Abstract

In a famous text Descartes has written this:Whenever the thought of God's supreme power occurs to me, I cannot help feeling that he might easily, if he so wished, make me go wrong even in what I think I see most clearly with my mind's eye. On the other hand, whenever I turn to the matters themselves which I think I perceive very clearly, I am so convinced by them that I burst out: ‘let who will deceive me, he can never bring it about that I should be nothing at the time of thinking that I am something, nor that it be true that I never existed if it is true that I exist now; nor even that two and three together make more or less than five, or any such thing in which I see manifest contradiction’.