Thanks to Bill Clinton, it is now widely appreciated that much rides on what the meaning of ‘is’ is. Time was, when only philosophers were aware of this. The fact that Clinton made the point to save his hide rather than to advance philosophical logic is irrelevant. Credit where credit is due. But enough joking around.
In our recent Trinitarian explorations we have thus far discussed the ‘is’ of identity and the ‘is’ of predication. We saw that ‘The Father is God’ could be construed as
1. The Father is identical to God
2. The Father is divine.
Both construals left us with logical trouble. If each of the Persons is identical to God, and there is exactly one God, then (given the transitivity and symmetry of identity) there is exactly one Person. On the other hand, if each of the Persons is divine, where ‘is’ is the 'is' of predication, then there are three Gods and tri-theism is the upshot. Either way, we end up contradicting a central Trinitarian tenet.
We explored the mereological way out and we found it wanting, or at least I found it wanting. God is not a whole whose proper parts are the Persons.
But there is also the ‘is’ of composition as when we say, ‘This countertop is marble,’ or in my house, ‘This countertop is faux marble.’ ‘Is’ here is elliptical for ‘is composed of.’ Compare: ‘That jacket is leather,’ and ‘This beverage is whisky.’ To say that a jacket is leather is not to say that it is identical to leather – otherwise it would be an extremely large jacket – or that it has leather as a property: leather is not a property. A jacket is leather by being made out of leather.
Suppose you have a statue S made out for some lump L of material, whether marble, bronze, clay, or whatever. How is S related to L? It seems clear that L can exist without S existing. Thus one could melt the bronze down, or re-shape the clay. In either case, the statue would cease to exist, while the quantity of matter would continue to exist. If S ceases to exist while L continues to exist, then S is not identical to L. They are not identical because something is true of L that is not true of S: it is true of L that it can exist without S existing, but it is not true of S that it can exist without S existing. I am relying upon the following principle, one that seems utterly beyond reproach:
(InId) If x = y, whatever is true of x is true of y, and vice versa.
(This is a rough formulation of the Indiscenibility of Identicals. A more careful formulation would block
such apparent counterexamples as: Maynard G. Krebs believes that the morning star is a planet but does not believe that the evening star is a planet.)
Returning to the statue and the lump, although S is not identical to L, S is not wholly distinct, or wholly
diverse, from L either. This is because S cannot exist unless L exists. Note also that while S exists it occupies exactly the same space as does L. As long as S exists, S and L are spatiotemporally coincident. What's more, they are composed of exactly the same matter arranged in exactly the same way. And yet they are not identical! Very curious. How could there be two physical things in the same place at the same time? But I have just shown that they cannot be identical. Suppose that the statue and the lump come into existence at the same time t and pass out of existence at the same later time t*. At all times they share the same matter, and at no time are they not spatiotemporally coincident. And yet they are not identical because modally discernible. In our world, L composes S now, but there are possible worlds at which L does not not compose S now.
The fact that there are bronze statues and that the statue and its matter are neither strictly identical nor strictly distinct suggests the following analogy: The Father is to God as the statue is to the lump of matter out of which it is sculpted. And the same goes for the other Persons. Each Person is to God as the statue is to the lump. Schematically, P is to G as S to L. The Persons are like hylomorphic compounds where the hyle in question is the divine substance.
Thus the Persons are not each identical to God, which would have the consequence that they are identical to one another. Nor are the persons instances of divinity which would entail tri-theism. It is rather that the persons are composed of God as of a common substance. Thus we avoid a unitarianism in which there is no room for distinctness of Persons, and we avoid tri-theism. So far, so good.
Something like this approach is advocated by Jeffrey Brower and Michael Rea, here.
But does the statue/lump analogy avoid the problems we faced with the water analogy? Aren’t the two analogies so closely analogous that they share the same problems? Water occurs in three distinct states, the gaseous, the liquid, and the solid. One and and the same quantity of water can assume any of these three states. Distinctness of states is compatible with oneness of substance. On the water analogy, the Persons are to God as the three states of water are to water.
Liquid, solid, and gaseous are states of water. Similarly, a statue is a state of a lump of matter. The main problem with both analogies is as follows. God is not a substance in the sense in which clay and water are substances. Thus God is not a stuff or hyle, but a substance in the sense of a hypostasis or hypokeimenon. Beware of equivocating on 'substance.' And it does no good to say that God is an immaterial or nonphysical stuff. God is an immaterila being, but he cannot be or be composed of an immaterial stuff. Besides, 'immaterial stuff' smacks of a contradictio in adjecto. It sounds like 'immaterial matter.' Furthermore, the divine unity must be accommodated. The ground of divine unity cannot be amorphous matter whether physical or nonphysical.
In addition, one and the same quantity of H20 cannot be simultaneously and throughout liquid, solid, and gaseous. Similarly, one and the same quantity of bronze cannot be simultaneously and throughout three different statues. Connected with this is how God could be a hylomorphic compound, or any sort of compound, given the divine simplicity which rules out all composition in God.
In sum, the statue/lump analogy is not better than the water/state analogy. Neither explains how we can secure both unity of the divine nature and distinctness of Persons.