Robert M Watson Jr
Here 'Xin' must mean mind/spirit/heart? I don't quite understand the difference between 'desire' and 'intent' in this context.
My experience is it's best to take each term on a case by case basis as opposed to translating any of them directly as often times they won't make any sense or won't be in the proper context, which is why its important to have a good teacher to guide you.
For instance we can look at the term xin fa, which would translate literally as 'heart technique', which either doesn't make any sense or would give the reader entirely the wrong idea.
My Sifu calls it the 'heart method', which still sounds a bit vague, but he explains it like this;
The heart method is the essence of the teachers experience over their life time, transmitted to the student. It's the fine details that make the difference between just waving your hands around in the air and actually getting some tangible results from your nei gong. So the implied meaning behind the term xin fa is more like 'the secrets of the practice which only an experienced teacher can impart'. In many cases these terms are very contextual to martial arts practice and wouldn't even make sense to native speakers without a teachers guidance.