In Justice in Robes, Ronald Dworkin identifies a “Chicago School of no-nonsense jurisprudence” that he associates with Judge Richard Posner. In the new year's first WIP talk, Brian Leiter’s work-in-progress, "In Praise of Realism (and Against 'Nonsense' Jurisprudence)", recasts the Dworkin-Posner dispute as a disagreement about two different kinds of theories that he dubs “Moralism” (Dworkin) and “Realism,” a dispute whose history Leiter traces through Thucydides, Plato, Nietzsche, and Rawls, among others. The title of Leiter's piece is itself a jab at Dworkin's efforts to distinguish his "moralist" jurisprudential model from the "realists." Dworkin refers to himself as praising a "theoretical" account of judging, in contrast to the "anti-theoretical, no-nonsense jurisprudence" of his opponents. So, Leiter responds that this must make Dworkin an exponent of "pro-theoretical, nonsense jurisprudence".
Leiter's allegation is that Dworkin effectively has no account of how judges behave. Instead, he labors under Platonic "optimism" that simply takes on faith that a world properly understood will make moral sense. Consequently, when looking at how judges decide cases, we should take them at their word when they tell us they're decide cases in a way that is coherent with what comes before, is morally correct, and represents the one true "right" answer as a matter of law. And more importantly, we should do this even in the face of considerable empirical and social science evidence indicating alternative explanations. Dworkin wants to instead locate the "hidden logic" of judicial decisions in their "justificatory ascent" -- the degree to which we can hold judicial decisions accountable to the big principles inlaid within the legal regime.
But this isn't really what happens. Consider the example of the "privity of contract" doctrine rejected in MacPherson. It wasn't that MacPherson grasped, in any real sense, the "real" principle that had been progressively developed in prior cases applying the "inherently dangerous" standard. Rather, what had happened is that the latter standard had dissolved into near-complete incoherence. Circumstances changed, the rule no longer made sense, so Justice Cardozo resolved to change it. Neither Dworkin nor, for that matter, Cardozo provide any traditional legal justification for why the change occurred. The story of a "justificatory ascent" is nonsense made up after the fact. Without the pre-existing Platonic commitment to the notion that any sensible account of the world will also make moral sense, there is no reason to substitute perfectly good explanatory accounts of judicial behavior for poor ones because the latter have the "advantage" of conforming to systematic moral vision.
To be clear, Leiter is not opposed to pressing for particular normative claims, in legal contexts or elsewhere. The problem is when such commitments are recast as descriptive accounts of how courts actually operate. Realism, as the name indicates, is about clear, untinted descriptions of what courts really are doing. This is quite consistent with trying to muster whatever rhetorical, persuasive, or organizational tools available to get them to do something else.