I have not the hope of being immortal, because the desire of it has not given me that vanity.

The first promise exchanged by two beings of flesh was at the foot of a rock that was crumbling into dust; they took as witness for their constancy a sky that is not the same for a single instant; everything changed in them and around them, and they believed their hearts free of vicissitudes. O children! always children!

If you disturb the colors of the rainbow, the rainbow is no longer beautiful.

I feel, I think, I judge; therefore, a part of organized matter like me is capable of feeling, thinking, and judging.

This root [the potato], no matter how much you prepare it, is tasteless and floury. It cannot pass for an agreeable food, but it supplies a food sufficiently abundant and sufficiently healthy for men who ask only to sustain themselves. The potato is criticized with reason for being windy, but what matters windiness for the vigorous organisms of peasants and laborers?

All things must be examined, debated, investigated without exception and without regard for anyone's feelings.

Those who fear the facts will forever try to discredit the fact-finders.