1. Introduction

In June 2016, the prolific science advocate Neil deGrasse Tyson has described a virtual country called “Rationalia”. Rationalia, deGrasse Tyson described, should have a one-line constitution: “All policy shall be based on the weight of evidence”.

If you’re a science-minded person who believes that there is plenty of room for improvement when it comes to the role of science and scientific reasoning within politics, Rationalia probably sounds quite interesting to you. Also, what’s not to like about Neil deGrasse Tyson? He’s a very passionate and, in my opinion, charming proponent of science, and his efforts in science communication, such as, but not limited to the TV series Cosmos, are great.

In his role as a science advocate, Neil de Grasse Tyson is able to reach many people, and in doing so, he is not simply sharing his opinions, but also making his audience think about science and its role in society. His Rationalia tweet, in my opinion, is exactly that: A small thought-experiment, complete with a thick layer of implicit criticism (I would hazard a guess and say that Neil deGrasse Tyson is of the opinion that scientific evidence plays too little a role in real-life politics). However, plenty of online commentators have taken Rationalia pretty seriously and criticized Neil deGrasse Tyson heavily, as he himself explains in a follow-up text¹:

After this Twitter posting several weeks ago, I was intrigued by how many organizations and media outlets hated the idea, being sure that a country founded on evidence and rational thinking would be a “terrible” place.

In that text, deGrasse Tyson is not only summarizing what others thought about Rationalia. He explains where the idea of Rationalia originated, and that it is indeed a criticism of how irrational real-world politics seem to be at times:

This idea was prompted by how much irrational conduct currently drives world politics.

However, the text is also somewhat surprising. Whereas Rationalia-as-a-tweet was a very simple and provocative thought-experiment (I use the term “thought experiment” here in a very general, broad sense) as well as a criticism of the political status quo, the expanded Rationalia-as-a-manifesto seems to have the ambition to be taken not as a mere thought experiment, but rather, as a real-world political idea(l). Is Rationalia something that could actually be realized, in one form or the other, in the real world?

2. Some problems with the Rationalia manifesto

2.1 A constitution cannot be a one-liner

What is a constitution? If you spend any amount of time pondering that question, you are likely to come to the conclusion that there is no single “correct” way to define what a constitution is or is supposed to be. However, from a descriptive, functionalist perspective, there is at least some baseline agreement about what constitutions do. From that point of view, constitutions can be understood as²:

[C]odes of rules which aspire to regulate the allocation of functions, powers and duties among the various agencies and offices of government, and define the relationship between these and the public.

There is an elegant way of describing these various terms with one single concept: Constitutions can be thought of as precommitment strategies^{3 4}. The role of precommitment strategies is to create a system where all participants have rational confidence in the systems’s present and future stability. In less abstract terms, constitutions as precommitment strategies create social trust that the political system in question is real. When you describe constitutions in terms of such a concept, they can also be understood as a prototypical case of declarative speech act: Through the act of declaring that a certain polity exists, that which is declared becomes social reality^{5 6}. The declaration exerts a deontic power⁷— members of the polity in question feel committed to it.

Does Rationalia’s one-line “constitution” qualify as a constitution? No, obviously not. Of course, the declarative line “All policy shall be based on the weight of evidence” can exert some deontic, committing power. But that single line is not even close to being something that resembles a constitution — besides the declaration that policy should be evidence-based, it contains zero information about the actual constitution of the polity that is Rationalia.

2.2 What kind of “rationality” are we talking about?

A very prominent concept in the Rationalia manifesto is “rationality”. Indeed, the very name “Rationalia” is a testament to the importance of rationality for Rationalia. But what, exactly, is meant by “rationality”? Of course, the term “rationality” enjoys a very positive connotation, and we associate with it notions Curiously, the Rationalia manifesto contains no explanation of how rationality is understood therein. The concept “rationality” is not defined within the Rationalia manifesto. If there is one concept that merits a definitorial clarification, it is the concept of rationality — without being clear about what rationality is supposed to mean in the context of Rationalia, it is not possible to accurately explain and understand Rationalia.

The Rationalia manifesto is operating with an imprecise notion of rationality. The biggest problem of operating with the concept of rationality in this en passant manner is that implicitly, two different definitions of rationality are applied. The idea of rationality that is, probably, the one deGrasse Tyson is implicitly and knowingly operating with is epistemic rationality. In a nutshell, epistemic rationality is concerned with the quality of belief justification. A person is being epistemically rational when they have good reasons to hold the beliefs that they hold. If there is no good justification of a belief, a rational person will let go of that belief. Oftentimes, what I have labelled as “good” justification will involve some sort of empirical evidence in order to find out how well a belief fits reality. The question of what exactly makes a belief epistemically rational is complex⁸, but the main idea of epistemic rationality is simple: Epistemic rationality means discriminating amongst beliefs according to how well they are justified.

Implicitly and, I believe, unknowingly, deGrasse Tyson is operating with a second form of rationality: Instrumental rationality. Now, just to prevent confusion: I don’t think deGrasse Tyson is unaware of the concept of instrumental rationality, but rather, I believe he is unaware that he is applying the concept of instrumental rationality in the Rationalia manifesto. Instrumental rationality is concerned with actors behaving in such a manner so as to achieve the goals that they want to achieve. Instrumental rationality is the kind of rationality that rational choice theory is interested in. In rational choice contexts, actors are understood to have so-called transitive preferences, and they are expected to “maximize their utility”, or, in other words, to act in such a way that they achieve outcomes that are as close as possible to their preferences^{9 10}.

How does Rationalia apply both epistemic and instrumental rationality and fails to differentiate between them? On a very general level, Rationalia seems to promote the idea of epistemic rationality:

In such a country, data gathering, careful observations, and experimentation would be happening all the time, influencing practically every aspect of our modern lives. As a result, Rationalia would lead the world in discovery, because discovery would be built into the DNA of how the government operates, and how its citizens think.

Even though the language in the above excerpt is rather imprecise, the main message seems to be that, to paraphrase, beliefs should be justified by evidence. However, all the examples in the Rationalia manifesto that describe political decision-making in Rationalia are very clearly focused on instrumental rationality. Take, for example, the question of whether there should be funding for art in schools:

In Rationalia, if you want to fund art in schools, you simply propose a reason why. Does it increase creativity in the citizenry? Is creativity good for culture and society at large? Is creativity good for everyone no matter your chosen profession? These are testable questions. They just require verifiable research to establish answers. And then, the debate ends quickly in the face of evidence, and we move on to other questions.

Herein lies the central logic of Rationalia: Rationalia is completely about instrumental rationality when it comes to policy-making. There are at least two major flaws in such a system:

1. The arbitrariness trap: If binding social norms, such as proposed laws, simply need to demonstrate that they are instrumentally rational, i.e., that they achieve some empirical goal, then it is almost trivally easy for any proposed law to become law. For example, a proposed law can specify the goal of becoming law, and then, by being passed and actually becoming law, the proposed law has achieved its goal. You might think that this self-referential instrumentalism is merely a bit of sophistry, but it isn’t — it demonstrates that instrumental rationality in and of itself cannot be enough in politics. A crucial step in real-world politics is choosing which goals to pursue and which ones to ignore. Real-world Politics is the art of constant triage.
2. Instrumental and epistemic rationality can be at odds: Instrumental and epistemic rationality can be perfectly compatible with one another, but they can also be at odds. For example, say that Rationalia passes a law with the goal of increasing vaccination rates. One of the measures to do so is a large public information campaign. The main claim of that pro-vaccination campaign is that people who are vaccinated are more sexually attractive and find sexual partners with great ease. Even though such a claim is clearly epistemically irrational — it’s entirely made up — , it might very well be instrumentally rational, in that it would actually motivate people to get vaccinated.

Of these two flaws, the second one, the potential incompatibility of instrumental and epistemic rationality, is probably the greater one. As far as I can tell, there is no sign in the Rationalia manifesto that this problem has been considered.

2.3 If instrumental rationality reigns supreme, where’s the evidence that Rationalia achieves its goals?

The central tenet of the Rationalia manifesto is that binding norms, such as laws, are legitimate when and only when there is evidence in support of them. As deGrasse Tyson describes it:

In Rationalia, the Constitution stipulates that a body of convincing evidence needs to exist in support of an idea before any Policy can established based on it. In such a country, data gathering, careful observations, and experimentation would be happening all the time, influencing practically every aspect of our modern lives.

Evidence, then, is clearly and unambiguously the guiding principle of Rationalia. If there is no evidence for a law in Rationalia, then that law will not be passed. deGrasse Tyson explains this very clearly:

In Rationalia, for example, if you want to introduce capital punishment you’d need to propose a reason for it. If the reason is to deter murder, then an entire research machine would be put into place (if it did not already exist) to see whether, in fact, capital punishment deters murder. If it does not, then your proposed policy fails, and we move on to other proposals.

As I have described in section 2.2, the Rationalia manifesto is sloppy in its understanding or rationality, since it is not differentiating between epistemic and instrumental rationality. In the context of Rationalia, evidence serves an instrumental purpose: Evidence is supposed to show whether the proposed binding social norms achieve what they aim to achieve. If we translate this notion into a general principle, it can be understood as something like this:

• Binding rules, such as laws, can be justified in different ways.
• In Rationalia, the only permissible justification mechanism is instrumental rationality.
• Instrumental rationality means that binding rules specify goals, and evidence needs to show whether those binding rules actually achieve those goals.

Obviously, if one is in favor of Rationalia, then one accepts this rule. However, if one accepts this rule, then the direct consequence is that there needs to be evidence that shows that Rationalia itself works— Rationalia cannot be merely a philosophical normative idea, but instead, it must demonstrably achieve its goals. In other words: If one accepts Rationalia’s core idea that binding norms have to be instrumentally justified, then the very idea or Rationalia in and of itself must be instrumentally justified as well. Of course, there is no evidence whatsoever that Rationalia achieves the goals it aims to achieve. Not only that: Somewhat ironically, the manifesto doesn’t even specify what Rationalia’s instrumental goals should be. Rationalia itself, then, is presented in a way that is not permissible under Rationalia’s “constitution”.

This logical flaw is a common type of “paradox” when operating with absolutes: If instrumental rationality is the absolute guiding principle of Rationalia, then Rationalia itself cannot be introduced with a precommitment strategy like a constitution, because that violates the absolute guiding priniciple that is instrumental rationality. It’s very difficult make logically sound normative political arguments when working with absolutes.

2.4 What kind of “evidence” are we talking about?

The Rationalia manifesto, as well as the Rationalia “constitution”, are very heavy on “evidence”. Evidence is the be-all and end-all in Rationalia, because it is declared the one and only permissible justification for binding social norms. As I have already mentioned above, deGrasse Tyson describes the central role of evidence in the following manner:

In Rationalia, the Constitution stipulates that a body of convincing evidence needs to exist in support of an idea before any Policy can established based on it.

There needs to exist “a body of convincing evidence in support of an idea” before “any Policy can established based on it” [sic]. That sounds, at first, simple enough — if you want to create a law, then the “idea” underlying the law must have “convincing evidence” in support of it. Simple enough. Unfortunately, and crucially, the manifesto fails to offer any form of definition of what is considered to be “evidence”. The notion of “evidence” is treated as something that is self-evident, and thus in no need of explanation. The closest thing to a definition there is is the following sentence:

In such a country, data gathering, careful observations, and experimentation would be happening all the time, influencing practically every aspect of our modern lives.

But what is “data gathering”, “careful observation” and “experimentation” supposed to mean? Talk about “evidence”, “data” and so forth is very soothing to science-minded people — after all, “evidence” is something like the opposite of “bad” things like gut feelings and emotions. But just proclaiming “evidence” to be king is in and of itself meaningless, unless one specifies what exactly evidence is supposed to mean. A discussion of the nature of evidence one prefers is, of course, a debate about epistemology: The question of what constitutes knowledge^{11 12}. If we understand knowledge as justified beliefs (I’m taking the liberty of omitting the debate around justified true beliefs¹³), then “evidence” is a justification mechanism for beliefs. That is a plausible setup, and that’s the main idea of empirical science.

However, just asking that beliefs be justified via “evidence” does not yet say anything about the epistemological nature of that evidence. “Evidence” is the means to finding out how well our beliefs correspond to reality, but many things can be valid “evidence”, entirely contingent on how we believe valid evidence can be produced. I presume that the Rationalia manifesto operates with the epistemological framework of science, but that is neither the only possible epistemological framework, nor is it self-evident why the epistemological framework of science should be preferable to others. Let me give you an example. In a paper¹⁴, I have written about what I believe to be the main problem of so-called complementary and alternative medicine (CAM). That problem is not a lack of evidence — indeed, there is plenty of evidence to justify CAM beliefs. Instead, the problem is that the epistemological framework of CAM is not only different from the epistemological framework of science, but that it is demonstrably defective.

Rationalia’s epistemological framework, as I said, seems to be that of science. But the manifesto contains no information about what exactly the epistemological framework of science is supposed to look like. The closest to there is to a discussion of epistemology is the following description:

Unlike what typically occurs between adversarial politicians, in scientific discourse, when we disagree with one another there’s an underlying premise: Either I’m wrong and you’re right; you’re wrong and I’m right; or we’re both wrong. The unfolding argument actually shapes the quest for more and better data to resolve the differences so that we can agree and move on to the next unresolved problem.

Even though it’s difficult to unambiguously comprehend what exactly is being described here (the whole manifesto is written in rather vague, imprecise language), the gist of the argument is that the epistemological framework of science revolves around determinism. That’s the essence of the description “Either I’m wrong and you’re right; you’re wrong and I’m right; or we’re both wrong.” — epistemic problems can be clarified in a binary fashion; either a belief is false or a belief is true.

Determinism, I believe, has no place in scientific epistemology. The truth status of beliefs cannot be deterministic, but instead, it must be probabilistic. Applied to the example above, that would translate into something like this:

• The probability that you are wrong, Pr(you), is between 0 and 1.
• The probability that I am wrong, Pr(me), is between 0 and 1.
• The probability that we are both wrong is Pr(you)*Pr(me).

One of the main principles of the epistemologic framework of science, I believe, is that it is explicitly probabilistic. The idea that a valid epistemology should operate probabilistically is, of course, nothing new¹⁵.

3. What about democracy?

Some criticism of Rationalia has been levelled at Rationalia’s potential incompatibility with democracy. To me, that criticism misunderstands Rationalia — obviously, it is impossible for Rationalia to be a democratic system, because binding social norms can only be accepted by means of instrumental rationality. It is exceedingly clear that any notion of democracy in the sense of popular sovereignty has to be completely absent in Rationalia, and it has to be so by design — the proceduralist notion of the “will of the people” is incompatible with absolute instrumental rationality.

4. Conclusion: Scrap the manifesto, and keep the thought-experiment

I am somewhat fond of the Rationalia tweet. In my own reading, it’s a criticism of how political actors sometimes disregard the best available evidence in favor of their ideological beliefs. In that sense, political actors can be and sometimes are both epistemically and instrumentally irrational, and Rationalia-as-a-tweet builds awareness for that. Rationalia-as-a-tweet is food for thought, a conversation starter, a little bit of provocation.

Rationalia-as-a-manifesto, however, elevates Rationalia to the level of real-world politics and tries to explain and justify Rationalia in that light. If Rationalia is to be taken seriously as a real-world political idea and ideal, as the manifesto seems to propose, then the breadth and width of Rationalia’s implications have to be considered — and then, it becomes abundantly clear that Rationalia suffers from many problems that, for any practical purposes, make Rationalia impossible.

Even though Rationalia-as-a-manifesto is impossible practically, the simpler Rationalia-as-a-tweet is still valuable: It’s a crude exaggeration that criticizes the political status quo, and in doing so asks for a greater appreciation of scientific evidence in politics. That is probably not a bad thing.

1. deGrasse Tyson, Neil. 2016. “Reflections on Rationalia.” Accessed August 11. https://www.facebook.com/notes/neil-degrasse-tyson/reflections-on-rationalia/10154399608556613/.
2. Finer, Samuel Edward. 1979. Five Constitutions. Harvester Press.
3. Sunstein, Cass R. 2001. Designing Democracy: What Constitutions Do. Oxford University Press.
4. Sunstein, Cass R. 1991. “Constitutionalism and Secession.” The University of Chicago Law Review 58 (2): 633–70. doi:10.2307/1599969.
5. Searle, John R. 2006. “Social Ontology: Some Basic Principles.” Anthropological Theory 6 (1): 12–29.
6.  — — — . 2010. Making the Social World. Oxford: Oxford University Press.
7. — — — . 2015. “Social Ontology and Political Power.” In The Mystery of Capital and the Construction of Social Reality, edited by Barry Smith, David Mark, and Isaac Ehrlich, 19–34. Open Court.
8. Schoenfield, Miriam. 2012. “Chilling out on Epistemic Rationality.” Philosophical Studies 158 (2): 197–219. doi:10.1007/s11098-012-9886-7.
9. Shepsle, Kenneth A. 2010. Analyzing Politics: Rationality, Behavior, and Instititutions. W W Norton & Company Incorporated.
10. Quackenbush, Stephen. 2004. “The Rationality of Rational Choice Theory.” International Interactions 30 (2): 87–107. doi:10.1080/03050620490462595.
11. Dancy, Jonathan. 1985. An Introduction to Contemporary Epistemology. B. Blackwell.
12. Williams, Michael. 2001. Problems of Knowledge: A Critical Introduction to Epistemology. OUP Oxford.
13. Gettier, Edmund L. 1963. “Is Justified True Belief Knowledge?” Analysis 23 (6): 121–23. doi:10.2307/3326922.
14. Kovic, Marko. 2016. “Evidence-Based vs. Complementary and Alternative Medicine: It’s about Epistemology (Not about Evidence).” Swiss Skeptics Discussion Paper Series 1 (2): 1–27. URL: https://www.skeptiker.ch/epistemology-complementary-medicine/
15. Galavotti, Maria Carla. 2014. “Probabilistic Epistemology: A European Tradition.” In European Philosophy of Science – Philosophy of Science in Europe and the Viennese Heritage, edited by Maria Carla Galavotti, Elisabeth Nemeth, and Friedrich Stadler, 77–88. Vienna Circle Institute Yearbook 17. Springer International Publishing. http://link.springer.com/chapter/10.1007/978-3-319-01899-7_6.