Many a man will have the courage to die gallantly, but will not have the courage to say, or even to think, that the cause for which he is asked to die is an unworthy one.

Morality in sexual relations, when it is free from superstition, consists essentially in respect for the other person, and unwillingness to use that person solely as a means of personal gratification, without regard to his or her desires.

Man needs, for his happiness, not only the enjoyment of this or that, but hope and enterprise and change.

There are two motives for reading a book; one, that you enjoy it; the other, that you can boast about it.

When all experts agree, you need to watch out.

I conclude that, while it is true that science cannot decide questions of value, that is because they cannot be intellectually decided at all, and lie outside the realm of truth and falsehood. Whatever knowledge is attainable, must be attained by scientific methods; and what science cannot discover, mankind cannot know.

I used, when I was younger, to take my holidays walking. I would cover 25 miles a day, and when the evening came I had no need of anything to keep me from boredom, since the delight of sitting amply sufficed.