“I have never met a man so ignorant that I couldn’t learn something from him.”

In the sciences, the authority of thousands of opinions is not worth as much as one tiny spark of reason in an individual man.

Mathematics is the key and door to the sciences.

The sun, with all those planets revolving around it and dependent on it, can still ripen a bunch of grapes as if it had nothing else in the universe to do.

Nature does not act by means of many things when it can do so by means of a few.

It is a beautiful and delightful sight to behold the body of the Moon.

The deeper I go in considering the vanities of popular reasoning, the lighter and more foolish I find them.

Passion is the genesis of genius.

Earth, turning upon itself, moves round the Sun.

I do not feel obliged to believe that the same God who has endowed us with senses, reason, and intellect has intended us to forego their use.

You cannot teach a man anything, you can only help him find it within himself.

All truths are easy to understand once they are discovered; the point is to discover them.

Two truths cannot contradict one another.

I am certainly interested in a tribunal in which, for having used my reason, I was deemed little less than a heretic.

In time you may discover everything that can be discovered, and still your progress will only be progress away from humanity.

That sculpture is more admirable than painting for the reason that it contains relief and painting does not is completely false.

See now the power of truth; the same experiment which at first glance seemed to show one thing, when more carefully examined, assures us of the contrary.

It is better to be silent, than to dispute with the Ignorant.

When proven wrong, the wise man will correct himself and the ignorant will keep arguing.

Nobody is qualified to become a statesman who is entirely ignorant of the problem of wheat.

It isn’t so much that liberals are ignorant. It’s just that they know so many things that aren’t so.

The more dependent you are, the more ignorant you must be, and that’s how they want you.

If the history-deniers who doubt the fact of evolution are ignorant of biology, those who think the world began less than ten thousand years ago are worst than ignorant, they are the deluded to the point of perversity.

When ignorant folks want to advertise their ignorance, you don’t really have to do anything, you just let them talk.

No people can be both ignorant and free.