The simplest principles become difficult of practice, when habits, formed in error, have been fixed by time, and the simplest truths hard to receive when prejudice has warped the mind.

Equality is the soul of liberty; there is, in fact, no liberty without it.

the language of truth is too simple for inexperienced ears.

We have ... dreamed so much and observed so little, that our imaginations have grown larger than the world we live in, and our judgments have dwindled down to a point.

There is but one honest limit to the rights of a sentient being; it is where they touch the rights of another sentient being.

All that I say is, examine, inquire. Look into the nature of things. Search out the grounds of your opinions, the for and against. Know why you believe, understand what you believe, and possess a reason for the faith that is in you.

The best road to correct reasoning is by physical science; the way to trace effects to causes is through physical science; the only corrective, therefore, of superstition is physical science.