  To explain the contribution of the “created” causes of knowledge, Bonaventure noted that the content of human knowledge comes from four kinds of “created” causes: the passive intellect within the individual soul as material cause, for it receives knowledge; the individual agent intellect as efficient cause, for it abstracts the content of knowledge from sensation; the essence of an individual creature known as formal cause, for the creature is “what” we know; and epistemological truth as end. These “proper principles” of knowledge do not involve  God.[47]