“Liberty is the possibility of doubting, the possibility of making a mistake, the possibility of searching and experimenting, the possibility of saying no to any authority - literary, artistic, philosophic, religious, social, and even political.”

“...[C]ontrary to your Earth experience and its derived cynicism, on Mars, such things are possible. Yes, fully possible, even for you, a person who obviously was a complete social failure on Earth--otherwise you wouldn't be here.”

“Free will, though it makes evil possible, also makes possible any love or goodness or joy worth having.”

“It is a very grave mistake to think that the enjoyment of seeing and searching can be promoted by means of coercion and a sense of duty. To the contrary, I believe it would be possible to rob even a healthy beast of prey of its voraciousness, if it were possible, with the aid of a whip, to force the beast to devour continuously, even when not hungry.”

“Freedom is not possible without authority - otherwise it would turn into chaos and authority is not possible without freedom - otherwise it would turn into tyranny.”

“Religious faith is the one species of human ignorance that will not admit of even the possibility of correction.”