The assertion that consciousness is a property of certain individuals and not others--rather than of the entire universe--implies a very special moment in the ontogeny of those individuals. This is the moment of individual consciousness origination, before which the individual (e.g., a gestating human) is not conscious, and after which it is. Would anyone disagree that this moment is implied by most theories of mind given merit in academia? By consciousness I mean nothing vague but quite simply "the subjective character of experience," a no-nonsense definition as worded by Thomas Nagel.
In light of that implication, a physical theory of consciousness must either:
(a) address the nature of that moment, describing a physical arrangement that gives rise spontaneously to consciousness; or
(b) deny such a moment's existence and ascribe consciousness to the entire universe (some sort of pan-psychism).
While (b) is typically considered the mystical and unacceptable stance, as a naturalist I find (a) to seem...