▶︎ 0:01 Welcome to Lecture 2, Rethinking Metaphysics as Conceptual Engineering. In Lecture 1, I gave some reasons for thinking that metaphysics, certainly as it's been practiced in analytic philosophy since the 1950s, has become dysfunctional. I talked about the ways in which it seems to present a rivalry with the natural sciences, if we think of it as trying to discover deep truths about what the world is like or what exists. I talked about the proliferation of metaphysical views since then, with no real clear agreement on how we could even resolve these debates or how we could come to know the truth of these metaphysical claims. And I talked about the kind of skepticism that's resulted even within philosophy about whether we can know the kinds of truths that metaphysics traditionally has claimed to present to us.
▶︎ 0:49 I also gave a diagnosis, and to me, that's the most important part, of where it's gone wrong in these ways. That all these different conceptions of metaphysics assume that metaphysics is a completely general inquiry into all sorts of things whatsoever, physical objects, moral obligations, modal properties, possible worlds, numbers, whatever, while assuming that all the discourse works in the same way, or often working from a model that thinks of the way our talk of dogs and tables and chairs and trees works and applying it to all discourse whatsoever. And that's what I call the functional monist assumption.
▶︎ 1:28 Now, there is an alternative, and that's what I'll talk about today. I'm not suggesting that we just get rid of all metaphysics. Instead, I think that it can be worthwhile, deeply important, and even world-changing in ways I'll talk about in Lecture 6. But I do think that we need to rethink what we can do and how we can do it in metaphysics. We need to think of its work in somewhat different terms than has been common in recent analytic philosophy. And that, I think, can enable us to get some clarity about what we can do and how we can do it, and to distinguish what's worthwhile from what's just mistakes.
▶︎ 2:07 What should we do instead? The suggestion is that we rethink metaphysics, not as a kind of deep worldly inquiry, but as a kind of conceptual engineering. I think of conceptual engineering in really broad terms as including both what I'll call reverse engineering, that involves asking questions about our extant language or concepts, asking how it functions, what it does for us in human life, and what kinds of rules it follows, and how it can be introduced to our discourse. And also questions of evaluative engineering. Should we keep these terms or concepts? Should we keep them as they are or change them? And do we need to construct new elements of our language or conceptual system?
▶︎ 2:52 In both directions, the reverse and the constructive and evaluative engineering, I think of these as very strongly functionally oriented. We want to understand what functions past language and concepts have served, and also think clearly and explicitly about functions we want them to serve and that they can serve going forward.
▶︎ 3:14 The goals in this lecture. I'll start with the history of conceptual engineering. It's really an idea that is fairly recently introduced to philosophy under that name, although something like that idea has been around in various pockets throughout the history of philosophy. I'll also talk explicitly about what conceptual engineering is, how I'm thinking of it, how we should think of it, I think, and when we need to engage in it, and why. And I'll talk about how the work of conceptual engineering is related to historical work in philosophy, including in metaphysics.
▶︎ 3:48 I'll try to show how this can avoid the problems for metaphysics that I discussed in the prior lecture, and how we can go about doing work in conceptual engineering. In later lectures, I'll talk about how we can put this approach to work to reevaluate and often shed new light on central old philosophical problems.
▶︎ 4:08 The history of conceptual engineering. It's not a term that's been around for a long time in philosophy or elsewhere that I know of. The term was really introduced, as far as I know, by Richard Creath, who is a scholar of Carnap, and he introduced it to describe what Carnap is doing, but it's not a term that Carnap was using. Carnap was an Austrian philosopher working in the 20th century, first in Vienna and then later in the US. So classically, the work of conceptual engineering gets traced back to Carnap. But that's not the earliest or the only source of philosophical work on conceptual engineering. It actually reaches back a lot more deeply.
▶︎ 4:51 It's at work in ways that I'll try to describe later in a lot of work on traditional conceptual analysis, like you get in work in ordinary language philosophy, also work by some of the modern philosophers like Berkeley and Hume, for example. It's also at work in transcendental questions like Kant asks about what kinds of concepts we need to experience a spatio-temporal world of phenomena at all. Those will fit, and I'll talk more about them later, under the mode of reverse engineering, understanding how our conceptual or linguistic scheme does work. But part of the idea of conceptual engineering, as it's even carried in the name, is the idea that we can also change our language and our concepts. And this, too, is an idea with a really rich philosophical history, though it's not one that's been often focused on.
▶︎ 5:44 One really early source of this idea is in Nietzsche. In The Will to Power in 1901, Nietzsche wrote, I'll just read you the quote, "Philosophers have trusted in concepts as completely as they have mistrusted the senses. They have not stopped to consider that concepts and words are our inheritance from ages in which thinking was very modest and unclear. What dawns on philosophers last of all? That they must no longer accept our concepts as a gift, nor merely purify and polish them, but first make and create them, present them, and make them convincing. Hitherto one has generally trusted one's concepts as if they were a wonderful dowry from some sort of wonderland, but they are, after all, the inheritance from our most remote, most foolish, as well as most intelligent ancestors. What is needed above all is an absolute skepticism toward all inherited concepts." So you get here very clearly a sense that our concepts are things that are human inventions, that can be created, that can be evaluated, and that can potentially be changed.
▶︎ 6:54 Now, the Canadian philosopher Cheryl Misak has also traced a really deep history of the idea of conceptual engineering to the American pragmatists, starting with Charles Sanders Peirce. As Misak says, the conceptual engineering movement was always there in the pragmatist tradition, ready for the taking. People just hadn't used that term or even noticed it so much. You can see it in Peirce, who argues that we should hone our concepts so they're connected to experience and practice and so are useful to us.
▶︎ 7:24 There's also this wonderful paper by the American philosopher C.I. Lewis, who was a teacher of Quine and of Sellars, and himself was influenced by Peirce, who has this paper on ways in which we can treat concepts and categories, including the very most basic ones that make experience possible, as being open to revision and assessment and evaluation. As Misak says of him, our conceptual frameworks are peculiarly social products, reached in the light of experiences which have much in common and beaten out like other pathways by the coincidence of human purposes and the exigencies of human cooperation. In C.I. Lewis's view, we do inherit our concepts, but the responsibility is ours for correcting and refining them, and he thinks that we can refine them on pragmatic grounds when they're no longer useful to us or not useful for the work we need to do in the sciences.
▶︎ 8:21 The idea of conceptual engineering was also popular in the early 20th century in Poland, and the Lwow-Warsaw School also clearly had the idea that philosophical work can be directed at improving our conceptual scheme. And you can see this, for example, in a paper by Jan Lukasiewicz on causation and trying to figure out what concept of causation we need now to do our scientific work well.
▶︎ 8:50 The locus classicus for work in conceptual engineering that you see most people refer back to, and most folks who are doing conceptual engineering now will trace their work back to this, is in the work of Rudolf Carnap, who I mentioned before. Carnap was a member of the Vienna Circle, which met in Vienna from 1924 to 1936. This was where positivist views were formulated, as I mentioned in lecture one, and then Carnap moved to do the rest of his career in the United States eventually. His 1950 paper on explication is really the original source of some of the ideas of conceptual engineering that we now draw on. The work in conceptual engineering has only become explicit as a movement in analytic philosophy in the last 20 years or so, but it's become extremely popular, especially in Europe, I'd say.
▶︎ 9:42 Anyway, Carnap in 1950, in this famous paper on explication, introduces this idea of explication as something philosophy can do. He was very skeptical of traditional metaphysics, but he thought one use for philosophy is as what he called a handmaiden to the sciences. Part of what we can do is construct and refine concepts so they'll be better usable in our theories in the natural sciences. So he's got a division between conceptual work and empirical work, but his goal is to try to help create concepts that will be more useful for the sciences.
▶︎ 10:17 Explication, as Carnap has it, is a procedure of transforming a pre-scientific, inexact concept, or sometimes a prior scientific one, into a more exact one that will be more useful in our scientific theorizing. As we explicate it, we want to introduce specific rules for its use. As Carnap says, we will introduce it, for example, by a definition which incorporates it into a well-constructed system of scientific, either logical, mathematical, or empirical concepts. If you have multiple possible explications, you can try out different ideas. Which one to choose is a practical problem. Which one's going to be the most useful for our purposes? It's not a question of which is true, gives us the true account of probability or something like that.
▶︎ 11:06 And Carnap laid out four different criteria that we can use in practically choosing among different possible explications, ways of refiguring some of our old concepts and terms so they can be more useful for our scientific theories. They were similarity, exactness, fruitfulness, and simplicity. Similarity is the idea that once you've explicated the concept, it ought to still be pretty similar to the old one as far as possible, so that it can be used in most of the same cases and help avoid confusion. Exactness, that is, the rules for its use should be given explicitly and precisely so that it can fit in a well-connected system of scientific concepts and tell us which inferences we can make and can't make from it.
▶︎ 11:54 Fruitfulness, I think, was really the most important for him. Fruitfulness in Carnap's hands means this concept is going to be useful in formulating a lot of generalized laws suitable for explanation and prediction. And simplicity is really just a tiebreaker for Carnap. He doesn't put a lot of weight on it, but you want to make the new term as simple as possible, both in terms of its definition and the laws connecting it to other concepts, provided it'll still do the same work and have the same level of fruitfulness.
▶︎ 12:24 Here's an example of what he was up to. This is his own example. He talks about the concept of fish. The concept of fish as he traces it out, originally, if you've read Moby Dick, you've seen this. Fish was used just to name any kind of swimming aquatic creature. And so, of course, Melville goes on for, I think it's at least a chapter, on why the whale is clearly a fish.
▶︎ 12:47 As we discovered that there were really important differences among the creatures that we called fish, differences between those that had gills and scales and so on, versus those that breathed air and fed milk to their young and so on. And so gradually, the concept of fish first was divided. And we no longer count the whales and the dolphins and the seals as fish, although they swim in the sea. And what we can get is greater theoretic generalizations about how these creatures are made inside, what we can expect to find if we dissect them, how they breathe, how they bear young, et cetera, by dividing the concept in this way.
▶︎ 13:34 The change that was brought about then in the zoologist's concept of fish was brought about not as a correction, as the quote from Carnap, in the field of factual knowledge, but a change in the rules of the language, when you're allowed to apply the term fish and when to say, no, it's an aquatic mammal. But this change, notice, was motivated by empirical factual discoveries about the way whales breathe and reproduce and so on. Because zoologists discovered that animals living in water generally, quote, "have by far not as many other properties in common as the animals which live in water are cold-blooded vertebrates and have gills throughout life." So we divide it.
▶︎ 14:14 Of course, if you're tuned into debates about whether we should keep the concept of fish at all in biology, you'll see that's now in question. You can find articles called things like, There's No Such Thing as Fish, because now if you're doing evolutionary biology and you want to try to divide types of animal according to their evolutionary ancestry, there's no good way to do that and keep all that we call fish together. The lobe-finned fish, the ray-finned fish, and the cartilaginous fish all have very different evolutionary ancestries, and the lobe fins have much more in common ancestrally with land creatures than with the other kinds of fish. So the concept of fish is again being rethought after Carnap's time, but with similar goals in mind of serving better now in our evolutionary biological theories.
▶︎ 14:56 That's a case of explication. And if we go on in biology to drop the concept of fish altogether, maybe you'll keep it in restaurants or in fisheries, then you can see that this is motivated as a conceptual revision motivated by empirical discoveries, including now evolutionary discoveries. That's just a very quick picture of Carnap's view of explication.
▶︎ 15:20 Notice these things about it. Carnap's work on explication is forward-looking. We're changing our concepts. We're just diving in and figuring out what concepts we need to figure in our scientific theories. It's also focused on a narrow set of purposes. The purpose Carnap cares about in that paper, surely, is the purpose of serving well in our predictive and explanatory scientific theories, especially by enabling us to make new kinds of generalizations suitable for prediction and explanation.
▶︎ 15:49 Now, there's a complement to this work of Carnap's in the work of Wittgenstein. Again, if you know Wittgenstein's later work, the Philosophical Investigations and later, you'll know that Wittgenstein insists on the idea that language serves many purposes. You can think of Wittgenstein as engaged in what I call reverse engineering. He wants to look at the breadth of our, he really focuses on language, linguistic uses, and to see the many different functions that they serve in human life. And he also thinks that by identifying these different functions, we can disentangle ourselves from a lot of old conceptual confusions.
▶︎ 16:27 As Wittgenstein puts it, the philosopher's treatment of a question is like the treatment of an illness. We want to figure out what's gone wrong and disentangle it. And he thought we can do this by attending to the different functions of different parts of language, or as he liked to put it, in different language games. He also used this analogy that the different parts of language are like the different handles in the cabin of a locomotive, that each work in different ways. You might pull one and push a button in another, and they might do all sorts of different things for your locomotive. And you don't want to just collapse them by thinking of them all as having a single function.
▶︎ 17:01 But Wittgenstein's focus, unlike Carnap's now, so he's interested in a much broader range of purposes and of language games, you might say, than Carnap, who's focused on the scientific, but Wittgenstein's is all reverse directed. It's built on understanding how our language works and what different functions it's used for, what different rules apply to different language games. It's not forward-looking, trying to change it. In fact, Wittgenstein was rather against that. He often said things like, "Philosophy may in no way interfere with the actual use of language. It can, in the end, only describe it."
▶︎ 17:34 So we have two different views here going into conceptual engineering. You can actually see that Wittgenstein's approach turned constructive and forward-looking, so it's not just in reverse engineering, in the work of some of his students who picked up the idea that language has many functions, but thought that we aren't limited to just trying to describe language, but we can also engage in trying to change it, and that brings in the constructive conceptual engineering idea much more clearly.
▶︎ 18:08 The best version of this that I know is in the work of the American philosopher Alice Ambrose. She was a student of Wittgenstein. She was one of those who compiled the blue and brown books, but then she spent most of her career working as a professor at Smith College. She has this wonderful paper from 1952, Linguistic Approaches to Philosophical Problems, where she argues that many philosophical theories and past works in the history of philosophy, they look like factual disputes. But what's really going on is they're implicitly proposals to alter language. Here's a quote from her: "Philosophers are neither analyzing concepts nor stating correct usage and giving a view, but are doing something else equally linguistic, namely revising language."
▶︎ 18:52 I'll come back to her views later. Another neat idea here, and that what philosophers can do is revise language, is that it enables us to better bring into the picture of conceptual engineering a lot of past work and philosophy that we can see as either explicitly or implicitly engaged in revising language.
▶︎ 19:11 Another lovely work in this direction is by the British philosopher Mary Midgley. She has this article called Philosophical Plumbing, where she argues that our conceptual scheme is like an old plumbing system in an old city. That is, in both cases, our system of concept or of plumbing is unseen, we don't often think about it, but when it goes wrong, something terrible happens, and we need to pay attention to it and correct it. So she calls it, the conceptual scheme, "a fairly complex system, which is usually unnoticed but sometimes goes wrong with serious consequences." And she says, "We need to remember how large and powerful the hidden system of ideas is so as to be ready to spot any particular elements of it when they do make trouble."
▶︎ 19:59 When we bring out the work of Ambrose and Midgley, following up from Wittgenstein and from Carnap, we can get a more complete picture of this idea that we can think in terms of both understanding how our inherited conceptual scheme does work and what functions it serves. And we can also ask questions about whether, and if so, how we should revise it going forward for various purposes. And that's the more complete idea of conceptual engineering that I want to bring into the picture.
▶︎ 20:27 What is conceptual engineering? As I said, this is not a term that's been around in philosophy for a long time, though a lot of the ideas have been kicking around, and you can find them there once you look back. I think it's helpful to think of conceptual engineering on analogy with mechanical engineering or civil engineering, if you like. It's tempting for those of us who aren't engineers to think of mechanical or civil engineering as a matter of some engineer sitting down and designing something on a blank slate at their drawing board. But that's certainly not all there is, even to civil or mechanical engineering.
▶︎ 21:03 Engineers are also involved in reverse engineering. If there's a piece of malware that pops up on your computer, you call in the computer scientists to figure out what it does and how it does it. That's reverse engineering. It's the civil engineers we call in after a hurricane or an earthquake to do a kind of assessment of whether the building is still structurally sound and if we can use it, and if not, what kind of retrofitting it might need in order to be usable safely going forward, or if we need to just raze it to the ground and start again.
▶︎ 21:38 So engineers are involved not just in designing new gizmos on a blank slate, but also in this kind of understanding how things currently work. If you had an old bit of machinery, you didn't know how it worked, you bring in the engineer to figure out what this engine did and why. And what we can do about them, what we can keep using, what needs modification, what kinds of modification would be suitable. That's the more complete picture that I'm looking at.
▶︎ 22:02 So most of our conceptual work, I think, is more like that. If you want an analogy, it's not like just designing some new gizmo on a blank slate. Maybe occasionally we have to do that. Maybe you'll find examples. But mostly, we have this huge inherited, ancient conceptual and linguistic system. We're not starting on a blank slate. It's more like building a new structure in Rome, where you have to be attending to all the old structures surrounding it, all the history and archaeology underneath the surface, how it interacts with the electrical systems and the transportation systems and the plumbing systems and so on. Not just design on a nice, clean blank slate.
▶︎ 22:37 Now, once we see it in that way, we can see this work in conceptual engineering as explicitly functional. We need to understand functions in order to do the reverse engineering and understand how our language and concepts work, to assess whether they work well at doing that, and also whether that's something we really should be doing. And also going forward to figure out what functions we aim to serve going forward and why.
▶︎ 23:02 Understanding conceptual engineering in this broad way also makes it much more cohesive with work in the history of philosophy. So the reverse engineering side of work, we can see as work in understanding, even globally, how our conceptual scheme works. If you want to know what kinds of concepts we have to have to be able to experience a world at all, those are questions that Kant was asking and Husserl was asking, and they have some really interesting thoughts about how that works.
▶︎ 23:32 Strawson, similarly, P.F. Strawson was asking in the ordinary language tradition, are there essential components to any conceptual scheme? And if so, what are they? These are all reverse engineering questions. They're all part of the project of philosophy as I'm reconceiving it.
▶︎ 23:48 You can also see a ton of history of philosophy work on particular concepts and their relations. So if you think of David Hume's work on how should we understand the concept of liberty, and what's its relationship to necessity, and is there any conflict between them. That's conceptual analysis. That's figuring out how our concepts work. And he even talked about how they're connected to other practices, like our moral practices. Or Locke's work, John Locke's work on understanding persons and the way the concept of person is connected to the idea of memories and of responsibility. That's also reverse conceptual engineering work, trying to figure out how these parts of our conceptual scheme fit together.
▶︎ 24:28 Then you can also engage in this kind of evaluative and reconstructive engineering project, and I think that begins from assessment. In the reverse engineering, you figure out what functions have been served, what is having this kind of term or concept do for us, what has it done for us or for some of us, maybe. It's not necessarily beneficial for all. And then once you've got those functions on the table, you can say, are these functions that we should continue to serve? Maybe sometimes not. I'll talk about race concepts in a later lecture.
▶︎ 25:01 You can also ask whether these functions continue to be served well in the current context. We're always going through changes, social changes, technological changes, environmental changes, changes in what we know. Do the concepts still serve us well? The concept of fish, as I was saying, it no longer serves you well if you have a purpose of doing explanatory biology and now you know that actually, the gilled fish function and are constructed and raise their young very differently than the aquatic mammals.
▶︎ 25:32 Then you can also engage in reconstructive work once you've assessed. Should this whole conceptual scheme or this part of it, or this part of language, be rejected entirely? Should it be revised? Should it be retained? Should we add to it or modify it in some way to serve some functions or to stop serving some functions that have turned out to be problematic? Again, I'll give examples of all these different kinds as we go forward.
▶︎ 25:57 I will give reasons for thinking that our property and number talk is in good order, and we do really well to keep these, but there's a lot more questions, for example, about our race talk, and we might need a lot more changes to concepts like privacy, intelligence, and so on in the current context. At any rate, once we've got the functions on the table, then our work on these concepts can be non-arbitrary, because it's not arbitrary to choose what best fulfills the function or to choose fulfilled functions that you endorse and not ones you think are terrible or problematic.
▶︎ 26:32 When do we need to do conceptual engineering? Well, look, we can do it anytime, and I think there is a global and enduring interest, certainly among some portion of philosophers, in just trying to understand our conceptual system writ large. And as I say, this is what I see the work of people like Kant and Husserl and Strawson as doing. You can just jump in and do that. But there's also times when we are prompted to do a reverse engineering of particular concepts when we find there's certain kinds of puzzles or paradoxes or problems that they lead to.
▶︎ 27:03 Kant, of course, started from looking at antinomies, that is, apparent tensions in our concepts of space and time, causation and necessity, and this prompted his work. George Berkeley, the philosopher, also was brought to deny that there was matter by seeing that there were certain contradictions in the conception of matter that was predominantly forwarded by Locke before him. Gilbert Ryle, ordinary language philosopher, British mid-20th century, found certain kinds of paradoxes and problems in the way we use mental concepts like belief, desire, and so on, and aimed to, as he put it, "rectify the logical geography of our mental concepts," setting them straight so we can avoid these problems and paradoxes once we understand how they really work and aren't misled. Even recent work, like Kevin Sharp has done some conceptual engineering work on truth to try to avoid the truth paradoxes.
▶︎ 27:53 That's one big prompt of conceptual engineering. If you see us as having concepts that lead to problems, paradoxes, unacceptable conclusions, that's some reason to look at them and figure out why there's something wrong with these concepts or with our understanding of them. Sometimes, though, you need to look at our concepts for different reasons, not because they've led to puzzles or paradoxes, but because we see reasons to change them for social or moral reasons. And this is one of the great broadenings of the conceptual engineering project.
▶︎ 28:27 People had tended to think of it on Carnap's model of engineering concepts for use in the natural sciences. It was really the American philosopher Sally Haslanger's work on race and gender concepts that brought to people's attention that, hang on, we can ask these kinds of questions and do this kind of conceptual engineering work also on our socially relevant concepts. We can ask questions about how our race and gender concepts work and what we want them to be, to use Haslanger's terminology. And there's been a ton of recent conceptual engineering work on trying to understand what we should do with our concepts of race, gender, sexual orientation, rape, et cetera. So the drive for social change is another prompt for conceptual engineering.
▶︎ 29:13 There's also reasons for engaging in conceptual engineering when your old concepts aren't working so great anymore in the new context. I talked about fish and what we know now of fish. There's a lovely paper by Bernard Gert and some others on death. I'll talk more about that towards the end, but the way our concept of death worked perfectly well when most people died at home, and we didn't need more precision than a day or so when they died, but became much more problematic in contemporary medical technology contexts where we have life-preserving technology that can keep unconscious people alive almost indefinitely, and we have possibilities of organ transplant that work better the sooner they're done. But we don't want to go taking anybody's organs if they're not dead. You can also think about the ways in which we need to rethink our concepts of intelligence, privacy, plagiarism, even of friends in the modern context of AI and digital surveillance and other such changes in technology.
▶︎ 30:14 Sometimes we need to do conceptual engineering to serve new scientific purposes. The concept of gene, you can talk about when that was invented and its importance in biology. Space time as a singular concept and its role in being able to even formulate relativity. You can look at the huge range of new concepts that have been introduced in psychiatry in the diagnostic and statistical manuals that change every few years also as they modify these concepts for new purposes of diagnosis and treatment.
▶︎ 30:41 And sometimes you can introduce concepts or modify them for other purposes, social and moral purposes. You could talk about the introduction and modifications in the concept of human rights, or about the introduction of the concept of homophobia, or the new gender concepts that have become very popular in recent years. So there's a whole range of purposes for which we might want to do conceptual engineering. It makes it both very powerful, but also a very diverse literature in terms of the topics people work on and why they care about them.
▶︎ 31:10 Whatever your goals are when you're doing conceptual engineering, I think there's some important factors to attend to. First and foremost, I think, is the functions. You want to start by understanding the functions of the discourse. You don't want to make any changes, take any organs out of the human body, for example, until you understand what they do, what functions they perform. Similarly, I don't want anyone taking a part out of my car's engine unless they understand what its functions are first. So we've got to do the functional work before we can clear-headedly go about making changes or considering whether we should make changes.
▶︎ 31:46 You also have to attend not just the concepts individually. I think a common mistake in the conceptual engineering literature is to think of concepts as just individual things. So, okay, what should we do with the concept of woman? But our conceptual schemes are very holistic. The concepts are interconnected. So just as if you are reconstructing part of Rome, you have to be aware of how the foundation of your building might intersect with the plumbing system, for example, or with the stability and shade thrown on neighboring buildings or gardens or whatever. So if you're thinking about changing our conceptual scheme, you've got to be aware of how these all connect. So if you are working on the concept of freedom, you've got to be aware of its connection to concepts of responsibility and human action and so on. And Hume was very much aware of this.
▶︎ 32:39 You also, I think, have to attend to, again, there's a nice analogy from the engineering case, from the civil or mechanical engineering case, to human factors. That is, we're the ones who are going to be using these concepts eventually. Who's to use it and how? Is this to be used by scientists who are going to be particularly trained in the inferential procedures governing evolutionary biology, or is this just a concept that we all use in our everyday lives, say like woman or something.
▶︎ 33:05 Carnap listed exactness as one of the criteria that makes an explication good. That seems right for his purposes, but it's not clear that we want so much exactness for a lot of our philosophical concepts. Suppose you consider replacing the concept of a chair with a more precise concept of particles arranged chair-wise. Yeah, okay. But we can't see particles. We can't count them. We wouldn't want to if we're just trying to arrange a dinner party. So that level of exactness and precision may be exactly what we don't want for these kinds of everyday purposes. So you have to also consider our perceptual and conceptual capacities in figuring out what's going to be a workable and helpful change.
▶︎ 33:48 And of course, we have to consider the context, what we now know, what the social context is, the environmental context, the technological situation, and so on. As with other forms of engineering, we have to take these all into account, and once we do, it's not just arbitrary which route to take. Some will be better than others. So think about building a bridge, say, over the Connecticut River. There'll be some options that are better than others. If it's not going to stand for more than 10 years, that's not going to be great. If it can't carry the weight of the cars it's supposed to carry, that's not going to be great. But we may have different constraints if we want the pedestrian bridge or a rail bridge or a road bridge for a two-lane road or a six-lane highway.
▶︎ 34:36 Even when we narrow that down, there might not be a uniquely best solution. Some are better than others, but there could be two equally good solutions to how to build a pedestrian bridge over the Connecticut River that can be completed in a year's time or whatever. So it gives us a way of having constraints and non-arbitrary solutions without thinking that there always has to be a unique truth. It's not true that this is the bridge to build unless there's really a very narrow range of options. There may often be more than one good option.
▶︎ 35:13 That's roughly how I think of conceptual engineering. Let me talk now a little bit about how it avoids the problems that I talked about in lecture one that recent conceptions of metaphysics face. One problem that I talked about was an apparent rivalry with the sciences, which was really made most sharp by that quote from Stephen Hawking and Leonard Mlodinow. I think there's two things to say about this. One is the reverse engineering work. If we think of this in descriptive terms as trying to understand how our language or concepts work, there is, in this case, work to be drawn on and to be done in accord with the sciences.
▶︎ 35:53 Cognitive science, psychology, and linguistics have all come on enormously in the last 70, 80 years. I don't think we should think of that as a rivalry. I think we, as philosophers, should build on and learn from their work wherever possible, and maybe we can help contribute to it also by making use of our conceptual expertise. I'll model some of this in a later lecture when I show how work in linguistics can really help us understand conceptual functions. I don't think at this current stage of inquiry, we can just sit back and wait for them to give answers, because often the questions philosophers have aren't the same as the questions the linguists have so far. But I do think we can learn a lot from working linguistics that can help us better understand how our modal concepts or concept of number or whatever work. So there, there's not a rivalry, they're working together.
▶︎ 36:44 But then there's also the forward-looking conceptual engineering. And this involves all those questions about what we should do with these concepts. These should questions are what philosophers call normative questions, questions about what we ought to do or should do. These kinds of questions, what ought we to do, they're often informed by the work in the sciences, but they're not directly addressed by empirical work in the sciences. Scientists aren't in the business of addressing should questions. They're in the business of addressing is questions. Or rather, when they do address these kinds of should questions, what concept of species should we use in biology, for example, then they're doing conceptual engineering, too.
▶︎ 37:25 And my goal here isn't to preserve a business for philosophy, but to separate the kind of work we have to do in understanding how our conceptual and linguistic scheme works from the work we have to do in figuring out how it should work and answering those questions. And that kind of normative should work I think of as distinctively philosophical work, whether it's done by philosophers or others.
▶︎ 37:48 What about proliferation and skepticism? As I mentioned, there are lots of proliferation of recent metaphysical views. But if we think of it in engineering terms, this is no longer an embarrassment. We can have alternative solutions to engineering problems. This is a set of riches that we can choose from as we try to figure out how to solve our conceptual problems. So we no longer think of it as hidden deep facts that are eluding discovery, but as practical decisions to make, and we can weigh up the options.
▶︎ 38:20 What about epistemological mystery? Here again, I think we can avoid the epistemological mystery. We're no longer thinking of metaphysics as trying to discover some deep and hidden facts, but rather as engaged in conceptual work, we can make use of the work in linguistics and cognitive science to help us, and practical work of addressing these kinds of practical questions about what we should do and why. I'll talk more about how to address practical questions in the lecture on moral discourse and metaethics. So I think we can do better at all these problems that plagued the recent conception of metaphysics by thinking instead in conceptual engineering terms.
▶︎ 38:58 Before I close, let me just turn to say something about how this is connected to historical work in metaphysics. Again, I want to emphasize that I'm not trying to eliminate metaphysics, and that the problematic ways of thinking about metaphysics are mostly those that arose explicitly in 1950 and later in analytic philosophy. A lot of older philosophical work is either explicitly or implicitly, I think, doing this kind of conceptual work, this kind of work in conceptual engineering. I've mentioned work by Kant, Husserl, Strawson, ordinary language philosophy, phenomenology, as all working on this kind of reverse engineering projects.
▶︎ 39:40 In terms of the forward-looking engineering projects, I think we can often see these done in past philosophical work by seeing that work as engaged in what David Plunkett and Tim Sundell in 2013 called metalinguistic negotiation. This is basically a way of formally describing what Alice Ambrose was talking about, that often when philosophers are disputing things that look like factual disputes, what's really going on is negotiating for views about how the language should work, what we should do with our language of causation or freedom or whatever. So here's what Plunkett and Sundell say. In our daily lives, quite a lot of the time, we engage in disputes that look factual, but turn out to be really undercover disputes about how we ought to use the language.
▶︎ 40:33 One of their examples that they take from Peter Ludlow is debates about whether the racehorse Secretariat is an athlete and belongs on, I think it was the Sports Illustrated lists of the best 100 athletes of all time or something like that. People are for and against. They can agree on all the facts about how many races Secretariat won, about how Secretariat trained, about the capabilities of horses, et cetera, and yet still disagree about whether Secretariat was an athlete. Why? Because what's behind that is a disagreement on how the term athlete is to be used. Should it be a term that we can apply to non-human animals or should it be restricted to humans? And that matters because there's a lot of at least prestige and sometimes other things that go with having the status of an athlete.
▶︎ 41:18 Another case they talk about is torture. All the debates that happened about whether waterboarding is torture. These were implicitly arguing about what definition of torture we should use going forward, and the distinction between the U.S. definition and the UN definition. We can see this all the time in our casual conversations, especially when we get a little philosophical, and at work in the history of philosophy.
▶︎ 41:43 So take John Locke's work on what a person is, the nature of persons. He knows that this isn't a view of what a person is that reflects what everybody thinks or would say. He says something like, "Person is a forensic concept used for assigning praise and blame." And it's because of the use of same person, as you only want to be punished for the crime if you did it, if you're the same person who did it. So we need a concept of personal identity, but then we need one that's going to be justly applied in praising and blaming, and for that, Locke thought, we've got to include a continuity of memories as part of the criterion. So he's implicitly suggesting that we revise how we think about persons, revise the concept of persons or the use of the term person here, not reporting how we do use it or some deep metaphysical discovery.
▶︎ 42:34 Free will debates, a whole lot of them, maybe not all, but the vast majority of them can be seen in these terms. Hume asks what liberty is and how it relates to necessity, and he suggests that we should understand liberty as a matter of acting or not acting according to the determinations of the will. That is, you can do what you want without external constraint. And again, part of the reason he suggests this is because he thinks it fits better with our moral practices of praise and blame and so on. And then you can see a philosopher like Paul Edwards comes later and says, "No, that's not enough to justly apply praise and blame, and therefore also to call somebody's actions really free in the sense relevant to responsibility. We ought to require more. We ought to require that they could choose their own character." And then you see other views about what we should require of freedom in order for moral praise and blame and responsibility to apply in a whole lot of other philosophers, in the work of people like Frankfurt and Susan Wolf and Daniel Dennett.
▶︎ 43:38 Debates about what art is. Clive Bell's work on art as significant form was explicitly suggesting that we revise how we think about art and no longer think of it in terms of a mimesis of what's out there in the world, but rather in terms of a presentation of significant form in order to better bring under the umbrella of the work new non-mimetic works of art by people like Cézanne and Picasso and Matisse and so on. Arthur Danto suggested further changes. So very often it's really worth rereading a lot of works in the history of philosophy as implicitly engaged in metalinguistic negotiation for how we should use our terms for person, freedom, causation, time, whatever it may be. And once we see it in that way, then we can see that these are debates that are really in conceptual engineering. They're debates about how we should use these concepts.
▶︎ 44:30 So understood, I want to emphasize that conceptual engineering is really very much continuous with a whole lot of past work in philosophy, including in what could get reprinted in metaphysics anthologies, and it preserves its importance. What we're doing is denying the recent interpretations of it, the scientistic interpretations of it as involving quasi-scientific world discoveries. And thinking of it in this way also, and I'll come back to this in lecture six, makes the work of metaphysics non-mysterious, transparent, and worthwhile, rather than lost in what look like ancient and unknowable mysteries.
▶︎ 45:08 All right. One final question on conceptual engineering for today. Should we engineer concept or language? I've been shifting back and forth in which I'm talking about, and that's not accidental. I think we can ask about either, and it's worthwhile to ask about both.
▶︎ 45:25 If you think of yourself as engineering concepts, you've got to say some stuff about what concepts are. I'm not going to get into that, but it's very plausible that we do have some concepts prelinguistically before we get to language, and maybe that even having some of those enables us to develop language. And I think some of these prelinguistic concepts that enable us to experience a world as a world of mind-independent, ordinary objects in space and time and so on, are really plausibly prelinguistic. These are some of the concepts that, like Kant and Husserl are primarily interested in elucidating. So that's awesome.
▶︎ 46:01 You can also consider in this kind of work some work in psychology. So Susan Carey has this wonderful work in The Origin of Concepts, arguing that there are some built-in concepts to us, a handful of them prelinguistically, that we share with a lot of our evolutionary ancestors. And there's other interesting work on conceptually engineering our concepts, all of these mental entities by current philosophers like Edward McHenry. Just one word of caution, though. If you go the conceptual route or the linguistic route, just be careful to not assume that concepts just have one function, to track features of the world, because then you'll fall into this functional monist problem.
▶︎ 46:47 That being said, I think it's also really useful and we can learn a lot by looking at language and doing conceptual engineering. So you could think of it as linguistic engineering instead, if you prefer, but the term conceptual engineering is out there. Why? Well, look, metaphysics, it's done using language. We have to pose our questions in metaphysics and our answers using language. There's some helpful features in looking at language rather than at mental concepts.
▶︎ 47:15 One is you can debate about concepts, especially those prelinguistic ones, but it's much more natural to think of language, and less controversial to think of language as an explicitly human construction that evolves and changes as we do. There's whole work in historical linguistics that can trace the ways in which language has changed over time. And there's some neat philosophical theories by David Kaplan and Irvin Ermak that involve treating language as a kind of artifact, an abstract artifact that we create over time and that's changeable, just like a vase or a statue is changeable.
▶︎ 47:50 Another reason for thinking about language is that at least many of our concepts, including plausibly a lot of those centrally interesting to metaphysics, it seems that they've probably got to be linguistically articulated, even those that aren't distinctive to metaphysics, like tax obligations. It's hard to see how you could have anything like that concept or any of our legal concepts without language. And often there, it's grammatical distinctions that are important in these metaphysical debates. If we want to move from saying that this is red, the apple is red, to saying it has the property of redness, we need to be able to attend to these grammatical distinctions, and language is a clear, natural place for doing that. We don't quite have the same way of distinguishing conceptual grammar.
▶︎ 48:30 Another reason for thinking about these things in linguistic terms is that people tend to think about concepts as if they were private and internal. Now, you probably don't have to. There's other views of concepts on the table. But what's clear about language is it's clearly public and it's clearly social. And so the kinds of interactive functions and interpersonal functions we have for language when we greet each other, when we insult each other, when we insinuate what our views are or express our ideas to each other, these are really visible in language, and they've been articulated by linguists. So that's going to be really helpful in enabling us to see the various different functions the parts of language have.
▶︎ 49:13 Finally, by looking at conceptually engineering language, we can make use of work in linguistics, and I've found some work in linguistics that I think is just super helpful in enabling us to understand and say things clearly about the different functions of different parts of language that are relevant and have been central to metaphysics. So I'm going to follow mostly the language track here, but that doesn't mean that I don't have a lot of respect for and interest in the conceptual track as well.
▶︎ 49:44 Whichever way we go, whether we think in terms of concepts or language, whether we think in terms of reverse engineering or constructive engineering, we need a notion of function to evaluate whether the functions that the current language or concepts do serve or have served are ones we still should serve, are ones that they still serve well in the new context, and whether we should continue to try to serve them going forward. So you might ask, how can we understand functions in these terms and identify the functions of these different bits of language? I'll turn to that in the next lecture.