"A person may cause evil to others not only by his actions but by his inaction, and in either case he is justly accountable to them for the injury."

"The only security against error is in the discussion of every subject, with the greatest freedom of speech."

"The despotism of custom is everywhere the standing hindrance to human advancement."

"He who lets the world, or his own portion of it, choose his plan of life for him, has no need of any other faculty than the ape-like one of imitation."

"A person should be free to do as he likes in his own concerns; but he ought not to be free to do as he likes in acting for other people, under the pretext that the affairs of other people are his own …"