In fact, the ancient divorce system had a clear marriage and divorce system as early as Zhou Li. The main form of divorce is "getting married", and on this basis, it is supplemented by "harmony without difference", "righteousness" and "litigation".
Become a wife; This is a way for a man to divorce his wife by force, and it is also the most important way of divorce in ancient society. The book "Big Dai Li" records seven reasons why a man divorces his wife, which is the so-called "Seven Laws": "A woman has seven things to do: disobeying her parents, not having children, going whoring, being jealous, getting seriously ill, gossiping and stealing."
Harmonious divorce: harmonious divorce is a form of divorce after the husband and wife reach an understanding, and no reason is needed. "Zhou Li" has a record of divorce: "Anyone who marries a wife and has children will write it." As mentioned above, in the divorce agreement of the Tang Dynasty, both husband and wife didn't like each other, so life really couldn't go on. Let's discuss it and just leave it alone. This belongs to harmony and difference, and an agreement can fix everything.
One-off: One-off adoption does not necessarily mean that the husband and wife are not in harmony and want to divorce. There are usually some criminal consequences. For example, there is no contradiction between husband and wife, but serious criminal cases have occurred with relatives, such as fighting and even killing and setting fire. In this case, the law will force the couple to divorce, and if they don't leave, they will be punished.