Holding back the spirit (“Zan-shin”) or letting go the spirit (“Ho-shin”) should be used appropriately according to the existing objective as well as the temporal circumstances.
Whilst holding the sword you should usually let go the outer spirit (“I-no-kokoro”) and hold back the inner spirit (“Shin-no-kokoro”). But in the moment when you strike the opponent in earnest, you should let go the inner spirit and hold back inside the outer spirit.
The methods of this holding back or letting go the spirit differ greatly depending on the various situations.
This should be carefully considered.
Musashi talks a lot about the spirit, the mind, and with good reason. Given the relative differences between two swordsmen who have both had some training, the largest advantage one will have over the other will be in the mindset, in the spirit. Consider the differences between the lethality of a swordsman with three years training and one with ten. Now compare that to the differences between, say, the Taliban in Afganistan and the united Western forces who fought them. Compared to such an imbalance, we may as well call any two swordsmen evenly matched. And yet, with a rediculous inbalance of actual killing power, a superior military may not have the correct mindset to ultimately defeat a guerilla force. Given sufficient ideological motivation and promises of rewards in an afterlife, this mindset may need to extend to killing every man, woman and child in the hostile country, and then colonizing the empty land.
Or in the terms of pre-Edo Japan, killing every member of the opposing family, including the children so that they do not rise again to oppose you in a generation. Or in Tokugawa Japan, keeping wives and children hostage in Edo to ensure loyalty in the hinterlands.
But Musashi is not talking about this sort of strategic mindset, rather of the tactical practicalities of a single fight. He speaks of the spirit in several terms here, the first is zanshin. Zanshin is a lingering mind, to stay the attention on the opponent or on an aspect of the fight. We are most familiar with it as that attention we pay to the opponent after we have scored a point, or the lingering awareness on the kata at its finish, when we are separating from our partner. If we think about this for a moment, zanshin is not much different than fushin, the frozen mind, the mind stuck on something, as opposed to the freely-moving mind of fudoshin. Musashi is especially careful to warn us about this frozen mind and suggests in several places that we must have a generalized attention, a freely moving spirit, yet he tells us here that there is need of zanshin in its proper place. Indeed there is, the time just after we think we have won a bout, or the time when two armies separate after a cease-fire is highly dangerous. We must watch our opponent carefully until we are sure we are clear. What was the cold war of the 20th century but a 40 year Zanshin after the two World Wars.
Next Musashi contrasts zanshin to hoshin, which is often compared to mushin, the empty, flexible mind, but is better thought of as the release of zanshin, the release of the spirit. Hoshin comes when we stop concentrating on one thing and allow our mind to become wide once more, when we allow our spirit to expand and take in the overall picture.
On a physical level it can be compared to the release of our gaze from a sharp, detailed seeing to a softer, wider “enzen no metsuke”. In Muso Jikiden Eishin Ryu iai we have different places in the three levels of practice where we use this sharp and unsharp metsuke, with the highest level having the least amount of sharp focus, coincidentally this is also the level of multiple opponents and widest danger.
Next we come to i-no-kokoro, the outer spirit and shin-no-kokoro, the inner. These have been translated as volitional mind and ideative mind, or perhaps more simply, will and thought. Musashi says that usually when we are fighting we show our will, the outer determination and we hold back the mind, the thought. It is our intent to cut the opponent, our willpower expressed toward this goal that allows us to find and exploit openings.
What does Musashi mean by hold back the spirit? Perhaps hold down rather than hide. If the ideative, the rational mind fixes on something it becomes frozen, it is dragged around by that thought and we cannot move our body freely. Hence we try no to think too much lest we either freeze ourselves or we show our plans to the opponent. We simply show him the iron curtain of our willpower.
But when we strike, we must strike with intention or it is simply a hit, we must strike with our thoughts as well as our sword, with all our inner spirit. Yet Musashi says we hold back the i-no-kokoro, the outer spirit at this point. What does this mean? Why would we hold back our willpower when we cut?
Because if we do not hold back the will we try too hard. Musashi tells us not to change our grip when we cut, not to use too much muscle, yet what do we inevitably do when we try really, really hard? We over-muscle it, we don’t “let it happen”, we try to control the sword instead of letting it go. The result is that we hit with the flat as if we’re using a rice spatula, we don’t strike, we don’t cut.
One can imagine many ways of holding back and letting go of the spirit, the body and the sword. In fact, one can imagine that these are the verbal hints your sensei gives you every class as he teaches you the kata. I’m sure you can think of examples of holding down and letting go your inner and outer spirit right now.