 122)
By the “individualization of the form” Geach and Anscombe mean that particular entity by which a substance belongs to the relevant kind. In creatures, there are particular individual forms by which a substance is powerful or wise. The individual accident by which Socrates is wise is distinct from the individual substance by which he is powerful. But in God’s case, it is God himself by which God is wise, good, and powerful.
As a result of this fact, our predications of ‘goodness’ or ‘wisdom’ or ‘power’ to God are analogous to the predications of the same predicates to a creature. Socrates is not identical to his own wisdom, while God is identical to His own wisdom. This does not mean that there is anything defective or merely metaphorical or in any other way less than fully true about our predication of wisdom to God. To the contrary, the predication of wisdom to God is supremely true.
The Analytic Thomist 