Darwin, Galileo, Mayr, Copernicus, Edelman, Newton, and Hayek all rethought the very fundamentals of their sciences, from the problems and explanatory strategies of their disciplines, to the logical status and conceptual role of the elements of their activities. Yet among these, only Hayek is attacked by professors for being a “philosopher” — and attacked as not being a “scientist” — for having done so. And only the work of Hayek is constantly smeared by the professors as “philosophy” and not “science”.

Yet Hayek is hardly the only economist who has worried about the explanatory fundamentals of economics and the conceptual status and role of the elements of their explanatory practices. Indeed, economists are recurently agitated about their explanatory failures and the self-evident conceptual hand-waving they do when attempting to justify their cognitive practices to themselves, other economics, and to the public at large. The list of figures in economics who have done this begins with many of the leading figures of the discipline today and extend to almost every leading economist across the history of the discipline. For example, former IMF economist Oliver Blanchard has been attempting to defend his explanatory program in macroeconomics and his vision of the conceptual role of his preferred math models here, here, here, here, and here. Esther Duflo used her Ely lecture at the AEA to argue for conceiving economics not as science like physics, but as a field of blue-color engineering like plumbing. Harvard economist Dani Rodrik has written a book trying to explain to economists and the public what economists are doing and what they are in fact justified in doing with all of the math modeling and statistical work. World Bank economist Paul Romer has launched an ongoing attack on the dominant explanatory practices current among many of his follow economists here, here, and here, and has offered a defense of his own explanatory practices and conceptual preferences here, here and here. The response to Romer has been almost endless, with responses and replies coming from across the discipline of economics, for example here, here, here, here, here, here, here, and here.

There a some big issues involved here, almost none of them any different from the ones that induced and inspired Hayek to rethink the explanatory problems and strategies of economics and the conceptual role of its various logical elements. What I want to do here is lay out how economics constantly generates these problems, how Hayek has successfully resolved these problems, and why and how the natural of mathematical and logic, combined with our conceptual traditions in economics and our philosophical tradition, have blocked economists from finding their way out of conceptual fly bottle that sciences like Darwin’s explanatory science of biology have managed to escape. In the way will will resolve some linguistic issues concerning different uses we can make for central but conceptually brought words “philosophy”, “empirical”, “science”, “causal”, “explanation”, etc.

Larry Wright shows us how everyday reasoning and argument differs substantively from those points in our practices where we are advised to take time to deliberate and rethink what it is we are doing and what we might do instead. There can be all sorts of things which inspire us to deliberate and rethink things. Thomas Kuhn has written an important book and a number of essays on the topic as it arises in science. If you read closely the work of Darwin, Newton, Galileo, Edelman, Mayr, and Hayek etc you will find that this rethinking often requires a rethinking of the background tradition held among men of learning about what it is to do science or create knowledge. Newton, Darwin, Galileo, Mayr, Edelman and Hayek all discuss how their explanatory efforts defy and redefine both traditional and contemporary norms of what it is to do science and produce knowledge. Is science suppose to be demonstrative and not hypothetical, is science suppose to be induced from facts and justified by direct evidence, does it work with and support to Platonic kinds and Aristotelean forms, conceptions and categories? Newton, Darwin, Mayr, Galileo, Edelman and Hayek were prepared to defy all of these demands for what science and knowledge must be. What we will find in economics is a new set of dogmas, developed in the wake of Kant and the neo-Kantians, which continue to ensnare the minds of economists. Hayek, we will show, suggests a way out, one similar in important way to that taken by Darwin, and one which was seen already by Adam Smith, Carl Menger and in various ways by other giants of economic science.

But for now lets get back to simpler issues and more concrete examples, using Esther Duflo Ely lecture and economist Beatrice Cherrier’s discussion of that lecture as firm and easily understandable bone to chew upon. Cherrier points out that economists have repeatedly sought to conceive their science on the picture of what they imagine to be the practices found in other fields, from physics (here, here, and here), morals and art, to medicine , dentistry, and plumbing. What Duflo is working to do, it to encourage here peers to move from what is today the dominant physical picture of economics, to a more practical, hands-on conception of economics as the everyday, craftsman-level engineering of a plumber, water-system technician or pipe-fitter. So what are these two models and where do they come from?

Significantly, in large measure, these models of “physics” and “plumbing” do not come from the actual practices of physics or plumbing, they come from what economists imagine to be the practices of physics and plumbing, shaped by their training in elementary philosophy and from watching a plumber working on their pipes under the sink. That is, the conception of “physics” in the head of economics has much more to do with the philosophical ideas of Mill, Hume, Mach, Kant, Popper and Carnap than it has to do with what Copernicus, Newton, Galileo, or Einstein achieved or how they achieved it.

We can see this in any detailed study of the most influential economists of the last 80 years, as we can with such seminal figures as Paul Samuelson and Milton Friedman. Samuelson directly tells us that his model of “science” came from the Viennese positivist Ernst Mach and the American operationalist Percy Bridgman. Samuelson makes it clear both in his public declarations and in his personal diary that the philosophical picture of what “science” is came first, and his economic practice was derives from the lessons he took from that picture. As Samuelson writes in his diary in 1930:

“Science is essentially the establishing of Cause and Effect relationships. This knowledge can be utilized in controlling causes to produce desired effects. It is the realm of philosophy to decide what these objectives shall be, and that of science to achieve those decided upon.”

The prediction and control model of science suggested above by Samuelson was in fact part of the common currency of the time, and was put into canonical form in 1934 in Cohen and Nagel’s widely used textbook, An Introduction to Logic and Scientific Method. There is a history to this model of science, one that is due more to the work of Kant, Mill and Hume than it has to actual science, something of significance we will discuss in more detail later.

The “plumber” model of economics also has a history, one also tied to the philosophical tradition, but one which also reflects the ethos Frenchmen and Americans who imagined the role of economists as something like that of engineers and craftsmen who want to design things to do something and then tinkering with them until they “just work”. Math and statistics in this care are developed and collected with the ambition to use them to engineer systems and then re-adjust the system settings with updated data readings as you go. Duflo recent reminder is that much of any engineering project is handled at the mud and piping level my craftsmen such as plumbers with practical hands-on understanding of what needs to be done to make the job successful, as much as it needs engineers and technical people constructing schematics, taking measurements and re-dialing system settings.

So here we have two basics models of what economics is or can be, models which have done much to shape the course of economics as a discipline over the last 150 years. We have made clear that each of these models has more to do with the conceptions and ambitions in economists heads that it has to do with the practices and achievements of actual physicists and plumbers. And we’ve suggested that there is a history to each of these conceptions tied to the philosophical tradition. What I want to do now is ask a very basic question. If we were to use either of these models to understand another basic yet fundamental science, say Darwinian biology, do these models help? Are these models even minimally competent in grasping the nature of the massively successful explanatory endeavor which is Darwin’s biology?

Let me submit that the answer is no, and that these models fail just as spectacularly when it comes organizing our understanding of what we are doing when we are trying to make sense of the task of comprehending economic phenomena. Dissertations could be written on how Darwinian explanation charts an explanatory form unlike that of the physics taught to undergraduates, and indeed, many books and essays have been published laying out how explanation in Darwinian biology and much of the rest of the biological world differs fundamentally from explanation in many other parts of science. I’ve met and I’ve taken classes with leading figures in the literature, and I’ve written my own dissertation length essay touching on central aspects of the topic. I’d particularly recommend the writings of David Hull, Ernst Mayr, Larry Wright, Michael Ruse, Friedrich Hayek, Elliott Sober, and Alex Rosenberg on the topic, among that of many others. Michael Ruse and David Hull discuss a bit of the history of failed attempts to force Darwinian explanation into the vise of the classic “physics” model of scientific explanation (“the received view”) inherited via the philosophical tradition developed in the wake of Hume, Kant, the neo-Kantians, Mill, Frege, Mach and others. The story of how Wesley Salmon came to accept Larry Wright’s landmark work on functional and teleological explanation after first balking at Wright’s dissertation is paradigmatic of the vise grip hold the traditional model of science and scientific explanation once held on the imagination of university professors.

Perhaps the best concise account of of the explanatory problem and causal explanation provided by Darwinian biology can be found in Ernst Mayr’s One Long Argument, and as full length explanatory narratives it is hard to beat Richard Dawkin’s The Blind Watchman and Darwin’s own On the Origin of Species by Means of Natural Selection.

What do we find when we looks at Darwin’s explanatory problem and the strategy he conceived to account for the problem-raising phenomena identified in his problem? What we find are teleologically and functionally characterized entities and characteristics that when situated in a particular way give rise to a truly puzzling problem in our experience, one which helpfully and more clearly framed in the process of providing an underlying causal mechanism to account for the phenomena which give rise to the empirical problems asking to be explained.