Descartes’ Viable Notion of Knowledge

Renee Descartes' Meditations concern the philosopher's search for absolute knowledge. He wishes to find only those truths which, to him, exist as clear and distinct. In attempting this, Descartes reasons his knowledge of himself and of an infinitely perfect being, and utilizes these revelations to extrapolate more knowledge about the world and the nature of existence. Utilizing only self-evident insight and reasoning, Descartes intends to create a model of truth which rests only in those truths which are clear and distinct; an indestructible system of knowledge. Descartes' notion of knowledge, founded on the absolute knowledge of the self and ultimately a corporeal world, justified by the existence of God, provides an intriguing insight into the idea of truth and what man can claim as absolute knowledge.

Descartes' notion of knowledge begins with the question of absolute certainty. In his search for that which can be defined as "knowledge", Descartes accepts only that which is absolute knowledge. Absolute knowledge, further, is defined as those truths which cannot be doubted, and if they can be doubted, that doubt may be sufficiently answered. Thus, Descartes intends that his notion of knowledge be rooted in this absolute foundation, and he must begin only with what is assured and reason from that point. In doing so, Descartes must discard everything he currently believes to be true and begin considering what he knows to be true.

This notion of knowledge strips away all information previously gleaned through the senses. As the senses have been known to be unreliable (man is often deceived in what he believes he perceives), they are therefore ruled out as a source for absolute knowledge, and by extension, any knowledge at all. Even seemingly immediate perceptions, such as one's physical existence in a specific place and time, cannot be trusted. Man often experiences dreams in which perceptions are strikingly vivid; so vivid in fact they cannot be distinguished from reality except upon later reflection. These principles invalidate any notion Descartes may have had of tangible certainties. Further still, however, even intangible universal truths may be distrusted, for Descartes introduces the idea of a great deceiver. This great deceiver may be creating numerous illusions, including the illusion of those natural universal truths.

Thus, Descartes is left with the sole existence of himself. Once stripped of all sensory information, the only being remaining is the mind. This mind, distinct from any physical property, exists in and of itself. Descartes' cogito ("I am; I exist") begins as the sole knowledge which he possesses. Defining further, Descartes notes he is "a thing which thinks", which is "a thing which doubts, understands, conceives, affirms, denies, wills, refuses, imagines, and feels". In this same vein, he can now be assured he exists, in that at any point he doubts his own existence, he knows he must exist to do the doubting.

Descartes' notion of knowledge also includes the existence of God, which he reasons to through a couple of arguments. Firstly, Descartes contains within him the idea of a perfect being. He asserts also that the cause of this idea must have as much formal reality as the idea itself. Since he is not perfect, he could not have created this idea, and therefore this perfect God-being exists externally. Descartes creates a variety of arguments to prove the existence of God, but for his further notions of knowledge they are altogether inconsequential; only one proof is necessary.

With the absolute knowledge of his own existence and God's existence, Descartes' notion of knowledge expands and becomes extremely workable. God's existence rules out any sort of evil deceiver, as God would not allow Descartes to be deceived in such a manner. Simultaneously, it is now absolute knowledge that some form of corporeal objects exists, as these ideas in Descartes; mind are involuntary and must come from some outside source.

Descartes' notion of knowledge is justified primarily through his belief in the existence of God. Before reasoning a proof of God's existence, the only absolute knowledge available was the existence of the self. This sort of solipsism presented by Descartes' Meditation I allows no certainty for the existence of corporeal objects, other minds and beings, literally anything outside of the mind itself. By proving the existence of God, however, Descartes opens a world of possibilities in knowledge. He knows, at the very least, that his perceptions are not entirely deceptions, as God created him with the nature to assume his perceptions are at least somewhat accurate, and it would be deceitful for this perceived reality to be nonexistent. This notion, however, is still limited by