To follow imperfect, uncertain, or corrupted traditions, in order to avoid erring in our own judgment, is but to exchange one danger for another.

It may be said, almost without qualification, that true wisdom consists in the ready and accurate perception of analogies. Without the former quality, knowledge of the past is unobstructive: without the latter it is deceptive.

A man will never change his mind if he have no mind to change.

Habits are formed, not at one stroke, but gradually and insensibly; so that, unless vigilant care be employed, a great change may come over the character without our being conscious of any.

As an exercise of the reasoning faculties, pure mathematics is an admirable exercise, because it consists of reasoning alone and does not encumber the student with any exercise of judgment.

Reason can no more influence the will, and operate as a motive, than the eyes which show a man his road can enable him to move from place to place, or that a ship provided with a compass can sail without a wind.

He only is exempt from failures who makes no efforts.