Study as though you cannot catch up to it, and as though you fear you are going to lose it.

When you breathe, you inspire, and when you do not breathe, you expire.

Shall I tell you what knowledge is? It is to know both what one knows and what one does not know.

If a superior man abandon virtue, how can he fulfil the requirements of that name?

I used to listen to what others said, and expect them to act accordingly. But nowadays, I listen to what they say, and then observe what they do.

All wisdom is rooted in learning to call things by the right name. When things are properly identified, they fall into natural categories and understanding becomes orderly.

To err and not reform, this may indeed be called error.