In my interaction with my horses, I try to ask another question for setting the boundaries of what I do and don't do. Instead of asking about duty, I try to ask about ability. That is, whenever possible, I don't ask whether something is okay (as in "am I justified to do this?" or "do I have to do that?") but I try to conveive of a situation in terms of what I CAN do. Do I have the capability to be gentle? Is it possible for me to come up with clever solutions that motivate the horse? Am I interested enough in this friendship to make me want to invest the energy to listen? For me, seeing such situations as a chance to test and improve my capabilities is far more interesting.
Usually, when horses balk and pull, this is not a sign of being very motivated, or finding the joint activity purposeful. Accordingly, that is something I can change. In terms of how to change it, there is a lot of info in this forum. But the question a person needs to answer before is whether he wants to.