“By denying scientific principles, one may maintain any paradox.”

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.

The Divine intellect indeed knows infinitely more propositions.

To be humane, we must ever be ready to pronounce that wise, ingenious and modest statement ‘I do not know’.

The most effective way to destroy people is to deny and obliterate their own understanding of their history.

Pain is only bearable if we know it will end, not if we deny it exists.

The state controlling a woman would mean denying her full autonomy and full equality.

The marriage institution cannot exist among slaves, and one sixth of the population of democratic America is denied it’s privileges by the law of the land.

Those who deny freedom to others, deserve it not for themselves.

It is downright mockery to talk to women of their enjoyment of the blessings of liberty while they are denied the use of the only means of securing them provided by this democratic-republican government: the ballot.

Reason is not automatic. Those who deny it cannot be conquered by it. Do not count on them. Leave them alone.

He who denies the existence of God, has some reason for wishing that God did not exist.