Over at Legal Theory, Larry Solum has generously linked here and posted an helpful response. The key part seems to be his analogical move from how we decode the meaning of ordinary documents (like maps) to how we therefore ought to do so with constitutions. It's an argument that reminds me of Gary Lawson's rhetorically brilliant "On Reading Recipes ... and the Constitution" (Georgetown Law Rev 1997), and it strikes me as problematic in much the same way.
Solum's example is of a treasure map from 1689 that uses the word "agolanad", whose meaning has shifted from "oak" to "elm" from 1689 to the 1860s. As he puts it:
"If we want to know what the map meant, we will use the conventional meaning that prevailed at the time, and we certainly won't use the meaning that came into being more than a century later. On the other hand, if we couldn't determine when the map was created, the meaning would be ambiguous, and we would have good reason to look for the location of either an Oak or an Elm."What I find interesting and problematic about this example is that what does the work here in fixing meaning at 1689 rather than 1862 is a set of linguistic guidelines whose force seems to flow entirely from pragmatic, genre-dependent considerations about successful communication. The reason we care about the map's meaning is to find the treasure, and for that purpose, we want to have as direct access as possible to the information that was being communicated by its creation. In short, there's an implied minor premise here about what meaning is, in the circumstances, supposed to accomplish.
But moving from maps (or recipes) to constitutions makes this minor premise more controversial. It's still a colorable one, but it's now something much more like Barnett's argument that I cited earlier--an argument about what constitutions are for (in Barnett's case, generating the stability needed for the rule of law) that gives reasons for preferring fixed over mutable meanings. And I think here, considerations like those pressed by Andrei Marmor and Jeremy Waldron (and, for that matter, Jefferson) carry the day. Language and the natural conservatism of a well-governed polity will provide enough stability for rule-of-law purposes; seeking more would be to grant the framers authority that simply can't be justified.
It's possible to make a more conceptual, less functional, claim instead--that there's something about authorship and fixity inherent in our linguistic practices, perhaps. We read Shakespeare through the light of Elizabethan meaning not because we think it makes the plays better (though it does) but because extricating ourselves from this fixed-at-creation conception of textual meaning would simply be unnatural to us. And I think there's something to this argument, but not enough.
I think its strength, much like the strength of the functional claim, is both genre- and context-dependent. It draws for its force on the Romantic idea of authorship, and is weaker in those areas where this idea plays less of a role. I suspect it would seem much less natural if the text in question was one known to have been banged out by a group of monkeys, or if we were considering lines of computer code that, by freakish coincidence, also executed flawlessly (but in a very different way!) on an entirely different machine than the one they were written for.
To return to constitutions: to my mind, the first and most important truth about constitutional meaning is to view it through the practice of governance that makes it the constitution of some polity rather than an inert text. This is one reason why I think arguments like Lawson's about how constitutions are transparently and necessarily like recipes are misguided: such claims leave little room for understanding, eg., a Canadian constitutionalism that seems to have decisively rejected originalism without falling into anything resembling conceptual incoherence.
Any decisive originalist argument will have to be one internal to the constitutional practice in question. Of course, such arguments must be consistent with (external) theories about what it is to make an internal argument and what truth in such matters could consist in, but I doubt this constraint by itself will settle much.
[UPDATE: Solum continues the conversation here. A clarification--when I claimed that originalism gives more authority to the framers than is warranted, I meant both that it defers too much to their generation, and that, within that generation, it grants the framers in particular too much power. Both these points are fully compatible with rejecting intentionalism, as most originalists do; the framers were still the ones to choose the words, even if we subsequently ignore their internal mental states. That's power, a power I believe unjustified. A fuller response to follow.]