Methodology
In Sects. 4.2 and 4.3, respectively, I will present cases which tend to give rise to intuitions incompatible with the stronger forms of transparency presented in Sect. 3.1. This provides some evidence against these forms of transparency. Furthermore, the contents of these judgements can be used as premises in arguments against transparency, and the contents of these judgements are entailed by some popular, plausible views in philosophy of language and mind. I take this to be a reason to reject the two stronger forms of transparency if one either has these intuitions or has independent reasons to endorse the views that entail their contents. In Sect. 4.4 I will argue that only one or other of the two stronger forms of transparency could motivate the weakest form, and that because both stronger forms should be rejected, therefore the weakest form is unmotivated.
In Sect. 4.5 I will present another argument against all forms of transparency.
In Sect. 5 I will discuss two positive arguments for transparency and reject them.
Transparency of Content
Transparency of content entails that if a speaker utters a sentence which has P as its semantic content then the speaker knows that P is the content. The following examples discussed in the philosophical literature provide support for rejecting this claim. Each one involves a different linguistic construction.
Mirror universe (pronouns) (Strawson 1959)
Swapped pictures (demonstratives) (Kaplan 1978)
Twin Earth (kind terms) (Putnam 1975)
Rip Van Winkle (‘automatic’ indexicals) (Kaplan 1989, p. 538; Evans 1985; Perry 1996)
Mirror Universe In their respective halves of a symmetrical universe JohnA and JohnB see MaryA/B sprint and utter ‘She’s fast’ thereby expressing the proposition that MaryA is fast or that MaryB is fast. If the Johns express singular propositions at all they include their local Mary, but they cannot discriminate between their states.
Swapped Pictures Mary points at a portrait without looking at it while uttering ‘That is the greatest philosopher of the 20th century’; her portrait of Rudolf Carnap has been swapped with one of Spiro Agnew. The proposition expressed is about Spiro Agnew, not Rudolf Carnap.
Twin Earth Mary utters ‘Water is wet’ on Earth, where the stuff in the rivers is H2O; the content expressed is the proposition that H2O is wet (\(\langle \mathbf{wet },\text {H}_{2}\text{O}\rangle\)). Twin Mary utters the same sentence on Twin Earth, where the stuff in the rivers is XYZ; the content expressed is the proposition that XYZ is wet (\(\langle \mathbf{wet },\text {XYZ}\rangle\)).
An alternative to the Twin Earth case treats different linguistic communities on Earth as equivalent in some ways to the two worlds. It is more plausible that speakers move between these communities than that they are moved between worlds (Ludlow 1995).
Deference John defers to his community about what sort of plant ‘turnip’ refers to. Furthermore, he moves between two communities that, unbeknownst to him, differ in this respect.Footnote 6 John utters ‘I would like a turnip’ several times in different communities. Different propositions are expressed.
Rip Van Winkle Rip Van Winkle wakes up after twenty years asleep. He utters ‘Yesterday was 3 July 1766’. The proposition expressed is about the day before his utterance, 3 July 1786, not 3 July 1766.
These cases generate strong intuitions about content among philosophers of language. All these cases have been taken as evidence about the semantic contents of sentences. And they all suggest, in one way or another, that semantic content is not transparent. Furthermore, if the cases are as described then transparency of content is false. So, nobody can accept the intuitions prompted by any of these cases and accept transparency of content. Note that in all these cases, the change in the environment that leads to a change in content might not be detectable by the speakers involved.
Two cases in particular, mirror universe and Twin Earth, are particularly important because they have been used as motivations for whole research programmes in contemporary philosophy of language (and philosophy of mind). This is especially true of the Twin Earth case which is a key motivation for externalism about natural kind terms (Putnam 1975; Pessin and Goldberg 1996). The example of a mirror universe has been used to motivate the existence of singular contents (Strawson 1959; Evans 1982).
That the kind of externalism motivated by Twin Earth cases and their various variants raises this kind of issue for transparency is well known, see Brown (2004) for a discussion that includes a summary of the debate. Rejecting this kind of externalism is one way to go, but does not fit neatly with the project of assigning the referents of expressions as their contents and identifying the contents of sentences with structured, Russellian propositions. This gives those working in such a framework a prima facie reason to reject transparency of content.
Focusing on the Twin Earth case and its consequences for transparency brings out the connection between some of the key notions used in philosophical theories about content. In particular, the idea that referential properties of expressions are responsible for the truth conditions of sentences, and that this should be captured at some level of a theory of meaning. In the present view, these properties are captured by semantic content. This raises deep questions about the relationship between semantic content and linguistic competence: what might be pre-theoretically described as knowledge of meaning. This is what is interesting about the issue of transparency, apart from the narrow issue of how to respond to the transparency intuition and its role in arguments like those Dickie makes. If reference determines truth conditions and if reference differs according to factors that are not discriminable by speakers, then linguistic competence cannot require infallible knowledge of truth conditions any more than it can require in infallible knowledge about content. We would therefore have to look for something else for linguistic competence to consist in.Footnote 7
It is important to emphasise that while an externalist must accept that the content of e.g. ‘water’ is not transparent, it might well be that a speaker can come to correctly believe that it is H2O; such a speaker may even know this. The lesson of externalism is not scepticism about content, but that knowledge of content is often partly empirical.
The point made in this section does not require rejecting the plausible claim that speakers can know that a pair of sentences have the same semantic content. For example, someone who knows that Cicero is Tully might know that a pair of sentences differing only in that an occurrence of ‘Cicero’ in the former is replaced by an occurrence of ‘Tully’ in the latter must have the same content. The point is not that speakers cannot ever know anything about content, or relations between the contents of sentences, but that linguistic competence does not require being able to identify content.
Transparency of Structure
My argument will require first getting clear on what propositional structure is. The question of structure in general, and propositional structure in particular, is a vexed one (Keller 2013; Gilmore 2014; Merricks 2015, chaps 4–5; Glick 2017). I am avoiding some issues by assuming that propositions are structured, and I will not offer a view about what it means for a proposition to be structured. This is a deep metaphysical question which needs to be solved, but not here. For my purposes, a rather simple notion of structure can be used which is sufficient to capture the facts about propositions that are supposed to be transparent (or not).
I will start with a definition of what it is for two propositions to have the same structure.
Same Structure Propositions P, Q have the same structure if and only if P and Q are identical in their number and type of constituents and in the predicational relationships between them.
By ‘type of constituents’ I mean that objects are one type, n-place properties another for all values of n, etc. The following propositions will have the same structure, according to this definition:
\(\langle \mathbf{dances },\text {John}\rangle\)
\(\langle \mathbf{sings },\text {Mary}\rangle\)
The following pair will also have the same structure which differs from that of the first pair:
\(\langle \mathbf{loves },\langle \text {John},\text {Mary}\rangle \rangle\)
\(\langle \mathbf{loves },\langle \text {Mary},\text {John}\rangle \rangle\)
The idea of propositional structure can then be derived from equivalence classes of propositions with the same structure.
Now that it is clear how to characterise structure, I will argue against its transparency. I will use a case drawn from the literature on unarticulated constituents inspired by Perry (1986); the case itself is adapted from Recanati (2002). There is a large literature on the theoretical implications of this sort of example which I will not try to summarise (Bach 1994; Taylor 2001; Martí 2006, 2015; Borg 2005; Cappelen and Lepore 2007; Sennet 2008; Recanati 2007; Sennet 2011). I accept the conclusion of John Perry, François Recanati, and others, that there are unarticulated constituents. However, someone who rejected this would not be moved by the present argument. In that case, I will rely on the argument against all forms of transparency in Sect. 4.5.
Eating Mary utters ‘John is eating’. In a suitable context the semantic content is that John is eating o where o is a salient poisonous mushroom. However, this element of content is both (i) optional and (ii) is not the semantic value of anything in the sentence uttered: it is an unarticulated constituent of semantic content.
The optionality of unarticulated constituents is required because otherwise the claim would be compatible with different propositions with the same structure being expressed in different contexts. But the claim that unarticulated constituents are optional allows for the semantic content of (1) to have the structure of either of the propositions listed below.
- (1)
John is eating.
\(\langle \mathbf{eating }_{\mathbf{1}},\text {John}\rangle\)
\(\langle \mathbf{eating }_{\mathbf{2}},\langle \text {John},\text {Mushroom}\rangle \rangle\)
Assuming unarticulated constituents, this shows that there are sentences such that they have different contents in different contexts and that these contents are structurally different. However, this fact in itself is not incompatible with transparency of structure because nothing so far rules out the possibility that detecting this difference is part of speakers’ linguistic competence.
Someone defending transparency might now give the following argument. Whether or not sentences such as ‘John is eating’ or, Perry’s original example, ‘It is raining’ have contents containing objects/locations depends on whether the speaker intended to say something about an object or location. And, this sort of intention is transparent to speakers. So, which structure the contents have is transparent to speakers.
This argument can be resisted by pointing out that it is possible to be linguistically competent and express contents containing locations without having intentions directed at those locations. Perry’s case of the Z-landers can be used to illustrate this point.
Consider a small isolated group living in a place we call Z-land. Z-landers do not travel to or communicate with residents of other places, and they have no name for Z-land. When a Z-lander sees rain, he will say to others not in a position to look outdoors, ‘It is raining’. His listeners then act appropriately to there being rain in Z-land: they close the windows in Z-land, cancel plans for Z-land picnics, and grab umbrellas before going into the Z-land out-of-doors (Perry 1986, p. 144).
The case shows the coherence of such a possibility: these speakers have no conception of the location of their utterances as distinct from other locations and no intentions, at least not such as are transparent to them, directed at locations.Footnote 8 If this is possible, and the Z-landers are linguistically competent, then such intentions are not required for expressing a proposition with a particular structure. If the intentions are not required then their transparency does not show that the structure of content is transparent.
At most, the transparency of the relevant referential intentions shows that speakers often do know something which entails facts about the structure of content. Speakers who know that they intend to be speaking about e.g. some mushrooms could infer from this that the content they express has a particular structure. However, a speaker can be competent both if they fail to make the inference, and even if they lack the intention which they could take as a premise in such an inference.
Transparency of Structural Type
Both transparency of content and transparency of structure would entail transparency of structural type. I have argued against both in Sects. 4.2 and 4.3. I will now argue that, given these conclusions, there is no motivation for transparency of structural type.
For the purposes of this paper transparency of structural type is transparency as to the difference between singular and a nonsingular content. nonsingular contents might be general, or perhaps something else e.g. gappy propositions (Braun 1993; Salmon 1998).Footnote 9 I will assume that we can make sense of this distinction, perhaps along the lines of Glick (2017); my argument doesn’t require any particular account of singular propositions.
As I have said, transparency of content and transparency of structure would both entail transparency of type. But, as I have argued, neither of these should be accepted. What is required to defend transparency of type is an argument that the distinction between singular and nonsingular content is special in a way that the difference is transparent in a way that other properties of content are not.
Someone might claim that the transparency of type is just obvious. But I see no reason to accept this. What would it be like to have immediate access to this property of semantic content without having such access to either content or structure? This is primarily a dialectical point: if transparency of structural type is being appealed to as part of an argument against a view that entails its negation, and if the other forms of transparency have been rejected, appealing to the intuitive obviousness of the claim will not be effective against an opponent who denies it. The result will be an impasse.
One possible response here is to identify arguments for transparency of structural type. One candidate is what I will call transparency of aboutness numerosity. The idea is that it is transparent how many things a proposition is about (on a certain metaphysical picture this amounts to it being transparent how many objects are constituents of the proposition modulo cases where propositions are about properties). If i is the number of objects P is about then P is singular if and only if i is strictly greater than zero.Footnote 10
There are two reasons to reject transparency of aboutness numerosity. Firstly, cases of unarticulated constituents would be counterexamples. In these cases a speaker might believe that the proposition expressed has n constituents when in fact it has n + m where m is the number of unarticulated constituents.
A second argument does not rely on this controversial case. Consider sentences (2), (3), and (4).
- (2)
Mars is Venus.
- (3)
Venus is Venus.
- (4)
Hesperus is Phosphorus.
A standard Russellian view holds that (2) has the first of the following as its content, and (3) and (4) the second.
\(\langle =,\langle \text {Mars},\text {Venus}\rangle \rangle\)
\(\langle =,\langle \text {Venus},\text {Venus}\rangle \rangle\)
The first of these is about two objects and the second is about one. But if this was transparent then it would be transparent that [['Hesperus']] = [['Phosphorus']]. But this is not transparent, which is why identity statements can sometimes be informative.Footnote 11 I will generalise this point in Sect. 4.5.
An alternative argument would appeal to judgements about the modal profiles of various sentences.Footnote 12 The idea would be that speakers make judgements about the modal profiles of sentences such as (5) and (6) which are explained the different structures of their respective contents, and speakers’ access to this difference.
- (5)
Aristotle was fond of dogs.
- (6)
The teacher of Alexander the Great was fond of dogs.
The thought might be that even though speakers might not be able to identify the specific contents, the transparency of type is what explains their judgements about modal profile; they know that whatever the contents are, they are of different types with distinct properties.
This, the argument from modal profile, like the argument from aboutness numerosity, is of the right form to establish transparency of structural type. However, the argument is only as good as the claim that not only do (5) and (6) have semantic contents of different types, but speakers make judgements that that fact would explain. One challenge for this argument would be to point out the seeming variability of the intuitions here. For example, the point about modal profile was argued for by Saul Kripke, and a related point was made earlier, but in a more formal context, by Marcus (1961) and Kripke (1980).Footnote 13 The difference, even if we accept it, was not just obvious to the people that Kripke was arguing against, including Russell (1905). If the judgements are not universal then there is no need to posit transparency of structural type to explain them. As I will discuss in Sect. 4.5, the key point once again is that transparency of structural type would make it too easy to resolve certain disputes in philosophy of language which are in fact difficult.
I take this to be a dilemma for the defender of transparency of type. On the first horn, transparency of type is supposed to follow from the transparency of something else. But there are no good candidates for what this would be. I have considered and rejected content, structure, referential intentions, and numerosity of aboutness in the preceding discussion. On the second horn, it is something special about the singular nonsingular distinction itself. It just is transparent. But without an explanation of why this is so, this just amounts to repeating the transparency intuition. This is not helpful in the context of the debates in which transparency of structural type is appealed to, such as the paper of Dickie’s I referred to in Sect. 2.
A possible response here is to claim that transparency of structural type is a methodological principle.Footnote 14 More precisely, it is supposed to a methodological principle that the semantic type of expressions is transparent. And this is supposed to entail, via the claim that the semantic type determines the structural type of the content, that structural type is transparent. I concede that this is compatible with the arguments of this paper so far. So, if someone thinks that this is a methodological principle I have given them no reason to change their mind. In Sect. 4.5 I will give an argument that should convince them. In any case, I see no compelling motivation for the principle; there is nothing that it allows us to explain that could not otherwise be explained.
Easy Knowledge
I will now give a different argument against transparency that targets all the degrees of strength discussed in Sects. 4.2, 4.3, and 4.4. The argument builds on the argument against transparency of aboutness numerosity in Sect. 4.4.
Transparency, of any strength, would entail that speakers are in a position to know things about semantic content that they are not in fact in a position to know. More precisely, speakers are not in a position to know these things through the kind of introspection that transparency would allow them to make use of. I will illustrate this point with debates from philosophy of language. I could have used at least one more example: the view about empty names that Dickie is discussing in the passage quoted in Sect. 2. However, I don’t want to make claims about this case as part of the argument against transparency because my interest in transparency is in the way it can contribute to the debate over empty names.
The first example is quantifier domain restriction. The key datum is not particularly controversial. Most theorists agree that an utterance of (7) is typically used to say e.g. that every bottle of beer in the house is empty.
- (7)
Every bottle is empty.
But there has been a significant dispute over what the semantic content of (7) is, and how that interacts with what is said. In particular, there is a dispute over whether the semantic content is a proposition true if and only if every bottle (punkt) is empty, or one that is true if and only if every bottle of beer in the house is empty. The latter view might be combined with the view that the syntactic structure of the sentence is richer than it appears. The former view would be combined with an account of how the sentence with one semantic content can be used to say the more specific proposition. For this debate see e.g. Stanley and Szabó (2000); Stanley and Szabó defend the view that the domain restriction is effected by a covert variable present in syntax. As Stanley and Szabó (2000, p. 240) note, Kent Bach is the philosopher most associated with the pragmatic view, see Bach (1994, 1997).
This debate proceeds by subtle theorising that aims to balance intuitions about what is said with the best theories we have about syntactic structure. This debate would be wholly misguided if competent speakers had direct access to semantic content. Given that the debate does not seem to be misguided, this is evidence that competent speakers do not have this direct access.
The quantifier domain restriction case counts against transparency of content, but not against transparency of structure. Two other examples play this role. The first example is the semantic content of sentences containing definite descriptions such as (8).
- (8)
The largest university in South America is in Mexico.
According to the classic analysis of Russell (1905) the semantic content of (8) is general i.e. it has a structure reflecting the logical form \(\exists x(Fx \wedge \forall y\,(Fy \rightarrow x = y) \wedge Gx)\) (Ludlow 2013). This claim has been much debated (Neale 1990).Footnote 15 Whatever one thinks about the analysis, this is not something to be decided by introspection.
Another case is that of complex demonstratives. The debate is over whether sentences such as (9) express singular or general propositions (King 2001, 2008; Braun 2008).Footnote 16
- (9)
That big dog is friendly.
This debate could be resolved if Sect. 4.4 is true. But, like the other cases, this would make it easier than it in fact is to get knowledge about semantic content.
Related to all the above examples is another point against transparency. Philosophers of language and linguists generally agree that it is easy for speakers to confuse semantic content with what is said. This is a very widely discussed phenomenon, see e.g. Salmon (1991); Borg (2004); Cappelen and Lepore (2005). But, if semantic content is transparent this would be very hard to do. Instead, it seems as if competent speakers in ordinary conditions find it quite easy to identify what is said. But, they often simply do not consider semantic content and when they do they tend to make judgements that conflict with the best theories about semantic content.
There are two related issues here. The first is that we just do not access semantic content through introspection, which we could if it was transparent. From this we can conclude that it is not transparent. The second point is that discovering semantic content is hard, whereas it would be easy if it was transparent. From this we can also conclude that it is not transparent. The claim that accessing content is hard can be used to argue that we do not access the content through introspection, because introspection would be easy. The two points taken together offer an explanation for the fact that identifying semantic content is hard.
I conclude from these examples that no form of transparency can be reconciled with the way that philosophy of language and linguistics actually proceeds. In general, both speakers and theorists proceed to knowledge of semantic content, when they have it, by a mixture of empirical and theoretical considerations. The empirical considerations are more relevant when the content of simple expressions, e.g. ‘water’, is under consideration, and theoretical considerations are more relevant to judgements about the structure of content. It is harder to get knowledge about semantic content than would be the case if any form of transparency held, and when we do have it, we do not get it from introspection.
This concludes my arguments against transparency in its various forms. In Sect. 5 I will strengthen my case by responding to two promising arguments for transparency.