Question

I don’t quite understand the relationship between them. For example, you write in the second chapter of What Makes One Walk, that a command, by its very nature, is binding. But my own decision is still needed in order for me to be obligated. I didn’t understand: if a command is binding by its very nature, that means I am obligated by the very nature of a command. It’s true that I have to decide whether to obey that command, but that’s a trivial claim. Obviously, as a free human being I choose what I want to do, but that doesn’t mean I’m not obligated. It’s exactly like morality: by the very fact that X is immoral, that binds him (= I am obligated to comply with it), but in practice I choose what I do. 
 
And from your writings I felt that it’s not only that I choose what I do, but that I also choose what I am obligated to. And that is exactly the point I didn’t understand.