Proposition
In logical positivism, a proposition whose truth value cannot possibly be decided is meaningless (Quine, for instance, believes that propositions generally have no clear criterion of identity). For example, statements about the existence of deities cannot be proved under logical positivism. Because the statements have no truth value, a logical positivist would consider propositions about deities (such as "God exists" or "God does not exist") to have no logical meaning.