 From my childhood I have been nourished upon letters, and because I was persuaded that by their means one could acquire a clear and certain knowledge of all that is useful in life, I was extremely eager to learn them. But as soon as I had completed the course of study at the end of which one is formally admitted to the ranks of the learned, I completely changed my opinion. I had found myself beset by so many doubts and errors that I came to think I had gained nothing from my attempts to become educated but increasing recognition of my ignorance. (Descartes 1637 [PWD: 112–113])