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

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’.

Philosophy is written in this grand book, the universe, which stands continually open to our gaze.

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

Philosophy is written in this grand book, the universe, which stands continually open to our gaze.

We see only the simple motion of descent, since that other circular one common to the Earth, the tower, and ourselves remains imperceptible.

What greater stupidity can be imagined than that of calling jewels, silver, and gold “precious,” and earth and soil “base”?

I do not know what to say in a case so surprising, so unlooked for and so novel.