At this week’s
I say that people see a ‘tension’ between the two doctrines. The tension is not incompatibility. It’s hard for a doctrine to be incompatible with truthmaker theory because, without further constraints, it’s just too easy to be a truthmaker theorist. The tension arises because, allegedly, the only way to be a truthmaker theorist and a presentist is to accept the existence of things that violate some other norm governing what we should postulate in our ontology. Consider, for example, the Lucretian reconciliation of truthmaker theory and presentism, defended by Bigelow. Bigelow thinks there are properties like being such as to have been a child, and the state of affairs of me instantiating this property is the truthmaker for the fact that I was a child. Sider and Merricks agree that this is not an attractive reconciliation: they both charge these Lucretian properties with peculiarity and both claim that it is a cheat to appeal to them. I want to offer the presentist a truthmaker that isn’t peculiar in the way that the Lucretian’s truthmaker is peculiar.
So in what sense are the Lucretian properties peculiar. In the paper I settle on the following: those properties are peculiar because they make no contribution to the intrinsic nature of their bearer at the time of instantiation.
An assumption in the paper (that I think the presentist should definitely grant) is that it makes sense to talk of the intrinsic nature of an object at a time as opposed to the intrinsic nature of an object atemporally speaking. An object’s currently instantiating being such as to have been a child does indeed tell us something about the intrinsic nature of that object if by its intrinsic nature we mean its atemporal intrinsic nature; but, I want to say, its instantiating that property now doesn’t tell us about how it intrinsically is now. That is what’s peculiar about properties like that, I claim: properties should make a difference to their bearers; since, for the presentist, the bearers are not temporally extended objects, a property can only be making a difference (in the relevant sense) if they’re making a difference to its present intrinsic nature. Lucretian properties don’t, so we shouldn’t believe in them.
If I’m right about what makes Lucretian properties peculiar, then the challenge for the presentist truthmaker theorist is to find properties the present instantiation of which makes a difference to the present intrinsic nature of the bearer but which are also such that the bearer couldn’t instantiate them without some truths of the form ‘the bearer was F’ being true. That is, the presentist needs properties which make a difference both to the present intrinsic nature of their bearers and which fix the truths concerning how the bearer was in the past.
So that’s the basic idea. The draft paper is here; comments are, of course, welcome.