Many traditional theists have said that
(i) God is propositionally omniscient,
i.e. knows all truths. Many traditional theists also hold that
(2) God is timeless.
That is, these theists hold that though God exists, there is no time at which He exists, and He does not exist earlier or later than anything. Some recent philosophers, among them Arthor Prior, Robert Coburn, Norman Kretz mann, Nicholas Wolterstorfl Richard Gale and Patrick Grim, have argued that
(3) There are truths to whose expression ‘now’ is essential, and that (1)–(3) compose an inconsistent set of propositions. These writers argue that due to the semantics of ‘now’, a timeless God cannot know truths to whose expression ‘now’ is essential. To know a truth, it is claimed, one must be able to mentally token a proposition expressing what one knows. To token a truth to whose expression ‘now’ is essential, one must token ‘now’. ‘Now’ and relevantly similar terms (such as tensed verbs) inter alia locate those who use them in time: if one says truly that it is now 3 p.m., it follows that one exists at 3 p.m. So a timeless being cannot use ‘now’ and relevantly similar terms, and so (it is claimed) cannot know truths for whose expression ‘now’ and its ilk are required.