David Thorstad is Assistant Professor of Philosophy at Vanderbilt University, Senior Research Affiliate at the Global Priorities Institute, Oxford, and Research Affiliate at the MINT Lab, ANU. His research focuses on bounded rationality, inquiry, and the ethics of emerging technologies. In this Recently Published Book Spotlight, David discusses his most recent book, Inquiry Under Bounds, in which he develops a novel and comprehensive theory of rational inquiry influenced by the work of Herbert Simon as well as recent work in cognitive science. Inquiry Under Bounds is an open-access title, which can be read through Oxford Scholarship Online.
What is your work about?
Humans are bounded agents. Some of our bounds are internal. We have limited cognitive abilities, and in exercising those abilities we incur costs. Other bounds are external. We are born into environments that we did not choose. These environments shape the strategies available to us and the results that our strategies will have. Theories of bounded rationality ask what rationality requires of bounded agents.
Herbert Simon held that the fundamental turn in the study of bounded rationality is the turn from substantive to procedural rationality. Theories of substantive rationality ask normative questions about attitudes such as belief, credence, preference, and intention. Theories of procedural rationality move a level up, asking normative questions about the processes of theoretical and practical inquiry that produce and modify our attitudes. If Simon was right, then the fundamental element of a theory of bounded rationality is a theory of rational inquiry for bounded agents. We need, that is, a theory of inquiry under bounds.
Inquiry Under Bounds situates the bounded rationality paradigm against a competing Standard Picture on which rationality is exhausted by requirements of consistency, coherence, or structural rationality. The book develops a reason-responsive consequentialist view of bounded rationality, then provides three arguments in favor of this view. The book applies the reason-responsive consequentialist view to shed light on traditional questions about bounded rationality, emerging questions in the epistemology of inquiry, and the relationship between ideal and non-ideal theory.
How does it fit in with your larger research project?
The primary focus of my research is bounded rationality. Theories of bounded rationality have always been deeply concerned with inquiry. We ask, for example, when it is rational to inquire heuristically, and which heuristic processes of inquiry agents are rationally required to use in any given situation.
There has been a surge of recent interest in inquiry among epistemologists. My aim in this book is to do two things. First, I want to explain why bounded rationality theorists have tended to treat bounded rationality and inquiry as deeply intertwined, as a way of explaining my own theoretical approach to the subject. Second, I want to set the foundation for deeper engagement with problems and insights from the bounded tradition. Thousands of scholars across many disciplines have spent large parts of their careers studying bounded rationality. I think that this literature has a good deal to contribute to contemporary discussions about inquiry, bounded rationality, ideal theory, and other descriptive and normative debates within philosophy.
What directions would you like to take your work in the future?
My aim with this work was to set a baseline from which it will be possible to engage in more detailed and specific dialogue with traditional problems, insights, and paradigms from the bounded tradition. I was advised by my dissertation committee at Harvard that it would be helpful to provide an accessible introduction and defense of key claims as a way of generating interest and background knowledge relevant to more detailed work.
In the future, I would like to tackle some of the most important problems in recent discussions of bounded rationality, which have not always received enough attention from philosophers. For example:
- Ecological rationality: Just what does it mean to say that rationality is ecological, or environment-relative? And how can the seeming externalism of leading approaches to ecological rationality be squared with the fact that bounded agents must make judgments based on limited information about the world?
- Cognitive bias: What does it mean to say that something is a cognitive bias, and how, if at all, are allegations of bias connected to other paradigmatic normative categories such as rationality and blame?
- Maximization: What sense, if any, can be made of the common refrain that bounded rationality is not a form of maximization? In particular, how if at all can it be rational to fail to maximize what matters?
I would also like to collaborate more with social scientists. There is a great deal of exciting research on bounded rationality being done by psychologists, economists, behavioral scientists, and others. I want to make a more direct contribution to this body of work.
Who has influenced this work the most?
The very most important influence on my work has been the work of Herbert Simon, as continued by his heirs in the fast-and-frugal heuristics program, such as Gerd Gigerenzer and Ralph Hertwig. These theorists set the agenda for research in bounded rationality and defended a number of claims that I think are important and underappreciated, but also in need of philosophical analysis and defense.
Within philosophy, my closest neighbor would be Stephen Stich. In his book, The Fragmentation of Reason, Stich set out to articulate a consequentialist approach to bounded rationality. My aim in Inquiry Under Bounds is to provide a theory in this vein.
The book from which I learned the most is Edward Stein’s Without Good Reason. Most of what we know about bounded rationality was learned from the school of hard knocks. Many early strategies for vindicating the rationality of seemingly irrational behaviors did not work. These strategies suffered from conceptual, empirical, and normative problems. Stein did more than anyone else to carefully deconstruct some of the best-known lemons, clearing the way towards many of the more successful modern vindicatory strategies that have given many theorists increasing faith in the rationality of humanity.
From Jennifer Morton, I learned the practical importance of theorizing about bounded rationality in making sense of the lived experience of many of the most vulnerable members of society. Morton’s “Reasoning under scarcity” helped me to understand how careful vindicatory theorizing could help us to see a range of seemingly irrational behaviors associated with material poverty as rational responses to a difficult situation, in the process motivating kinder and more humane responses that blame situations rather than individuals, and intervene to make those situations better.
One final influence has been recent Bayesian approaches to bounded rationality. Until a few decades ago, Bayesian cognitive science was often an armchair matter and enjoyed a mixed reputation. Bayesians won an excellent reputation for themselves in recent years by constructing detailed and empirically-motivated approaches to a range of cognitive challenges. In the process, they have increasingly incorporated cognitive bounds such as limited cognitive resources, limited abilities, and the structure of task environments. Many bounded rationality theorists, including myself, see this as an important opportunity for reconciliation, learning, and growth. While I am not a Bayesian, I have learned a great deal from Bayesian philosophers such as Thomas Icard, Thomas Sturm, and Gregory Wheeler, as well as Bayesian cognitive scientists such as Joshua Tenenbaum, Thomas Griffiths, Mike Oaksford, and Nick Chater.
Until I came to the study of bounded rationality, I was confidently and firmly Bayesian about all matters. When I first encountered bounded rationality, I lost my faith in most areas of Bayesian theorizing. I have been slowly regaining my faith. One day I hope to have most of it back.
How have readers responded? (Or how do you hope they will respond?)
Reactions have generally been positive. The people studying inquiry are nice folks, and I have learned a lot from engaging with them.
I hope that readers will see this book as an invitation to engage more heavily with bounded rationality, and to begin that engagement from a detailed study of the existing scientific literature.
Many readers have been very caught up with the question of whether or not the type of rationality discussed in this book is epistemic. I do understand that this is an important question to many philosophers. At the same time, I hope that readers will zoom out and place this reaction in context. There are many different fields engaged in the study of bounded rationality, most of which use nothing like the concept of epistemic rationality and certainly do not take it as given that the relevant type of theorizing must be, in any special sense, epistemic. I hope that this book can help us to see what a substantive and positive approach to the study of rationality could look like if we did not begin with the goal of developing an approach that is, in some philosophically traditional sense, epistemic. I am much more concerned with finding a theory that makes sense of traditional problems and insights in the study of bounded rationality.
I also hope that readers will take this book as an opportunity to join me in the study of bounded rationality. Many of the most traditional problems, theories, and approaches to bounded rationality are significantly under-theorized within philosophy. Because these theories have substantial conceptual and normative content, there is a good deal of room for philosophers to make substantive contributions that advance the normative and descriptive study of bounded rationality.
I would be very happy to see more uptake of this work among social scientists. This is an important audience that I would very much like to reach.
Did you encounter any problems getting yourself published and, if so, how did you overcome them?
I sent a full draft of this book to Oxford University Press within a year of completing my PhD. The handling editor, Peter Momtchiloff, was rightly skeptical about publishing a book at my age, and he advised me to wait for a few years until I had built a stronger reputation within the field.
This was not possible. The reason I published this book was to make space for more detailed engagement with theorizing about bounded rationality in a style that is not familiar to many philosophers. I could not do that work without first making space for it, and this book was my way of doing so.
To his credit, Peter took me seriously. He read a proposal, immediately sent the book out for review, and gave me a contract based on two positive reviews. Many editors, especially editors in his position, would not have taken a chance on an author at my career stage. I am deeply grateful that Peter was willing to give me a chance when I needed one.
David Thorstad
David Thorstad is Assistant Professor of Philosophy at Vanderbilt University, Senior Research Affiliate at the Global Priorities Institute, Oxford, and Research Affiliate at the MINT Lab, ANU. His research focuses on bounded rationality, inquiry, and the ethics of emerging technologies.
Maryellen Stohlman-Vanderveen is the APA Blog's Diversity and Inclusion Editor and Research Editor. She graduated from the London School of Economics with an MSc in Philosophy and Public Policy in 2023 and currently works in strategic communications. Her philosophical interests include conceptual engineering, normative ethics, philosophy of technology, and how to live a good life.
