<i>Definition and Dispute: A Defence of Temporal Externalism</i>

Metasemantic externalism holds that facts external to speakers or thinkers—say, the fact that the watery substance in their environment is H2O—can partly determine the meanings of their expressions, and the contents of their thoughts. Temporal externalism (TE) posits that “facts about what happens at later times can play a role in determining the meaning of our words (and the contents of our mental states) at earlier times” (3). This intelligent and rich monograph offers the first book-length defense of TE, which makes it mandatory reading for anyone interested in metasemantics. The book does quite a lot besides defending TE. Among other things, it rebuts the aspiration of conceptual engineers to provide a novel methodology distinct from theorizing (chap. 3), it argues that paradoxes like the liar are hard for the same reasons of scale and dearth of resources that makes scientific challenges hard (chap. 4), and it offers a pragmatics on which the conversational parameters determining who counts as ‘tall’ or what counts as ‘funny’ are retroactively set by the judgments the participants arrive at in the end (chaps. 8 and 9). However, I will exclusively consider the case for TE. Just like the author, I focus on TE as a metasemantics for language rather than for thought.Much of the discussion in the book concerns what the author calls ‘definitional disputes’ (2). These are those common “disputes that seem (in some sense) to turn on matters of definition” (2) we engage in whenever we discuss issues such as: Is same-sex marriage possible? Is Pluto a planet? Is free will compatible with determinism? Are atoms mereological simples? Must art be intended to be beautiful? Definitional disputes are ostensibly driven by reasons and argument. Suppose you surmise, “But art has to be beautiful!” I might bring you to change your mind by pointing out that artists may well intend their works to be disturbing rather than beautiful—just think of Marcel Duchamp and his urinal. Now ‘art’ is a vexing term, and debates about art are hard to interpret by anyone’s standard. Still, the author uses ‘art’ and something like our little dispute as his default examples throughout the book.Definitional disputes play a dual role in the author’s view. First of all, their outcomes are seen as metasemantically relevant. TE holds that future facts can determine the present meanings of terms such as ‘art’. Which facts are these? The author sees TE as particularly committed to the idea that future discursive facts can play this role: “The conclusion we reach at the end of the debate can act as a stipulation that determines what we meant all along” (101). Suppose that our dispute about art eventually leads to a number of claims we accept. On TE, these future claims can provide a meaning-determining implicit definition for ‘art’ that “fixes what all parties to the dispute meant all along, regardless of what they believed at earlier times” (101). Whose future claims are relevant? Yours and mine? Those of our distant discursive descendants? The author doesn’t commit. He defends TE as a generic view for ‘art’, ‘atom’, and their ilk. This allows him to defer all issues of theoretical detail to the last chapter and discuss them as matters of mere choice.So—why should we agree that TE has to be right? It is here where definitional disputes come in again. The author believes that TE has to be right because this metasemantics offers the best explanation of how definitional disputes work. More specifically, he thinks that TE proves right once we establish the following claim:Meaning Sameness is a contentions idea. It runs counter to the view that definitional disputes are metalinguistic negotiations. It also doesn’t square with the Ramsey–Carnap–Lewis metasemantics the author himself enlists in his argument against conceptual engineering. For if our meaning of ‘art’ is fixed Ramey–Carnap–Lewis-style by our collection of platitudes about art, and if my observation about Duchamp’s urinal and its disturbing qualities—which concerns art rather than ‘art’ and so isn’t metalinguistic—brings us to drop the platitude “Art has to be beautiful,” then our theory of art and the meaning of ‘art’ will both change.Although the dialectic is somewhat intricate, it seems fair to say that the author’s extensive case for TE very much pivots on Meaning Sameness. On the most natural reading, his first two signature arguments are meant to support Meaning Sameness, while the third argues from Meaning Sameness via generic externalism to TE. First, the Wrong Kind of Reasons Argument (chap. 3.2) aims to rebut the competing view of definitional disputes as exercises in metalinguistic negotiation that effect changes in meaning: If definitional disputes are metalinguistic and thus “about how to use words,” practical “reasons to speak a certain way” in the forms of threats or bribes should settle these disputes (27). Since they don’t—they are the wrong kinds of reasons for this—definitional disputes are not about how to use words. The limits of this argument become apparent once we recognize that our metalinguistic negotiation does not concern the unqualified question “How should we use ‘art’?” It rather concerns the more specific question “How should we use ‘art’ in order to sensibly classify things?” Bribes or threats don’t settle this matter, even though it explicitly concerns language use.Second, the Argument from Charity (chap. 6.4) aims to show that charity compels us to take retrospective reports of error such as the following at face value:There is much to be said here. Our situation is arguably more complex: We initially introduced atoms as those indivisible objects that play a specific explanatory role in chemistry-cum-physics but later found that being indivisible and playing that role came apart. According to the Ramsey–Carnap–Lewis view, we had a choice between concluding that there are no atoms after all and implicitly redefining their characteristic properties by adapting our platitudes, and we opted for the latter. Still, the most important thing to note is that for all their apparent naturalness, condensed and decontextualized (self-)reports make for equivocal evidence at best. This becomes apparent once we see that reports which explicitly say that meaning has changed may feel just as natural. Consider: “I used to say ‘Atoms are indivisible’, because I thought that atoms are indivisible. But then modern physics changed the meaning of ‘atom’, and I saw that I had been wrong. It turns out that atoms are divisible after all.”These arguments convince the author that we should accept Meaning Sameness. (Here I go with his summary on page 97.) He understands Meaning Sameness to establish some form of externalism, since this metasemantics best explains how ‘art’ and ‘atom’ can have stable meanings even though our beliefs about art and atoms differ a lot. But which variety of externalism should we accept? The Argument from Spurious Evidence (chap. 5.3.2) is meant to rule out externalist rivals to TE. The idea is this: Kripke-inspired views see meanings as fixed by initial introductions. But then “considerations about the historical origin of the practice of using a word” (84) should settle definitional disputes. Since they don’t—historical facts just aren’t relevant—these externalist alternatives to TE fail.This argument against causal-historic externalism hardly makes a strong case for TE. First, let’s agree: Evidence about past usage does not settle definitional disputes. But why should evidence about future usage fare any better? (Pointing to present paradigms such as Duchamp’s urinal does fare better, which supports the views mentioned below.) Second, Kripke (1980: 138–39) himself hints at a dynamic picture when he allows that “the ‘original sample’ gets augmented by the discovery of new items.” Third, externalist metasemantics such as Sally Haslanger’s (2012: 374) ‘objective type externalism’ or my own ‘paradigm term semantics’ (e.g., Nimtz 2017, 2021) see meanings as externally determined by the paradigms we presently accept (and, on my account, a suitable equivalence relation that does rather a lot of explanatory work). The author discusses no such views. True, neither approach considers ‘art’. But we are comparing generic theories, and we haven’t yet seen a detailed TE for ‘art’ either. The author is also right to emphasize that there may be no suitable unique objective type for ‘art’ (169). But this just means that ‘art’ may be indeterminate, polysemous, or context dependent. Given that we have no assurance that the future discourse on ‘art’ will converge rather than fragment, this hardly speaks in favor of TE. In actual fact, it may simply underscore once again that ‘art’ is a rather vexing term to begin with. So there is no easy argument for TE even if we accept Meaning Sameness for the likes of ‘art’ or ‘atom’—which, for the record, I don’t think we should.Beyond arguing for TE, the book provides a broad discussion of issues pertinent to this metasemantics, such as the metaphysics and epistemology of properties that things have at times in virtue of what happens at later times, such as being good on a consequentialist view that has goodness depend on the actual outcome (chap. 7), or the meta-metasemantic underpinnings of TE (chap. 10.4). Incidentally, I feel that the latter reveals much about the general perspective the author takes throughout the book. In virtue of what does TE hold true? Noting that the standard idea—that this is due to the dispositions speakers have (Cohnitz and Haukioja 2013)—doesn’t quite fit his case for TE, the author gives a fundamentally different answer: Future facts play a role in determining meanings “because [this] is the best way of interpreting us so that our definitional disputes and inquiries are reasonable and make sense” (177). This idea is highly instructive. For once we read TE as an interpretationalist metasemantics, it appears a far more enticing and, given the robustly realist moorings of standard externalism, a far more radical view indeed.