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.

Men do not often dare to avow, even to themselves, the slow progress reason has made in their minds; but they are ready to follow it if it is presented to them in a lively and striking manner, and forces them to recognize it.

[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.

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

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.

A great man, who was convinced that the truths of political and moral science are capable of the same certainty as those that form the system of physical science, even in those branches like astronomy that seem to approximate mathematical certainty. He cherished this belief, for it led to the consoling hope that humanity would inevitably make progress toward a state of happiness and improved character even as it has already done in its knowledge of the truth.

As the mind learns to understand more complicated combinations of ideas, simpler formulae soon reduce their complexity; so truths that were discovered only by great effort, that could at first only be understood by men capable of profound thought, are soon developed and proved by methods that are not beyond the reach of common intelligence. The strength and the limits of man