Larry Solum's remarks on questions of philosophical immortality also include some reflections on immortality in legal theory and philosophy of law, broadly construed. Solum's list of candidates for immortality: O.W. Holmes, Karl Llewellyn, Hans Kelsen, H.L.A. Hart, N. Luhmann, Ronald Coase, Richard Posner, Joseph Raz, Ronald Dworkin. I agree on Holmes, Kelsen, Hart, and Llewellyn; am uncertain about Posner and Raz; and am skeptical about Coase, Luhmann, and Dworkin.
Holmes has already lasted a century fairly well, so betting on another century seems reasonable. Kelsen and Hart are, uncontroversially, the dominant figures of 20th-century legal philosophy, read and studied internationally, who give deep and often very compelling answers to fundamental philosophical questions about law. Insofar as those questions are asked in the future--let's assume they will be--it's hard to see how Kelsen and Hart won't be read for answers.
Llewellyn's corpus is large, and having spent a chunk of my academic career trying to make philosophical sense of the legal realist movement in which Llewellyn was so important, I think I'm entitled to offer the verdict that a lot of it is crap (or, when not crap, very temporally bounded in its interest and significance). But when Llewellyn is on target, he has a deeper and more subtle sense for the nature of legal reasoning in the common law countries than anyone writing before or since. Insofar as the common law lives on for another hundred years (it's done well for several hundred already!), Llewellyn will remain a live figure in legal theory as well.
Coase is famous for a theorem that generates predictions that are, in fact, false, as Robert Ellickson has shown. (OK, I'm being flip--there is interesting discussion of the matter here.) Generating false predictions may not, in fact, be a problem in economics now, but there is reason to hope that will change over the next century, as the pretense of economics to be "scientific" actually comes to mean something. I am sure Coase will be a figure of historical interest; but I imagine that he will be viewed a century hence much as philosophers now view Fichte: how did intelligent people bring themselves to believe those things?
Luhmann seems to be a case study in Nietzsche's dictum: "Those who know that they are profound strive for clarity. Those who would like to seem profound strive for obscurity." Luhmann is, shall we say, a bit obscure at times. There is a reason.
That brings us to Dworkin the legal philosopher. It is uncontroversial among legal philosophers that Raz is the most significant living figure in the field, and that Dworkin lost the famed Hart-Dworkin debate (cf. my article on the Hart/Dworkin debate in the forthcoming symposium issue of the American Journal of Jurisprudence). Relatively few outside legal philosophy seem to know this is the consensus. Perhaps the consensus among experts is wrong, though in this case the reasons supporting it are powerful and damning. Even putting aside Dworkin's numerous and now notorious misrepresentations of legal positivism, Dworkin did raise some excellent questions and challenges for legal positivists; the problem is that Dworkin's answers were not very plausible, and the positivist answers more than adequate. If Dworkin survives in legal philosophy, it will be as a footnote to Hart and the 20th-century positivist tradition.
If we distinguish between being read for "historical interest" (e.g., the way Fichte is read) and being read because the author is more-or-less right (or right enough to be taken seriously, or wrong in ways that are highly instructive to an on-going debate, or the best representative of a view that still needs to be taken seriously, etc.), then I'm more uncertain about Posner and Raz. Posner, like Llewellyn, is more a lawyer than a philosopher, and that has its costs. He will surely remain a figure of historical interest because of his foundational role in developing law and economics, but the question here has to do with his jurisprudential writings.
In the Posnerian corpus, there is nothing, I think, that compares, say, to Holmes on "The Path of the Law." A better analogy is to Cardozo on The Nature of the Judicial Process: like Cardozo, Posner is that rare judge who says with candor, and flair, what it is judges are doing and ought to be doing. It used to be said that Posner couldn't be nominated to the Supreme Court because of past writings like the economic analysis of rape law or the argument for a market in babies. (Posner would be loathed by the Texas Taliban, and their like-minded compatriots in Washington, if they understood his views.) But the real obstacle is if any right-wing pundit or Senator read his views about "pragmatic adjudication" in The Problematics of Moral and Legal Theory (Harvard U Press, 1999), such as:
"pragmatist judges always try to do the best they can do for the present and the future, unchecked by any felt duty to secure consistency in principle with what other officials [meaning both judges and legislators] have done in the past" (241)
which means of course that pragmatic judges like Posner believe it is their job to make policy (i.e., new law) when the existing resources (precedents, statutes) give bad answers as a matter of policy. Now this, in fact, is what judges do quite a lot of the time, but it is rare to read, in print, such a candid defense of the undertaking. It wouldn't play well with the "judges should apply the law, not make law" crowd. (The problem is compounded by the fact that Posner is no social conservative, so his policies wouldn't be pleasing to the Ashcroft crowd.)
Raz ought to be read, since, in my judgment (not mine alone, to be sure), he is the richest of all the major 20th-century figures in writing on law from a philosophical point of view. Far more important, it seems to me, than the old Hart/Dworkin debate, is the Hart/Raz debate about the character of law's normativity--the kinds of reasons the law gives for action--and its implication for fundamental questions about the nature of law and the relationship between law and morality. So Raz ought to be read, and insofar as Hart continues to be read, Raz should be as well. But Raz is difficult, and parts of his philosophical corpus depend on intuitions (e.g., about the nature of authority and authoritative reasons) that may not survive the test of time: it's just impossible to predict.
Certainly one thing working in Raz's favor is that during his long tenure at Oxford he has trained an enormous number of legal philosophers, who now dominate the landscape in the United Kingdom and in many U.S. law schools as well: it is surely a non-trivial sociological fact that professional legal philosophers are overwhelmingly Razian or Raz-trained. Oddly, despite three decades at Oxford, Dworkin trained literally only a handful of legal philosophers, only two of whom are influential defenders of views that are more-or-less Dworkinian: Stephen Perry at NYU and Nicos Stavropoulos at Oxford.
Larry Solum's list left unrepresented 20th-century natural law theory. Given the powerful religious dimension of this tradition, and the strong likelihood that the religions in question will remain important a century hence, it seems to me inconceivable that some natural law theorists of the century just past won't remain "live" subjects of philosophical discussion.
Finally, of course, I aspire to be a figure of historical interest for the program of naturalized jurisprudence. One indication that my aspiration is not idle is that my work has resulted in a new entry in the on-line (but password access only, I'm afraid) Oxford Jurisprudence Glossary:
"Naturalism. Don't worry about it and don't mention it until you come to write your doctorate. (But if you insist, read all about it in the Stanford Encyclopaedia.)"
(UPDATE: Believe it or not, it appears someone out there in Cyberspace didn't get the joke.)