ABSTRACT
Can we say what is neither true nor false, but might have been, had the world spoken of been suitably different? One might think we cannot; for we cannot get so far as saying what even might be true without thereby saying what in fact is, if not true, then false. Thus Aristotle suggests, in a simple case:
there cannot be an intermediate between contradictories, but of one subject we must either affirm or deny any one predicate.
(Metaphysics, Book IV, Ch. 7, (1011b 23–4))