It is often difficult to fill an active healthy man's leisure. He is bored when not working; he paces the floor like a caged animal and sinks naturally into vices which are merely the means of getting numberless vivid sensations from his body with which to fill his empty hours. Modern civilization, with its inventions and machines, has increased the number of these hours, and we must learn how to use them.
Un Art de Vivre (The Art of Living) (1939) - The Art of Working