For philosophers of a realist stamp, psychological nominalism, understood as the claim that all awareness is a linguistic affair ( EPM 160), is of a piece with philosophical behaviorism, which allegedly denies the reality of consciousness.
If psychological nominalism is complicit with this denial—which strikes many philosophers as absurd—some would say it deserves to be relegated to the dustbin of philosophical history along with its behaviorist sibling.
Wilfrid Sellars first coined the expression “psychological nominalism” and
defended the doctrine throughout his long philosophical career. But he also
distinguished between two aspects of the mind, thinking and sensing, and laid claim to realism about both. This distinction between thinking and sensing (which can be traced back to Kant) essentially prefigures David Chalmers’s more recent distinction between the functional- psychological and the phenomenal experiential aspects of mind (see Chalmers 1995 and 1996 ). The crucial difference, however, is that while Chalmers endows phenomenal- experiential states with a cognitive authority equal to if not greater than that of functional-psychological states, Sellars reserves cognition for functionally characterized thinking alone and characterizes sensation as a non- cognitive state that plays a causal but not justificatory role in empirical knowledge.
Yet Sellars cannot be accused of downplaying the significance of the
phenomenal- experiential aspect of mind. Indeed, his account of sensory
consciousness leads him to make the controversial claim that sensation has a metaphysical purchase insofar as it (indirectly) reveals a fundamental aspect of physical reality: its intrinsic, qualitative aspects, which, as he sees it, cannot be reduced to the extrinsic or dispositional properties of things.