Descartes asserts that aspects of mathematics and geometry—like the triangle postulate—exist innately in his mind, yet he also “clearly and distinctly perceive[s]” the natures of the properties of such concepts (Med V.68). Descartes’s mathematical certainty does not stem from physically viewing a triangle with his eyes or feeling a triangle’s three sides with his hands, instead, Descartes clearly and distinctly “perceives” the innate and unchangeable properties of a triangle—its three sidedness, its angles adding up to one-hundred-eighty degrees and so forth. Descartes uses similar logical reasoning when he asserts God’s
Descartes asserts that aspects of mathematics and geometry—like the triangle postulate—exist innately in his mind, yet he also “clearly and distinctly perceive[s]” the natures of the properties of such concepts (Med V.68). Descartes’s mathematical certainty does not stem from physically viewing a triangle with his eyes or feeling a triangle’s three sides with his hands, instead, Descartes clearly and distinctly “perceives” the innate and unchangeable properties of a triangle—its three sidedness, its angles adding up to one-hundred-eighty degrees and so forth. Descartes uses similar logical reasoning when he asserts God’s