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.

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.

It is not that pearls fetch a high price because men have dived for them; but on the contrary, men have dived for them because they fetch a high price.

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

To know your ruling passion, examine your castles in the air.

The Eastern monarch who proclaimed a reward to him who should discover a new pleasure, would have deserved well of mankind had he stipulated that it should be blameless.

He only is exempt from failures who makes no efforts.