In his essay on Justice Holmes and the Nature of Law, Morris Raphael Cohen makes it clear that a fruitful science of law cannot be built if we restrict ourselves to the study of law as uniformities of behavior. He warns us against “doing away altogether with the normative point of view in law”. We regard legal rules as binding norms, says Cohen, and not just as mere descriptions of uniform behavior. Insisting on the normativity and bindingness of legal rules, Cohen anticipates contemporary legal philosophy, which takes this normativity and bindingness of law to be a pre-analytic datum to be accounted for by legal theory.
“The theory of law as coercive orders”, says H.L.A. Hart, “… started from the perfectly correct appreciation of the fact that where there is a law, there human conduct is made in some sense non-optional or obligatory…In building up a new account of law… we shall start from the same idea”. Ronald Dworkin starts his discussion of jurisprudence by asking: “Why do we call what ‘the law’ says a matter of ‘legal obligation’? Is ‘obligation’ a term of art, meaning only what the law says? Or does legal obligation have something to do with moral obligation?’
Accounts of the normativity of law resorting to morality, to sanctions and those viewing legal duty as a term of art, are amongst the commonest solutions to the problem under discussion.