[About Pierre de Fermat] It cannot be denied that he has had many exceptional ideas, and that he is a highly intelligent man. For my part, however, I have always been taught to take a broad overview of things, in order to be able to deduce from them general rules, which might be applicable elsewhere.
Rene DescartesI concluded that I might take as a general rule the principle that all things which we very clearly and obviously conceive are true: only observing, however, that there is some difficulty in rightly determining the objects which we distinctly conceive.
Rene DescartesIf I go for the alternative which is false, then obviously I shall be in error; if I take the other side, then it is by... chance that I arrive at the truth, and I shall still be at fault.... In this incorrect use of free will may be found the privation which constitutes the essence of error.
Rene DescartesBefore examining this more carefully and investigating its consequences, I want to dwell for a moment in the contemplation of God, to ponder His attributes in me, to see, admire, and adore the beauty of His boundless light, insofar as my clouded insight allows. Believing that the supreme happiness of the other life consists wholly of the contemplation of divine greatness, I now find that through less perfect contemplation of the same sort I can gain the greatest joy available in this life.
Rene Descartes... regard this body as a machine which, having been made by the hand of God, is incomparably better ordered than any machine that can be devised by man, and contains in itself movements more wonderful than those in any machine. ... it is for all practical purposes impossible for a machine to have enough organs to make it act in all the contingencies of life in the way in which our reason makes us act.
Rene Descartes