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.