Panrationalism (or comprehensive rationalism) holds two premises true: 1. * A rationalist accepts any position that can be justified or established by appeal to the rational criteria or authorities. 2. * He accepts only those positions that can be so justified. The first problem that needs to be dealt with is: what is the rational criterion or authority to which they appeal? Here the panrationalists diverge into two groups: Descartes is considered the founder of rationalism and gave the illustration cogito ergo sum as the paradigm to demonstrate what he believed.