Interesting topic. For me, I just "feel" it. I suppose if one wants to examine it in a more scientific way, we tune our senses. We don't practice the foo foo, "Don't throw me too hard" or "During Randori, everyone just punch o.k.?"..It's not realistic. It doesn't help sharpen the senses. It seems that over the years "Aikido" has become so watered down, that it becomes useless and students do not gain anything from it. We practice a harder style than most, and newbies from a different school look at us like we're crazy. Point is, you can't sharpen senses if your not allowed to actually experience what its like to HAVE to blend with an attack, or with anothers body. One has to MAKE their technique work. That's how you learn. Anyway, was getting off point, sorry. Ever notice the "feeling" before someone strikes? It's like a waiting game. You see every thing, and yet nothing. You hear every thing, and yet nothing. Your mind is focused, and yet you're not thinking at all. To be able to "feel" it is amazing, and something words really can not describe.