All of this reminds me of the difference between horsepower and torque.
Horsepower is the amount of work that can be done over a period of time, ie, moving 16 1/2 tons one foot in a minute.
Though technically torque is power turning around an axis, in cars it pertains to the delivery of horsepower. Acceleration differs when the same amount of horsepower is applied with different amounts of torque.
In other words, horsepower has to to do with energy doing work and torque has to do with applying that energy.
Is the pitch the ball moving, or the body moving the ball, and is this zen enough?
And Jerry's pitch can be thrown at different speeds using the same amount of energy.
So is jin closer to horsepower or torque?
Or does it have more to do with leverage inside our bodies?
As for "trained skill," if "li" is "raw strength" or "brute force" might "jin" be "refined strength" or "elegant force"?
I like "elegant force".
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Perhaps a clearer distinction should be made when we describe what we do, as opposed to when we try to describe what the Chinese concepts are.
For me the map is not the territory. As useful as maps are, I don't care if the mountain has an English or a German or a Chinese name, as long as I can get there.
And though I've generated my fair share of words in the last several months, Tai Chi is not in the words it is in the doing.