Descartes

Descartes Descartes is famed by is familiar notion, "I think therefore I am (Cogito, ergo sum.)." It is a conclusion he has reached in his second meditation after much deliberation on the existence of anything certain. After he discovers his ability to doubt and to understand, he is able to substantiate his necessary existence as a consequence. What we doubt or understand may not ultimately correspond, but we can never be uncertain that we are in the process of thought. This idea is a major component in Descartes’ proof of the external world. He relies on the existence of a non-deceiving God to ensure that an external world exists after calling it into doubt by the invocation of the dream argument. In this argument, Descartes suggests the possibility that none of our ideas are caused by external objects and therefore, such objects may not exist. He also raises the idea of a demon that may deceive us and allow us to perceive what is not really there. Although he assures himself of his own existence by his modes of thought, he remains uncertain of the reality of an external world. He doubts whether there is anything of material substance that provokes thought, external, god, existence, world, independent, descartes, being, anything, two, therefore, objects, mind, ideas, idea, exist, after, upon, must, matter, material, doubt, space, since, reality, rather, proof, perfect, perceptions, himself, else, both, believe, argument, understand, uncertain, trusted, think, takes, substances, sort, something, smaller, seems, provokes, process, perception, past, nor, non-deceiving, necessary