Mind:
The mind is a powerful weapon, and one that will be used more often in the modern world. While a strong body can help one fight once a conflict has started, the mind can help prevent the conflict from appearing in the first place. How many times have you walked into a building, and made a mental of the emergency exits? Or scanned the passerby on the street to assess their
threat level to you? By being more aware of our surroundings and situations, we can take control of our fate.
There are many aspects to training the mind, which start from learning confidence and self-esteem, to achieving concentration and focus, and finally reaching enlightenment through meditation and breathing exercises. As we gain physical strength and ability, we must be sure to make equal improvements in our mind to properly wield those tools. Power without control is dangerous; thus we make sure to develop both in parallel.
Spirit:
Spirit is one of the intangible characteristics that is cultivated more
than it is taught. A person's spirit is a core part of their being, and it is very difficult to train or change it. The best we can do is to encourage its growth and adaptation in certain directions. The best analogy to this is the bonsai tree. We can trim and encourage it to grow in certain ways, but ultimately the tree decides what path it shall follow.