Suppose you have correctly concluded that it is your legal obligation to act or refrain from acting in a certain way. Can you, from that conclusion alone, say anything at all about what you ought to do morally?
An affirmative answer to this question implies that law has moral value regardless of content or circumstance: without knowing what the act is that the law commands or even what legal system has enacted the law, one would, on this view, be able to link the conclusion about legal obligation with some conclusion about moral responsibility. Such a view seems quite far-reaching precisely because it asserts a connection between law and morality that is universal in scope. In another respect, however, the claim could be quite weak: the alleged link between law and morality, though universal in scope, might be weak in effect, in the sense of being easily broken or overcome by countervailing considerations based on the content of particular laws or the nature of a particular legal system. Whether one thinks an affirmative answer to the question is plausible may well depend on whether the breadth of the claim in terms of scope is offset by modesty in terms of claimed effect.
The Moral Value of Law,
Mich. L. Rev.
Available at: https://repository.law.umich.edu/mlr/vol84/iss1/3