"Vibrancy is never wholly lacking in the human being, in some degree or other, but it is often so faint and vague as to be almost indistinguishable and inoperative. Sickness impairs it, confusion and doubtfulness of mind render it ineffectual, and a wilful despondency may destroy it at its source. At its best, however, it is a great power; and like any other supreme characteristic of human clay may be cultivated with intelligent care or ignored and thwarted and ruthlessly destroyed."