Thought is merciless to privilege, established institutions, and comfortable habit.

When you meet with opposition, even if it should be from your husband or your children, endeavor to overcome it by argument and not by authority, for a victory dependent upon authority is unreal and illusory.

Faith: a firm belief for which there is no evidence.

One of the most interesting and harmful delusions to which men and nations can be subjected is that of imagining themselves special instruments of the Divine Will.

The human animal, like others, is adapted to a certain amount of struggle for life [and] the mere absence of effort from his life removes an essential ingredient of happiness. [. . .] He forgets that to be without some of the things you want is an indispensable part of happiness.

To expect a personality to survive the disintegration of the brain is like expecting a cricket club to survive when all of its members are dead.

The human heart as modern civilization has made it is more prone to hatred than to friendship. And it is prone to hatred because it is dissatisfied.