Celsus could never have spoken it as a physician, had he not been a wise man withal, when he giveth it, for one of the great precepts of health and lasting, that a man do vary, and interchange contraries; but with an inclination to the more benign extreme: use fasting, and full eating, but rather full eating; watching and sleep, but rather sleep;sitting, and exercise, but rather exercise; and the like.
 

塞尔撒斯教人养生长寿之道，最要的一端就是一个人应当把各种相反的习惯都变换着练习练习，但是在轻重之间却应当稍重那有益于人的一端；禁食与饱食都应当练习，但是宁可稍重饱食；警醒与睡眠都应当练习，但是宁可偏尚睡眼；安坐与运动都应当练习，但是宁可着重运动；诸如此类。