Objections and replies

I now address some challenges to generalised two-dimensional semantics. Some of these are objections found in the literature, while others are potential challenges that could be raised. Although my own application of two-dimensional semantics is restricted to analysing diagnostic terms, it is nonetheless worthwhile answering these challenges to the framework as a more general theory.

The first challenge is an objection by Diego Marconi (2004), who argues that generalised two-dimensional semantics is implausible because it suggests that all ordinary expressions are ambiguous. If a term has both a primary intension and a secondary intension, then it could refer to either one of two different things. Of course, Marconi concedes that there are some ordinary terms which express different things in different contexts. An example already considered in §4.2.1 is the term “parent”, which Haslanger (2006) observes could be interpreted as the immediate progenitor or the primary

caregiver of a child. However, according to Marconi, not all ordinary expressions are obviously ambiguous in this way, and so two-dimensional semantics cannot provide a general framework to analyse ordinary expressions.

In reply, I argue that two-dimensional semantics does not entail that terms are ambiguous. Rather, as noted by Chalmers (2010: p. 563), two-dimensional semantics states that a term has a complex semantic value involving a primary intension and a secondary intension, and it has this complex semantic value in all contexts. Furthermore, for a given term, the primary intension and the secondary intension may be coextensive in the actual context of utterance. Consider, for example, the term “water”. At first glance, the suggestion that 1-water roughly picks out the potable liquid found in lakes and

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rivers while 2-water picks out H2O might seem to suggest that the term “water” is

ambiguous. However, on Earth, it is an empirical fact that the potable liquid found in lakes and rivers is H2O. Hence, on Earth, the term “water” refers only to the substance

that has the molecular structure H2O, regardless of whether 1-water or 2-water is

assumed. The primary intension and secondary intension of “water” only come apart when different modal possibilities are considered, such as scenarios involving Twin Earth or other distant worlds. This suggests that “water”, in our ordinary usage of the term in the actual world, is not ambiguous, because the primary intension and secondary

intension refer to the same thing on Earth, even though they are associated with different modal relations when other possible worlds are considered. I argue that the same sort of analysis could also be applied to diagnostic terms.

The second challenge is an objection by Scott Soames (2005), who argues that two- dimensional semantics vindicates internalism about meaning. Internalism is the view that meaning is individuated by the internal psychological state of a speaker. This is contrasted with externalism, which states that it is at least partly individuated by the speaker’s

external environment. Indeed, some proponents of two-dimensional semantics, including Chalmers (1996) and Jackson (1998), suggest that primary intensions are determined by the internal states of speakers. Soames objects to this on the basis that it contravenes the important externalist consequences of the causal theory of reference developed by Kripke ([1972] 1980) and Putnam (1975a).

In reply, I argue that Soames’ objection is not applicable to all varieties of two- dimensional semantics, as not all proponents of two-dimensional semantics favour an internalist account of primary intensions. For example, Stalnaker’s (1978) interpretation of two-dimensional semantics assumes externalism about intensions.Even Chalmers (1996: pp. 58–59) concedes the possibility that primary intensions might be determined by appropriate causal relations between the referents and the speakers, as per the causal

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theory of reference. I propose that my own restricted application of two-dimensional semantics to psychiatric diagnoses is compatible with externalism, as the descriptions that express the primary intensions of the terms are not determined by internal states of the speakers, but are codified in an external resource, namely DSM-5.

A third potential challenge is that it is not clear why there should be only two dimensions of meaning. There may be other ways to break down the meaning of a term, and it is plausible that there are other aspects of a term’s semantic content that are not captured by a primary intension and a secondary intension. Therefore, the worry is that two-dimensional semantics is too narrow a framework to completely capture the full meanings of terms.

In response to this, I emphasise that the two-dimensional semantic framework I have presented is not to be taken as providing an exhaustive account of the meanings of terms. Rather, as noted by Chalmers (2010: p. 556), two-dimensional semantics is compatible with semantic pluralism, which allows a term to be associated with a number of different semantic relations. The primary intension and secondary intension of the term do not exhaust the meaningful content of the term, but are ways of capturing two of the aspects of a term’s complex semantic value. These are not two arbitrary aspects, but two aspects whose semantic relations have useful modal and epistemic roles. Indeed, there may be other aspects of its meaning that are not captured in terms of a primary intension and a secondary intension, but which might be captured by another sort of analysis. However, this can be taken as complementing rather than challenging the two- dimensional semantic analysis presented here. Different sorts of analysis provide ways of capturing different aspects of meaning that are useful for different purposes.

A fourth potential challenge is the worry that the two-dimensional semantic framework I present does not offer an account of the social processes that also influence the semantic practices surrounding psychiatric diagnoses. One such account of these

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processes in the literature on philosophy of psychiatry is Ian Hacking’s (1999) theory of dynamic nominalism. Using the example of childhood autism, Hacking (1999: pp. 114– 115) proposes that psychiatric disorders are interactive kinds. That is to say, categorising disorders results in looping effects that alter the natures of the disorders in question. He argues that since the diagnostic term “childhood autism” was coined, the ideas about the disorder that became prevalent in society have influenced the sorts of behaviour with which new cases present. This suggests that there is an aspect of the meaning of the term “childhood autism” that changes in response to social processes.

Again, in response, I propose that this complements rather than challenges the two-dimensional semantic framework I have presented. In fact, Hacking (1999: pp. 119– 124) himself is sympathetic towards the use of the causal theory of reference endorsed by Kripke ([1972] 1980) and Putnam (1975a) as a tool to analyse the semantics of diagnostic terms. For example, he considers the term “childhood autism” being used to designate the putative pathology P (Hacking, 1999: pp. 119–124). This suggests that childhood autism is an interactive kind with respect to its prototypical symptoms, but is presumed to be an indifferent kind with respect to P. I argue that this is consistent with the analysis that the changes that result from looping effects are with respect to the primary intension of “childhood autism”, whereas the secondary intension is posited as remaining stable in virtue of P. Of course, it may turn out that P is associated with a range of pathologies rather than a single definite pathology, but this might be accommodated with the analysis that the secondary intension of “childhood autism” is disjunctive. Nevertheless,

Hacking’s important observations highlight that there are social dynamics working at the level of classification that are not specifically expounded by the theories of reference discussed in this chapter.

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4.5 Conclusion

This chapter has explored how philosophical theories of reference apply to diagnostic terms, with the aim of resolving the conceptual problem regarding the tension between the descriptive definitions of psychiatric diagnoses in DSM-5 and their causal

conceptions in other clinical resources. After looking at descriptive and causal theories of reference, I sketched how a two-dimensional semantic framework that assimilates the causal theory of reference with descriptive considerations accommodates the two seemingly contradictory ways in which diagnostic terms are used in psychiatry. The framework I have presented suggests that invoking psychiatric diagnoses as causes of patients’ symptoms is not necessarily precluded by the fact that they are defined through symptoms. This partly addresses Szasz’s (1960) argument that a mental illness cannot explain behaviour because it is just a shorthand label for this behaviour. However, an important concession must be made, which I now consider.

While the two-dimensional semantic framework I have presented allows a diagnostic term to refer to the causal profile that normally produces a set of symptoms despite being defined through these symptoms, whether or not the diagnosis actually provides a satisfactory explanation of a patient’s symptoms also depends on the empirical fact regarding the nature of this causal profile associated with the diagnostic category. For some disorders, there are doubts about whether the underlying causal profiles will turn out to be sufficiently stable and repeatable for their respective diagnostic categories to be considered epistemically useful. In other words, it may turn out that the symptoms associated with a given diagnostic category can be produced in many different ways and that there is no unifying set of mechanisms that is shared by every instance of the diagnosis. Such a diagnosis would be like the case of dropsy mentioned in §4.3.4, where the secondary intension refers to a disjunction of several different pathologies. In a more extreme scenario, it may turn out that a given diagnosis may not be associated with any

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discernible regular causes at all, such that every case turns out to have a different causal profile. This is also of relevance to the cross-historical and cross-cultural comparisons of disorders discussed by Radden (2003). I noted in §4.4.3 that a two-dimensional semantic framework accommodates the conceptual possibility of equating Chinese depression and Western depression based on the assumption that their secondary intensions are the same. However, whether it is actually correct to equate Chinese depression and Western depression is ultimately dependent on whether their secondary intensions do indeed turn out to refer to the same kind of causative pathology. This is something that must be ascertained empirically.

In summary, the framework of two-dimensional semantics shows that it is possible for diagnostic terms to be defined descriptively through their symptoms, yet refer to the causal processes that produce these symptoms. However, in order to answer the question of whether or not psychiatric diagnoses provide causal explanations of patients’

symptoms, we need to examine the empirical facts regarding the causal profiles associated with the diagnostic categories. This will be the focus of Chapter 5.

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