Descartes: A Priori Proof Of God's Existence

In his Meditations on First Philosophy, René Descartes offers both an a priori and an a posteriori proof of God’s existence. Until Immanuel Kant introduced his epistemology—the notion of a priori synthetic judgments—Descartes’ a priori proof was generally considered purely demonstrative and analytic. However, analyzing Descartes using Kant’s epistemological foundations, reveals that Descartes’ a priori proof was both a priori and synthetic. Specifically, the Cartesian concept of clear and distinct perceptions, neatly mirrors the Kantian notion of synthetic judgments. The following will 1) explore and explain Descartes’ a priori proof of God’s existence and Kant’s epistemology, and 2) demonstrate how Descartes fused the a priori and synthetic to prove God’s existence. …show more content…
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