One of the unfortunate consequences of the intellectualization of man's spiritual life was that the word "spirit" was lost and replaced by mind or intellect, and that the element of vitality which is present in spirit was separated and interpreted as an independent biological force. Man was divided into a bloodless intellect and a meaningless vitality. The middle ground between them, the spiritual soul, in which vitality and intentionality are united, was dropped.

p. 82 - The Courage to Be (1952)