In literary usage, archaism is the use of “an archaic or old-fashioned word or expression, like oer, ere, shoon, or darkling” in order to “suggest a mythic and glamorous past” (Harper Handbook to Literature 46). As a key sign of original participation, a prime creator of strangeness in the poetic, and a contributor to the felt change of consciousness central to the experience of poetry, archaism plays an important role in Barfield’s theory of poetic diction. It is a kind of “stepping back to leap” (Koestler) which fuels the evolution of consciousness.

“The poet,” according to this theory, “while creating anew, is likely to be in a sense restoring something old. And if the most ancient rhythms of verse are but the sound, dying away, of just those ‘footsteps of Nature’ whose visible print we [observe], with Bacon, in the present possibility of true metaphor, we shall hardly be surprised to hear in the music which such a poet creates, albeit spontaneously, something like an echo of just those rhythms” (Poetic Diction 155)

Barfield is careful to distinguish true and false archaism. Archaism in its inauthentic form has nothing to do with the evolution of consciousness.

The mere confining of oneself to a choice of words, a grammar or a set of mannerisms which has been for some time and is still in general literary use, is not archaism, though archaism may seem in the long run (and especially in the case of grammar) to involve that. That should merely be called conservatism, or even—not to put too fine a point on it—dullness. And its cause lies, not in the nature of language, but in the nature of man, and especially of literary man.(Poetic Diction 156)

The real thing, authentic archaism implies “not a standing still, but a return to something older, and if we examine it more closely, we shall find that it generally means a movement towards language at an earlier stage of its own development” (Poetic Diction 160). In the history of literature it tends to reappear in

great movements . . . which are at the same time returns to Nature . . . , inaugurated, as we would expect, by the greater poets. They are led by poets with something to say, in other words, with something to give. It is these who break away from the old “poetic diction” in its futile sense, and it is not their fault that what they create eventually becomes a new one.(Poetic Diction 164)