Names, Nonsubstitutivity and the Tanney Puzzle

Abstract

If you know the movie Superman, you will probably agree that it is true that Lois kissed Superman before she kissed Clark Kent. But Clark Kent is identical with Superman. Yet obviously Lois did not kiss Superman before she kissed Superman, so the argument to that conclusion is invalid. Yet it appears that there are arguments that share the form of the ‘kissing Superman’ one, but that are valid. Julia Tanney has remarked: Normally, I would be very sympathetic with the claim that there was a time, t1, at which Lois kissed Superman but not (yet) Clark Kent. I note however that the sense in which Lois (at t1) had not (yet) kissed Clark Kent would be the same as that in which Oedipus, although having slept with Jocasta had not slept with his mother. But Jocasta hanged herself and Oedipus gouged out his eyes because there was no question for them of not accepting substitutivity. The difference between the first (kissing) argument and the second is that, sexually, we have moved from second base to fourth, but that should not make for a difference in validity-value. Yet apparently the first argument is invalid, the second is valid. This is what I am calling the Tanney Puzzle. It provides an important testing ground for theories of reference. I want to show how this puzzle is resolved by attention to views that Wittgenstein expressed, at PI § 525 and elsewhere, about the influence of context on the proposition expressed by a speaker when using a sentence on an occasion.