To have passed through life and never experienced solitude is to have never known oneself. To have never known oneself is to have never known anyone.

Metaphysics may be, after all, only the art of being sure of something that is not so and logic only the art of going wrong with confidence.

Every time a value is born, existence takes on a new meaning; every time one dies, some part of that meaning passes away.

It is disastrous to own more of anything than you can possess, and it is one of the most fundamental laws of human nature that our power actually to possess is limited.

We have not merely escaped from something but into something... We have joined the greatest of all communities, which is not that of man alone but of everything which shares with us the great adventure of being alive.

We must not judge the society of the future by considering whether or not we should like to live in it; the question is whether those who have grown up in it will be happier than those who have grown up in our society or those of the past.

Science has always promised two things not necessarily related; an increase first in our powers, second in our happiness or wisdom, and we have come to realize that it is the first and less important of the two promises which it has kept most abundantly.