Concept of Structure / Structural Realism / David Lewis on the Ramsey Sentence

0:00 Thank you. Test, test. Well, welcome to you all. I've given this talk on various previous occasions, so all the people who have already heard me have already fled the room. In 20 minutes I'm going to explain to you a current research program in philosophy of science I'm working on. And I hope you get away with the idea that here is someone doing something very interesting. So this is the outline. Three brief parts. The idea of structural realism, very briefly. Then a dilemma that the structural realist faces. and then taking one horn of the dilemma seriously. This is the introductory transparency on structural realism. It is rather well known. It is the example of John Worrell in his paper, The Best of Both Worlds from the Early 90s. He presented the following example. We have the intensity equations of Fresnel and the ratio of particular expressions of

2:30 of the angles of incidence, refraction, and reflection of a light ray when it passes from one medium to another, the ratio of these various expressions is the same as the ratio of a theoretical term called A, the amplitude. and the intensity is proportional to the square of the amplitude Worrell now presented two interpretations of this theoretical term A from the history of physics the first was an interpretation endorsed by Augustin Fresnel and that is it is the amplitude of an oscillating ether particle and the second interpretation is Maxwell's, it is the strength of the electromagnetic field now we can add two more of them we can interpret it as the photon density it's Einstein's interpretation or we can interpret it as the probability of finding a photon which is Feynman's interpretation. So we have now from the history of physics four different interpretations of one theoretical term. But what remains in all the theories which are behind these interpretations are these formulae of Fresnel. So John Worrell's conclusion was the equations fix the structure, not the interpretation. Structure remains and what changes is the interpretation. So if you believe in the reality of structures, yes, you are immune for the pessimistic meta-induction. That was his argument.

5:00 Another important paper was that of James Leishman. He discerned ontological and epistemic Structural Realism. Epistemic is all we can ever know about of the world is structure, and the ontological structural realist says all that there is is structure. So then it follows that all we can ever know is also only structure. So the epistemic variant is for the structural realist with cold feet, and yes, the ontic variant is for those who are a little bit more gutsy. The philosophy of mathematics has been meeting the philosophy of physics here, because structuralism is also an issue in the philosophy of mathematics, and in mathematics there is this distinction between antiren and in-race structures, and we're not sure whether this distinction is also meaningful in the context of science, in physics in particular. What is the additional motivation for ontological structural realism? James Ladyman and Stephen French, they have pushed the point of elementary quantum mechanics. The notion of an object as a consequence of the alleged violation of Leibniz's principle of the identity of indiscernibles motivated them to say that we need to abolish the concept of an object in quantum mechanics altogether and we move to the concept of a structure. This however is controversial. I think a far more stronger and rarely if ever mentioned argument in favor of ontological structural realism are the impossibility theorems for particle interpretations in quantum field theory, which are not of heart and controversial. That shows that really the concept of an object has to be sort of completely reconceptualized and if we're

7:30 going to do that we might as well take them to be structures. Now here's a dilemma. These are not the steps of a deductive argument, although So the last steps are. The first steps are more like steps in a dance. Okay, so structural realism has to, is a version that has to remain out of reach of the pessimistic meta-induction, but not that far that it cannot appeal to the no miracle argument, because it has to have some argument in its favor too, right? Yes, the next move is inserted because I knew status psilis would be in the audience. He himself is a favorite of a qualified realism in order to combat the pessimistic meta-induction. and he has criticized the structural realism in the past but one can look at structural realism simply as a principled version of qualified realism so Psyllos is in favor of investigating on a case by case basis what we should believe of a scientific theory how far we should go beyond the observable And if you're a structural realist, it's always going to be the structure. Now, how to characterize structural realism? That amounts almost to the same as how to characterize the concept of a structure. There are two ways of making this precise, currently known. The first is in set theory and the second one is in category theory. I'll give you one example from how this happens in set theory and how the structural realist is supposed to interpret this structure. Okay, we take a natrium atom in a magnetic field

10:00 and I have written down just an ordinary quantum mechanical model with the Hilbert space, one Hamiltonian, one state at one instance of time, and one generated probability measure. Now, if you go a little bit into the details how you construe this set theoretically, Yes. So just take a look at the picture here. You see that you have lots and lots of mathematical structures which are themselves in this quantum mechanical structure. And in order to make these quantum mechanical structures, you need lots and lots of sets. Lots and lots of sets you need. So if you are a little bit familiar with it, you see yourself with your shopping cart walking in the infinite supermarket along all the echelon sets of the Bulwaki company. When you have collected enough, you leave at the nearest ordinal level, then you have of your shopping cart with all these magnificent sets. But when you leave here the neoplatonic heaven of set theoretical structures, in the parking lot you are going to encounter physical reality, right? How are we going to interpret this in physical reality? Now, if you take this literally, this is just simply absurd. There is not a single soul on this planet who believes that a natrium atom in a magnetic field is a collection of gigantic sets, all of cardinality of the continuum. That is just absurd. So we revised the claim of the structural realist. I was a fool to think of this in the first place. Of course, it is not meant to be taken, literally, no. The structure represents the Natrium atom in the magnetic field. Okay, so we need a theory of representation, right?

12:30 Because what does that mean? This is just a word, representation. What does it mean? We have to say something specific because we still have this set theoretical structure, and we still have something out there in the world. And now, clearly, we have to say something here. So we need a new theory of representation. The same story can be told when you construe this in terms of category theory, which I won't do. Okay, so step four is, yeah, that's when the theory of representation, you simply take disjunction of the antecedents. But there is another possibility. We simply deny both antecedents. Another possibility is simply to not construing structure set theoretically and not construing structure category theoretically, but come up with a new concept of a structure structure that they can interpret literally, right? Okay, so that's the project. So we are going to do something alternative to these two things, a new theory of structures. Now, there are requirements and desiderata, and I've listed a few of them here. The first is simply taken from the literature on the subject. It is often said that, by James Ladyman and others, we have to take the structure as a primitive concept, so that's what we're going to do, right? and we're going to take relations too as primitive notions. Of course, the language must be rich enough to express what is called the structural content of a theory. This has been attempted in the past. Ramsifying the theory is an attempt. That attempt has failed. So we are in desperate need of something new. Of course, we're going to characterize physical theories as sort of types of structure.

15:00 And, of course, the axioms of my new theory of structure should at least be strong enough to be able to make all the mathematics that is needed, at least in physics. And if you can do that, you can make all the mathematics that is ever used in science. A desideratum is that somehow set theories should emerge as a sub-theory. Another desideratum is something that would be nice, but it's not necessary. That is, if the various applications there are of category theory in physics, we should be able to reproduce them too. Another thing I want to have is an elementary language, so no second-order things in there. Oh yes, a requirement I almost forgot. Of course, we should be able to prove that it is consistent. Okay, so now I'm going to throw you a few morsels of this new theory of structure. We have a language that consists of places. We have place variables, relation variables, structure variables, and object variables. you might immediately already protest what are objects doing there, weren't we not supposed to get rid of them. They're going to play an interesting role. The natural numbers are in there for the time being merely as devices of making the exposition more clear. Later on I can present you some ideas how to get rid of them. Okay, now here follow a number of primitive predicates that we have. Relations and structures, they have places, right? That's what relations have, places. And structures have places too. too. So I have an abbreviation for that. Objects, they can occupy places. So we have

17:30 two dyadic predicates for that, too, and also an abbreviation, this little curly arrow. We have, of course, identity. We have also a number place relation, so a relation can have first places. It is sort of a degenerate notion of a relation which may play the role We can have two places, then it's a binary relation, et cetera, right? So we have that too. And of course we're going to use the natural number, so we better have the piano axioms in there too. Identity can be handled in just the normal fashion. logic with identity, or we define it simply as indiscernible in the language, right? Now some axioms besides the Peano axioms. Every relation has a unique, has a unique arity. and so that's an axiom and the arity is defined as you see up above there. So if you have a relation with sort of only two places and then the M there is two. Places of relations are always numbered places of relations and conversely and that is to make on smoothly. Relations and structures, they are extensional. That's what we want too. That's going to help ourselves to the idea that if we have two different structures,

20:00 Now if we have two structures, but the only difference is that it is it is intuitively the same structure that is exemplified by different groups of bodies or different objects, then we would like to call the two structures identical. So that's what this axiom is going to take care of. Okay, we have a number of rather sort of commonplace definitions here. We have a notion of a substructure. It has, of course, all the places and relations in common with the structure. It is a substructure of. We're going to make compositions of structures. Yes, so a composition of two structure is just that structure that has all the relations and places in common of the two structures but not more. So the idea behind this here is that if we make structures in a set theoretical hierarchy we go up and up. We have to make successive applications of the power set. But here the idea is to remain just at base level by composing structures. Yeah, okay, so the extensionality axiom gives me immediately the theorem that composition is unique. Another candidate axiom is, of course, simply to say that I can compose every two structures. A few other helpful definitions. A null structure, that is a structure which has neither places nor relations. And so sort of the vague, analogon of the empty set. Genuine structures, they have places and relations. Onterim structures, structures, they have only unoccupied places. We have in-race structures, they have of course occupied places by object, so this is capturing a distinction from the philosophy of mathematics,

22:30 which I can now simply define in my language because it is rich enough. Relations without rilata, one of the alleged conceptual impossibilities according to critics of structural realism, there can be relations without rilata. Those are relations with unoccupied places. Sets, we can define what a set is. A set is a structure without relations and all places occupied by objects. So this is Cantor's idea of a set as a collection of objects. And of course we can then define the membership relation of set theory. Four minutes, okay. I'm nearly done, I'm nearly done. The notion of an infinite structure, this is a bit modeled on Dedekind's definition of infinity, right, so we don't need to appeal to cardinalities here. We use the concept of a function here, and this relation A, S, B, and this can all be defined language. We can talk about the domain of in-race structures. We can define what arrows are, so in that way we can have proper definitions of the primitive concepts of category theory. And here is a definition of M is a mother structure of another structure, if and only if it has at its places exactly the substructures of the other. And then an axiom suggests itself, namely an axiom asserting that there are no orphans. So every structure has a mother. Now, to give you just one example, a definition of a group structure, so don't go through

25:00 all the sort of the formal details, but I'm just exemplifying that my language is rich enough to define all the usual concepts of mathematics, right, and the point is now just is to find a minimum set of axioms that allows me to prove their existence. Okay, one final transparency of how to get rid of the natural numbers. Here I have taken a look at the category theory. William Laufer was puzzled by the problem how can we deal with natural numbers in category theory, and he did that by defining a natural number object. And so that is roughly a category for which we have a theorem of primitive recursion. Now you can also define, of course, a law for structure in the language of set theory, and that's what I have done here just for your convenience. You can also define in set theory what a Peano structure is, and then you prove on the basis of the actions of set theory that the two are isomorphic so that is an insight i now take a home and i now define in my primitive language what a law for structure is and if i have that then i have the natural numbers so that's how i can get rid of the natural numbers okay that's it So we have a couple of minutes for the structure, who has a question? Thank you. As I understand it, what you have presented is a way of analysing structures. But to me it is not clear at all why I now should be a realist about structures. I cannot understand how to conceive of a realist of structures. Should I be a realist about all these different components that you have presented?

27:30 How should I understand it? Well, yes, of course, to put the things in the right order, you see. must know what a structure is before we can even start thinking about how to interpret it. Of course the ontological structural realist will want to interpret these structures realistically. So the first part of the project is not mounting arguments in favor of structural realism, you know that's what already so many other people are doing. I'm doing something different. You were referring to the parallel of structuralism mathematics and then you said there are only two alternatives, the set theoretical and the category theoretical. Now if I remember correctly, Shapiro's form of structuralism, he has a different notion of a structure. I mean, according to, you first have models of some kind of language and then you have isomorphic models, that's well-defined and the structure is simply a property of models such that isomorphic models either fall under the same structure or both don't fall under the structure. So it's just property of models. So how does your notion relate to that notion? Yes, of course I have to know this and I have a few things to say about this. The first is that Shapiro takes the concept of a set as primitive two. which I don't know. He's working in second order predicate logic. No, no, read it very carefully. I have corresponded to this subject. So the first thing is he takes, so in his book, what is it, structure, and he often talks about the structures there, in this paragraph only, he said. So he writes down a few axioms which are very heavily modeled after set theory, not just a power set axiom and things like that, but just a little bit different. But he does take aboard the concept of a set in his language, which is primitive, right? I do not. So there is at least this formal difference between us. And furthermore, this is a remark on the side, he is not himself very happy about this. Just because of this.

30:00 So, at least my aim is to improve what we need. There was a question over there. I have a problem with your concept of the structure. You mentioned that the existence should be built in the way that that the structures which we are classed as identical in intuitive manner are indeed identical. So I understand this as a demand for flexible structures. What are your demands concerning structures in general? So is there a set of properties where axioms should fulfill in order to be axioms structures in your sense? In principle, I have completed my list of requirements and desiderata. Now really any set of axioms that will meet these requirements and desiderata but I am perfectly happy with it. So of course I'm going to look at how structure, how well as far as we know how structure behave and try to gain insight from that in writing down axioms so to make them also sort of intuitively possible, right? But the bare notion of structure here that it is something with relations and places. That's it, let's see. And I'm going to make sort of a domain of discourse in which you can compose them, et cetera. And you have a language which is rich enough to define what a group structure is, a group space, et cetera, et cetera. We only have back to one additional question, sir. Yeah, I don't see our language when projects are being found, like the libraries . So you have a, if you describe that in your language, that you actually have a unique structure in the sort of, you know, as you use the term property now as a question, which then actually is No, I have not worked this out in detail,

32:30 but I'm filled with hope about things like that. Those are things I have good hopes about. There are other things that I don't share with you now, which I don't have good hopes. What is a structure, I think we come out of this by being told that structure is something in place in relation, and I don't know what these are. Well, what shall I take home, what shall I take home, what shall I take home, talk about Listen, listen, bear with me. There is a canonical order in analytic philosophy about explications, right? Well, that's too bad for you. The first thing we can do is try to give a definition of a concept we don't understand in terms of concepts that are much clearer to us. So this happens in set theory and category theory. If you ask a set theorist, what is a set? Well, he doesn't have a definition, but he gives you the axioms. So that's sort of the second thing you can do. You don't have a definition, but you axiomatize it. That's what Hilbert said. If you don't have a definition, axiomatize it. So if you ask me what a structure is, the best I can do is present you my definitions. If you ask me what natural numbers are, the best I can do is give you the Peano axiom. satisfy you, then I don't satisfy you, but. That's a nice answer. So, thank you once again. We have to move on to our second speaker. Oh, yes.

35:00 Thank you. So, we're going to need a talk on structural realism, intermediate views, and laws of nature. That's what I call it. My PC. How can I open my... My PC. No, no, no. No, my PC. On my PC? And then your disc shows up. Ah, yeah. Disco local. Yeah, yeah. Yeah, yeah, yeah. I'll try the PDF file. Do you have a PDF? I have a PDF too. It seems to work. Ah, here we are. Okay, thank you, Bishop. So thank you, Dennis. Yeah, my talk is on, actually it has two parts. I'm going to talk about what I call the version of a variant of structural realism, which I like to call to me a structural realism, and then I like to present some views, not really worked out views, but ideas for a question which occurred to me during the last two, one or two years, that a structural realist should have a certain position about laws of nature. What exactly, what kind of view about laws of nature

37:30 should a structural realist have? So first of all, what I call intermediate structural realism, That is connected to the second topic, of course. To give you, of course, one has to say something about structure, and here's Shapiro again, and I just want to quote him. If I'm interested in a collection of objects with certain relations among them, you find a pattern of structure to be the abstract form of a system highlighting interrelationships among the objects and ignoring any features of them that do not affect how they relate to other objects in the system. So my working definition from the beginning is just structures, I consider structures as domains, that is to say sets of objects, with sets of relations and those of them. And that also means that those objects can be instantiated or individuated by the set of relational properties we can base to that. And structural realism is roughly in the view that we should be familiar in a structure rather than object-like content of a material scientific view of the structure of the content. To give you a particular example of a structural realist position, I take Chelesfeld's conception of what he calls moderate structural realism. And here's some quotes of one of his papers. he considers quantum theory and says look there's quantum entanglement and quantum entanglement shows that there are correlations among physical systems which amount to the whole having intrinsic properties that do not simply be non-intrinsic properties of the path beyond the failure of separability and quantum theory. And this in turn suggests, as he goes on, replacing a metaphysics of intrinsic properties with a metaphysics of relations. And from the metaphysics of relations, he goes on to what he calls moderate structural realism. Things exist, he says, but the relations in which there's been are all there is to the things at the basic level. You might also say that structural realism shows, if you think about what is a physical theory, that structural realism shows a close affinity to the semantic theorem of theories.

40:00 Classes of morals comprise a structural theory content rather than a concept about the object-like entities. Take literally the idea to individual theories by means of their pure structural content, however, is far too weak, and because we end up with what I would like to call the problem of unintended domains. That is to say, we have theories which seem to say something about highly different domains of objects, although on a structural level, on a formal level, They seem to be equivalent, they show up the same mathematical structure, I mean, as a rough example, for instance, compare classical electrolyte dynamics with hydrodynamics, where lots of mathematical structure are simply the same, right? We have continuity equations, we talk about currents and their properties, we have the hearings of housing still supply, and so on and so forth. We might also, in the video, theories by addressing the group, the symmetry groups which show up in the theories. Physicists in the 60s have wondered whether the SV2 gauge group could apply to the strong isostrain as opposed to the weak isostrain. Again, the mathematical structure of those two theories this is pretty much the same, but they talk about different domains of objects. Or if you want, it might show up as a temporal group, or it might show up as an age group, and perhaps in many other patients in physics and physical theory. So there are many examples like that, I take it, in physics. I was already talking about symmetries in physics, and that may take the opportunity to make a sure of that ration. The symmetry of the domain, you might think of the symmetry of the domain as a set of one-to-one mappings of that domain onto itself, that these mappings are called symmetry transformations, such that the structure of D is preserved. And that's a nice case, that the symmetry transformations form group, for example, by equivalence relations and partition D to equivalence classes. You might also, practically speaking,

42:30 why aren't you so interested in symmetries? Because symmetries can be viewed as tools to filter out the relevant aspects. In the sense of symmetry transformations, the leppics, leave the relevant aspects inverted. Now note that they should distinguish between symmetries where the symmetry transformations as opposed to symmetries without real sensations. And examples of the latter case are, for instance, scale transformations, auditory transformations, and also gaze transformations. I say this just, in fact, with referring to the talk of Richard Neely in the morning, I take it that both local and global gaze transformations are empirical in the sense that they don't possess real instantiation. So why are we still interested in theories and classifying theories by the symmetries if the symmetry transformations do not possess real instantiations? Well, because certain invariants pop out under those very transformations, and only those invariants in the case of symmetries without real instantiations, only those invariants allow for realistic interpretations. Now, of course, the structural content of monophysics theories is mostly given by a symmetry structure, and gauge theories are just the most important case. Again, gauge theories are possessed with instantiation, so only the invariants allow for realistic interpretations in the paradigmatic examples here are the Casimir operators, which give the mass and the spins and the various charges of the part of this. In a sense, you might think of it as a general feature, any, as we might call it, symmetry-based physics. We take symmetries as tools to filter out relevant aspects, and if there are symmetries among them where the transformations do not possess real instantiations, then all we can get out of this is invariance, and only those invariance of our realistic interpretation, but we cannot at the same time get rid of this. Those invariant properties of the domain of objects,

45:00 like mass, fin, charge, are the best candidates of what intuitively we would call the properties of the objects. That, as a physicist would have it, even in the case of a lone electron in a possible world, because the charge of the electron is an invariant feature of the atrons formation. So if you want our best theory about quantum-lector electronics, our best theory is about electrons. Even in that case, it is intrinsic property of the particle. But those intrinsic properties are, as I would have it, structurally derived, so to speak. We should not suppose objects in the form independently of the structure itself. So in a taxonomy of views about structural realism, there was this long-standing, since a very well-known distinction between ontic structural realism and epistemic structural realism. Where ontic structural realism is sometimes only construed as a hardcore position, so to speak, as an eliminativism about relata altogether. You might also have a non-eliminative variation where you think of may think of the relata as existing, but only defined by whatever the structural properties are. And in that sense, Esfeld's version of moderate structural realism is a variant of non-eliminative quantum structural realism, because he believes that relata exist, but are only individuated by the relational properties, No intrinsic properties exist. As I have shown you, we can't get rid of all the intrinsic properties altogether, so I propose an intermediate position here that there are relational and structurally derived

47:30 intrinsic properties, the invariance of those structures, which we will always have. But still, since those intrinsic properties are, is still viewed as a structural disposition. So that was probably my first comment. Structural realism is, I think, in the metaphysics of our modern theories and of modern physics. In modern physics, symmetry groups give us the relevant theory structure, so they give us relational properties, to define intrinsic properties. That doesn't mean that the position of intermediate structural realism collapses to entity realism, or the fashion of entity realism, because the intrinsic properties are, as I said, structurally defined, and we should not think of them as allowing us to pick out individuality, individual essences, or something, and I can't do that anymore. And that's also perhaps a possible solution or a way into the problem, and perhaps a way out and the domains. Because at the end of the day, structural equivalent models of theory can be distinguished and can individuate them by the structurally defined intrinsic properties over which those different theories talk about. In one case, for instance, Electrodynamics talks about the domain of objects which has electric charge as opposed to whatever fluids you are considering in a hydropathic. Now, let me go to the second part of the ocean. What kind of view of ocean nature should a structural realist have? Here's a simple argument. You might think that if a structural realist considers fundamental laws a symmetry structure is, Structural realism is a view about the reality of those structures, so structural realism is committed to a realness called laws of the nature. Is that true or not? Actually, I believe that it is true, and my position has slightly changed from what I've written in the abstract, actually. So you see it's really a work of progress.

50:00 But it's still a very peculiar position to which we end up. There's a very well known distinction between two standard views about laws. One, there's regularity theory, humanism about laws, laws are just regularities, and necessitarianism, those are necessary connections between, perhaps, universal problems. And then we might also think of a whole deposition which is a reductionism about laws as opposed to a realist about laws. An influence in view is, of course, who is his doctrine on what is called human supervenience. I guess I can skip this quote because I think that all of you know about this quote. The view that, as he put it in the end of the quote, we have an arrangement of qualities and that is all. There's no difference about difference in the arrangement of qualities. All counts supervene some intrinsic, natural, property properties. Jungian metaphysics, as usually construed, has at least three major ingredients. There's a view, there's a kind of microphysicalist view, that the super-median space is those Those intrinsic properties, perhaps natural, perhaps qualitative, of course, one must distinguish it. I only consider intrinsic properties. And those are categorical properties, non-propositions, non-dispositional properties. Usually unionists hold a regularity view of laws, and they are reductionists. because laws aren't real in the world, they are supreme on this human base. Now consider the position of structural realism. Are we committed to micro-culturalism? I'm not so sure. I think that at this point there's already a major distinction between the unionist and the old-fashioned tradition, so to speak, and the structural realism. And also, as far as the properties are concerned, the structural realist buys relational properties, of course, but he also has to buy structural and intrinsic properties. And we might end up with a realist view,

52:30 still a bit different from the view of the union. Well, first, union's obedience, the thesis as Lewis has presented this, is known today, I think it's safe to say that, is known today as a nonstop. It doesn't work. It simply doesn't work in view of modern physics. Because more or less every definition of separability if you don't like definitions of separability, I've used the notion of supervenience. You might also have come up with different definitions. Here's one, which does not use the notion of supervenience. The ideas of course is of course the same, but the qualities of a whole supervenience on the properties of the parts. And both economic and engaged theories, we find cases and instances which violate this requirement of separability. Intrinsic properties of holes do not supervise intrinsic properties of their parts. That's the case of tango metaphoric mechanics. And in gauge theories, there are other cases. Polonies seem to be best candidates of general entities in gauge theories, but they are non-local in a deep sense. I don't want to go into this. I just assumed that the doctrine of human supervenience fails as far as moral physics. In both cases, the main reason is that the parts simply do not possess the literature of the properties. All right. Now, in an attempt to combine human metaphysics and structural realism, at least one of the three conditions of the human must fail, the microphysicalism, the radioactive use of reductionism. We already see that number one has to go, but we might change it into a view which I would like to call union with all structures. Now, what about two or three? In order to know that, more must be said about structures or structural properties. I'm really interested in any structures.

55:00 is remember structures and sets of relations. Think of graphs, for instance, just imagine graphs. And just imagine graphs where there are only binary relations over a set of objects. Now you can have a picture in your mind where those binary relations are what they spread, so to speak, over the name of objects. And then there's perhaps a regular spreading of those binary relations. So the more regularity we find in a structure, the more we are inclined to think that we can have, that we can uphold generalizing statements about the domain of objects. So that's our view of our regularity of the objects and of the domain of objects. Structures, we are interested in structures say something about regular sense of relations. And that is of course what is captured in a, or should be captured in a few of our laws of nature. The regularity, the degree of regularity of the structure. Now at this point I should show you, I should come up with an account of how to measure the regularity of the structure. I don't have such an account. I have hope that someone could come up with something like that, but for a moment let us just assume that we can have measures of regularity and structure. Then the human structuralism, if we are on the way to a human structuralism, the change of the condition one of the union, the traditional union, would turn out like this. We consider structures not only as arbitrary sets of relations, but regular sets of relations, which are related in the latter, which are of course categorical in relation to property. And we consider them as global entities. The structure is not something which is locally, which is built up locally, but which exists as an extended thing, if you like, over the whole domain of objects. It's a global or a holistic entity. And the set of all possible structures gives us now the supervenous phase.

57:30 So instead of having a micro-physicalist view, we end up with, in a new sense, with at least with something different, you might call it holistic, physicalism, and it certainly must be spelled far more precisely, but it's at least an entirely different view than the view which we have, which we get from Louis' unionism. Now, what about the second condition of unionism? Well, the second condition, it might be fine, of course I'm sure. You might still have a regularity view about law In the sense that the opponent of the regulars is the necessitarian, so regulars, regulars theory means that we end up with a non necessitarian view of our laws. Look, there are no problems with the regularity of use and if human structuralism, the kind of structuralism I'm not proposing here, still holds a regularity of all laws, here's to answer those problems. Not all regularities are laws, they are the same laws, there are empty laws, non-instantiated laws, those are the more problems with the regularity of use. But what does the Guillaumean structuralist say? He considers the regularities as a global feature of the domain of objects in total. And so the regularity is something built in on this global level. Again, the convenience space of the structural realist should be the space of all possible structures. Once we have defined some structure in nature, then we can be confident that the structure holds all over the place. That would explain, that gives us also an idea, perhaps you might have a rich explanation of the universality of certain properties which we find in nature. Why does every electron have one and the same charge? Should we stick to universalism or essentialism

1:00:00 about properties, about those basic properties? No, we shouldn't, it's not necessary to do that. It's just that this is a global feature of our structure. But the structure might be different, could be different, we don't know that. It's not necessary that we find this structure as opposed to another structure. So this is where the regular list view comes in. And it also accounts for exceptionalism, because we only find those which are already filled in. Ah, I see, I see. It's almost the last time. The last condition, the election is about loss. Now, here really we have the offer from structural realism, so in a sense the argument I gave is correct. is in close affinity to a realist view about laws. But usually, the realist view is combined to a necessitarian view about laws. And here's an offer that we can have, we think of laws of nature as in-ray structures, as opposed to on-the-ray view. But we can combine it with a non-necessitarian view, because we still believe that there is a supervenient space, and in that sense, it's only a regularity of nature. So let me end, conclusion of those parts. I propose structural realism as a combination of on the one hand side, intermediate structural realism as in this taxon between systemic and optic, where we have not only relational, but structural and right intrinsic properties, and that one still can have, that one still can construe this view in a human fashion, not of realism style, But, if those three conditions are, kind of a kind of a kind of regularity view, but the regularity is built in a normal fashion, but it's not necessarily to end up in a necessary and it's a realist problem. Thank you. So we have only a couple of minutes for questions. very interesting. These are the first part. On your intermediate structural realism,

1:02:30 intrinsic properties are structurally derived. Can you give an explicit account of what you mean by structurally derived here? And if you can, is there any need to put in scare quotes, as you do every now and then? It's, usually people say that for a structuralist, there might be, a structuralist might only do that the structure comes first and then the relata comes, so to speak. But that might be, that might not be a good view because of, I don't, I'm not so sure whether in ontology we should end up with rankings or so, that one thing goes prior to something else. So, in a sense, the nations and relata are on a part. I understand that. But still, whatever we can say about the relata are, is that there are bunches of relation properties, and invariant properties of the automorphisms of the structure, so to speak, of those lackings which the structure are. And that was what I mean, what I put in quotes. If you say, still I hold the view that those intrinsic properties are, can be seen independently independently of whatever we say about the structure, then I'm down, but then it's perhaps a matter of taste. I would insist that you can't really tell why, at least if you stick with the view that those intrinsic properties exist independently of the structure, you have to give me a more, you have to tell a story of where they come from, whereas the structuralists already gave them the story, in the sense that they are structurally realized. Thank you, Jeff. Follow up on the same point. I find that especially human structural realism very suggestive, but I want to focus on the intermediate SR as well. Somebody who wanted to defend this interview would first of all presumably say that relational properties are also intrinsic. I mean, they're just a different variety

1:05:00 of intrinsic property to or in place intrinsic property. And again, I want to second your worry about structural derivation. That might be our way of sort of zeroing in on them and aesthetically, but however we arrive at a knowledge of the intrinsic properties, they're there. And that's independent of our means of deriving them. Right, there is an epistemic flavor here and I should get rid of that if I'm really doing physics and so on this analogy, but could you explain to me why you should think of the relational properties as intrinsic? Well, for any order relation, including zero-coder relations, mainly monadic properties, we can distinguish between intrinsic and extrinsic. So we can have intrinsic relations just like we can have intrinsic programs. I think it's a deep issue. It is, it is, I know, of course. Perhaps that is discussed outside of this meeting. That's why I don't have to buy it. Thank you very much. So, our next speaker, Ancelo Cheek, University of New York. Thank you.

1:07:30 Thank you very much. So, there's the size of the structure of you that's in the form of the U.S. and the ability. All right, well, thank you for having me here. I mean, I'll give you what that would be. If you walk, you can still go. You can all go. Okay, this has an inclination with a very good friend, that has been particularly supported when I was essentially thinking that this statement was completely mad at her. I'm afraid I was probably right. Anyway, let's keep going. So, those are, in general, the objective of the aims and the agenda of the epistemic structural realism. The epistemic structural realism has been put forward to try to bring together the two main arguments on realism, concept of realism at the moment. One of them insists is a counterfeit against realism, insists on the historical record, on the fact that historical record push us to be extremely skeptical about realist thesis. Well, because our best scientific theory is usually good. At some point, something breaks down, they don't work any longer. We replace them. We replace their entities, and these three sites sometimes look like a big, big dustbin full of entities that we believe on a long time ago or a while ago, and do not work any longer. Now, on the other side, we've got this strong intuition that I'm going to give you an argument. The idea that if science is successful, there has to be something that goes straight to the joints of reality. It can't be just a chance that we got it right, that we can predict certain phenomena, something particularly sophisticated or far away from everyday intuition. It has to be something stronger than that. Well, the only, the aim of the dystopic structural realism since the beginning was arguing that something in this sort of cemetery of old theories remains. Remains with us all the way through. So we keep, we keep finding this something in modern theories.

1:10:00 So in this form of concern with Romanians, we are, we are, we can still hold it, rely on these Romanians as much as a reality. Now... So, what remains? Miracle has put it in this terms, more or less. Referring to an example that has been already extensively quoted. Structural correctness, for now completely missing at the time, the nature of life, the life. But nevertheless, it is no miracle that this theory enjoyed the empirical predictors says that he did, it is non-mirrorable because Cornell theory, as science later saw it, attributable to the right structure. Now, the thing is, usually this quote gives you an hope on one side, and usually structural realists have a lot to say about hopes. And on the other side, it's a weird question. What is the structure? Another potential. This time, again, from the world, but from point correct, motion and current displacement are images that we substitute for the real objects, which nature will hide forever from our eyes. The true relations between these real objects are the only reality we can attach to. Now, this seems to be the way to cash out the structure. The structure is a set of relation, arranged in a certain way, captured by the equation of theory, and this explains why we keep repeating the equations and not the entities about, again, those relations are supposed to be interrelational. Because what we don't really know is nature now. All we know is that they stand with each other or with other things in a certain sort of relation. Now, one of the ideas inspired this talk is that this identification, or more precisely, the identification of structural realism with the notion of structure, with the quotation

1:12:30 kind of . It's called to the structuralist, or at least in some of them, more problems than benefits. At least in a sense, at least in this sense, one of the two strengths that you can find in structures is the idea that an historically informed analysis about how to write the framework change should suggest us that we have to be extremely cautious in creating our trust in science. We can't take everything. We cannot take everything face-to-face. Not everything that science says about certain processes and entities is true. Most of what science says is probably going to go. But on the other side, you can identify carefully what remains. This is, generally speaking, a fallibleist approach. And being historical in full is then to suggest us that what remains in a certain sense, or depending on how we define or capture it, is the structure. On the other side, in relation to Pocairelli, adding to a distinction which is in principle, is meta-historical. Pocairelli seems to have in mind something that doesn't have to do with the way in which style is historical anymore. rather pointing to something that necessarily suggests that science has to have moved in that way. Because there's something in principle that we can't reach. And there's something in principle that has nothing to do with our liberalism that, in other words, without faculties. Or, if it has, it's something that's structurally characterizes the way in which we know reality and leaves us beyond. So there is a hidden nature. The hidden nature is a nature that remains hidden, no matter what we do. The aim of this talk is to now see if it's possible. Okay, let me, a little close here. I believe that many of the ways to address some of the problems that structural realism encounter have been harrowing, in a certain sense, to the very first form of it. Are trying to develop a form of our liberals. I won't talk about those today. I think that they, on that road, problem that maybe the position I'm trying to highlight doesn't encounter. I will focus on the second one. I will try to give you an idea why I believe that that second strength

1:15:00 equates to the form of humility. Now, in the literature, humility comes in two forms, essentially. There is a Kantian humility, put forward by Ray Lenton, has an interpretation of Kant, I think that the counting there should be between inverted commas, because I don't really think that is a viable interpretation of count, but it might be a viable way to put what we mean by humility, and what we mean by structural realism in that second sentence. The second one is Rensian humility, defined by David Hewis, I think in his last word, published after his death. In one case we will see that there is a conception of intrinsicality, intrinsic properties that treat them, to use the language of contemporary metaphysics, as either. They don't do anything, that's why you don't know them. In the second case, rancification, or if you want, a rancid sentence driven sort of reason makes most of the work, and I will try to sketch what sort of work it does. But let's go on. There will be, in framing this position, and one of my aims is testing against the historical record. In other words, for the position to stand, the idea of humanity has to make sense of what happens in theory change, or what happens in specific cases of historical change. Do I think that this overlaps with the cases in which we're dealing with a problem of legalism? Yes and no. The fallibilist here has more manoeuvre than I have. Can claim, can invoke other properties, other forms, other pieces and bits of realities to fuel his position. I will have more constraints in a certain sense. I will have to tell you in a moment what sort of properties I believe we can know of reality and trying to make sense of the historical record, not today of course, of the historical record using just those aspects of reality. But yeah, I have to be able to draw, to derive from this physical view, a sort of working

1:17:30 hypothesis to contrast with the history of science. Now, which is even the reason I'm trying to show you two different forms of unity. that if you overlap the crossroad between the two, I can find, I can point over mapping the two or showing you the crossroad between the two. I can identify the working hypothesis to come to test on these slides. Now, here is the sketch of continuity, or how, if you like, how Rayleigh can intend. and then we can. Distinction. These in themselves are substances. So I agree on this point. I agree on this point with Olga on this point. We've got objects out there and they fit with intrinsic properties. You can't escape that. They define the identity of the objects. Phenomena, you can't see phenomena, are indiscrinsic properties of the objects. They are relational in nature, in the sense that you've got them only as long as the objects are in company with other things. No company, no phenomena. In a certain sense, if you buy into related view, our knowledge is an instance of phenomena. It's something that occurs because we interact with phenomena. So it is a specific case for phenomena. Receptivity. We know only what can affect us. The orchid, we know, has to be in some way, has to be able to affect us. We have to be able to interact and receive something from the orchid. Otherwise there is no knowledge. Irreducibility. Well, Relentum doesn't call it straight away in that way. I have to, for reason, for, well, because I don't have time to screen your word with you. So the idea is that the reason is that is because that is part and parcel of the, it's the most difficult part of the reconstruction of town, showing that there is discipline premise in town recently. We have this for free. So the idea is that the powers that things have are relational properties, and they are not reducible to the intrinsic setup of the entities.

1:20:00 So the idea is, you've got your entity is identified by a set of intrinsic properties. Those intrinsic properties don't allow you to derive the powers that the object has. So the way in which the objects affect you, that emerge where you are in the presence of the object, is not something that depends upon the intrinsic properties. Now, if you accept the three things, the three hypotheses, you end up with the idea of humility. You can't have knowledge of these intrinsic qualities, because using, again, borrowing the terms from the, from all the manipulations, they are ideas, they don't do nothing, they do nothing, they don't affect you, therefore, they don't feature in your knowledge of the world. Now, how about the Ramsey-Nuvillity? Ramsey-Nuvillity, when U.S. speaks about the romantic thesis, it means that it can show, through its work, that you can reach more or less the same sort of conclusion. How do we do that? Three ingredients. Ramsey sent its characterization on the role of puberty, I didn't see combinatorial . So the up-core of metaphysics, essentially. When I presented this for the first time, it was a form of perversion to assimilate. Then it used to structural realism. All there was going before. So there are at least two perverse people in the end. I was the only one last time, so this is an improvement. Now, let's get into the nitty-gritty of the physician. Assume that theoretical framework you have is the final theory. This is the theory that gives you all the possible information about the world surrounding you. Then yes, take this grand C sentence and formulate it, following the style that evidence has shown us, for instance, you now define correctness. Follow that sort of style, with one prediction, with one change, the terms you're going to ramcify it, the terms that you're going to replace with second-word variables, classify only intrinsic properties. Now, what you get, you get a ramcify sentence that tells you everything that the original theory says about the claims concerning the intrinsic properties.

1:22:30 The Ramsey sentence that characterizes the role that the intrinsic property plays in explaining and accounting for the processes that characterize the world, and the Ramsey sentence that, the Ramsey sentence is by a condition more trivialized. Now in terms, there's always impossible, possible, in principle possible, that we have some, and other examples of things that makes it true. It doesn't necessarily capture one single set of things, set of items, set of properties, in this case. Now, suppose that your intrinsic property can be grouped in classes that pertain at least two items. Combinatorial is another principle of using the physics that tells you that we can swap them. We can change them and we always bump into a world in which the swap of course, we are nice. So you're still portraying a world in which one. Suppose that we've got an intrinsic property like charge but in another world is the redness of a tomato, okay? It's another possible world. Everything that happens because you've got something in charge, electrical charge in this world, occurring in the other world because you have something red like a tomato. You have a fundamental thing that has this property. Now, that's what, for me, it tells you, you can swap them. And everything else is going to be a second. Quidditchism. The properties that we are talking about has a transworld identity. Despite which you know all these swaps, it maintains in some sort of a state that's something that remains identical despite the change. Now, how the rex and immunity follows? The role of intrinsic property in T is told you by, already by the rex sentence that can be able to be realized. You can swap your properties and everything remains the same. So what combinatorialism and put together tells you that your theory would be true in a world in which your intrinsic properties are completely different, but the rules are occupied by something of the same class. So in a certain sense, even in the presence of your fundamental theory,

1:25:00 you're dealing with something in the world that is in principle alone. You can't assess it because it might be very different from what it is, and the eventual base you have in your capital would remain the same. Now, if you conclude, if you have a conclusion. If we believe in this stuff, I'm not sure I do, but I think so, something similar might be up with. And if you believe in these things, the success of scientific theory should be explicable in terms of their intrinsic relational properties. And theory change, cases of theory change, and retention should be explained in terms of, should point us towards this intrinsic properties. Once we find them, they remain with us. that is metaphysical and metaphysical. In one case, if your form of humility goes along the Duesian side, you are accepting a form of combinatorialism, therefore you dismiss a form of necessarily law. You can't combine your combinatorialism with the idea that those of nature are fundamental because introducing these static connections between certain intrinsic properties and certain facts, for instance, would prevent you from swapping. You couldn't just have one the other the other. Or, if you go along the Kantian line, you have to accept the idea, which is quite foreign to more than physics, that your relations are not reusable So in a way, there are metaphysical notions that you have to be prepared to do. A metaphysical feel that you have to be prepared to pay. I think that's all right. Five minutes for questions. Marios? Oh, yeah. Oh, sorry. I'll go back. Is it so clear that my scheme and charge are not in principle, because I haven't really read any convincing arguments in the literature to that effect.

1:27:30 The second question is, do you really think that you can get me the knowledge in the future? Thank you. I don't think that this is an implication of the sort of metaphysical positions that are illustrated. You can still be saying that general notion of being an entity out there with certain characteristics. What are you inclined to brag in this picture? who brings to complete because you are set to a certain sort of metaphysics. And the interesting idea of comparing to you is that you seem to have it despite the sort of metaphysics, fundamental metaphysics you choose. You seem to reach an idea of something that you know of through different lines. I mean, the idea is that you can make sense of something systematically occurring in the history of science without necessarily appearing simply to the historical record. So if the historical record doesn't show me that we dismiss molecules, I don't need an explanation for that. As long as the molecules of the entity remain with us, I don't have a problem to account for. It might be the case that we have so much, we have so many intrinsic relations with that that they somehow capture in a stable way in the, in the, in the, in our scientific record. So there's no, we don't expect to dismiss them What we do, what might be sure is to me, to say that what we have to do is simply what the other thing is about, not this intrinsic profit of the tissue. I don't know if I'm answering to your question. What about the last few of you started?

1:30:00 What do you think that they are? Okay, there's two ways to respond to the question, and I would present that just as purely conjectural. My impression with the two lines of metaphysics there is that they split there. So in one picture, what you expect to say something like, well, your spin, or your electric charge, for instance, is something that you define via this principle issue. So it's just a negative thing. Yeah, that's it. Of course, we need something else to find out which is not the world. What you want me to say is something about, in that case, I'm not saying that there isn't anything about that. I'm just saying that I don't know it. Why I don't know it? Okay, so the idea, in general, is not that there isn't, it's just that there is a good reason to believe that what we say about electric charge of mass is reliable as long as it's embedded in a certain web of relations, you see what I mean? So is the sort of equations of, for instance, the structures of science like Goje invariance or something like that, that makes what we think about the electric charge reliable? We're not attaching it to something that really intrants it. But is this a etymology of electricity? This is what are the motivations behind it. Reality is made in such a way that we know our knowledge reached only one point. That's the idea behind the position. It's not enough to account for science. I think it might be. You go. In principle, I find structural realism not that bad idea, but if you go along the Lewis in line, the question, of course, suggested itself many possible worlds, too many structures around. And honestly, what I would expect of structural realism is that you give me a very definite structure that is then filled with some physical details.

1:32:30 And at least on the Kantian line with all the relaxers, the idea was that there's transcendental philosophy around which tells us that it isn't very difficult to qualify as conditions of the possibility, et cetera, et cetera. And certainly often there are ways how to control all those possibilities. So how would you, in your approach, that somehow combines these two ways, deal with the problem if you agree that somehow the goal that we have very few structures out there in describing social developments in physics. Okay, one, I'm not sure I'll interact with this question. One thing I want to...