Rene Descartes wrote "A Discourse on Method" where he advocated doubt as a means to knowledge and in which he replaced rhetorical means of knowing the world with a mechanistic and analytical method using doubt to distinguish facts from mere opinions.

Descartes hoped to remove unexamined bias from our beliefs about the world.

"My third maxim was to try always to conquer myself, . . . . . avoid precipitancy and prejudice. . . ."

(Discourse on Method, p. 41-47.)