Religion is what individual does with his own A. N. Whitehead ventured this description of in his Lowell Lectures of 1926,2 and since that time it has been frequently quoted, usually disparaged, and seldom understood in anything like way Whitehead intended. I propose in what follows to interpret meaning of this statement in some depth, trying to give it its proper setting within Whitehead's metaphysics and his theory of and to show that it is neither as one-sided, sentimental, or vacuous as it might appear to be on casual encounter. The description is not immune from criticism, and I shall try to bring out some of its weaknesses, but my main intent shall be to present its meaning as fully and sympathetically as possible. While social side of is important for Whitehead, it is not primary. The essence of is to be discovered, not in public dogmas, practices, or institutions, but in confrontation with the awful ultimate fact, which is human being, consciously alone with itself, for its own sake (RM 16). And although had its historical origins in collectivist rituals, emotions, and beliefs, these served merely as springboard for emergence of in its final nature as what man does with his own solitariness. We can best get at some of Whitehead's reasons for coming to this conclusion by contrasting communal religion, as he conceives it, with which grows out of solitariness. He calls latter purified religion or rational religion,