Abstract

I argue that, according to Descartes, even mathematics is not immune from doubt and absolutely reliable, and hence fails to grant the ultimate justification of science. Descartes offers two arguments and a corollary to support this view. They are sufficient to show that the mathematical atheist cannot justifiably claim to have absolutely certain knowledge even of simple mathematical truths. Philosophical reflection itself turns out to be the only alternative means to provide knowledge with a stable foundation.