Descartes elevate common basis for doubting beliefs, however he focus his attention mainly to fundamental ground for uncertainty. He first offers the argument dream which translate into doubt even the most clear of beliefs we obtain from our senses for instance current belief such as position of my hands. Descartes then provides us the deceiving God argument which clearly describes doubt not only as belief based on sense but also as belief concerning what we strongly held for example my belief that 2 plus 3 equals to 5.
He resolves to suspend judgment of all the beliefs in which those radical argument relate. Descartes discover that I exist can someway be reclaimed, and that he can also be convinced of claims where he characterized conscious condition to himself. Descartes held himself in the third mediation as informal principle in which effects cannot be greater compare to their causes and at the same time to the supplementary standard such that the justification of an idea must have a formal reality as the only objective reality.
He argues that since he is aware that he exist and has an idea about God, and his conviction that the contributory principles are true, he can be sure that his cause is God, a perfect being. In that case he was certain that his mind was created and hence his clear and dissimilar ideas are also true. According to the fourth and the fifth mediation, Descartes describe several clear and distinctive ideas indicating that he can be convinced that his beliefs in mathematics and some of his beliefs on the world of materials things is true.
At this moment Descartes recognize that he cannot evidently comprehend either the nature of his mind or materials things except when he consider them as completely distinct where mind is nonextended conscious and materials things regarded as nonconscious extended things. There is much on Descartes argument that I think is right. He was unquestionably impressed with the significance of mathematic and observed it was instructive. I am certain he also belief that one is in a better cognitive condition if he or she knows something than the one who had only a reasonable belief. I have no doubt with him when he said that one who poses knowledge must be ready to protect his beliefs against any skeptical attack.