Common Sense
Common sense is always the product of the evolution of consciousness. "The common sense of today1 is not something that is valid for all time, but something that has evolved from a common sense that was qualitatively different from it" (HGH 47-48).

"This world of outsides with insides to them, which we perceive around us and in which we dwell," Barfield insisted for over sixty years, "is not something unshakably and unalterably given, but is largely the product of the way we collectively and unconsciously think. It is correlative to our mental habit" (HGH 71).

See in particular, "Modern Idolatry: The Sin of Literalness," History, Guilt and Habit, Chap. 2 and Saving the Appearances, Chaps. IX and X.
1For Barfield, modern common sense entails (simply put) "becoming blind to one half of reality, while retaining the other. It has come to accept and value the outer for its own sake only and not as the manifestation or garb of another and immaterial component. Reality is assumed to consist of things, not of images" (HGH 48).