  Sayre’s argument aims at the conclusion “No statement can be treated as either true or false.” But Sayre goes via the premiss “Any statement remains true no longer than the time taken in its utterance.” If there are statements which are true, even if they are not true for very long, it is not clear why these statements cannot be treated as true, at least in principle (and in practice too, given creatures with the right sensory equipment and sense of time).