The structure of operations is therefore that of relational-complexes. There are operations of invention and operations of discovery. The content of an invented entity is determined by the nature of something from which it has been derived; it is thus reducible to that other entity and the operation of derivation. Its nature becomes clarified through the designation of a more clearly given occurrent with which it has a specifiable relation. In a moment of exaltation the artist suddenly finds himself in possession of a guiding idea—obscure as to its outlines and obviously an idealization of something actual. Thus it exhibits the spontaneity of unconscious operations, and the vagueness and reference of inventions. Among unconscious discoveries one is also tempted to include acts of scientific discovery, so-called, by which theories and explanatory notions are brought into awareness.