Never argue at the dinner table, for the one who is not hungry gets the best of the argument.

Trust, therefore, for the overcoming of a difficulty, not to long-continued study after you have once become bewildered, but to repeated trials at intervals.

As a science, logic institutes an analysis of the process of the mind in reasoning, and investigating the principles on which argumentation is conducted; as an art, it furnishes such rules as may be derived from those principles, for guarding against erroneous deductions.

Though not always called upon to condemn ourselves, it is always safe to suspect ourselves.

Of metaphors, those generally conduce most to energy or vivacity of style which illustrate an intellectual by a sensible object.

Sophistry, like poison, is at once detected and nauseated, when presented to us in a concentrated form; but a fallacy which, when stated barely in a few sentences, would not deceive a child, may deceive half the world, if diluted in a quarto volume.

When men have become heartily wearied of licentious anarchy, their eagerness has been proportionately great to embrace the opposite extreme of rigorous despotism.