[All phenomena] are equally susceptible of being calculated, and all that is necessary, to reduce the whole of nature to laws similar to those which Newton discovered with the aid of the calculus, is to have a sufficient number of observations and a mathematics that is complex enough.

The penalty of death is the only one that makes an injustice absolutely irreparable from which it follows that the existence of the death penalty implies that one is exposed to committing an irreparable injustice from which it follows that it is unjust to establish it. This reasoning appears to us to have the force of a demonstration.

The truth belongs to those who seek it, not to those who claim to own it.

Enjoy your own life without comparing it with that of another for there will always be others whose lives on the face of it appear better. However just remember and focus on the fact that your life could be much worse and be grateful it isn't. No matter what others or even you may briefly think you are lucky things aren't worse so be grateful.

Under the freest constitution ignorant people are still slaves.

People still retain the errors of their childhood, their nation, and their age, long after they have accepted the truths needed to refute them.

Enjoy your own life without comparing it with that of another.

Enjoy your own life without comparing it with that of another.[or you will create disappointment and envy, as every other person has something, small or large, better than you. Remember at these times what you have rather than what you don't and be grateful]