‘Even the farthest seers can’t bend their gaze beyond their era’s horizon of possibility, but the horizon shifts with each incremental revolution as the human mind peers outward to take in nature, then turns inward to question its own givens. We sieve the world through the mesh of these certitudes, tautened by nature and culture, but every once in a while—whether by accident or conscious effort—the wire loosens and the kernel of a revolution slips through’ (p. 8).