Learning hath his infancy, when it is but beginning and almost childish; then his youth, when it is luxuriant and juvenile; then his strength of years, when it is solid and reduced; and lastly, his old age, when it waxeth dry and exhaust.

学问也有幼年，初生时近乎稚嫩；继而是青春，繁茂而富有朝气；然后进入壮年，扎实而精练；最后步入老年，渐渐枯竭。