凡事天下要考察有无的原则,必定是以众人的耳目所见所闻的实情以知有与无来作为标准的。
The teacher who is indeed wise does not bid you to enter the house of his wisdom but rather leads you to the threshold of your own mind.
解释:冬天不洗冰水,并不是吝惜冰;夏天不烤火,也不是舍不得火。而是因为这样做对身体不适宜。