What light is to the eyes - what air is to the lungs - what love is to the heart, liberty is to the soul of man.

Hope is the only universal liar who never loses his reputation for veracity.

You cannot show real respect to your parents by perpetuating their errors.... Do you consider that the inventor of a steel plow cast a slur upon his father who scratched the ground with a wooden one? I do not consider that an invention by the son is a slander upon the father; I regard each invention simply as an improvement; and every father should be exceedingly proud of an ingenious son. If Mr. Talmage has a son, it will be impossible for him to honor his father except by differing with him.

To avoid pain we must know the conditions of health. For the accomplishment of this end we must rely upon investigation instead of faith, upon labor in place of prayer. Most misery is produced by ignorance. Passions sow the seeds of pain.

If the reason I give is a good one, you will act upon it. If it is a bad one I cannot make it better by piling epithet upon epithet. There is no logic in abuse; there is no argument in an epithet.

Science built the Academy, superstition the Inquisition.

The first step is for man to cease to be the slave of man. The second, is to cease to be the slave of the monsters of his own creation, the ghosts and phantoms of the air.