One day, Duke Huan of the state of Qi was reading woks by those sages of the past.

Lun Bian, a wheel-maker, believed that these books were just dross（渣滓，碎屑） from the ancients.

To prove his conception, he explained, "It is just like making wheels. If you do it too fast, the mortise and tenon will be too loose and the wheel won't be firm. If you action is too slow, the mortise and tenon will be too taut（拉紧的） and won't be put in. It should be not too fast and not too slow, not too loose and not too taut. The ingenuity of the craftsmanship is not inexpressible in words, but can only be sensed by insight, this is where the subtlety lies, I cannot teach my son this skill and my son cannot receive it from me either. Those ancients have passed a way and those things that could not be taught are also gone. So what is left must be nothing but dross."

一天，齐桓公在读记载了已经去世的圣人言论的书。

制车轮的轮扁却认为这书不过是古人留下的糟粕罢了。

为了证明自己见解的正确，他解释说：“这就像制造车轮一样，动作慢了，卯榫宽松，车轮做得就不牢固；动作快了，卯榫太紧，就装不进去。不慢不快，不松不紧，才能得心应手。这种艺术的精妙是不能言传只能意会的，技术的微妙也正表现在这里。这种技艺，我无法让我儿子了解，我的儿子也无法从我这里接受。古时的人和他们那种无法传授的东西一起死了，所以留下的只能是糟粕。”