It is clear that thought is not free if the profession of certain opinions makes it impossible to earn a living.

... mathematical knowledge ... is, in fact, merely verbal knowledge. "3" means "2+1", and "4" means "3+1". Hence it follows (though the proof is long) that "4" means the same as "2+2". Thus mathematical knowledge ceases to be mysterious.

The universe may have a purpose, but nothing we know suggests that, if so, this purpose has any similarity to ours.

The wise man thinks about his troubles only when there is some purpose in doing so; at other times he thinks about other things, or, if it is night, about nothing at all.

The use of self control is like the use of brakes on train. It is useful when you find yourself in wrong direction but merely harmful when the direction is right

Life and hope for the world are to be found only in the deeds of love.

For my part I distrust all generalizations about women, favorable and unfavorable, masculine and feminine, ancient and modern; all alike, I should say, result from paucity of experience.