So, my latest thing to consider has been a model of a person where the thinking part of the person is a rider on a horse, and the animal part of a person is the horse.
It is certainly true that the line between thought and instinct is a very difficult one to draw, but this idea doesn't need to be so very precise in order to be useful.
I like to think of the model as a motivational tool.
For example, I love donuts. The thinking part of me knows I shouldn't eat so many, and the animal part of me is stubbornly intent on eating as many donuts as possible. This becomes a great motivational tool when you pit your thinking brain against that dumb animal inside of you- who's better here? Thinking me or dumb me?
Well, the unfortunate truth is the rider is at the mercy of the dumb animal most of the time in most situations, but that's no fun to think about.
Another interesting aspect of this is to consider those around you... are they riding their horses, or being dragged along by them, or are they just horses riding horses?