The Law Is a Series of Slippery Slopes

From the outside it would appear as though a lot of legal discussion, especially when judgments are made, are essentially a recitation of a parade of precedence and so on. In other words, it feels from the outside like many legal arguments are inherently backwards slippery slope arguments. The essential thing in the law is that it's tethered to precedent, right? That's what makes it different from vague metaphors or vague analytical claims.