Left is the reformist school at that time. Like Li Hongzhang, he is a supporter of the slogan "Learn from foreigners to control foreigners". He founded Fuzhou Shipping Bureau, participated in the movement to suppress the Taiping Heavenly Kingdom, and recovered a lot of land for the Qing government. He was one of the important ministers in the late Qing Dynasty.

As for how to evaluate it, objectively speaking, some views of the Westernization School have made great progress than those of the conservative people at that time. At least they saw the progress of the west and tried to turn it into their own use, making a useful attempt (Fuzhou Shipping Bureau). In addition, Zuo and others also made great contributions to national reunification and recovered many territories.

However, living in that era will inevitably have historical limitations. After all, the left still maintained the decadent rule of the Qing Dynasty. People like Zuo, no matter how capable and talented they are, can't avoid the decline of the Qing government. What they did at most was to mend the cracks in the Qing Dynasty and even feudalism.