I see distinct differences between teaching, training and conditioning, with different uses and pitfalls for each.
Teaching is passing information from brain to brain. I can tell you that 'colors are how our eyes perceive different wavelengths of light,' or I can teach you the formula to convert celsius to fahrenheit. Teaching can be entirely cerebral.
It can go wrong in a lot of ways. There isn't always an automatic reality check, for one thing. I can give you the formula to convert to celsius, but if you calculate incorrectly it doesn't mean anything. A wrong number at the pure teaching level is just a squiggle on a piece of paper that doesn't look like the squiggle the instructor wanted. I can tell you that the earth is round or the earth is flat, and outside of a handful of professions, whichever you believe will not affect your life or anyone else's in any way.
Because there is no reality check, there is no inherent difference between good and bad information when it is taught. As long as it stays at this level, you can get a child to believe almost anything. Santa Claus and the Tooth Fairy are teachings. Most of what we think we know, most of what we have been taught, may be no more true. Because most of the things taught are not tested.
And this becomes dangerously bad, because we then believe these things we were taught are important. Sometimes worth killing over. You can be taught, as an obvious example, that your religion is objective truth, all other religions are lies created by an evil Adversary and killing over this is a duty...
You can feel very sure about your beliefs at this level, but you cannot be sure...any more than a child's insistence in the Easter Bunny makes him hop.
Teaching, though, allows us to transmit a huge amount of information, and to think through connections that would take lifetimes to try out in the real world. It allows us to imagine possibilities and juggle symbols. And teaching compounds over time. The questions that inspired Aristotle's "Metaphysics" have been outgrown.
Validity does not imply truth, however, only internal consistency. And bullshit can compound like any other information.
Training is guided practice in how to do stuff. I can tell you the celsius formula, but you have to put pen to paper for a while to become proficient at it. I can tell you what to do if you are ever attacked by a right over hand punch from a taller person... but if it is only taught, not trained, you will think and not act and you will eat that slow, clumsy punch.
Sometimes training has a touchstone to reality and sometimes it doesn't. This is crucial to understand. Training always has a touchstone (unless you are really doing it wrong) to something. You train to move a body by moving a body. You train to swing a stick by swinging a stick. If the touchstone is or simulates reality closely, no problem. You hit a guy hard enough, he goes down...
It goes to shit when the touchstone doesn't mirror reality. You hit a guy lightly or miss him entirely and he goes down because he is 'supposed' to... Or you spend your hours training against the way the instructor imagines bad guys attack instead of the way that they do attack.
It can also go bad when the metrics are wrong. When you measure success (one form of touchstone) by a poor standard. How a technique looks is not a tenth as relevant as how it feels on the receiving end, but if 'proper form' is measured against a picture you will get, and I have seen, instructors who pick themselves up and say, "You didn't do that right." Or, to dust off an old memory, I once choked a wrestling champion unconscious. When he came to, he explained to me that he had "won on points" before he lost consciousness.
Training is critical, though, in teaching us how and when to move. And when done right, it gets us used to the conditions we will face.
Conditioning affects a deeper part of the brain. It is how animals learn. In many ways, it is how we truly learn. We are creatures of sense and motion, constantly watching the world, constantly affecting the world. A part of our brain, the one that learned stove-hot, is always watching what we do and the effects it has.
Do this and things get better, do that and things get worse. X hurts, Y feels good? Do Y. A flatworm, with a single neuron works this way. Under immense stress, we might freeze, thinking about what has been taught. We probably, for the first several incidents won't remember our training. We will respond with our conditioning.
"You will fight the way you train" is a lie, and I am just as guilty of mouthing it as any other instructor. You will respond to any high-stress, low-time stimulus the way you have been conditioned.
Conditioning is natural and has an automatic correlation to reality. Your form is good and you see the center of the target disappear in a ragged hole. Your form is poor and your shots don't connect, dissatisfying and embarrassing.
But conditioning can go wrong even under good intentions. If you yell at the poor shot, increasing the embarrassment, do you empower the conditioning? Or do you instead condition the student to avoid the situation altogether, to avoid you? Conversely, if the students always win in scenarios have you 'programmed for success'? Or conditioned the hindbrain to know that results are always good and effort and judgment are wasted resources?
Under bad intentions...
We have all seen the instructor who makes an example of any student who does well. Training to win but conditioning to lose. The hindbrain remembers, and learns/knows that losing is a safer strategy than winning. That's screwed up, and the ultimate example of training to fail.
Conditioning can be complicated as well. Even simple organisms will move towards pleasure and away from pain, but a child can be conditioned to some mighty strange definitions of pleasure and pain. Confuse the two in just the right way and a child can be groomed into an eager and permanent victim. In individual cases it is not automatic that rewards are as we expect.
Three avenues to make your students better- teaching, training and conditioning. All have uses, all have potential pitfalls. The most important thing, IMO, is that the approaches be congruent. That what you teach and train and condition all work via the same tactics to the same goals.