Plato and Descartes both concern themselves with the notion of rationalism, though they approach the concept of rationalism and knowledge acquisition on different levels. Of the two Plato makes a much more convincing argument, suggesting that though rational deduction is necessary for knowledge acquisition, sensory perception does play some significant role in one's interpretation of events. His ideas are based on logical supposition. To the rationalist intuition and deduction are necessary to help identify how mankind can believe propositions related to a subject area. Based on this theory intuition becomes a form of "rational insight" whereby all things are knowable or become knowledgeable through intuition and rational deduction (Markie, 2004). Deduction is the process through which people can derive their conclusions via valid argumentation regarding the validity of a given subject area or object. Intuition and deduction according to Descartes and Plato, "provide us with knowledge a priori, which is to say knowledge gained independently of sensory experience" ( Markie, 2004).

             Descartes suggests that much of what mankind knows he knows as a result of information gathered from the senses (Descartes, 1710). Because the senses are not always reliable, it is very likely that people are consistently deceived. As a result, Descartes concludes that it is best that mankind doubt everything perceived through the senses. .

             The argument most valid to both Plato and Descartes is the notion that knowledge can be acquired through rational deduction, whether one relies on God and goodness as Plato suggests as the medium for analysis or whether one relies on purely non sensory intuition as Descartes might suggest. Much of this logic and reasoning is based on objective logical disagreement though personal opinion including that of Descartes and Plato does play a role. Descartes suggests that through careful examination and analysis man can determine what beliefs are valuable and which must be discarded because they are untrustworthy (Med.