ere the actual visible, positive shadow (“Yang”) is meant.
If your opponent holds his sword behind himself, so that you can only see his body, you should hold the hidden sword down with your spirit and at the same time empty your body, that is to say free it of all interference and strike with your sword at the protruding front of your opponent’s body. If you do this, his body will doubtless begin to move. When this movement begins, it is easy to gain victory.
This theory did not previously exist.
You should strike at the protruding part in order to avoid stiffening of your spirit.
This should be carefully tried out.
Musashi talks of an actual shadow here and gives the example of a sword hidden behind a body. If the sun is your vision, the sword is in the shadow. How do you move that shadow, that body that creates the shadow, so that the sword is revealed.
First, you have to assume there is something in the shadow, you have to place your attention, your spirit on that shadow precisely because you don’t know what’s in it. As Musashi says you hold the hidden sword down. Then you let loose your body to swing at the opponent’s body. This is what he expects and wants you to do so he will react. He will move in the way he planned to move and will show his sword to you.
In other words, you have sprung the trap and now, like the mouse-trap, the sword will follow the path that was set for it by your opponent. Notice that Musashi wants us to strike with an empty body, free of interference. That means we have no such planned strike, we simply begin our movement and react to the sword once it becomes visible. We are already holding it down with our spirit, we are watching for it, waiting for it and now that it has been shown we react to it.
What Musashi meant by “this theory did not previously exist” I don’t know. Was it new? I doubt that provoking a response to find out what was planned was ever new. But perhaps it was new to the reader, remember this was written to a student and perhaps it was new to them. Another suggestion, from Kikuchi, was that swordsmen of Musashi’s day were not patient, and would react to such provocation where in the old days they would not have. I simply don’t know what was meant here.
We now come to another point, that we should strike in order to avoid stiffening of our spirit. This stiffening can be a hyper-attention on a single point, in other words, a frozen mind (fushin), fixed on the hidden sword. This means we have already fallen into the trap. Such a situation can also induce fear as you imagine all the terrible things that could happen when that hidden sword is revealed. Nobody knows our weakness better than we do, so nobody can invent ways to exploit our weakness like we can ourselves. Instead of imagining and causing ourselves to become fearful, to freeze in fright, it is better to provoke the worst and deal with it.
Have you been putting off doing something because you have imagined all the terrible things that might happen? Do it and deal with it before it gets any worse.