ABSTRACT
The second category of propositions which arguably present a challenge to the possibility of an omniscient being are those which contain indexical expressions. The problem is this: we are familiar with the thought that for some sentences, whether they say something true is independent of who says them, or when and where they are said. For example, if I say ‘Water boils at 100o C’, you can express the very same fact by using the very same sentence. So too can anyone else, and they can use that sentence at any time, and in any place to express the same fact. Or if you say ‘It is better to have loved and lost than never to have loved at all’, I can express the very same thought by using the very same sentence – and again, where and when I or anyone else uses that sentence makes no difference to the fact which we thereby state. By contrast, there are other sentences which are such that whether the sentence says something true depends essentially on when or where or by whom it is said. For example, if you say ‘I am hot’, I cannot state the same fact by using the same sentence. I have to say not ‘I am hot’ but ‘You are hot’. Again, if you say today ‘Today it is raining’, and I want to express the same thought tomorrow, I cannot use the same sentence you used (another sentence token of the same type): I have to use a different sentence and say ‘Yesterday, it was raining’ – just as the weather forecaster expressing yesterday the same thought, has to use yet another sentence and say ‘Tomorrow it will rain’.
