Guiguzi’s classic sayings are as follows:

1. The world is impermanent, and everything is impermanent. From "Guiguzi·Disobedience".

Translation: There is no eternal noble thing in the world, and there is no eternal teacher in doing things. Everything in the world changes, and so does people's understanding.

2. The way of a saint is yin, and the way of a fool is yang. From "Guiguzi·Mou Chapter 10".

Translation: The principle of a sage's strategy is to know it well but not to show it, while the principle of a fool's strategy is to show it without knowing it.

3. Knowing oneself begins with knowing oneself, and then knowing others. From "Guiguzi·Reaction".

Translation: To understand others, start with yourself. Only after you understand yourself can you understand others. This sentence is intended to illustrate that if you want to understand others, you must first understand yourself. If you fail to do this, everything will be out of the question. To know yourself is not something that happens overnight. It requires continuous accumulation and reflection, timely discovery of your own shortcomings and mistakes, and learning from each other's strengths to make up for your own shortcomings, in order to achieve success.

4. Those who get rid of it indulge it, and those who indulge it take advantage of it. From "Guiguzi·Mou Chapter 10".

Translation: If you want to get rid of him, you must indulge him, and when the conditions are ripe, take the opportunity to get rid of him in one fell swoop.

5. Appearance is neither beautiful nor evil, so it is very affectionate. From "Guiguzi·Mou Chapter 10".

Translation: Observe a person who is displeased when he sees good and does not criticize when he sees evil. He is an emotional person and can be entrusted with confidential matters.