Abstract

The evolution of nervous systems culminating in human consciousness might best be studied through an analysis of wakefulness and its constituent functions of sentience and cognition. The operative assumption in this model is that wakefulness emerged at the dawn of phylogeny and has been successively in-formed by an increasing complexity of sensory and cognitive functions. Wakefulness constitutes the essence of human consciousness but the cognitive and sentient functions complicate the analysis of the forms of awareness afforded to lower species. Folk psychology is recognized as a proper starting point for the analysis, as against a philosophical behaviorism that dispenses with the supposition of infrahuman sentience. The concepts of a dim awareness and instinctive automatisms, hitherto applied to non-human animals, are shown to confuse the dimness of primitive sensory and cognitive processing with a phylogenetically invariant wakefulness that, by hypothesis, cannot be attenuated in any species. Mundane behavioral evidence from infrahumans must remain the touchstone by which models of consciousness are to be assessed, not any program interpreting empirical evidence to the end of outlawing phenomenal experience in humans or infrahumans.