Lets look a bit at something I said earlier, regarding letting energy stay in you or go through you, and how one could view the statement "aiki is love."
As I mentioned earlier, a teacher/IS person is being reallying nice to you if they are throwing you in such a manner that the power goes through you. They are showing "love" in that manner instead of using a shorter impulse to cause more pain or a stronger colision with the ground or other object. Using big arm movements (short vs long impulse), moving with your partner to blend in the "external" mode of movement (again a longer impulse), lessens the impact to a fully resisting opponent opon connection to their center. Of course, without connecting to the center of your opponents mass, these large "blending" motions are less likely to work on a fully resisiting opponent, whereas smaller motions are even less likely to work than the larger ones without a connection to the opponents center.
Why you may see so many people bring in IS into every discussion, is not because of some religious furvor, though it may appear to be.
Once you are exposed, you see it nearly everywhere as it not only breathes life into the founders words in a rather concrete and tangible manner, but glimmers regarding the how and why of his movement begin to appear when you watch his videos.
or the whole "absolute non-resistance" thing. Some might take that to mean we get out of the way, we don't impede uke, but since starting on this type of training I've seen how I can remain stationary, not move out of the way or get off the line and let you collide with me, yet still maintain "absolute non-resistance" with the forces you are sending at me. Even better when they find themselves in ikkyo and I still haven't moved my body... I'm standing on that damned floating bridge... and I don't plan on getting off it any time soon.