I spoke in short hand and so was misleading. My intent was not to advocate practice without cultivation of the spirit (By the way does anyone know what character corresponds to the "bao" of what Michael has quoted from memory as "bao shen"?), but to say that I feel the consequences of its lack only when playing around with fajin. For instance, in doing form, I can glance around and compare my postures with those of others around me or with my image in the mirror. As long as my intent is reasonably precise, the results seem more or less okay to me.
When doing fajin, I find that I have physical difficulty in executing movements without strongly alining my spirit with my intent. For instance, in regular form, I feel I can do a decent job at Deflect Downward, Parry, and Punch with my eyes darting here and there, with any kind of breathing, and with a silly grin on my face. Focusing on the mechanics and monitoring the flow of energy (jin) seems rewarding enough.
When I play around with fajin, however, I need more. I feel my eyes must be focused, I must expel breath to stabilize my "generous" gut, and my expression has to match what I am doing. Without these elements present, I cannot credibly pull off the technique. Alternatively, I can add local speed and power, but this leaves a feeling of awkard mishmash.
I would still maintain that "moral" aspects of the spirit, i.e., appropriate mixtures of humility, confidence, a spirit of challenge, honest self-assessment, etc. are important even for "laid back" execution of the form. Either giggling or sighing at what I see in the mirror is a definite no-no.
My basic point was to express a little bit of wonder at how certain concepts that sound like "high-level" theory or just mumbo jumbo seem all of a sudden to become quite immediate and practical in the right circumstances. Also, for me, much of these things seem more and more integral parts of Taijiquan at whatever skill level and not things merely to be added on as one improves.
Some of this approach has become increasingly important to me, because I assist occasionally in one of my classes. Recently, I have been trying to explain my understanding of how power circulates in certain moves, such as Roll Back and Step up to Seven Stars in the Saber Form and in the barehand form. One of the things I have stressed is that without understanding something of the intent within these movements, it is very difficult to perform them without major defects that are subtle, but definitely visible.
Because of my lack of teaching skills, I am occasionally met with protests that I am focusing on "high-level" details, excessive precision, or else prematurely expecting levels of performance that exceed the skills of the people involved. My own, perhaps mistaken view, is that these "high-level" details are meant to have immediate and visible effect, independently of skill level.
What I try to argue is that without some mental feel for how power is generated in the postures, it is hard to execute them accurately and that with even a little of this feel, it is hard to execute them wholly incorrectly. If the mind is used appropriately, the power and speed come naturally. If the mind is not directed appropriate, it is almost impossible to force power out of the movement.
In Step up to Seven Stars, most people naturally focus on the length and strength of the movement of the right fist and move as if this is the source of the power. I try to explain and demonstrate that this way of thinking does not apply to the Taijiquan we attempt to do. I usually have no success in getting my point across unless I both explain theory and demonstrate application of the theory to the extent I understand them. I find that people cannot really "see" what is being done without both some theoretical basis (e.g., one of the Ten Essentials) and some proof that understanding matters.
Yesterday, I tried to demonstrate some fajin to make my point, varying the length of the punch from the hip in Step up to Seven Stars from one inch to 24 inches to show that the speed and strength of my waist movement was more or less the same and that the extent of my arm movement, despite appearances, was largely irrelevant to the level of power I was generating.
I also tried to show various ways of assuming the final stance that in my mind do not satisfy "distinguishing full and empty," "continuity of movement," or "power from the legs that is controlled by the waist and expressed in the hands."
I further tried to describe how these other methods destroyed the power in the movement or else left me vulnerable to injury or attack as I "fell" or "froze" into position and could no longer change during the "committed" or "static" part of the move. This is one version of what I think Jerry once described as making the Ten Essentials concrete.
I have gone into some detail to explain how some of these theories have concrete meaning for me and do not appear optional, but all I have said I class in the arena of "mind intent" and not "spirit," or maybe "using mind intent and not raw strength" (yong yi bu yong li). Until recently, I had felt that worrying about "spirit" (shen), other than as a moral matter, was in another category. After playing around a little with fajin, I have been pleasantly surprised to discover that it is beginning to seem no different than the other aspects of Taijiquan theories, just a litle harder to demonstrate or experience. If I can ever overcome my general mental laziness, I may even try to incorporate this into my daily form practice.
By the way, despite what I say above, I want to reiterate my agreement with what you describe as your general approach to speed and power in training. I personally am not a fan of training with speed and power in the context of normal form practice, as opposed to using them in isolated groups of one or two postures. While I think performing fajin can reveal where power is lacking, I do not currently feel it is particularly efficient in cultivating power in the context of the regular form.
I hope all this is a little clearer. Any disagreement or anything to add?