Credulity is always a ridiculous, often a dangerous failing: it has made of many a clever man, a fool; and of many a good man, a knave.

Religion may be defined thus: a belief in, and homage rendered to, existences unseen and causes unknown.

Instead of establishing facts, we have to overthrow errors; instead of ascertaining what is, we have to chase from our imaginations what is not.

the language of truth is too simple for inexperienced ears.

... we have broken down the self-respecting spirit of man with nursery tales and priestly threats, and we dare to assert, that inproportion as we have prostrated our understanding and degraded our nature, we have exhibited virtue, wisdom, and happiness, in our words, our actions, and our lives!

These will vary in every human being; but knowledge is the same for every mind, and every mind may and ought to be trained to receive it.

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.