Julian Jaynes, Behavioral and Brain Sciences, 1978, 1.
Reprinted in Marcel Kuijsten (ed.), The Julian Jaynes Collection (Julian Jaynes Society, 2012).
Abstract: If we compare the vocabulary between early and late Greek texts over the first millennium B.C., or between early and late Hebrew texts over the same period, a dramatic change is obvious. Early texts have no mental words. The referents of words are concrete, indicant, objective, touchable, watchable. But, in a few centuries only, the human lexicon is suddenly aglitter with a network of new subjective words that to us are equivalent to mind, belief, know, remember, imagine, aware, purpose, intention, and so forth. The referents of such words are only observable, if at all so, by a new kind of mental process currently called introspection, previously reflection, or simply and more fuzzily thought. And the perculiar quality of these words, in constrast to cup, run, green, river, et al. is that they create their own referents on the basis of metaphor, becoming those analog behaviors which we call consciousness.