Man can adapt himself somehow with anything his imagination can cope with, but he can not deal with Chaos. Because his characteristic function and highest asset is conception, his greatest fright is to meet what he cannot construe-the "uncanny," as it is popularly called. It need not be a new object; we do meet new things, and "understand" them promptly, if tentatively, by the nearest analogy, when our minds are functioning freely; but under mental stress even perfectly familiar things may become suddenly disorganized and give us the horrors.

(Clifford Geertz "Religion as a Cultural System")