"Though it makes sense to inquire how and when consciousness developed into what we now experience as such," Barfield concedes in "The Evolution Complex," "it makes no sense at all to inquire how and when mind emerged from matter." Indeed, as Barfield goes on to show, "Mind and world are best compared not (as with Descartes) to two entire strangers who have somehow got into bed together, but rather to the obverse and reverse sides of a single coin" (EC 12).

In "Man, Thought, and Nature," Barfield quotes Rudolf Steiner's maxim:

    The mind is related to thought, as the eye is to light. (RCA 228)
See in particular "The Evolution Complex.