Self-evident truths concerning knowing and the known are discussed in the "Institutes of Metaphysic" (Ferrier is thought to have coined the term epistemology in this work, p. 46). It explains that the fact that any intelligence, in addition to knowing whatever it knows, must as the ground or condition of its knowledge have some cognizance of itself as the basis of the whole philosophical system. In addition, the only possible kind of knowable is one which is both known of an object and known by a subject (Object + Subject, or Thing + Intelligence). This leads to the conclusion that the only independent universe which any mind can think of is the universe in synthesis with some other mind or ego.