But here’s the problem: Scalia’s dissenting opinion, while correctly arguing that Congress, and not the Courts, is the law-making branch of government in America, opens with this line: “The law can recognize as marriage whatever sexual attachments and living arrangements it wishes … It is not of special importance to me what the law says about marriage.”While Scalia's dissent is brilliant in many ways, but while his personal sentiments are clearly Catholic, his legal reasoning displays the fatal flaw juridical positivism. What does this mean? In a nutshell, it means that law has no basis other than what is posited by human legislation. In other words, the basis of human law in natural law is no longer assumed.
Let me illustrate using an example from C.S. Lewis:
EVERY ONE HAS HEARD people quarreling. Sometimes it sounds funny and sometimes it sounds merely unpleasant; but however it sounds, I believe we can learn something very important from listening to the kinds of things they say. They say things like this: "How’d you like it if anyone did the same to you?"--‘That’s my seat, I was there first"--"Leave him alone, he isn’t doing you any harm"--"Why should you shove in first?"--"Give me a bit of your orange, I gave you a bit of mine"--"Come on, you promised." People say things like that every day, educated people as well as uneducated, and children as well as grown-ups.This is about the most concise illustration and explanation of natural law I can think of. The only justice of the Supreme Court who still shows any evidence of adhering to natural law as a foundation for human law is Clarence Thomas. (Interestingly, Joe Biden opposed Robert Bork's nomination to the SCOTUS because he DIDN'T believe in natural law, then opposed Clarence Thomas' nomination because he DID believe in it, which tells us something about the character of Catholic politicians these days.)
Now what interests me about all these remarks is that the man who makes them is not merely saying that the other man’s behavior does not happen to please him. He is appealing to some kind of standard of behavior which he expects the other man to know about. And the other man very seldom replies: "To hell with your standard." Nearly always he tries to make out that what he has been doing does not really go against the standard, or that if it does there is some special excuse. He pretends there is some special reason in this particular case why the person who took the seat first should not keep it, or that things were quite different when he was given the bit of orange, or that some thing has turned up which lets him off keeping his promise. It looks, in fact, very much as if both parties had in mind some kind of Law or Rule of fair play or decent behavior or morality or whatever you like to call it, about which they really agreed. And they have. If they had not, they might, of course, fight like animals, but they could not quarrel in the human sense of the word. Quarreling means trying to show that the other man is in the wrong. And there would be no sense in trying to do that unless you and he had some sort of agreement as to what Right and Wrong are; just as there would be no sense in saying that a footballer had committed a foul unless there was some agreement about the rules of football.
The very best introduction to the contemporary crisis in jurisprudence is Law and Revolution: The Formation of the Western Legal Tradition,which ought to serve our times as the equivalent of William Blanckstone's Commentaries on the Law of England for his time.
Related: Ann Barnhardt, "On Scalia’s Dissent" (Judica me, June 26, 2015).