I had become aware, as early as my college days, that no opinion, however absurd and incredible can be imagined, that has not been held by one of the… - René Descartes

But immediately upon this I observed that, whilst I thus wished to think that all was false, it was absolutely necessary that I, who thus thought, should be somewhat; and as I observed that this truth, I think, therefore I am (cogito ergo sum), was so certain and of such evidence that no ground of doubt, however extravagant, could be alleged by the sceptics capable of shaking it, I concluded that I might, without scruple, accept it as the first principle of the philosophy of which I was in search … I thence concluded that I was a substance whose whole essence or nature consists only in thinking, and which, that it may exist, has need of no place, nor is dependent on any material thing; so that ‘I’, that is to say, the mind by which I am what I am, is wholly distinct from the body, and is even more easily known than the latter …

That the reading of good books, is like the conversation with the honestest persons of the past age, who were the Authors of them, and even a studyed conversation, wherein they discover to us the best only of their thoughts. That eloquence hath forces & beauties which are incomparable.

was most keen on mathematics, because of its certainty and the incontrovertibility* of its proofs; but I did not yet see its true use. Believing as I did that its only application was to the mechanical arts,* I was astonished that nothing more exalted had been built on such sure and solid foundations; whereas, on the other hand, I compared the moral works of ancient pagan writers to splendid and magnificent palaces built on nothing more than sand and mud.