In work we act under the predominant motive of external, rational necessities; in pleasure, under the predominant motive of other, equally general necessities of human nature. Rest or recreation is the element in which the personality seeks to renew its strength from these stimuli that exhaust the reserve of human resources. It's an element introduced into life by the person himself.

What Is to Be Done? (ed. Cornell University Press, 1989) - ISBN: 9780801495472