Many people see Aikido people practicing and they say it looks like it's fake.
It looks like they are going along with each other, like a dance.
To a certain extent they are correct.
The first thing in Aikido is that you learn that you must comply with your partner so that when they throw or take you down, it doesn't hurt you. If you resist or go against the technique you can get injured badly. So yeah you are "going with" your partner so that you learn how not to get hurt when someone does a move like this to you.
The second thing is that by "going with" your partner, your learning how to feel your opponent's force. Now this may sound mystical but you can look at it from a physics point of view. If they throw or take you down, that requires energy and force, by complying to their technique you are learning how to sense that force and go with it. Kind of like a wave in the ocean, if you go with the wave you can find spots to breathe and naturally come up, but if you go against it, you can drown and wear yourself out. Or even a car crash, if you relax and go with the force, you can minimize the damage and only have superficial injuries, but if you tense up, you can really hurt yourself badly.
Trying to read the force is called sensitivity training. Many martial art styles have figured out that having good sensitivity can make you a much better warrior. So they have implemented ways to develop sensitivity.
Chinese styles like Wing Chun and Tai Chi practice sensitivity from hand partner exercises. Filipino martial arts also have something similar.
Back when I was learning Brazilian Jiu-jitsu, I noticed that when we sparred 99% of the time, we began from our knees. The first martial art that I ever encountered that worked from the knees a whole lot was none other than Aikido. So I tried to incorporate some Aikido into my BJJ practice.
It wasn't so much the techniques that I incorporated but the principals and especially the sensitivity. Once I started to do that, my BJJ skills became much better. I was able to transition from position to position, technique to technique much better. I was able to relax and become more efficient because I was tensing up less and trying to read my opponent's energy instead.
I decided to write about this today because I saw a video on Youtube with a Rickson Gracie black belt talking about connecting and disconnecting in what Rickson calls Invisible Jiu-jitsu. As I was watching the video I immediately thought, oh he is talking about sensitivity.
The difference though is not about connecting and disconnecting from your opponent, because the way I learned things was that if I'm separated from my opponent they can hit me and throw me, but if I connect with them, and become one with them, we become joined like we are one entity, then it becomes hard for them to throw themselves, or hit themselves.
So I don't exactly 100% agree with what the Rickson Gracie black belt said. But I am 100% for sensitivity. I remember in Russian martial arts training the idea of becoming one with your opponent was introduced to me from a Sambo throw. It makes it harder for your opponent to throw you and easier for you to sense when to throw them.
Becoming one with your opponent is the key principal in Aikido. To blend in with their movement, I always thought it sounded very ninja like. To me a good ninja would have Tai Sabaki similar to an Aikido ka.