"Those who are skilled in archery bend their bow only when they are preparing to use it; when they do not require it, they allow it to remain unbent, for otherwise it would remain unserviceable when the time for using it arrived. So it is with man. If he were to devote himself unceasingly to a dull round of business, without breaking the monotony by cheerful amusements, he would fall imperceptibly into idiocy, or be struck by paralysis"