"Seek the lost mind"... This is a saying of Mencius’s. It means that one should seek out the lost mind and return it to himself.
If a dog, cat, or cock has escaped and run off to some other place, one will look for it and return it to his house. Likewise, when the mind, the master of the body, has gone off on a wicked path, why do we not seek after it and restore it to ourselves? This is certainly most reasonable.
But there is also a saying of Shao K’ang-chieh’s that goes, “It is essential to lose the mind.” This is quite different. The general drift is that when the mind is tied down, it tires, and like the cat, is unable to function as it should. If the mind does not stop with things, it will not be stained by them and will be used well. Let it alone to run off wherever it will.
Because the mind is stained and stopped by things, we are warned against letting this happen, and are urged to seek after it and to return it to ourselves. This is the very first stage of training. We should be like the lotus which is unstained by the mud from which it rises. Even though the mud exists, we are not to be distressed by this. One makes his mind like the well-polished crystal that remains unstained even if put in the mud. He lets it go where it wishes.
The effect of tightening up on the mind is to make it unfree. Bringing the mind under control is a thing done only in the beginning. If one remains this way all through life, in the end he will never reach the highest level. In fact, he will not rise above the lowest.
When one is in training, it is good to keep Mencius’s saying, “Seek the lost mind,” in mind. The ultimate, however, is within Shao K’ang-chieh’s, “It is essential to lose the mind.”
Among the sayings of the priest Chung-fēng was, “Be in possession of a mind that has been let go of.” The meaning of this is exactly the same as Shao K’ang-chieh’s dictum saying that we should let go of the mind. Its significance is in warning us not to search for the lost mind or to tie it down in one place.
Chung-fēng also said, “Make no provision for retreat.” This means to have a mind that will not be altered. It means that a man should be mindful that, although he advance well once or twice, he should not retreat when tired or in unusual circumstances.