Probability but no truth, facility but no freedom--it is owing to these two fruits that the tree of knowledge cannot be confused with the tree of life.
It is the mark of an educated mind to rest satisfied with the degree of precision which the nature of the subject admits and not to seek exactness where only an approximation is possible.
An ingenious compound of desirability and appearance. Discovery of truth is the sole purpose of philosophy, which is the most ancient occupation of the human mind and has a fair prospect of existing with increasing activity to the end of time.
Even great spirits have only their five-fingers' breadth of experience - just beyond it their thinking ceases and their endless empty space and stupidity begins.
Don't imagine that you'll discover {the truth} by accumulating more knowledge. Knowledge creates doubt, and doubt makes you ravenous for more knowledge. You can't get full eating this way.
We cannot afford to differ on the question of honesty if we expect our republic permanently to endure. Honesty is not so much a credit as an absolute prerequisite to efficient service to the public. Unless a man is honest, we have no right to keep him in public life; it matters not how brilliant his capacity.