王安石

Yes, the second story of Sima Guang is his relation with Wang Anshi. In fact, the story of Sima makes no sense if we do not mention Wang.

The incident was, once again, well known to most of us: The Song empire was weak and faced an immense thread from her neighbours. When appointed by Emperor Shenzong (神宗) as the prime minister, Wang attempted a series of drastic socioeconomic changes - widely known as the Xī Níng Reform (熙寧變法).

Although the intention was good (for example, the Song government was running a huge budget deficit, and Wang proposed a new taxation system - the idea was actually very similar to what the Democrats of the States are now doing), Wang was more or less an idealist and did not pay sufficient attention to work out the practical details of his new system.

And here enter Sima Guang: When the Reform was first announced, he wrote to Wang and suggested the existing system should not be changed so quick and drastically. Unfortunately, self-confidence blinded the eyes of Wang, who considered Sima too old-fashioned and retorted in a lengthy letter. The two of them, used to be good friends with mutual esteem, broke off that and there. The new policies transformed and became a continual political struggle between the reformists and conservatives.

And the rest is history.