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.

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 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.

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

Under the freest constitution ignorant people are still slaves.

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

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.