The mismatch between sentence and reality

Or what we can learn from the Liar Paradox

I have long had a fascination with different philosophical paradoxes, not just because of inherent puzzles involved, but also for what they tell us about our assumptions, theories and mindsets. The peak of that interest was writing my PhD thesis on the Liar Paradox, with the very short (2,000 word) version available on this Substack. It turns out that I’m not the only author on Substack who has written a PhD thesis on this topic and who has published a summary of his argument (currently, but not always, paywalled). This approach from Ben Burgis has some similarities to my views but there are notable differences that, in my view, reflect a flawed way of thinking about the relationships between language, truth and world.

While it may be philosophically flawed, this way of thinking is common amongst logicians and philosophers, and widespread in our broader culture and online. To understand why it is flawed we first need to focus in on the key assumptions. As a result, the first part of this post is fairly technical and may not interest all readers, but the final section is more broadly applicable.

Does “is true” really mean anything?

For the sake of brevity, I want to hone in on one particular view, summarised in this quote from Burgis:

I subscribe to a view called “disquotationalism,” according to which the effect of saying, e.g. that the sentence “Snow is white” is true is simply to assert that snow is white. In other words, the effect of adding “is true” to a quoted sentence is just to remove the quotation marks.

Some technical context will be useful for this to make sense. For logicians and philosophers interested in these topics, the canonical use of the concept of truth is as the predicate “is true” and so they focus on sentences like:

“Snow is white” is true.

or

P is true. (where P is the name of some other sentence)

The disquotationalist position is therefore that that the predicate “is true” adds nothing meaningful to the original statement. It may have a different function in language, perhaps a marker of emphasis, like using an exclamation mark, but doesn’t add any additional information. As Burgis puts it (using more technical terms):

sentences of the form “‘P’ is true” inherit 100% of their propositional content from whatever proposition is expressed by P. Sentences of the form “‘P’ is not true” inherit their propositional content from the negation of P.

For context, the propositional content of a sentence is the claim it makes about reality and therefore the content against which we judge it to be true or false.

The motivation for disquotationalism is the intuition that a sentence like “snow is white” doesn’t say anything more or less about what the world is like than “It is true that snow is white” does.¹ Both are either correct or incorrect together. However, this intuition only holds if we assume that the primary or only function of language is to make descriptive statements about the world (or reality), and that the only meaningful sentences are those that do so.

A more complex relationship

There are various ways to critique this view,² but one important one is that this view of language assumes there is a relatively neat and straightforward mapping or correspondence between our language (and the statements we make) and the reality we are trying to describe. This assumption misses the messiness and partial nature of the relationship between language and reality. The words and statements we use normally only partially describe or specify what we mean. Context, gestures, background assumptions and shared communal norms are all important for determining exact meanings but aren’t explicit parts of our language.

Given this messiness, our languages have inbuilt concepts and apparatus for clarifying some of these relationships between language, context and reality. One of these is the concept of truth.

To explain, let’s consider an example I’ve used elsewhere from fiction. Take the sentence “Sherlock Holmes lived on Baker St.” If someone asked you “Did Sherlock Holmes live on Baker St?”, the correct response would normally be “Yes”. However, if someone asked “Is it true that Sherlock Holmes lived on Baker St?”, the question suddenly gets much more difficult.

For a start, the fact that our answers to these two questions are not immediately the same is evidence that disquotationalism can’t be correct. But the reason why this question is difficult is that, as I wrote previously, our knowledge that Sherlock Holmes lived on Baker St is knowledge about the fictional world created by Arthur Conan Doyle. Given the context of the statement or question, we naturally assume we are talking about this fictional world, and so would answer ‘yes’ to the original question. However, if we are challenged about the truth of the statement, that typically brings the question back into the real world, in which case the answer turns into various forms of ‘No’.³

This is a good illustration of the complexity of the relationship between a sentence and reality in the language we use in every day situations. There are at least three different components we need to understand or grasp about a sentence before it makes sense to decide on whether it is correct or incorrect, true or false. These are:

1) The immediate meaning of the sentence or statement.

2) The meaning of (or information being expressed by) the sentence within the particular time, place, and context, it is uttered or written in.

3) What the information expressed is about - it could be the real world, a particular discipline, a scientific theory, a fictional world.

The typical assumption in many logic and philosophical discussions, and often shared by people more broadly today (especially on social media), is that we only need the first of these to decide on the truth of a statement (perhaps with rare exceptions). From the meaning of a sentence we can decide whether it is true or false.

The Sherlock Holmes example demonstrates that it isn’t that simple, and given our human affinity for story telling, jokes, irony and wordplay, I’d argue that the straightforward, straight-line examples favoured by logicians and philosophers are the exception rather than the rule.

If we accept this analysis, contra disquotationalism, the assertion that a sentence is true does have an important role and meaning in our language. It is a slightly complex assertion that multiple things hold, namely that a sentence is (i) meaningful; (ii) legitimately about the real world and (iii) is a correct description of the world.⁴

Sentences can fail to be true when they fail against any of these criteria. Obviously, a sentence that isn’t meaningful cannot be true. And if it doesn’t provide a correct description of the world it clearly isn’t true. But there are also different ways a meaningful sentence can fail the second criterion and not be legitimately about the real world.

Fictional statements are one example. Others are statements with false assumptions built in, such as the common philosophical example that “George stopped beating his wife last year”. The statement is not true if George never beat his wife or isn’t married. Importantly in both of these cases we also can’t say that “George didn’t stop beating his wife last year”. Instead, the original statement fails to be about the real world as it assumes something that isn’t the case. I have argued that the Liar Paradox falls into this category - it doesn’t succeed at saying anything about the real world - which prevents the paradoxical logic biting.⁵

Looking at it this way, there is something correct about the disquotational view: the statements “snow is white” and “it is true that snow is white” don’t give us any different information about the world. But the latter statement gives us important information about which world we are talking about and specifies that the statement holds for the real world. This means that we cannot simply dismiss “is true” as not adding any additional meaning. Instead the meaning is about the relationship between language and the world, rather than the world itself.

Not just an esoteric argument about language

This article so far might read like classic academic nit-picking, but the assumptions it reveals matter in daily life. I’ll illustrate with respect to social media as it is an extreme case, but the point holds more generally.

It is common for people to make the same assumption that the logicians and philosophers do, namely that all we need to be able to evaluate the truth of some statement is to know what it means. This drives a huge amount of outrage online as people read a tweet, post or article and react to the simple statements based on what the reader takes it to mean.

The problem is often that people ignore context, background, and implicit assumptions (i.e. everything covered by point (2) above). The reader therefore takes it to mean something different from what the original person intended. This is particularly an issue when people are making jokes, playing with ideas or riffing off each other as what is often being said is either (a) not about the real world and/or (b) means something different from what is literally being said.

Human communication and relationships thrive on these gaps between language, meaning and reality and we play around with these in all sorts of interesting and sophisticated ways. Assuming a literal correspondence between language and reality misses what it means to be human, and so often provokes outrage and confuses people over things that should be easy to understand.

Philosophers end up puzzling over things like how fiction works. Fact checkers end up tying themselves in knots trying to fact check memes and jokes. Social media users can’t help but fall for rage bait. And builders of generative AI systems end of using everything online as a single training data set based on the assumption that everything there is equivalently about the real world and is all useful for determining what is true.

1. For reference, I prefer using the grammatical form “It is true that .....” rather than “…. is true” as it is more natural in most languages for the types of examples we want to look at.

2. For example, jokes, irony, play, stories, emotional support, power relationships and similar dynamics are all central to human language but only sometimes make sense in a declarative statement model.

3. As an aside, I would argue that we can say that it is not true that Sherlock Holmes lived on Baker St because Sherlock Holmes never existed in the real world. But this is different from the assertion that Sherlock Holmes did not live on Baker St, as that would typically assume he lived somewhere else. I take this as evidence against Burgis’ claim that ‘Sentences of the form “‘P’ is not true” inherit their propositional content from the negation of P.’

4. Of course, given how humans operate it is not always that simple. A group can set the overall context that matters as being about a fictional world and then ‘is true’ will refer to canonical information within that world. But this is a less common use.

5. As a technical note for anyone interested, this means that the T-Schema is incomplete as a definition of the concept of truth. See my thesis for a long and hard to read explanation, or reach out and I’ll share more info.