the mode of delivering a truth makes, for the most part, as much impression on the mind of the listener as the truth itself.

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.

An opinion, right or wrong, can never constitute a moral offense, nor be in itself a moral obligation. It may be mistaken; it may involve an absurdity, or a contradiction. It is a truth; or it is an error: it can never be a crime or a virtue.

Credulity is always ridiculous.

You have heard of, and studied various systems of philosophy; but real philosophy is opposed to all systems.

If we bring not the good courage of minds covetous of truth, and truth only, prepared to hear all things, and decide upon all things, according to evidence, we should do more wisely to sit down contented in ignorance, than to bestir ourselves only to reap disappointment.

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.