In the panel on the right there is a quote from Saito Sensei about piercing through the center of opposition. When I first saw this demonstrated, probably by Dennis Tatoian Sensei, and later by Hans Goto Sensei and a few others, I thought, "wow, that was fast!"
The cut is straight through the attacker's center, piercing like an arrow, through everything inconsequential, or rather, making everything else inconsequential.
Here's Martine doing it to Carmen at class last night. We were practicing a ki no nagare variation of Morote Dori Kokyuho, one that our old teacher Dennis Tatoian had really liked. As the attacker reaches for your arm you capture his mind and move your body so that is is like a jo, straight and thrusting up through the attacker's center.
As I remember Tatoian Sensei, this piercing through the center was the main theme of his Aikido. He didn't waste time or energy with lots of leading uke around in circles. He would simply go straight through your center, regardless of what technique he was demonstrating, and you'd have an abrupt meeting with mister mat.
An especially clear example of this principle, and one that really distinguished him from other teachers, was his irimi nage.
Instead of drawing uke into a converging spiral, most of the time he would simply cut immediately through uke's center at the neck as he moved behind the attacker. The experience of this is that of having your neck on the edge of being neatly snappped. I remember him holding me at this edge for long seconds while he talked to the class about body position, hanmi, and so forth. It was very scary, though I knew I was never in any danger, unless I were to try to get away.
Now that Tatoian Sensei is gone I am hoping that we can keep alive a practice that elevates this simple principle of fiercely cutting through the center. It seems to simplify, which is a good thing in an art as confusing as Aikido.
As I watch young students like Martine I get the feeling that this principle that Saito Sensei, and his senior students in turn, held to be so important is not getting lost, and that makes me happy.