Rationalism: The Cartesian notion that ideas are innate and thus a priori. This form of rationalism implies an interpretation of the notion of ideas and forms as atemporal, aspatial, but complex structures i.e., the idea of “a horse” (i.e., with a head, body and legs). It also matches well with the interpretation of the knowing subject as a created being (ens creatu). God created man after his own image and thus provided the human mind with an adequate set of ideas to understand his creation. In this theory growth, of knowledge is a priori limited. Creation of new ideas ex nihilo is impossible. This view is difficult to reconcile with the concept of experimental science.