Now is the time.
The aim of this paper is to consider some logical aspects of the
debate between the view that the present is the only 'real'
time, and the View that the present is not in any way metaphysically
privileged. In particular I shall set out a language of first-order
predicate tense logic with a now predicate, and a first order
(extensional) language with an abstraction operator, in such a way that
each language can be shewn to be exactly translatable into the other. I
shew that this translation is preserved at the metalinguistic level, so
that equivalent truth conditions can be defined in a tensed metalanguage
or an indexical metalanguage. I then make some remarks about the
connection between proofs of relative consistency and metaphysical
truth; and some historical remarks about Arthur Prior's use of
formal logic in expressing his presentist views.