I've been reading a little bit on legal positivism and the whole sphere of argument that it is involved in, and I have to say it is completely fascinating. The idea more or less states that law and morality are separate (but Bentham and others don't deny that the two do cross paths; a bit like the chicken and the egg). It's fascinating because the essential question is how you can balance two extreme points of view. On the one hand, law can not be seen as arbitrary but related to some sort of moral standard, less everyone decides the law doesn't apply to them because they don't see it as moral, or that law is inherently moral and thus should be obeyed at all times, regardless of the actual moral content of the law in question. This is the kind of question that Plato's Republic actually sets out to answer. When the question is posed to Socrates, "What is justice?" he systematically addresses the idea of what justice is; dismissing the idea that justice is the advantage of the strong (ie, adherence to law).
I get the impression that HLA Hart disapproves of the anti-positivist position because it fails to address the tricky situations in which law and morality do intersect. It simply shoves the problem under the carpet and appeals to "natural" law in solving the problem. The great example is the Nazi regime and how law functioned within that society. "Law is law", as Hart points out, was used to justify a lot of atrocities that were committed. In one example, Hart cites a case in which a woman was tried for exposing her husband's anti-regime position after the regime had passed. Her argument was that it was legal at the time for her to do so, while the prosecutors ultimately ended up appealing to natural law to convict her. They cited that such a law was not moral, and thus, even if legal, she should rightly be punished. He addresses the criticism of legal positivism well, and articulates all the issues that proponents of natural law tend to sweep under the table.
It's really a fascinating thing to study and makes me think about things that I've never really thought about before. Are laws inherently moral? To be sure, morality and law have often crossed paths, but it's hard to say with certainty that law is moral, especially considering some tumultuous periods in our history. Anyway, I don't really know all too much about what I'm writing about, other than the fact that I know it is exciting to be engaging in this kind of thinking.