Love should be a tree whose roots are deep in the earth, but whose branches extend into heaven.

The harm that theology has done is not to create cruel impulses, but to give them the sanction of what professes to be lofty ethic, and to confer an apparently sacred character upon practices which have come down from more ignorant and barbarous times.

Science, in its ultimate ideal, consists of a set of propositions arranged in a hierarchy, the lowest level of the hierarchy being concerned with particular facts, and the highest with some general law, governing everything in the universe. The various levels in the hierarchy have a two-fold logical connection, travelling one up, one down; the upward connection proceeds by induction, the downward by deduction.

Citizens as conceived by governments are persons who admire the status quo and are prepared to exert themselves for its preservation. Oddly enough, while all governments aim at producing men of this type to the exclusion of all other types, their heroes in the past are of exactly the sort that they aim at preventing in the present. Americans admire George Washington and Jefferson, but imprison those who share their political opinions.

No nation was ever so virtuous as each believes itself, and none was ever so wicked as each believes the other.

Men who are unhappy, like men who sleep badly, are always proud of the fact.

[Industrialism's soon diminishing] capacity to supply human needs could be prevented if men exercised any restraint or foresight in their present frenzied exploitation.