Published online by Cambridge University Press: 01 January 2020
Descartes contended that “I am obliged in the end to admit that none of my former ideas are beyond legitimate doubt” (1964, 64). Accordingly, he adopted a method of doubting everything: “Since my present aim was to give myself up to the pursuit of truth alone, I thought I must do the very opposite, and reject as if absolutely false anything as to which I could imagine the least doubt, in order to see if I should not be left at the end believing something that was absolutely indubitable” (1964, 31). Similarly, other philosophers have raised doubts about the justifiability of beliefs concerning the external world, the existence of other minds, and moral principles; philosophical skepticism has a long history (Popkin 1979).