Rene Descartes (1596-1650), founder of Analytical Geometry and Modern Philosophy
“I have always been of the opinion that the two questions respecting God and the Soul were the chief of those that ought to be determined by help of Philosophy rather than of Theology; for although to us, the faithful, it be sufficient to hold as matters of faith, that the human soul does not perish with the body, and that God exists, it yet assuredly seems impossible ever to persuade infidels of the reality of any religion, or almost even any moral virtue, unless, first of all, those two things be proved to them by natural reason. And since in this life there are frequently greater rewards held out to vice than to virtue, few would prefer the right to the useful, if they were restrained neither by the fear of God nor the expectation of another life.” (Descartes 1901).
2. “It is absolutely true that we must believe in God, because it is also taught by the Holy Scriptures. On the other hand, we must believe in the Sacred Scriptures because they come from God.” (Descartes 1950, Letter of Dedication).
3. “And thus I very clearly see that the certitude and truth of all science depends on the knowledge alone of the true God, insomuch that, before I knew him, I could have no perfect knowledge of any other thing. And now that I know him, I possess the means of acquiring a perfect knowledge respecting innumerable matters, as well relative to God himself and other intellectual objects as to corporeal nature.” (Descartes 1901, Meditation V).