Fifteen Eighty Four

Section 1: What are Thought Experiments For?

Thomas Kuhn famously asked how it was possible for thought experiments to lead to new scientific knowledge in the absence of new data. In philosophy, research on thought experiments has mainly followed the trajectory established by Kuhn, focusing on their role in the sciences. Kuhn’s asks what thought experiments contribute to the bank of human knowledge. My book takes a different starting point, beginning from the philosophy of Søren Kierkegaard and his contemporary, the scientist Hans Christian Ørsted. For Kierkegaard and Ørsted, thought experiments were less about acquiring new knowledge and more about training the mind to think well.

A lot of the time, they feared, our minds can lose the thread of an important concept without realizing that we have. We may perform the right actions and maybe even use the right words, but without understanding the reasons for what we’re doing and saying. Ørsted, especially, was influenced by Immanuel Kant, who argued that many terms we use regularly, such as “self” and “universe,” don’t mean what we think they mean. By default, we think of these terms—just like any noun—as referring to object we could possibly experience, like “flower” or “house.” But Kant argued that terms like “self” and “universe” can’t possibly refer to real objects. A flower is an object we can experience with our senses, but the universe as a whole is more like the implied background for experiences of things like flowers and houses. Kant tried to establish how abstract terms that don’t relate to objects can still be meaningful. He used the term “cognition” [Erkenntnis]for what we do when we genuinely understand an idea and can relate it meaningfully to experience. We can do this either by having an experience that falls under its heading (such as by perceiving an actual flower) or by understanding its role in experience (for example, recognizing that the world is the background of possible experiences).

Cognition may lead to knowledge, but it doesn’t always. For Kant, knowledge includes additional requirements of believing that something exists. When I perceive a flower, I not only understand what a flower is but gain the further belief that there is one in front of me. This can happen in a moral context, for example, when I consider a possible action and realize I have a responsibility to others, not just myself, in performing it. I argue that for Ørsted and Kierkegaard, thought experiments are another way we can bring thoughts to cognition—that is, make thoughts meaningful. One conclusion of book is that the work of cognition is more fundamental than the question Kuhn asked about how thought experiments provide knowledge. The work of keeping us honest about our concepts and what they refer to is more fundamental.

Section 2: The Defining Features of Thought Experiment

The book highlights three essential characteristics of thought experiments. These  characteristics are based on the work of Kierkegaard and Ørsted as well as Ernst Mach, who was (wrongly) thought by many scholars to have coined the term “thought experiments.” Three essential characteristics of thought experiments I discuss in the book are:

1. Variation: All experiments intentionally vary a situation to see what happens. Empirical experiments change something physical (e.g., by adding heat). Thought experiments change something too, but only in the imagination. Variations are most obvious in famous cases like the trolley problems where there are actually multiple versions. What happens if we change the number of people on each track? What if we have to actively push someone onto the tracks to stop it who would otherwise be an innocent bystander? What if the person making the decision has a role-related responsibility to some of the people (e.g., is the mayor)? Even thought experiments with only one version vary a feature of reality for the imaginary context.
   
2. Freedom: For Ørsted, the ability to introduce new variations that are freely chosen by the experimenter is what makes thought experiments properly “experimental.” Remarkably, the presence or absence of empirical data in the result is not, according to him, definitive of what it means to be an experiment. Whether or not we agree on the results, what matters most to Ørsted is the ability to control the situation by adding or removing feature whose presence makes a difference. He is heavily influenced by Kant’s theory of autonomy in scientific experiments, and so it matters to Ørsted that the variations in thought experiments are deliberately designed. The fact that the variations are merely imaginary doesn’t matter here; in fact, the fact that the human mind is the only limit means we are even more free than we conduct experiments by changing things in the physical world.
   
3. Authenticity: Thought experiments don’t provide new knowledge but change how knowledge or concepts are appropriated. The focus isn’t on the bank of knowledge but on its relationship to individual learners. Concepts and connections need to be actively made by researchers. For this reason, both Ørsted and Mach emphasized the importance of thought experiments for pedagogy. Students in a classroom do not typically gain new knowledge in the sense of being the first to make a discovery. Instead, they perform cognitive work that is new to them,that introduces them as particular individuals to knowledge already gained by others. Thought experiments are one way that new generations can come to fully understand and take responsibility for the discoveries they inherit from others.

Throughout the book, I emphasize how similar Ørsted’s views are to Mach’s. This is a controversial emphasis in contemporary scholarship of thought experiments, because up until now scholars have paid more attention to Mach than Ørsted. By highlighting the similarities between them, I show that Ørsted deserves more attention in accounts of the history of thought experiments than he typically receives.

There are also a number of similarities between Kierkegaard’s discussions of thought experiments and Ørsted’s. Like Ørsted, Kierkegaard hopes that thought experiments can help readers make sense of terms and concepts that have no visible representations. Kierkegaard’s work famously addresses transcendent concepts like faith, love, and forgiveness. Terms like these easily lose meaning through overuse or by attaching them to the wrong kinds of experiences. (For example, we might reduce “love” to being kind to people from whom we have something to gain.) Kierkegaard uses examples and complex imaginary scenarios to enable his readers to think difficult concepts in more meaningful ways.

My forthcoming book delves into the history of the concept of thought experiments (focusing especially on Kant, Ørsted, Kierkegaard, and Mach). I also show the broader importance of cognition for human thinking. Shifting the role of thought experiments from knowledge to cognition solves some problems in contemporary accounts of how thought experiments work. Throughout the book, I apply these discoveries to contemporary thought experiments like the trolley problems and body swap/mind swap cases. I argue that even when thought experiments strike us as bizarre and fall far outside the bounds of normal experience, they can still train us to be better, clearer, and more authentic thinkers.