Why such an interest in consciousness at the present time? Could it be because of a feeling that we might in this phenomenon be in the presence of something absolutely inexplicable? After all, not everything is explicable. The greatness of a particular work of art, while not pure mystery, is a matter of ‘noumenal’ depth, a bottomless well, beyond demonstration. Is consciousness such a thing? Are we in this phenomenon running our heads up against the limits of explanation?
This seems unlikely. It is worth remembering that at some point during the history of the life-system of which we are part, consciousness evolved into being, and that the laws of physics cannot have relaxed their hold upon physical phenomena as it did. And it seems equally certain that supervenience must have characterized the emergence of consciousness upon such a physical basis, and that it is inconsistent with a radical contingency. If one physical condition corresponds to consciousness in one animal in one life-system in one sector of physical space, it is not going to correspond to unconsciousness or something quite other either in another animal or in a different life-system in another part of the universe. These considerations suggest that there cannot be much to the idea that consciousness is an essentially inexplicable phenomenon. What that explanation is, and whether we can ever hope to ﬁnd it, are naturally enough other matters.
And so when people speak of ‘the mystery of consciousness’, they perhaps mean that nothing could explain the appearance of so radical a novelty on the world scene. But it is possible that what they are thinking of is something rather different. It could be that what they have in mind is, that whatever the explanation of consciousness may be, that explanation must be one that is marked by a natural depth which is barely to be plumbed in its entirety. And it is easy to sympathize with such a sentiment. And yet why single out consciousness in this regard? Are we to assume that a comparable attitude is out of place concerning Mentality itself—or even Life? Are not these phenomena marked likewise by depth of this particular type, and in that speciﬁc sense of the term by ‘mystery’ of a kind?