When you see senior students practising jiyu waza (free technique) in the dojo, you sometimes hear us telling nage to be more proactive, rather than meekly allowing uke to attack however he likes.
While it is important to allow uke to take a firm grip in attacks at junior levels of practice to learn the mechanics of the technique (static practice), movement and awareness must be practiced at the higher levels (dynamic practice).
Stan Pranin, the editor of Aikido Journal, has written an article related to this topic and points out that it is a cornerstone of O-sensei’s technique and of high-level practice in general. It is well worth a read.
“I am always going first. I am moving forward first every time. I initiate and let him take my hand. I initiate and let him grab me. It never happens that he grabs me first, after which I start to figure out what to do. I am always going first. I must not wait for the other person to act.”
– Michio Hikitsuchi-shihan