If you hate, there is no way for any other feeling to be born out of that hate, except some other negative one. Same thing, when you love, you don't feel hate, nor anger, they don't really matter when you're around something you love, right? So, coming out of the things said above, I'd say, yes, the natural laws do apply to the soul as well. However, if you bear pain with you, that pain can give birth to any other negative feeling, according to your circumstances. But that as well, follows the natural laws.