The mind of the scholar, if you would have it large and liberal, should come in contact with other minds. It is better that his armor should be somewhat bruised by rude encounters even, than hang forever rusting on the wall.
That was the birth of sin. Not doing it, but KNOWING about it. Before the apple, [Adam and Eve] had shut their eyes and their minds had gone dark. Now, they peeped and pried and imagined. They watched themselves.
Whereas young people become accomplished in geometry and mathematics, and wise within these limits, prudent young people do not seem to be found. The reason is that prudence is concerned with particulars as well as universals, and particulars become known from experience, but a young person lacks experience, since some length of time is needed to produce it.
We assume a common sense as the necessary condition of the universal communicability of our knowledge, which is presupposed in every logic and every principle of knowledge that is not one of skepticism.
Error has made man so deep, sensitive, and inventive that he has put forth such blossoms as religions and arts. Pure knowledge could not have been capable of it.
We have not the reverent feeling for the rainbow that the savage has, because we know how it is made. We have lost as much as we gained by prying into that matter.
The true bounds and limitations, whereby human knowledge is confined and circumscribed,... are three: the first, that we do not so place our felicity in knowledge, as we forget our mortality: the second, that we make application of our knowledge, to give ourselves repose and contentment, and not distates or repining: the third, that we do not presume by the contemplation of Nature to attain to the mysteries of God.
If I had an hour to solve a problem and my life depended on the solution, I would spend the first 55 minutes determining the proper question to ask, for once I know the proper question, I could solve the problem in less than five minutes.
We have no organ at all for knowledge, for truth: we know (or believe or imagine) precisely as much as may be useful in the interest of the human herd, the species: and even what is here called usefulness is in the end only a belief, something imagined and perhaps precisely that most fatal piece of stupidity by which we shall one day perish.
Thoughts without content are empty, intuitions without concepts are blind... The understanding can intuit nothing, the senses can think nothing. Only through their union can knowledge arise.