There is nothing more unequal than the equal treatment of unequal people.

The legitimate powers of government extend to such acts only as are injurious to others. It does me no injury for my neighbor to say there are twenty gods or no god. It neither picks my pocket nor breaks my leg.

I [am] obliged to recur ultimately to my habitual anodyne, "I feel: therefore I exist." I feel bodies which are not myself: there are other existencies then. I call them "matter". I feel them changing place. This gives me "motion". Where there is an absence of matter, I call it "void", or "nothing", or "immaterial space". On the basis of sensation, of matter and motion, we may erect the fabric of all the certainties we can have or need.

But every difference of opinion is not a difference of principle.

I never submitted the whole system of my opinions to the creed of any party of men whatever, in religion, in philosophy, in politics, or in anything else, where I was capable of thinking for myself. Such an addiction is the last degradation of a free and moral agent. If I could not go to heaven but with a party, I would not go there at all.

While wading through the whimsies, the puerilities, and unintelligible jargon of this work [Plato's Republic], I laid it down often to ask myself how it could have been that the world should have so long consented to give reputation to such nonsense as this?

The most fortunate of us, in our journey through life, frequently meet with calamities and misfortunes which may greatly afflict us; and, to fortify our minds against the attacks of these calamities and misfortunes, should be one of the principal studies and endeavors of our lives.

I am myself an empiric in natural philosophy, suffering my faith to go no further than my facts. I am pleased, however, to see the efforts of hypothetical speculation, because by the collisions of different hypotheses, truth may be elicited and science advanced in the end.