Cartesian Dualism

Doubt and Descartes Existence

The proposition ‘I am, I exist’ (ego sum, ego existo – hereafter, referred to as the ’ego’), is of special importance in the argument of Descartes’ Second Meditation for many reasons. More generally, it is important because of the implications it has for Descartes’ overall philosophical project. For example, it implicitly rejects religious authority in favor of a personal standard of knowledge in an era in which Galileo faced aggressive persecution; it also forms the nascent beginning of the still ongoing nature-nurture debate, and it ultimately makes Descartes something of an Augustinian. But these topics are far too broad to cover adequately in a brief essay. Since the language of the question at hand focuses exclusively on the the Second Meditation and specifically the argument within it, a much narrower interpretation seems more appropriate. Namely, why is the ‘ego’ necessary for Descartes to achieve his goal in the Second Meditation, and how does it facilitate that goal? On this point, I will argue that there is one fundamental reason. Namely, without the ego, Descartes has no means by which to recover from the corrosive power of his own method of doubt. I will outline and analyze this reason, focusing on whether the ‘ego’ satisfies the logical and epistemic demands put upon it by the method. Finally, I will argue that because Descartes is unclear in his justification for the ego, it remains unconvincing as a basis for epistemic certainty.