Theory of Good Human Nature
- hidet77
- Sep 17
- 3 min read
The foundation of the Toyota Production System is built on the Theory of Good Human Nature.
Kaneyoshi Kusunoki
Mr. Kusunoki is a key figure at Toyota who helped develop the Toyota Production System. He led TPS efforts after Ohno and Suzumura left. Without him, TPS wouldn't be organized the way it is or as successful. His contributions deserve more recognition.
He passed away on September 16, 2020.
The above quote is from one of the interviews with Mr. Ikebuti, another leader of Toyota.
“People will work since they don’t want to stop due to their responsibilities.” Because of such a theory of good nature, I think we gave the authority to stop the line to the worker. “Raise your hands if you don’t feel well. The team leader will substitute.” When there's nothing you can do, stopping the line is about respecting humans. When there is a defect, if you stop the line, we can fix it easily. When it is a complete vehicle, it is hard to find the defect, and the repair is complex. If we detect early, with the small lot size, we can definitely countermeasure. Yet, we often hear that other companies claim they don’t know when it started to go wrong. By allowing workers to stop the line, all aspects, including productivity, humanity, and quality control, move in the right direction. By stopping the line, the problems become apparent. By repeating Kaizen, we ultimately built a line with a strong constitution that doesn’t stop the line. Additionally, the repair rate was reduced, and the quality of the produced vehicles improved. I think the base of the Toyota production system is the theory of good human nature, human trust. Without the theory of good human nature at the base, we won't permit the workers to stop the line or develop management by sight with humans as the main constituent. The fact that this theory serves as the basis, the public does not fully understand.”
Society of Automotive Engineers of Japan, Inc. (1997, December). Production technology development and the Toyota Production System, Kaneyoshi Kusukoki
This “Theory of Good Human Nature” has been a topic of debate since the early days of Confucianism. I briefly discussed virtue and law in this post. However, the debate between the theory of good human nature and the theory of evil human nature involves many misunderstandings.
The theory of good human nature was started by Mencius (BC 371-289). He claimed that although there are bad people, human nature is good 【善】. He left a famous phrase, everybody has unhideable human hearts【不忍人之心】. He also highlighted the four signs of the heart【四端の心】. Those four are:
🔹 Sokuon 【惻隠】; heart to care about others
🔹 Shuo 【羞悪】; heart to be ashamed and hate the evil
🔹 Jijyou 【辞譲】; humble and respect
🔹 Zehi 【是非】; Capability to judge good and bad
People have these four hearts; therefore, we need to strengthen them through training. Evil originates from the environment.
The opposing theory, the theory of evil human nature, was proposed by Xunzi (BC 313-238). He argued that human nature is driven by greed. However, he believed that goodness is something learned from the environment and develops over time. He calls this artificial 【偽】. Therefore, this school focused on law and etiquette.
The interesting part of this discussion is that neither side denies the existence of good and evil. Both emphasize the importance of education and training. Another factor is the environment. Instead, this debate highlights the significance of education and the environment.
A factory started punishing workers for producing defects. The result? Internal defects disappeared. However, the company's reputation suffered greatly. Although extreme, many companies also try to pressure workers similarly. “Don’t stop the line. Don’t make defects. Termination is an option. No training since it is costly. Team leader to help is costly, too. Actually, don’t even think about help.” What kind of environment is this? And putting a light and calling it an Andon in such an environment does more harm than good. As a worker said, “I got yelled at for turning that switch on.”
TPS believes that people care for and respect each other. We understand that everyone wants to do their best. People can judge what is right or wrong. Whether that is from nature or the environment does not matter. It is essential to create a system that encourages this kind of thinking. Many TPS philosophies, like Andon, rely on this basic mindset. An Andon light without support, words of care and gratitude, and an opportunity to stop and understand problems do not promote good human qualities. In fact, if every part of this system were used without this belief in good human nature, it could be harmful.