When Judo was first found it was based on two main principles Seiryoku Zenyo and Jita Kyoei (with this post focusing on the latter). Jita Kyoei is the counterpart to Seiryoku Zenyo. Efficient use of energy is only half the story. What’s also important is what it is used for. Jita Kyoei is often translated as “Mutual Welfare and Benefit”.
The idea of mutual benefit is common in judo with respect being stressed. This can come in many forms from helping others learn to being a good uke or opponent. With cooperation and mutual welfare comes improvements in all aspects of your Judo game. It’s important to stress here that, as mentioned, this applies to opponents also. Opponents should always be treated with respect. Going even further than this you should strive to not take actions that will win you matches using anything other than good judo. Looking for loopholes in the rules or actions that are technically allowed but likely considered unsportsmanlike are definitely against the spirit of Jita Kyoei.
It’s easy to see how this can be applied outside judo and the idea of being nice to your fellow man isn’t a concept unique to judo. Jita Kyoei is not just about helping people however, it’s also about doing good for society as well.
While Jita Kyoei is less directly applicable to judo it is no less important than Seiryoku Zenyo it’s not only important in becoming a better judoka but also a better person.