Ronald Dworkin, answered from the texts and cited to the page.
Law as integrity is the central jurisprudential virtue. Judges in hard cases — cases where the rules run out, where the precedents conflict, where the parties offer competing interpretations of the same legal materials — must decide by finding the principles that both fit the legal history and justify it morally. Hercules, the ideal judge with unlimited time and information, would on this view arrive at the right answer in every hard case.12
He is not a literal description of how flesh-and-blood judges work; he is the standard of what good adjudication aspires to. The two-dimensional test is rational reconstruction, not psychological report. H. L. A. Hart's positivism — the rule of recognition, the plain-fact pedigree thesis, the claim that judges in hard cases exercise discretion in the strong sense — misdescribes legal practice; it treats judges as legislators in the gaps when they are not.
Joseph Raz's pluralism about legal values, with its objection that integrity cannot speak with one voice because law's values are genuinely plural, also fails: integrity does require coherence, and the cost of incoherence in legal practice is real. Richard Posner's pragmatism, which would have judges decide by reckoning consequences without principle, abandons the jurisprudential project altogether.
The competing positions name a real disagreement about what law is, and I have argued the integrationist position across four decades.345
I made Hercules decide the several cases I offered as working examples in Chapter 1, and my claims of fit can be checked by comparing his reasoning with the kind of arguments that seemed appropriate to lawyers and judges on both sides of those cases.Law's Empire, pp. 412–413
The interpretive judgment must notice and take account of these several dimensions; if it does not, it is incompetent or in bad faith, ordinary politics in disguise. But it must also meld these dimensions into an overall opinion: about which interpretation, all things considered, makes the community's legal record the best it can be from the point of view of political morality.Law's Empire, pp. 411–412
This process is in fact under way in Anglo-American law, as is, though less securely, a new unification of private law that blurs even the long-established and once much firmer boundary between In the next three chapters we continue constructing Hercules' working theory of law as integrity by exploring in more detail issues raised in three departments of adjudication: common-law cases, cases turning on statutes, and…Law's Empire, p. 255
They are the answers I now think best. But law as integrity consists in an approach, in questions rather than answers, and other lawyers and judges who accept it would give different answers from his to the questions it asks. You might think other answers would be better.Law's Empire, p. 240
We prefer an account of what law is, and of how it is to be identified, that incorporates the value—integrity—whose pertinence and importance we recognize. If one way of deciding Mrs. Sorenson's case will treat her as equal before the law, in the sense that integrity assumes, and another will not, then we prefer a conception of legality that encourages the first and discourages the second decision.Justice in Robes, p. 178
The Hart-Dworkin debate is the central debate of twentieth-century analytic legal philosophy. Hart's posthumous Postscript to the second edition of The Concept of Law (Oxford, 1994) treats Dworkin as having misunderstood positivism; Dworkin's reply in Justice in Robes (2006) Ch. 7 treats Hart's response as inadequate. The post-Hart positivist tradition (Joseph Raz, Jules Coleman, Andrei Marmor, Brian Leiter, Scott Shapiro) has developed inclusive legal positivism, exclusive legal positivism, and planning theory in response to Dworkin's critique; the field has not converged. The Burley volume Ch. 15-17 (Raz, Postema, Waldron) is the principal recent engagement with integrity. Stephen Guest's Ronald Dworkin (Stanford UP, 3rd ed. 2012) is the canonical sympathetic monograph. The American successors in interpretive theory include Mark Greenberg's The Moral Impact Theory of Law and Scott Hershovitz's work on the conceptual structure of law.