Zitat von Gozo Shioda, Aikido Shugyo, pg. 71
The opponent can be broken without causing him pain. This is where the essence of Aikido lies. You should think of your training in joint-locks as the first step towards attaining this end. As long as you enjoy inflicting pain on your training partner, you will never attain the heights of Aikido. It would be better to think of joint-lock techniques as a way of conditioning the wrists. Ueshiba Sensei used to refer to it as "cleaning the crusts from the joints". Applying joint-lock techniques improves the blood circulation, stimulates the metabolism, and is well suited to promoting one's overall health. Practice them on each other all you want!