Well, the definition itself isn't blurry I'd say, since it's pretty much universal: the examples you cited should be encompassed as possibilities by the model.

Well, the definition itself isn't blurry I'd say, since it's pretty much universal: the examples you cited should be encompassed as possibilities by the model. It's just hard to define because it involves the complexities and oddities of morality, happiness and the like -- our objective knowledge of those is so restricted and sparse that we're better off just "winging" judgements from our legacy of humanities study.