Question

Hello Rabbi Michael Abraham
 
I’m trying to understand the difference between rabbinic Jewish law / fences / fixed and unequivocal decrees that appear in the Talmuds and the Mishnah, which were ruled by the authority of the Sanhedrin, and what appears in the Talmud to be a moral statement written in harsh language. 
For example, there are several things written in the language of “liable to death,” such as a Torah scholar who is found with a stain on his garment. Or: any Torah scholar who has no understanding—an animal carcass is better than he is; anyone who has no understanding—it is forbidden to have mercy on him, and other such statements. As I understand it, things like these were not ruled as Jewish law, and certainly he is not actually liable to death in practice; it is an exaggeration. But if so, how do we know how to distinguish what is Jewish law and what is not? Does it have to explicitly say something like “forbidden,” and the like? Or is it only the extremity of the sages’ language that is meant to lead us to something kosher or disqualified? It seems to me that many of those statements are simply the sages’ moral opinions regarding their own time and situation. I’d be glad to hear your view.