I had been assured I could acquire a clear and certain knowledge of all that is useful in life. I had an extreme desire to learn them. But as soon as I had completed the course of study, at the end of which one is usually received into the rank of the learned, I entirely changed my opinion. For, I found myself embarrassed by so many doubts and errors, that I thought I had gained nothing else from trying to instruct myself, than to have more and more discovered my ignorance. I had learnt all that others learnt; - I had run through every book treating of such matters - that I could lay hands on - I did not see that I was deemed inferior - my own times appeared to me as fertile of good wits as any that had gone before. All of which made me think that there was in the world no such learning as I had been led to hope for. I took pleasure, above all, in mathematics, because of the certainty and the absoluteness of its reasons; but I had not yet found out its true use; and, thinking that it served only for the mechanical arts, was astonished that, its foundations being so firm and solid, nothing had ever been built on them that was more exalted. Concerning philosophy I will say nothing, except that, seeing it had been cultivated by the most powerful minds that had lived for many centuries, and that nevertheless there was not yet to be found in it one single thing which is not disputed, and therefore open to doubt, I had not the presumption to hope that I should succeed better than others; and considering how many different opinions there are, touching one and the same matter, all of which are maintained by learned persons, while it was impossible that more than one of them could be true, I regarded as little better than false everything that was merely probable. Then for the sciences, since they all borrow their principles from philosophy, I judged that nothing solid could have been built on foundations so far from secure.