Imagine a carpenter carrying a toolbox with nothing but hammers. As long as all he encounters are nails, he’s good to go.
But there’s not a lot of things you can build using nothing but a hammer. You’ll need to measure, cut, level… in other words, you need more than a single tool.
How does this relate to self defense and martial arts? Sensei explains in the video below:
Every person, every situation is different. Sometimes you need to stand your ground like Earth. Sometimes you need to be analytical like Water, or give a passionate Fire response. And the toolbox is complete when you can be the Void, cycling through each element as needed.
Once every element is in our toolbox, we can spend a lifetime improving our mastery of it.