"The only security against total error is discussion."

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

"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."

"War is an ugly thing, but not the ugliest of things: the decayed and degraded state of moral and patriotic feeling which thinks that nothing is worth war, is much worse."

"The sole end for which mankind are warranted, individually or collectively, in interfering with the liberty of action of any of their number, is self-protection."