Biological foundations of the psychoneural identity hypothesis are explicated and their implications discussed. "Consciousness per se" and phenomenal contents of consciousness per se are seen to be identical with events in the (unobserved) brain in accordance with Leibniz's Law, but only informationally equivalent to neural events as observed. Phenomenal content potentially is recoverable by empirical means from observed neural events, but the converse is not possible. Consciousness per se is identical with events which do not represent anything distal to sensory (...) receptor-transducer systems. Thus, on the psychoneural identity hypothesis, consciousness per se comprises directly physical events-in-themselves rather than being a Euclidean representation of physical events as is the case for phenomenal content. After comparing consciousness per se to "onta," a paradox is suggested: rather than being irreducible to physical reality, consciousness per se is the only experience congruent with the ultimate nature of physical reality as conceived by contemporary physics. (shrink)