Descartes success and work was mainly based on the principle of cogito which proved to be a turning point in the history of modern philosophy in which both principles and tasks of philosophy were modified: consequently, a question of possibility and conditions of knowledge was prior to understanding the nature of things. Descartes success was closely interwoven with the principle of cogito which as the forefront of the philosophical process was represented with a knowing subject and its ability to provide a completely obvious and reliable foundation for all knowledge.
“Reflections” of Descartes were a systematic attempt to exclude any opinion, which was not admitted solely on the basis of some authority – in other words, he encouraged people to work out their own ways of thinking which would be based on one undeniable fact – the fact of cogito. On this fact, used as a criterion of clear and distinct ideas, Descartes elevated system of reliable knowledge, “universal mathematics”, all provisions of which were deduced from the original intellectual intuition. A solid foundation of Descartes’ “universal mathematics” is pure consciousness, free from sensual components, access to which is provided by the methodical procedures doubt. Therefore, it can be proved that Descartes was successful in finding and proving his beliefs. Justifying the method of doubt, Descartes points to everyday sensory experience of the world. He proved that only real things in everyday life were not under doubt: the ones which could be touched or seen. Hence, mind finds nothing absolutely reliable. Any statements, even those that seem to be the most reliable have no guarantee of their truth as illusion often leads to a mismatch between our thoughts and objects of thought, things that are beyond the reach of consciousness.
What is more, the success of Descartes shows that doubt as a method of Descartes philosophy has not practical, but a theoretical value. Apart from this, his approach has a positive, but not a negative sense. In other words, doubting, a meditating philosopher makes a turn to the mind every time, making it an object of thought which is not approved with characteristics of true or false, but with his own cogito – the source of any allegations and assessments. Universal doubt, in other words the one which can be subjected to all the conscious experience, does not eliminate the latter. On the contrary, it relates to the beginning or base, establishing evidence as cogito – the first obvious statement and the first direct object.
Thus, the criterion of truth is drawn by Descartes from the evidence of subjective experiences as any provision that is as obvious in one’s own thinking of a being as true: “Everything I perceive very clearly and distinctly is true”. The success of Descartes is evidently huge since opening of the fundamental basis of truth has affected all European philosophy, defining the absolute primacy of a person subjected to the New Age of science, as well as the orientation of a subject in the scientific and theoretical knowledge of the world. Therefore, Descartes was a successful mathematician and a philosopher who created a new philosophy, mounting it on a secure foundation of indubitable knowledge. He was completely dissatisfied with the whole body of knowledge which he acquired in college, so he wanted to review all historical tradition, but unlike Bacon he referred not to experience, but to the mind. Another proof of Descartes success is the fact that his circle of friends going on a community of interests later evolved into the Academy of Sciences of France. Moreover, as a creator of modern algebra and analytic geometry, and one of the founders of mechanics, Descartes proved undeniable truth: “I think, therefore I exist”. It is impossible to question such obvious truths so his success is just as undeniable as his statements.