“How then is perfection to be sought? Wherein lies our hope? In education, and in nothing else.”

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

“Skepticism is thus a resting-place for human reason, where it can reflect upon its dogmatic wanderings and make survey of the region in which it finds itself, so that for the future it may be able to choose its path with more certainty. But it is no dwelling-place for permanent settlement. Such can be obtained only through perfect certainty in our knowledge, alike of the objects themselves and of the limits within which all our knowledge of objects is enclosed.”

“By a lie a man throws away and as it were annihilates his dignity as a man”

“Nothing is divine but what is agreeable to reason.”

“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 , purify itself of errors, and progress in general enlightenment. That would be a crime against human nature, the proper destination of which lies precisely in this progress and the descendants would be fully justified in rejecting those decrees as having been made in an unwarranted and malicious manner.The touchstone of everything that can be concluded as a law for a people lies in the question whether the people could have imposed such a law on itself.”

“One age cannot bind itself, and thus conspire, to place a succeeding one in a condition whereby it would be impossible for the later age to expand its knowledge (particularly where it is so very important), to rid itself of errors, and generally to increase its enlightenment. That would be a crime against human nature, whose essential destiny lies precisely in such progress; subsequent generations are thus completely justified in dismissing such agreements as unauthorized and criminal. The criterion of everything that can be agreed upon as a law by a people lies in this question: Can a people impose such a law on itself?”