Descartes' Method of Doubt

Introduction

René Descartes (1596-1650) pioneered “Method of Doubt” and his maxim of Dubito, ergo sum (I doubt, therefore I am) as well as his foundational idea of undulatio reflexa (or automatic bodily movement). His ideas served as points of departure for the modern period (from about 1600 to 1960) and the physiological foundations of psychology. This paper present and explains Descartes' Method of Doubt and how he used this method to call into question his knowledge of external objects and of mathematics and geometry. It also discusses the Cogito and the Wax example.

Discussion

In November 1619, at the age of 23, Descartes was earnestly seeking a direction in life, and when he arose from a dream-filled sleep he was led to it. He dedicated his life to determining what knowledge was beyond doubt through the formulation of an analytical geometry and the establishment of a philosophical system grounded in mathematics and rationalism. Although always a person inclined to worldly pleasures, Descartes now concentrated more and more on the life of the mind. (Rorty 125-130)

In his Discours de la Méthode (Discourse on Method 1637), Descartes began by rejecting all dogma, authority, and everything else except that of which he was absolutely certain, including those ideas that he claimed were indubitable or intrinsically incapable of being doubtful. He identified four rules for determining certainty in any area of inquiry, which included (a) trust your doubt so as to accept as true only those clear and distinct ideas about which you have absolutely no doubt, (b) divide big problems into smaller parts to promote a series of small wins, (c) begin by first fully understanding simple ideas and then move to more complex ideas in an orderly step-like fashion, and, lastly, (d) enumerate all elements of the problem and review ...