What about the rational philosophy it should be noted that it developedmainly on the continent. Its founderís considered the French philosopher Rene Descartes.
Being from the so-called gentlemen of mantle he got an excellent education in the Jesuite College La Fleche, where among other subjects he studied mathematics, the knowledge of which made the decisive impact on all his philosophizing. In order to have enough time for going in for science he subscribed into an army and there conducting a life of officer he could have enjoined scientific investigations in full measure. Besides philosophy he went in for mathematics, physics and medicine. In mathematics till now the suggested by him coordinatesí system (the so-called Descartesí coordinates) is used. During all his life he dreamt also about making a significant medical discovery but did not succeed in this sphere. And thus his main achievements are in the field of philosophy and mathematics. The main cognitive premise of Descartes in philosophy is clearness and obviousness of matter a statement is being made. Thus the truth is obviousness according to him. If a matter isnít clear and obvious it should be cleared up by decomposing it into constituents which would be clear and obvious. The main rules of such clearing are given in his treatise ďRules for managing the reasonĒ. The theses of this book became the common base for all new time rationalistic philosophy.
The proper philosophy of his is expounded in his ďMetaphysical MeditationsĒ, ďMeditations on MethodĒ and some other works. It starts with the declaration that everyone should at least once in his life doubt all he usually before has thought being doubtless. So the world around may be doubted because maybe itís only an illusion, the reality of oneís own body and all material things around, the correctness of mathematicsí grounds may be doubted in the same way (because maybe we have been created by God in that way to err constantly). In short itís necessary to doubt all that only in some way can be doubted and not to doubt only that that canít. What is it? That canít be doubted. This is beforehand that himself who doubts. Itís possible to doubt all and impossible to doubt that who doubts (i.e. oneís own existence). Whence the famous Cartesian dictum ďCogito ergo sumĒ (ďI think therefore I amĒ).
What else canít be doubted? The existence of God canít. Because of the experience of Godís presence being immanent to our consciousness, as an idea of a Supreme All-perfect Essence. It canít be engendered by our consciousness on its own because the Higher canít be given birth by a lower. That means the thoughts of the Supreme are inspired to humans by the Supreme itself. That is this experience isnít from our ego, but from the Supreme or God. This is the so (as itís sometimes called) epistemological proof of Godís existence.
Only the God can be a guarantee of the outer worldís existence as well as our correct cognizing of it. The God canít lead us into errors because heís the All-perfect One and such leading would contradict to his perfection. Thus according to Descartes only a believer in God can go in for science (for unbeliever there is no guarantee and fundamentals for his investigation). Descartes even said he did not understand how an atheist could go in for physics e. g. What are in this case our mistakes from? They are from the incongruity between our reasonís and willís abilities. Our reason is similar to that of God but limited, but our will is unlimited, there is our errors come from.
The world has two main attributes: extent and thinking or material and ideal. This is the famous Cartesian dualism. Bodies are extent, reason and consciousness are not. The extent is a property of matter, which is subordinated to strict deterministic laws of nature. So the bodies are material and the living bodies are like very complex mechanisms managed by souls. The soul is consciousness which isnít material and therefore free. The soul is connected with its body in the field of cerebellum. Thus it turns out that a free soul manages a mechanism-body subordinated to cause-consequence chains existing in nature. This is the main contradiction of the Cartesian philosophy [1, p. 44 Ė 55].