ABSTRACT
This chapter focuses on 19th-century philosopher – Charles Sanders Peirce. Peirce then explained four methods of moving from doubt to belief: tenacity, accepting one alternative to the doubt and rejecting all possible criticism of it; authority, submitting to the state's or the church's tenaciously held beliefs; the a priori method, relying on the inclination to believe; and science. Every work of science great enough to be well remembered for a few generations affords some exemplification of the defective state of the art of reasoning of the time when it was written; and each chief step in science has been a lesson in logic. The essence of belief is the establishment of a habit; and different beliefs are distinguished by the different modes of action to which they give rise.
