Hans Vaihinger's Fictionalism as a Foundation for Scientific Truth in a Post-Truth Era

Index

1 Let’s talk about Truth

2 Classical Theories of Truth
2.1 Correspondence Theory of Truth
2.2 Weaknesses of the Correspondence Theory of Truth
2.3 Coherence Theory of Truth

3 The Establishment of Scientific Truth
3.1 Fullers "Post-Truth" Approach
3.1.1 Scientific Truth and Power
3.1.2 Scientific Truth as a Social Construct
3.2 The Veritist Approach to Truth
3.3 Scientific Truth from a Pragmatic Point of View

4 Hans Vaihinger: Philosophy of "As-If"
4.1 The Pragmatic Notion of Truth
4.2 Vaihingers Fictionalism
4.3 The Act of Thinking
4.4 Fictions as Fruitful Lies
4.5 Fictions as Maps

5 The Fiction of Global Warming
5.1 Recap
5.2 Example: Let’s pretend as Climate Change would be real
5.3 The Real Truth about Man-Made Climate Change

1 Let’s talk about Truth

"The concept of global warming was created by and for the Chinese in order to make US manufacturing non-competitive” (US President Donald J. Trump on Twitter, 6 November 2012).

So, let’s talk about truth. The tweet above is just one in a long line of climate change skeptical comments that the former US President submitted via the online platform Twitter in the past years, and it could make us wonder how somebody as important as the US President¹ can state something that is so far away from "truth"² or "facts" and still get away with it (Matthews 2017)? To answer this question means to understand what we imply when we say that something is "true" or a "fact" in general, and what we mean by scientific facts or truths in particular.

But before diving into this topic, let me first explain what kind of truth I want to talk about. This is neither an empirical study of how people use the term truth, nor an attempt to answer what truth "is" in an objective or metaphysical sense. Instead, I want to throw a certain light on the concept of truth by posing a pragmatic question: "What is it good for to tell that something is either true or false?

General truths or facts like "look, there is a tree outside" at first seem pretty unproblematic. I can point at the tree and everybody can come, look at it and even touch it. In classical philosophical terms, we can say that there is a "correlation" between the fact (the tree) and our perception of it. But at the latest when we want to talk about scientific truths or facts the notion of truth gets problematic, as scientists seldom just point at trees. They want to describe or explain complex phenomena that are composed out of interrelated facts, and instead of pointing at objects they point at data. Consequently it is very hard to gain absolute consensus in regard to what should count as a scientific fact.

We can not look at global warming in the same way we can look at a tree and for sure we can not touch it. We can only experience something that somebody tells (interprets) is its consequence and look at (meaning interpret) data. And since those interpretations can and do differ, we are not able to establish "the truth" of global warming. To fully understand this fact about facts means to enter something that Stephen Fuller calls the "Post-Truth" condition. In this condition we do not only dispute about whether something is true but also about how this truth should be established. Consequently there are as many conflicting truths as observers.

Yet, we need a strong meaning of truth in order to guide our actions as individuals and as a society. While lots of people tell us that we have to stop burning fossil fuels today in order to mitigate the effects of global warming, others tell us that global warming is nonsense. So how should we act, and who should we listen to, if we know that nobody can tell what the "real" truth is? It almost seems like truth is something that we desperately need but can not have.

I begin my search for answers by looking at two of the most fundamental theories of truth: the Correspondence Theory of Truth and the Coherence Theory of Truth. Those two can be considered "basic" or classical answers to the question of truth, while several others, like Tarski‘s Theory of Truth, Realism and Antirealism, Deflationism, and others either try to cope with the problems that arise in the context of those classical conceptions or state completely new ones (for an overview see Glanzberg 2021).

Since I am ultimately interested in the notion of scientific truth, the second chapter is dedicated to the discussion of two modern theoretical approaches to the problem of truth, Steve Fullers critical "Post-Truth" approach and the positive "Veritist" approach represented by Baker and Oreskes, that aim to explain how scientific truth differs from everyday truth and how scientists establish consensus among each other.

As both approaches substantially differ in their interpretation of the problem, I discuss Hans Vaihingers Fictionalist Theory of Truth in an effort to “sublate” (“aufheben” in Hegels words) both approaches in a synthesis afterwards.

Finally, I use the newly gained knowledge and apply it to the example of man-made global warming. My proposal is that it could be beneficial, if we would stop trying to establish global warming as a scientific fact and start seeing it as a socially constructed fiction, that can positively guide our actions.

2 Classical Theories of Truth

The term "truth" derives from the old English word "troth" which means "good faith" or "loyalty" (Hoad 1993, 506). Yet, there has been a historical shift in the meaning of the word in the last millennial (Fuller 2018, 26). While originally truth meant faith or loyalty to a higher order like the Catholic Church or a person like a general, at the latest since Aquinas truth is more connected to the target of philosophical inquiry.

2.1 Correspondence Theory of Truth

Aquinas memorable phrase "veritas est adaequatio intellectus et rei" (Thomas 1986, I 1) marks the beginning of a line of thought that later became the so-called Correspondence Theory of Truth (short: CRTT). If we try to find a definition for the main idea of the modern CRTT it could be something like: "a belief is true if and only if it corresponds to a fact” (Glanzberg 2021, 7).

For instance the statement "the pen is on the table" seems to be true, if my mental representation of it "being there" matches with my sensations. I can see it, touch it, feel its weight, and maybe even smell it. In everyday language, one could say that: "something really ‚is‘ like one thinks or says".

It’s hard to tell if the CRTT became intuitive or if it built on intuition, but one could argue that most people, at least unconsciously, use the word truth in the sense of CRTT.

However, from a philosophical point of view, the CRTT has its weaknesses. For example the CRTT is not self-referential. This means that I can not tell that the statement "the CRTT is true", is actually true, by referring to the CRTT, as there seems to be no external thing I could compare this statement to. For the same reason the CRTT does not apply, if we want to express moral statements like "murder is morally wrong", personal statements like "I like Jelly Beans", hypothetical propositions like "if I work hard on this paper I will get a good grade" and mathematical or logical truths like 4/2=2. With all those statements, it is hard to find a "thing" in the world that the statement could correlate to.

2.2 Weaknesses of the Correspondence Theory of Truth

The major problem with the CRTT is, that we need to be able to find two different entities that could correlate. Firstly something in our minds (like thoughts, ideas, conceptions) and secondly something objective that is different from our minds and that we can find, mostly with the help of our senses, in the outside world. But the notion of “objectivity” seems at least as problematic as the notion of truth itself. One could even argue that the whole scientific enterprise is about the search for objectivity and that there has been some major disputes in the history of philosophy about the extent to which we rely on sensory experiences in our efforts to gain knowledge (see Markie 2017).

Kant argues, that in order to be able to compare some object with our cognition, we would have to recognize it first. But by recognizing it we transform the object, or better: our perception of it, into thought. To establish correlation, our cognition should therefore confirm itself, which is by no means sufficient for truth. For since the object is outside us and the cognition is in us, we can only ever judge whether our cognition of the object corresponds to our cognition of the object (see Kant Log, AA09: A 70). So we end up comparing thoughts with other thoughts.

But even if we assume that we can get objective knowledge with the help of our senses, we would still need some way to store and distribute this knowledge. Some philosophers and scientists that formed the Vienna Circle thought that we could do so with the help of so called "protocol statements" (see Carnap 1931; Neurath 1932).

Rudolf Carnap imagined that we could build all science on simple statements of the form "now here indicator needle on 5" (Carnap 1931, 438). But I follow Moritz Schlicks opinion, that even such simplest protocol statements are hypotheses in the end, as they only have immanent meaning at the moment of the actual observation (Schlick 1934, 495).

As soon as the physicist writes her observation down, it becomes a hypothetical statement of the form "if I design my experimental set-up exactly as I did back then, then the indicator needle should point at 5 again". Ultimately, Schlick argues that any statement is a hypothesis, as we can divide any statement into the statement itself and the moment or possibility of its validation. This means that, at least in science, we deal exclusively with hypothetical statements which we somehow have to bring into a coherent order (ibid. 500 pp.).

2.3 Coherence Theory of Truth

Schlicks reflections in regard to protocol sentences lead us to the second big theory of truth that I want to discuss here. The Coherence Theory of Truth (short: CHTT) builds upon the idea that we can never recognize things-in-themselves, but only their appearances and that "a belief is true if and only if it is part of a coherent system of beliefs” (Glanzberg 2021, 11 f.).

To clarify this, let’s take the statement from above and modify it. There was a pen on the table and now it is gone (I suppose it fell down, but I don’t know if it did). From the perspective of the CHTT the statement "the pen is on the ground" is true because there is a coherent network of other statements that support it. "I sense that the pen is not on the table any longer” + "I heard something hitting the ground” + "Somebody else heard something” leads to "The pen is on the ground.”

The good thing about CHTT is, that it works great with hypotheses and therefore seems more suitable to explain how come that we count something as true in science. Let’s take the statement that "black holes exist" as another, more scientific, example. We can not see them directly, but there is coherent data that supports that statement. Light that travels nearby gets deflected by them, they draw matter inward when traveling through clouds of interstellar matter, we can see their gravitational influence on nearby systems etc.. So the big advantage of CHTT over CRTT is, that it does not only work with everyday statements, but also with logical, mathematical and hypothetical statements. This is why the CHTT seems much more suitable to explain how scientific truth gets established (see Thagard 2007).

Still, the CHTT also has it’s downsides. The first one is the so-called specification objection, firstly formulated by Russel in "On the Nature of Truth" (Russell 1906). It says that you can have a coherent set of propositions that nevertheless supports a false statement (ibid. 33). Conspiracy theories³ are a good example of something one might call an echo chamber of falsity. The second big problem with the CHTT is the transcendence objection (see Young 2018). One could argue that there are prepositions that are true, despite not cohering with any set of beliefs. An example could be something like the preposition: "it took me 10 seconds to write down this sentence". You don’t need much context or knowledge other than basic vocabulary to believe in the truth of such a sentence.

However, for me the biggest problem with the CHTT is, that it demands a radical idealism in regard to the world, as it certainly feels like we are relating to some objective world when we talk about truth. And scientists, among others, seem to believe that when they talk about black holes for instance, they talk about something that is equally true and real, as the trees outside their laboratories or pens on their tables.

[...]

¹ Besides Donald Trump there are dozens of famous climate change skeptics (see e.g. Cook et al. 2016; Powell 2017; Denelle 2021).

² From here on I will try to refrain from using exclamation marks around the words truth and fact, while keeping a critical attitude towards those words.

³ The fact that we even call such narratives "theories" shows us that in reality it is hard to differentiate true theories from false ones.