American psychologist, best known for his book
The Origins of Consciousness in the Breakdown of the Bicameral Mind, in which he argues that ancient peoples were not conscious as we consider the term today, and that the change of humans mode of thinking occurred within recorded historical times.
The first part of his theory is unexceptionable, since at some point humans must have become conscious; but his contention that this happened long after we became the modern human species, and actually within the last few thousand years, is regarded as far more contentious.