https://answersrip.com/question/index?qid=20111013042944AATiCMQ
Others have asked us about aikido principles and I just did a search and got that previous answer of mine.
The people who answered that question, actually trains in aikido and they also, as a bonus, understand aikido principles, not just techniques.
Aikido is what I call a hybrid internal/external art. Whereas kyokushin karate is external and focuses on using muscle power or speed, aikido focuses on body weight and its momentum, but the reflexes required for it derive from external branches of sword jutsus or technique lineages, so that's why I call it a "hybrid". A lot of aikido's techniques were designed in mind that the user was a samurai or at least had another weapon in hand to use, such as jo, bo, sword or dagger. Thus if they lost their weapon, got disarmed, or somehow got tackled, they can use "aikijutsu" now. Aikido is the modern, gendai, interpretation of the same.
I'm not going to recommend one take aikido. All I will do is help explain so that people can understand the intellectual concepts.
The Book of Five Rings, like the Art of War, is very deep. Rereading it when you have gained more experience and wisdom, will unlock even more insights.
From previous questions I've asked, there is a general consensus amongst certain groups of individuals here in this section that if you have a solid background in external training, you can make good use of aikido training methods. Especially if you know the destructive side of lethal force techniques or crippling joint breaks. Aikido then moderates that and teaches more control and variations.
Many people try to learn aikido by using the least amount of force, when they don't even know how t use the maximum amount of force to get it done. Others here like JWBulldogs or other karateka often described how they learned to not use their muscular power in aikido, whereas before they thought they were already "soft". That is certainly true for those that learned grappling in karate and throwing in judo, compared to them at least they were much softer. So it's much better to start from the latter, than the former. Learn to use maximum force, effectively, then use aikido's training methodology to train the use of no force.
I don't grade people's understanding or abilities based upon their belt. I grade it based upon what the individual can demonstrate. Someone who fully understands the Art of War, in both its intellectual, spiritual, and pragmatic realms, has a very good chance of defeating black belts that have not, even though they are fighting a black belt with a white belt.
P.S. You will often hear aikidoka speak of "ki" or "blending". Ki is basically bio-mechanics dealing with bone structure and how the muscles work. If you want to delve into the other aspects of ki, you will have to learn Chi in Chi Gong, Chinese, lines. This can be found in internal arts such as Tai Chi Chuan. As for "blending", that's basically another way of saying "get close enough so you can control their center of gravity with your own". It's basically the same thing as in a hip throw. You replace their base, with your base, now you can carry someone, on your hips, and throw them whenever you like, cause they are now on your base, not their own.