Depend upon it there comes a time when for every addition of knowledge you forget something that you knew before. It is of the highest importance, therefore, not to have useless facts elbowing out the useful ones.
Conversation with a friend will only bear good fruit of knowledge when both think only of the matter under consideration and forget that they are friends.
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.
Not to know what has been transacted in former times is to be always a child. If no use is made of the labors of past ages, the world must remain always in the infancy of knowledge.
Enlightenment is the liberation of man from his self-caused state of minority... Supere aude! Dare to use your own understanding!is thus the motto of the Enlightenment.
To know how little one knows is to have genuine knowledge. Not to know how little one knows is to be deluded. Only those who know when they are deluded can free themselves from such delusion. The intelligent people are not deluded, because they know and accept their ignorance as ignorance, and thereby have genuine knowledge.