Ayer, A. J.

A.J. Ayer (1910-1989) is a well-known British logical positivist. In Language, Truth, and Logic (1936), he champions the “verification principle,” the idea that empirically verifiable propositions (or propositions verifiable upon a “finished” science)  are the only sorts of cognitively meaningful propositions. Thus, unverifiable statements, such as those belonging to pseudo-sciences or traditional Western metaphysics, are essentially meaningless. In contemporary analytic philosophy, the verification principle is generally considered too limiting, since science can produce meaningful and interesting propositions which do not seem to be potentially empirically verifiable.
==Stevens and Ayer==
Stevens apparently refers to Ayer once only.  The mention occurs in the short essay, “Imagination as Value.” Steven is discussing the difference between “the imagination as metaphysics” and imagination “as a power of the mind.” For Stevens, Ayer seems to help dispense with the “imagination as metaphysics” thesis. Stevens quotes this relevant passage from Language, Truth, and Logic:
It is fashionable to speak of the metaphysician as a kind of displaced poet. As his statements have no literal meaning, they are not subject to any criteria of truth or falsehood; but they may still seem to express, or arouse, emotions, and thus be subject to ethical or aesthetic standards. And it is suggested that they may have considerable value, as means of moral inspiration, or even as works of art. In this way, an attempt is made to compensate the metaphysician for his extrusion from philosophy. (qtd. in Collected Poetry & Prose 727)
From this perspective, Stevens believes that the “imagination as metaphysics” at least seems to have value, even if metaphysics and poetry both play second fiddle to science and philosophy. Stevens, however, cannot resist noting that, under logical positivism, that references to God are also “non-verifiable” and therefore nonsense.