The three intertwining careers of William Torrey Harris [1835-1909] in philosophy, philosophy of education, and educational administration converge in twelve of the Annual Reports of the board of directors of the St. Louis public schools, most of the essential features of which he formulated as the superintendent of schools from 1867-79. These twelve reports, comprising philosophical and educational principles, have been acclaimed nationally and internationally to be among the most valuable official publications in American educational literature. The major purpose of this paper is to clarify the nature and scope of the philosophical principles of Harris expressed in his Annual Reports. The areas of philosophy represented are metaphysics, anthropology, epistemology, ethics, and philosophy of religion. While the motivation and context of these philosophical principles are pedagogical in orientation, it is evident that Harris produced here a philosophical synthesis worthy of consideration in a formal survey of the history of American philosophy.