Ken writes: "Generally there is a tendency to stop Uke's movement and then do the technique. Dan views attempts to use Uke's energy to power the throw as ineffective and superficial. He has got it backwards. The Using of Uke's energy to such a high level was the breakthrough in Aikido. Breaking internal balance, Atemi, posture, these are all necessary at times but they are secondary to how Aikido works."
This is the point where online debate breaks down. I completely disagree with all of this, but the questions you're raising are the core and central questions of what makes Aikido. So it's a debate worth having, but a debate that's very hard to have without working with each other in person.
There are various "tricks" we can use to make our Aikido work. I regard joint locks, using momentum, using timing to lead uke off balance, as tricks. They may be effective in certain circumstances, and even worth practicing, but they aren't what I regard as the core of Aikido. (I heard one guy, who is very much into the aiki stuff--and whose name is not Dan--say that Saotome Shihan gets by with 'the trick of perfect technique.' Some trick. I wish I could pull that one off.)
I regard the core of Aikido as the center-to-center connection--making that connection instantly and using it to master the situation. I view the aiki skills as a set of concepts for understanding, a language for talking about, and exercises for practicing, that connection. I view blending as a "trick" which works only against an unskilled attack, because blending against a skilled attack leaves you being controlled by the attacker.
If your blending works--or Mary's, upthread--I'll claim that you're not purely blending but in fact have figured out how to make a connection and take balance within the movement you call blending. This is more than just semantics--I'm distinguishing two concepts and giving them labels so that we can talk about how they operate independently in practice. But until I've felt your technique I dont' know if that's what's going on or not.
Ken writes: "It [aiki] seems to be defined as grounding and breaking internal balance. Where then is the aiki in sword?"
Absolutely the same place as in taijitsu. Gleason Sensei has been teaching for a while how the same aiki principles that power taijitsu apply to sword and, in fact, have always been there. When I go back and look at his old sword videos I can absolutely see how they are manifest.
Ken, I think you're raising all the right questions. If you're seeing an attack on Aikido in the IP/aiki posts, I wish you would blend with it and irimi to engage with it. Right now, you're fighting it so hard you're making the opposition stronger and more absolute than it really is. Keep in mind most of the posts you dislike have been written by committed and sincere Aikidoka. Dan, though not an Aikidoka, works with us in sincerity and friendship at our request.
Skeptics who call bullshit when we fall into groupthink are always valuable. But it's more valuable if you know what we're actually saying and doing.
Here are a couple tidbits (gems) that may have relevance to parts of this post.
1. Aiki starts at home - you develop aiki within you via the balancing of yin-yang/in-yo - Ueshiba said it himself: (paraphrase) "you will never learn aiki unless you know in yo ho" (don't ask for a reference to where he said it, look for it yourself - it has been posted recently)
2. You don't blend with Uke's energy, you allow uke's energy to blend with you; then YOU control the joining of the two as one - this is as much ki blending as a physical blending - actually, more ki
3. Once you have created aiki within you, everything that touches you becomes part of you and is controlled by you; this includes sword and jo, and whatever.
Oh, one other thing, this ALL so soft and natural, you should not even break a sweat