On Identity and God

We often make identity statements where those things seemingly identified could have existed without being so identified. A putative example is 'The Morning Star is the Evening Star'. Presumably the identity here is contingent; while it is true that 'Morning Star' and 'Evening Star' pick out the same object, this is only contingently so. Presumably, there are possible worlds where 'Morning Star' picks out another object than Venus, and thus cannot be a co-referential expression with 'Evening Star'.

As is well-known, Saul Kripke argued four decades ago that we must in situations like this disentangle the relevant epistemic, metaphysical and semantic notions. Starting from the simple metaphysical and logical truth that identity is reflexive - - each and ever object and each and every term is identical to itself - - he argued that necessity applies to identity in the nature of the case. Each thing that is is necessarily identical to itself. I can imagine no possible word in which an object is not itself. I can not imagine a kind of thing not being the kind of thing it is, and I cannot imagine an individual thing not being the individual thing that it is.

Famously, Kripke argued that terms are "initially baptized" such as to apply to objects. Sometimes realization of this baptism takes time. 'Morning Star' was baptized to apply to the object in the sky that turned out to be Venus. The same is the case with "Evening Star'. So the truth of 'The Morning Star is the Evening Star" has the same logical and metaphysical status as the truth 'Venus is Venus'. Because of this, the two statements have the same modality; both statements are necessary.

Kripke terms words that pick out the same object in all possible worlds "rigid designators." Names are, accordingly, rigid designators. This is true of proper names like 'Hesperus' as well as common names like 'heat' or 'mean molecular kinetic energy'. Because 'heat' rigidly designates the same objective state of affairs as 'mean molecular kinetic motion', the statement that 'heat is mean molecular kinetic energy' has the same modal status as the statement 'the state of affairs designated both by 'heat' and 'mean molecular kinetic motion' is identical to itself'. While 'heat is mean molecular kinetic energy' is true in all possible worlds, it is not true that P's sensation of heat is identical to mean moleuclar kinetic energy. How heat is sensed is merely a contingent matter. Heat could have been sensed in such a way as not to feel hot, to feel loud, or not to be felt at all. Sensing by contingent beings does not change the objective reality of heat, or the objective fact that it is just mean molecular kinetic motion.

Kripke argues quite plausibly that if theoretical reductions like 'heat is mean molecular kinetic energy' are necessarily identical, if they are identical at all, then any putative theoretical reduction of pain to a particular brain state would involve a necessary, not merely contingent identity statement. Pain of type x would be thus be necessarily identical to neurophysiological actualization of type C. Moreover, it would seem, that the tokening of type x would be necessarily identical to the tokening of type C. Because the instantiation of the pain state x essentially involves its sensation, identities between pain and brain states are disanalogous to other kinds of theoretical identities. Whereas one can distinguish the sensation of heat from heat, one cannot distinguish the sensation of pain from pain. While it is a contingent fact that the sensation of heat has been correlated with heat by human percipients, there is no possibility of any contingency between the sensation of pain and pain. While the seeming contingency of statements like 'heat is mean molecular kinetic motion' can be explained by the fact that heat and the sensation of heat are only contingently correlated, there is no analogous method allowing identification of pain and the sensation of pain. In sum, to say that 'pain x' is brain-state y' is to utter a statement that we have no explanation whatsoever of how we could have failed to know it!

The question for the theologian is, of course, is the term 'God' a definite description like 'the inventor of bifocals' and thus something that picks out different objects in different worlds, or is 'God' a rigid designator? Do we not want to say that 'God' must be distinguished from our experience of God and surely the conceptual machinery we employ in picking out God? Has not the tradition's emphasis on the incomprehensibility of God presupposed that we are yet talking about something even when we have only a very inadequate conception of what it is that we are talking about?

It seems that we must perhaps claim an initial baptism of 'God' with that being who did a number of salvific things for His people, including being the Father of Jesus the Christ. Making this identification rigidly means that 'God is the Father of Jesus the Christ' is necessarily true in the same way the 'Morning Star is the Evening Star' is necessarily true. The question of human experience of God, and even the human conceptual apparatus to identify God - - I am thinking here about 'that which none greater can be thought' - - is a question that involves contingency. It is perhaps contingently true that 'God is that which none greater can be thought'. It is perhaps necessarily true that 'God is the Father of Jesus the Christ'. This is an interesting way to think about old terrain that all of us have felt has been well-established for a very long time indeed.