"

El sabio puede cambiar de opinión. El necio, nunca.

"

But, though all our knowledge begins with experience, it by no means follows that all arises out of experience.

"

In every department of physical science there is only so much science, properly so-called, as there is mathematics.

"

An age cannot bind itself and ordain to put the succeeding one into such a condition that it cannot extend its (at best very occasional) knowledge , p...more

"

An age cannot bind itself and ordain to put the succeeding one into such a condition that it cannot extend its (at best very occasional) knowledge , p...more

"

Two things fill the mind with ever new and increasing admiration and awe, the more often and steadily we reflect upon them: the starry heavens above m...more

"

That all our knowledge begins with experience there can be no doubt. For how should the faculty of knowledge be called into activity, if not by object...more

"

I had to deny knowledge in order to make room for faith.

"

(On the seeming futility of metaphysics) Why then has nature afflicted our reason with the restless striving for such a path, as if it were one of rea...more

"

Philosophical knowledge is knowledge which reason gains from concepts mathematical knowledge is knowledge which reason gains from the construction of ...more

"

...Reason should take on anew the most difficult of all its tasks, namely, that of self-knowledge, and to institute a court of justice, by which reaso...more

"

[At the beginning of modern science], a light dawned on all those who study nature. They comprehended that reason has insight only into what it itself...more

"

All our knowledge begins with the senses, proceeds then to the understanding, and ends with reason. There is nothing higher than reason.

"

...[P]hysics... [is] the philosophy of nature, so far as it is based on empirical laws.

"

...[M]oral instruction, although containing much that is convincing for the reason, ...accomplishes... little... [because] the teachers themselves hav...more