The third and final solution to the problem of the Trinity that we want to explore invokes what might be called the ‘relative-sameness’ assumption. This is the assumption that things can be the same relative to one kind of thing, but distinct relative to another. If this assumption is true, then it is open to us to say that the Father, Son, and Holy Spirit are the same God but distinct Persons. Notice, however, that this is all we need to make sense of the Trinity. If the Father, Son, and Holy Spirit are the same God (and there are no other Gods), then there will be exactly one God; but if they are also distinct Persons (and there are only three of them), then there will be three Persons.
The main challenge for this solution is to show that the relative-sameness assumption is coherent. … In some of our own recent work, we have attempted to address this concern, arguing that reflection on statues and the lumps of matter that constitute them can help us to see how two things can be the same material object but otherwise different entities. …
Consider Rodin’s famous bronze statue, The Thinker. It is a single material object; but it can be truly described both as a statue (which is one kind of thing), and as a lump of bronze (which is another kind of thing). A little reflection, moreover, reveals that the statue is distinct from the lump of bronze. For example, if the statue were melted down, we would no longer have both a lump and a statue: the lump would remain (albeit in a different shape) but Rodin’s Thinker would no longer exist. This shows that the lump is something distinct from the statue, since one thing can exist apart from another only if they’re distinct. (A statue can’t exist apart from itself!)
It might seem strange to think that a statue is distinct from the lump that constitutes it. Wouldn’t that imply that there are two material objects in the same place at the same time? Surely we don’t want to say that! But then what exactly are we to say about this case? Notice that this isn’t just a matter of one thing appearing in two different ways, or being labeled as both a statue and a lump. Earlier we noted that ‘Superman’ and ‘Clark Kent’ are really just different labels for the same man. But our statue analogy isn’t like this. Superman can’t exist apart from Clark Kent. Where the one goes, the other goes too (at least in disguise). But the lump of bronze in our example apparently can exist apart from The Thinker. If that’s right, then, unlike Superman and Clark Kent, the statue and lump of bronze really are distinct things.
Philosophers have suggested various ways of making sense of this phenomenon. One way of doing so is to say that the statue and the lump are the same material object even though they are distinct relative to some other kind. (In ordinary English, we don’t have a suitable name for the kind of thing relative to which the statue and the lump are distinct; but Aristotle and Aquinas would have said that the statue and the lump are distinct form-matter compounds.) Now, it’s hard to accept the idea that two distinct things can be the same material object without some detailed explanation of what it would mean for this to occur. But suppose we add that all it means for one thing and another to be “the same material object” is just for them to share all of their matter in common. Such a claim seems plausible; and if it is right, then our problem is solved. The lump of bronze in our example is clearly distinct from The Thinker, since it can exist without The Thinker, but it also clearly shares all the same matter in common with The Thinker, and hence on this view is the same material object.
By analogy, then, suppose we say that all it means for one Person and another to be the same God is for them to do something analogous to sharing all of their matter in common (say, sharing the same divine nature). On this view, the Father, Son, and Holy Spirit are the same God but different Persons in just the way a statue and its constitutive lump are the same material object but different form-matter compounds. Of course, God is not material; so this can only be an analogy.
