Haecceities, individuation and the Trinity: a reply to Keith Yandell.

Introduction

According to Keith Yandell, a prima facie case can be made for the thesis that 'if one is a Christian Trinitarian theist, then -- given certain plausible claims -- one should reject the view that God has logically necessary existence Trinitarians should, in all consistency, avoid Anselmianism'. (1) The proposition God exists necessarily, together with other (hopefully) obvious truths, allegedly entails the proposition God is not a Trinity of persons. In this paper, I shall attempt to show that the claims upon which Yandell's case is constructed are not in fact plausible. Indeed, the Anselmian Trinitarian can escape the charge of inconsistency by making use of a special sort of property -- what Alvin Plantinga calls an essence or haecceity, a property without which a given object could not exist, but also such that nothing else could possibly have it. (2) Each Trinitarian member (though necessarily existent) has at least one haecceity, I argue, and is thus distinct from the other members of the Godhead. Moreov er, what I take to be the main Yandellian complaint against using haecceities in this way is unsound, since it subtly confuses the connection between having a property in a world and having a property simpliciter.

What is Anselmian Trinitarianism?

You are an Anselmian monotheist, on Yandell 's view, if you believe that:

(TA) God exists

expresses a necessary truth, that is to say, if you believe that (TA) is true and could not possibly be false. If you are also a Trinitarian, you will go on to affirm that (TA) entails each of the following:

(TB) The Father exists

(TC) The Son exists

and

(TD) The Holy Spirit exists

so that each of these propositions is itself necessarily true. Let's call the set of (TA), (TB), (TC), and (TD) the 'T-set'. An Anselmian Trinitarian believes each member of the T-set and, furthermore, believes that each member is a necessary truth. But she goes still further. For according to classical Trinitarian doctrine, the members of the Godhead are distinct persons; no two members of the Trinity are identical with one another. The Father is neither identical with the Son nor the Holy Spirit; and the Holy Spirit is not the same person as God the Son. Thus the Anselmian Trinitarian holds that (TB), (TG) and (TD) express distinct propositions. For, of course, if they expressed the same proposition, all Trinitarian distinctions would collapse.

Can we make Trinitarian distinctions?

Now what is supposed to be the problem here for the Anselmian Trinitarian? Why ought she to give up believing that (TA) is necessary given that she pays the same compliment to (TB)-(TD)? The problem, says Yandell, is that if you think each member of the T-set expresses a necessary truth, then you won't be able to provide an account of Trinitarian distinctions; indeed, your Anselmian views will commit you to the utter collapse of all such distinctions. But why should we think so? In the first place, could it not simply be a brute unexplained fact that there can be several distinct but indiscernible divine persons? Following an Unendorsed suggestion of Swinburne, perhaps we could take it as a surd given that 'If there exists more than one divine individual, they could [still] have all their properties in common, and yet be different'. (3)

Unfortunately, this suggestion is fraught with difficulty. For one thing, it seems to fall prey to what Gale and Pruss call 'the taxi-cab objection': arbitrarily dismissing a request for explanation (like a passing cab) when it suits one's purposes. (4) Surely if a given pair of Trinitarian members is said to be distinct, it is reasonable to ask: 'In virtue of what?' What is it, ontologically speaking, that grounds the distinction? An explanation is clearly in order here; there must be something true of the one member but not the other. Now of course requests for explanatory grounds can get out of hand. For example, they cannot go on forever; eventually we must come to an explanation-ender. But the point is that to refuse to set one's toe on the explanatory turf at all is nothing like an explanation-ender; it is an explanation-dismisser and a contextually inappropriate one at that.

It is interesting to note in this connection that Swinburne is compelled to invoke (on behalf of this view) what he calls an 'underlying thisness' -- a suppositum or ultimate subject of predication -- in order to distinguish between two indiscernible divine individuals. But in the present context this is fatal. For unless supposita are to be construed as bare particulars, it is reasonable to suppose that distinct supposita will possess distinct properties. At the very least, they will differ in their basic identity properties: for any supposita a and b, a will have the property being identical with a and b will not. After all, if b had being identical with a, it would be the very same thing as a, in which case it would lose all of its individuative powers. For surely, if supposita are to properly serve as individuators, distinct objects must have distinct underlying supposita. It is therefore far from obvious that there could be two or more distinct divine individuals, which nevertheless held all their proper ties in common. (5)

So it seems to me that Yandell is right: the Anselmian Trinitarian must provide some principled basis for …