“What is it that breathes fire into the equations and makes a universe for them to describe?” Stephen Hawking wondered, recognizing the quixotic nature of his quest for a theory of everything — a complete and final explanation of the universe, a universe only rendered real in the mind. Around the same time, on another landmass, watching finches cling to the swaying branches in the wind, a scientist as original and unrelenting in his own quest was wondering about the “internal fires that fuel these wisps of feather and bone,” recognizing that each mind is itself a universe, that inside every skull, even the smallest, is a place black and fathomless as pure spacetime, housing an umwelt of which an outside observer can only ever have an incomplete theory.…