We agree here. However, I think you are escaping my point - simple swift corrections need not exist if you are paying attention. And if you are not and your horse progresses (or rather regresses) to a bad place, it is not his fault so why whip him? Fix yourself, stay on it and the horse will come back to you. Question is: how much time and patience do you have? Or is it easier to "swiftly correct"?
Read the entire thread. Really appreciated that drink a few pages back.
You know the old saying "Practice makes perfect"? I learned a while back that it is dead wrong. Practice makes permanent. Whatever it is you learn to do, done often enough, will become the go-to routine muscle memory with repetition. So, when we practice with an aim to improve, we must be constantly changing bits so they are closer to the ideal (whatever that is for a given discipline).
So, if my goal is a healthy horse sound in mind and body that is able to do a certain task as near to correct as possible, why would I let him practice doing it wrong when correcting him quickly will end it immediately? As an example- I let my horse eat while we're out on the trail (a divisive issue all by itself, I know) but with the proviso that he must stop eating and move along when I tell him to. Those are the rules, exactly as they have been for a couple of years. Every so often, he wants to flip me the bird. He gets a solid smack (your "swift correction") for that and then we'll be good for a few weeks. I could stop letting him eat entirely and sidestep the issue, but I prefer not to. This is a case of a horse who knows the correct answer but chooses, on occasion, not to give it. I honestly cannot fathom how saying, with a quick smack, which horses well understand and use on eachother with biting or kicking, "No- Wrong Answer!" is going to be detrimental to the horse or our relationship.
Now, for a horse that honestly doesn't understand what is being asked, is fearful, is overwhelmed, or any of those things, a different approach is certainly in order. But that is the dance- you have to know what you're asking, your horse has to know what you're asking, and you have to know that your horse knows what you're asking. Like the earlier example of the seasoned trail horse not wanting to move out away from the trailer, yes, you can work them there until they agree leaving is the easier way. That is certainly one option. But if the horse knows its job, giving them a quick smack is both less time consuming and less tiring for you both if you have a long day out ahead of you. Why waste time re-teaching a lesson the horse already knows well and is just seeing if they can conveniently 'forget' for the day?
A horse who understands a properly asked request and decides to ignore it should be disciplined. I want my horse to go because I said so. Not because he thought it would be a good idea. At the end of the day IMPO a horse should listen to the human because the human is the leader, and horses (at least mine) tend to make stupid and potentially dangerous decisions left to think for themselves in a world full of man-made monsters and dangers.
The idea that no horse will ever make a bad/lazy/wrong choice just seems silly to me, as is the idea that it is never the horse's fault. Of course 99% it IS the human causing the problem, but yes, sometimes horses choose to do something foolish too, and you cannot always prevent it, only try to reduce the likelihood of it happening again. (See: ways horses try to kill themselves in pasture, or in stall, or in field, or in the wild, etc)