What is Aiki, how is it different then Jiu?
It's pretty common knowledge that Aikido is the study of Aiki; but what is Aiki? Do people other then martial artists use Aiki? Is Aiki magic? Is Aiki science? Does Aiki exist? These are all very important questions to which many never get fulfilling answers.
What is Aiki. Well first, lets look at the root words that make up Aiki. The first is Ai (合). Ai is the Japanese word for Accord, or meeting. It basically means to be in sync or come together with. The second word is Ki (気). Ki is the Japanese word for energy. Many people attach some mystical meaning to ki, but that will take us away from where we are trying to get to in this article. If for now you simply understand Ki as energy, the same as we use the word here in the west it will serve us well. By looking at these two words in conjunction we will get a very direct translation for aiki, of: in sync with energy.
For myself, I look at Aiki like music. Several musicians playing music together must use Aiki. The energy is the sound they are producing, and the accord is them working together to produce a cohesive piece of music. Music is a very good example to use because there is no physical interaction, it is simply and directly related to the harmony of the energy produced (the sound).
In my opinion an abstract example like this, is the clearest example of what Aiki is. Not to say that you cannot have Aiki when there is physical connection, but with physical interaction many other things may be things happening other then Aiki. This can cloud our understanding of what we will come to understand as Aiki.
Do people other then martial artists use Aiki? Well as we have seen in our example above, yes, certainly musicians use Aiki, but others do as well. Another clear example of someone using Aiki would be an American Football running back. The running back is the guy often given the ball behind the line of scrimmage (where all the other players are fighting to get to the ball) his job is to run past all the other players on the line and try and make forward progress. Oftentimes you will see one or several players from the other team brake the line and attempt to tackle the running back. However a good running back, with just his intent and a slight move of his hips is often able to make the other players miss him, and even fall in the process.
This is a "real life" example of what we in Aikido would call a "no touch" throw. The other players are trying so hard to get him, he convinces them that he will be in the place they suspect. Once he knows they are fully committed, he changes his direction and with out even touching them they will lose their balance and fall to the ground. This is not unique to Football, it can also be seen in soccer, basketball, and many other contact sports.
In our two examples above Aiki is being used in different ways. One is using Aiki to make a perfect harmony with the other musicians, and the other is using Aiki for a more personally beneficial end, however both are allowing their actions to come in sync with another energy; Aiki.
So how does one make Aiki? Active Aiki can only be achieved by allowing your mind to open to what is going on around you. Aiki is not a solitary practice, you must have something to harmonize with. What you harmonize with can be conscious or not, either way you can still achieve Aiki with it. However you can only "trick" an aware entity. For example if you are catching a ball, you will likely use Aiki. You will see the ball coming, and match the motion of the ball, so it lands softly in your hand. The ball is not conscious, however you still achieved an Aiki interaction with it. But the ball cannot be tricked, if you don't make contact with the ball it will follow it's natural path no matter what you do. Conscious entities can be tricked However. A bull for example, during a bull fight; the Matador can trick the bull into thinking things that are not true, and make the bull follow a new path. This is also Aiki, but used differently.
The Aikidoka must allow his mind to open to his surroundings, and seek to blend with what is going on around him. He must seek to be in harmony with his environment by detecting not only the physical motion of random objects, but also the intentions of his fellow man and beast. Truly beautiful Aiki (for us who study Aikido) starts with understanding your partner's intentions, and what motivates his action. After this is understood, you must choose actions, yourself that coincide with his desires, and blend with him to make a perfect Aiki interaction.
What is the difference between Aiki and Jiu? Depending on who you ask (particularly in relation to the styles that accompany the principals) you will get a multitude of different answers. These will range from the very mislead "Aikido is gentle and Jiu-jitsu is hard", to the overly simplistic, "they are basically the same thing".
Personally I've always hated the translation of Jiu (柔) as soft. Soft is what I would call a cotton ball. Jiu is like an inflated beach ball. I wouldn't call a beach ball soft per say, but it's not hard either. It has give, but also structure; it's springy. It's not without resistance. A bow (as in bow and arrow) is another good example of Jiu, it has flexibility, but it's certainly not soft, a good bow takes plenty of force to pull. While Jiu is yielding, it is also stable and strong, like the branches of a healthy tree.
Many people confuse the concept of Jiu and Aiki. While in physical interaction it's hard to tell the difference, they are still distinct principals, unique to themselves. Personally I would say the hard and fast rules are: Aiki is best used when you are not touching, and Jiu is best used with physical contact. In fact Jiu must have physical contact in order to be used. If you set a black inflatable ball next to a bowling ball, so they look identical, you would never know which one has Jiu (the inflatable ball) unless a physical force acted on it. Jiu is more receptive, and Aiki is more proactive.
While it's not impossible to use Aiki while in physical contact it's less clearly seen, and harder to understand. If you watch film of Judo great Kyuzo Mifune, you can see he often use's Aiki to throw instead of Jiu. He will strike a rhythm with his partner, by beginning to prance a bit, and the second his partner falls into his rhythm, Mifune will throw him. This is a great example of using Aiki in physical interaction, but hard for someone with little experience to see.
Aiki and Jiu are both present in Aikido as it is practiced today. While we call our art Aikido, it is not completely devoted to only the study of Aiki, but Jiu also. The deeper and more clearly we can understand the differences the more profound we can make our practice.