"I think, therefore I am" vs. "As a man thinks in his heart, so is he." - René Descartes

For ’tis not enough to have good faculties, but the principal is, to apply them well.

...the perusal of all excellent books is, as it were, to interview with the noblest men of past ages, who have written them.

But as soon as I had finished my course of study, at which time it is usual to be admitted to the ranks of the well educated, I completely changed my opinion, for I found myself bogged down in so many doubts and errors, that it seemed to me that having set out to become learned, I had derived no benefit from my studies, other than that of progressively revealing to myself how ignorant I was.