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.

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.

... the yearly expenses of the existing religious systemexceed in these United States twenty millions of dollars. Twenty millions! For teaching what? Things unseen and causes unknown!... Twenty millions would more than suffice to make us wise; and alas! do they not more than suffice to make us foolish?

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.

Do we exert our own liberties without injury to others - we exert them justly; do we exert them at the expense of others - unjustly. And, in thus doing, we step from the sure platform of liberty upon the uncertain threshold of tyranny.

Do not confound noise with fame. The man who is remembered, is not always honored.

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