The purpose of this essay is to indicate the chief tendencies of ancient Egyptian speculation in regard to the god Thoth. Taking as the basis of his work a fairly complete examination of the chief references to the god in Egyptian literature and ritual, the author has tried to distinguish the more important phases of Thoth's character as they were conceived by the Egyptians, and to show how these aspects, or phases, of his being help to explain the various activities which are assigned to him in the Egyptian legends of the gods and in the ritual of tombs and temples.