 The paper is titled Essence Without Modality, question mark, provocative title by I'm going to be talking about the relationship between essence and modality unsurprisingly. And the goal here is really to sketch a theory of modality based on essence, which you might call a reductive theory of modality. That's where we get the essence without modality. Essence is sometimes perceived as a modal concept. If you'd conceived it as a non-modal concept, but as a basis of modality, then effectively you get essence without modality. But the point of the idea is that you get a basis for modal truths from essence. And I'm not actually going to take much of a stand on whether essence itself is a modal notion or not. The point of it is just that we can ground or reduce all modal truths to essential truths. And the background is, of course, probably familiar to most of you. Sort of a neo-Aristotelian view of modality and essence based on the work of people like Kit Fline and E.J. Lowe. So I'll tell you a little bit about that. And I've got a paper published called Possibly to Precede Existence, which is a background for this paper. So I'll tell you that as a starting point, but I'll go through some of the things I say in that, because I don't assume that you've all seen that before. But I'm trying to go a bit beyond it in this sort of overall project where I'm working on the basis for modal truths. Okay, so the background, as I say, is Aristotelian or neo-Aristotelian, Finian essentialism, where essence is prior to modality. So you might think of Fin's paper Essence and Modality, where this view is popularized, but E.J. Lowe has a number of papers where he talks about very similar ideas. And I often take Lowe as my starting point because he was my supervisor and mentor. So he has a couple of nice little phrases, and one of them was on your handout there from the possibility of metaphysics. He says, metaphysical possibility is an inescapable determinant of actuality. Now that's a bit of a puzzling phrase in itself, but the thought here is that possibility or modal truths like this come in some sense before actuality. And he had both an epistemic and an ontological agenda for that type of notion. So he also says that it's a precondition of something's existing, that its essence, along with the essences of other existing things, does not preclude its existence. And then we've got these two phrases on the handout Essence precedes existence and possibility precedes actuality. And I took the second one of those and I published a paper with that title. I sometimes have to specify that the essence precedes existence is not in reference to Sarkra who defends the opposite of this that existence precedes essence. This is a different kind of thesis, perhaps not entirely unrelated but in any case the context is slightly different. But whatever we're going to say about this sort of relationship between essence and existence by essence and modality, it's going to have to involve some specification of what essences are supposed to be. And that I find is often the most difficult part of my discussion with anyone because people come with very strong preconceptions of what they think essence is. And this often is based on Kripke's work of course but Kripke never really specified what he means by essence anyway so that's not entirely helpful. Certainly I do not mean to commit to anything like Kripke and origin essentialism or anything like this when I talk about essence. So those are things to be specified. Lo says some things that I agree on by what he thinks essences are but he also didn't really specify the notion of essence in as much detail as you might hope. So he says that essences are not entities themselves and I agree with that. But then he specifies in citing Locke that the essence is just the very being of the thing and that doesn't necessarily add anything much to what you might have already been given. And of course Fine talks in similar ways sometimes and talks about real definition as well. But Fine sometimes writes as if essences are some kind of entities actually and I'm not sure whether he intends to commit to that idea. But he sometimes writes in a way that suggests that essences are a type of proposition or a set perhaps. And of course there are people who think that that is the case. And some people also think that essences are just bundles of properties. Sort of a bundle theory of essence. Now none of these views are right if essences are entities themselves because all those things that I mentioned sets propositions as both bundles of properties or properties themselves. They are entities. So what are essences if they are not entities? And why couldn't they be entities? Well, Locke has a little bit of an argument I'm not going to go through it in detail. But he thinks that essences themselves cannot be entities of infinite regress. And the reasoning is as follows. If every entity has an essence, which is a view shared by a lot of people who talk about essences, then it seems that essences themselves would have to have an essence. And if the essence of those essences is an entity, then that essence itself would have to have an essence. And this does not look like a promising route to specify what essences are. There's a couple of papers contributing to that. We can talk more about it if you're interested in this question. But I take it as a starting point that essences themselves cannot be entities. But we need to specify what they are supposed to be. So I propose to read the notion of essence as shorthand for something like this. The identity and existence conditions of an entity. So the essence, you might say, expresses or states the identity and existence conditions of an entity. Now it's easy to slip up here and I often do that in speaking because it's difficult to avoid it. That essence is a proposition expressing the identity and existence conditions of an entity. But of course the essence is not a proposition. It's not a sentence. It's not a linguistic entity. But we can say that to state something's essence is to state its identity and existence conditions. So all you have are the entities. And indeed, on the view that I'm developing here, all you have are actual entities. So this is going to be a sort of actualist theory of modality if you like. This sort of old fashioned way of thinking about it. And all the actual entities have an essence. So when we talk about essences, we're talking about the relationships between those actual entities and relations such as dependence relations between those actual entities. And the thought is that just by looking at those identity and existence conditions which includes dependence relations between the entities, we can get truth makers for the more truth. Okay, so I'm going to have to give you some examples as I go on so that we get to the bottom of what essences are supposed to be on this view. But I thought I might read a quote where Low specifies he's sort of near Aristotelian or fine-connected view of essences as well. So Low cites passage, well, he doesn't cite the passage but he refers to fine books of modality and intense. And I think he has this passage in mind when he tries to specify the facetious view. So let me just read this from fine's modality and tense. Kidd Fine says, although there may be something about how the matter of Socrates turns out that is relevant to its constituting a man, there is nothing about how Socrates himself turns out that is relevant to his being a man. If I am right, then this means that philosophers have been mistaken in thinking that Socrates can be a man unless he exists, that existence must precede essence. Socrates must already be a man if I may put it that way before the question of how things turn out for him can even arise. So it's a funny way of writing there from Kidd Fine, but I think the thought is right that there's something that is the essence of Socrates as it were that we must have either grasped epistemically or must be the case ontologically before we can specify how things stand for the actual Socrates. In other words, the essence of Socrates precedes his existence and that is just to say that the identity and existence conditions of Socrates precedes his existence. So before we know what Socrates is, we must know what must hold for him to exist. So I think that the idea of essence preceding existence and the conception of essence as identity and existence conditions of entities is actually on the background of a lot of things that Fine says as well, but he never states it very clearly. So this passage that I just read is probably the closest that I've come to to find the idea in his work. Okay, so this view of course relates to this idea that modality is grounded in essence or moral truths are true in virtue of essentialist truths and I'm going to return to that reductive question later on, but a couple of preconditions to sort out first as well. So I'll give you examples of what the identity and existence conditions could be later on but I can already say something a bit more. I think that the basis of the conditions, and I've written this on the handout as well, will have to be the categorical structure of modality, whatever we think that structure to be and the formal ontological relations that hold between the categories would govern that structure. Now, if you're operating in an EJLO inspired ontology, he's defending four category ontology where we have two kinds of universal, substantial kind universals, and I talked a little bit about yesterday, property universals and tropes or modes, so particularised properties and substance or individuals. Now, I'm not going to be committing to that four category ontology view, but I'm sympathetic to the distinction between substantial kind universals or natural kinds universals and property universals. So you might say that some of the formal ontological relations that govern this sort of category or structure are the relations between these different kinds of categories. So Lo himself talks about instantiation and characterisation. So the kind universals are characterised by the property universals. If water is a natural kind, it's characterised by, I don't know, it's boiling point or melting point or something like that. Or you might say that the property universals must always be instantiated in some substance, so following the principle of instantiation, which we also talked a little bit about yesterday. So these would be requirements that govern the category or structure of reality. And as I say, I'm not committing to any particular view about this now, but if you think that this sort of category or analysis is the right way to go in the first place, then you can apply what I'm saying into whatever you prefer view on this might be. I hope. Okay, one final thing, which I also touched on yesterday a little bit when I talked about substantial kind universals, is that I'm only going to be operating with the notion of general essence, really. So general or natural kind essence, rather than individual essence. Now here I depart from Lo's work because Lo talked about individual essences, but I think that the Aristotelian basis is more sympathetic to just the general essences or natural kind essences. I'll use these more as synonyms. Maybe I should state the distinction. I think I have a quote from Lo where he makes this distinction. So why does Lo use that? So Lo says, X's general essence is what it is to be a K, an object of kind K, while X's individual essence is what it is to be the individual of kind K that X is, as opposed to any other individual of that kind. That kind of idea of a general essence can be found also, for instance, in Fabry's career's work, who talks about objectual essences. And the thought then would be that all the members of a given natural kind would share the same general essence. And they wouldn't have necessarily any individual essences over and above that. Okay. Good. So I'm approaching the end of the first section. So here are three assumptions that I've put on the handout. Essences on our entities. I'm trying to specify that idea. They're the identity and existence conditions of entities. Two, I am committed to this idea that every entity has an essence, but not an individual essence, a general essence. And three, only actual entities exist. So that's the actualist model ontology that I'm trying to build out of this view. Now, that obviously leaves over the question of how are we going to find the truth makers for the model, interesting model truths in the actual entities. So I'm going to try to give you some examples of how we might go about that. All right. I hope that makes proper sense so far. We can go into the details a bit further in discussions in the future. Can I ask you a question? Please. You say that you take the sense to be conditions of possibility of identity and existence of an entity. But yes. But on the other hand, you know, essences are not entities. Okay. Do essences exist then? Because if only actual entities exist, it seems to be a contradiction. I mean, I wouldn't say that essences exist because only entities exist. So the entities exist, and by their very existence it means that there are some conditions for their existence. Right. So, or how do you identify? What distinguishes this entity from this entity? That would be its identity conditions. So essences on entities do not exist. Right. So, I mean, if you like, it is a type of anti-realism by essence. But also, the notion of essence is at the very core of what I'm telling you. It's just a question of reading it in the right way. But as I say, it's very easy to slip in speaking into sort of ray-flying essences. Or I'm going to say that I'm going to give you the essence of this object now. But that is just to talk about the object in question. And to tell you how that object depends on or differs from other objects. It will be clear to say just that the entities only actually exist. Right. Therefore, but it's necessary all entities have functions for identity and their existence. And those, so, well, there's a variety of these. Yeah. Well, I mean, if we're in the business of trying to reduce what an attitude to essence, then I better not use a primitive modality in defining that. Those are the existence conditions. But the thought here is, of course, that the identity and existence conditions will have more implications. Right. So anticipating a little bit. So, I mean, strictly speaking, I could talk about all these things without mentioning essences at all. I could just talk about identity and existence conditions. But it is often quicker and easier to talk about the essence of the entity as a sort of a shorthand for the identity and existence conditions. Because once we specify that, then we should be, hopefully, on the same page. But I'm happy to, I have to go and affirm these all by now. So, I do not mean to say that it's a unique general essence. So, I think this came up yesterday as well a little bit. So I think, well, if we are humans, we all share the same general essence. We all participate in the same general essence. Which is just to say that we all have the same identity and existence conditions with regard to that natural kind. Being human or being a living organism or what have you. And indeed, all gold atoms, if you like, share the same general essence of, you know, having topic number 79 if we use that example. So, every natural kind needs to have a unique essence, right? But every entity doesn't have to have a unique essence of that. Typically, we will have many essences, right? Yeah, if it's, I say typically entities will have many essences. Yeah, so yes, but I mean I guess that's controversial. So you might say, you might say, you know, all electrons sharing having the essence of electron, but they also have the essence of being a fermion. Right. But here we are already postulating that there are higher level kinds. You know, you might say that there's just the fundamental natural kinds and those are the most precise kind. Well, so we can make a distinction on the narrowest kind that an entity belongs to as it were. And then we can leave open whether there are other high level kinds that the entity belongs to. You know, you might say, well, the electron is also a matter of material, particle and all material things share the same general essence of being a material entity or something like that. Now, whether that is a kind, whether that is a general essence that is a genuine essence as it were might be debatable. But I'll leave that to one side now. But you could read this all. And maybe I should say that I am slightly sympathetic to the idea that you could read this all very reductively if you like. There are just fundamental natural kinds and there is only one narrowest essence, general essence that every entity has. But I mean, it's the right question to ask. I just have a follow-up. So it would be open to the idea of pluralism, if you have a different natural kind that are from the same entity if there is a different constitution for existence or a different way to exist for one entity if there is a different kind. So, I'm not sure if I followed you on time. So you have pluralism in the sense that... You say that general essence is a condition of existence for an entity. So if an entity has a different general essence that is a different condition for existence, is there a different way to exist? Are you okay with the logical parallelism? Well, I'm not sure if you have to commit to anything very radical even if you are open to that. So as I said, I mean, to use the example that I mentioned, if the electron is both a fermion and an electron, it's not like these conditions are in contradiction or anything like that. Indeed, to be an electron, you have to be a fermion, presumably. So the question is whether there's a hierarchy of these natural kinds, right? And then you do have tricky cases there because you might have entities... Well, you might have examples that don't follow a neat hierarchical structure of natural kinds like this. There's some discussion about... like, emitobium, for instance, is a good discussion about these sort of cases. So, I mean, it gets tricky when you... especially when you start to talk about biological kinds, for instance. But I would... So there's a basic behind that. I would kind of link that open. But, you know, if in doubt you might say, well, there are no biological kinds in terms of... if they're not fundamental. So you could just start... I'd be satisfied if we could just start with the ontology of fundamental natural kinds and then we can specify further, depending on other views. Yeah. I mean... I mean, I'm not saying I've solved all the problems on the way here, but, you know, before we get to the nitty-gritty... I'll try to give you some examples. I'll sort some of that out. Okay, so let me go to the second section. So on candid essence is an essential dependence. So here's a personal controversial claim based on what we discussed yesterday as well. Any logically coherent set, and biologically, I mean, some of my classical logic, any logically coherent set of identity and existence conditions is a candid essence form, and see if that could exist. So a candid entity, if you like. And we do need to make this distinction for every systemic reasons because we don't know what all the things are that exist. We don't know. To use an example, dark matter. Well, we refer to dark matter in our scientific theories. Maybe we don't quite have an established view about whether dark matter exists so much. We know what it does, some of the things that it does, if it does exist or if it would exist. So we say dark matter is a candid entity that would serve certain roles in our theories if it did exist. But we don't have conclusive evidence for its existence. So we can state it's candid essence because only the existing entities have essences. So dark matter does not have an essence if it doesn't exist. So there might be some other entity that explains the things that we think dark matter explains, which does exist. And it might have some of the same identity and existence conditions as this candid entity dark matter. But perhaps it would be slightly different. So we have to have some sort of talk about those sort of cases just because I have extremely limitations. So I'd prefer to just put word candidly in front before we express more firm commitment to the existence of some entity. Good. So fairly truly avoid, but perhaps worth making. And as I noted earlier, and this goes with something that Lowes said in that quote that I had earlier on there, essences of other existing things can preclude the existence of candid entities. So what we're interested in is coming up with a collection of entities, collective identity and existence conditions, if you like, that are mutually possible, are mutually not contradictory. Because whatever the actual entities are that exist, they better not preclude each other's existence. Now it's not easy to come up with good examples of this, but try to think of some examples. I'm thinking if we are committed to the existence of oxygen and we think we've got good evidence for the existence of oxygen, that might be seen to preclude the existence of phlogism, which was used as a sort of candidate entity that could have explained some of the things that now we know of the existence of oxygen. So it would seem that those two things are probably not going to exist at the same time because their identity and existence conditions would conflict in some ways. I haven't worked out this example in detail. Maybe it would be an interesting exercise to do so. But that might be one example. Okay, so if that's true, if we have cases like that, then that obviously has something that would look like direct model implications. So the existence of one entity X might necessitate the existence of another entity Y, but it also preclude the existence of a third entity. I've gave you an example of this preclusion, which is a trickier case. It's much easier to state connections of necessitation or dependence like this. So if water molecules exist, then they seem to depend for their existence of hydrogen and oxygen atoms. And we can model all these sort of relations with essential dependence relations, logical dependence relations. So I've given you just two on the handout. So the first one, EDE, is effectively a rigid kind of dependence relation. So an entity would depend on a specific entity for its existence. If it's part of the essence of that entity, it only exists if the other entity exists. Now, I should maybe say that there might not be very easy examples of this if you don't think that there are individual essences, because they'll be looking for something, some particular entity that all the entities of a given natural kind would depend on for their existence. But there might be one easy example, namely the natural kind universal itself, if it is an entity. So take the water example. So if it's part of the essence of the natural kind, water that all its members depend on oxygen atoms for their existence, then we might need that property universal oxygen if that is a property universal. That natural kind universal rigid depends on. But it's not so easy to come up with sort of examples that are not directed from the formal ontological framework. Generic dependence will get as much further though, and that's the looser connection here anyway. So we might say that every sample of a given natural kind, such as water, will depend for its existence on there being those oxygen and oxygen atoms, but not on any particular oxygen and hydrogen atoms. So it just means that there needs to be some examples of those other entities in existence. So that's why it's a generic dependence relation. So those sort of modelling relations, essentially more dependence relations will help us to put a bit more structure into the modelling space. That's the idea. And I think that already gives us more or less all the things that we need to build up the ontology for modality based on a session of dependence relations that I'm proposing here. But I can give you a little bit more examples on the way. Yeah, I think I have some more examples in the next stage anyway. But I think I might push on to the third section already and get back to those examples. Because there are a couple of things on the background here just about the relationship between essence and modality that might be positive and have been addressed in the literature. So if we have this type of picture of reducing modality to essence, called finding and essentialism, then there might be issues that people could take with it and indeed, Warner and YD have taken issue with just this type of reductive finding and essentialism. So I have their definition for FEO finding and essentialism on the handout there. So every metaphysically necessary truth is grounded in one of the more essentialist truths. Now that is more or less what I've been proposing to you here. But if that's the statement of finding and essentialism, then you might think that you can't get the kind of reductive analysis that I was proposing from this. In fact, they cite me being so committed as well, so that's why I'm wanting to address this issue. So they don't regard this type of eliminative reduction plausible that you might have to have some sort of double primitivism perhaps, but you've got the same modality in this sort of picture and grounding as well, because they say X being fully grounded in another entity, Y is not typically thought to entail that the grounded X is not real and you can so find himself on this. There are questions about the relationship between grounding and reduction in the background here, but that is a pretty common way to think about grounding, but it doesn't entail production, so that eliminates this reduction like the one that I'd be sort of hinting at. Now, I think it's a mistake to formally find an essentialism like this. Now, or maybe I should say the thought of essentialism and I wouldn't imagine it to be in any case leaving one to find to one side. I think that if we do want to give a reductive analysis of modality in terms of essence which I'd like to do, we have to do something a little bit different. It's just to say that every essential truth has these model implications that I've been hinting at before and more specifically, if you look at an example in the line that I've formulated before on the second page of the handout, take the essence of something like methane, if that essence of methane suggests that methane contains hydrogen, then that should be read as methane depending generically on its existence on hydrogen, and that generic dependence relation will give you that necessitation, that model implication that we were looking for here already. Now, then we would just follow that all instances of methane must contain hydrogen by necessity and once we see that that's the case and we have evidence for it, we'll think that that's a good candidate for the essence of methane as it were, then that's really all we need to establish, the model truth, that's relevant to you. Now, that doesn't need to involve any reference to grounding in the formulation of that, I assure you it's true. But you might still think that there's something that is missing here from the formulation, so effectively the idea that every metaphysically necessary truth is in fact an essentialist truth. So, if that's a worry, that is a worry that has been formulated by William Wolland himself and also by Anton Wolland-Watz who talks about a sort of epistemic friction in these sort of cases. So, how do you come to know that every essential truth is a metaphysically necessary truth? Or the other way around, a metaphysically necessary truth How do you know that? You need some sort of bridge-pins principle before you can make this sort of influence, if you like. So, I've got a quote here from William Wolland who tried to come back to do another case of reduction and I think that's a good way to try to think about what's going on here. So, the reduction of biological facts to chemical facts if there is such a reduction. So, they suggest that the mere fact that biological facts could be reduced to chemical facts if that is indeed true, would rest on the identification of some sort of bridge-pins principle that takes us from one special science to another science. So, what it is that allows us to reduce biological facts to chemical facts. And that bridge principle would then be what justifies you in your inference in specific instances of the general reduce of biological facts to chemical facts. So, if you want to say protein function reduces to chemical properties something that I've thought about before then you would need some sort of general principle about reducibility of biological chemistry whatever that might be in order to be able to infer that in order to support that inference. Now, I'm not sure why you think about that particular example but I think that there's a broader issue of broader mistake or confusion that goes if we try to make that type of argument. And the issue is just this. The bridge principle that we're interested in here doesn't operate at the level of the individual agent who's doing the inferring in a particular case. So, the individual agent is mortal epistemology. That should be at the level of our theory of mortal epistemology if you like. So, if you already take it back to the essence of what I think if you already buy into the finding an essentialist picture which I certainly do then it just follows that every metaphysical and necessary truth is an essentialist truth whether you know it or not whether an individual agent knows it or not. So, similarly, in a biology and chemistry case if you have that basis or if you have that reductive basis in chemistry for a given biological truth that reductive basis is there whether you know that it's the case or not. So, if you know the chemical basis for it then you have the tools to express the biological truth whether you actually know that there's this general reduction between biology and chemistry or not. And, in fact, I think that we operate more on the basis of those individual cases anyway when we try to perform scientific reductions. So, I think that there's a question here for individual mortal epistemology when you try to make inferences and then there's a question for the level of the theory of mortal epistemology. And once you've bought in the theory you get the reductions for free, at least. So, good. But if you put your, so to speak, by hand in a bridge principle and isn't that the term, the truth, the disinterpreting truth that you think of? Well, no. I mean, the bridge... So, good. So, the bridge principle, whatever it is it still needs justification. But you don't justify it in the same way as you justify the individual cases, necessarily. So, if you're buying to find intercessionism why would you do that? Well, probably because you've read Finds Essence and Modality and you've seen examples of the signals of Socrates and the idea that, well, maybe you don't buy the signals of Socrates' example based on the laughter, but whatever the examples might be that are plausible here. So, those sort of examples are supposed to motivate the general theory, right? That there is this bridge principle. But, so you don't put the bridge principle in by hand, as it were. You try to develop theory based on examples, right? But if you've got the theory there it's not like you always have to go and refer to the bridge principle in one of those cases. If you think that that theory is true then you've established that there is this connection between Essence and Modality. Well, reduction, in fact, in this case between us. Another thing, coming back to water or methane if the equipment say, for example, that your water is at age 2. Methane is at age 3. CH4. CH4, yes. And the methane but then if you think that there is aspirin here that that water is a meteorological dependence of water upon oxygen it becomes a meteor. So, you're going to need the empirical work that establishes the connection between that water and whatever it might depend on. So, it seems to me that whatever we're doing here it's not going to become analytical. Now, I think what you have in mind is something like the kind of the old Kripke apartment proof of the necessary posterior, right? Which is something like where you need the necessity of identity, right? Which is almost like an logical truth in this sort of scenario after you've got the empirical truth. Is that kind of what you have in mind? No, I agree. I certainly disagree with what you put down. I think that the water is in the first place identified by empirical properties and then by, as you say, empirical work and scientific work you discovered that the water is in all worlds each to go, right? And so, I think that's a necessary truth. But it's not an analytical truth. Okay. So, I think I did it to agree with you. So, my question was how would you reply to work and, you know, the reference as well as by, I think, my query, you know, but I think you already answered because you actually do a pretty good one. Yeah, yeah. So, it is, it ought to be based on, I mean, look, so where I take issue, maybe this is better way of putting it, where I take issue with some of the sort of classic Kripke apartment picture on this, or at least how it's sometimes presented, there's much more packed into that empirical part than we often acknowledge. It's not just, well, we've discovered the empirical truth now. Well, no, you've discovered some dependencies. Exactly. So, and that's what gives you the ontological structure, the dependencies between, you know, water and its cost to pass between things. So, that empirical part is much richer in ontological content, if you like, than it's sometimes put. And indeed, it's not purely a cost to write history either because those dependencies... No, I think you're mistaken by the expression bridge principle in the old... Oh, yeah. Yeah, so the bridge principle is kind of the old... I mean, this is how... Yeah, yeah, so I wouldn't use necessarily the notion of bridge principle then myself, but that's the old... Yeah, okay. That is the old-fashioned way of putting what you need for a reduction, right? Or even a negative reduction, right? But, yeah, I would agree. I think we're roughly on the same page. Good, okay. Good, well, I've taken a fair bit of time already, but it's good that we've been able to clarify some of the issues as we go. So, I can go to the last section, which might not take me too long, but there's a sort of case study that we could spend a lot of time on, but maybe I'll just mention it. So, I've labeled the final section of the consequences of the view, which is... Partially, this is just a summary of some of the things I've already said. So, as I said, the goal is an actualist basis for modality, so actuality would have to consist of existentities that could exist. In that sense, possibility precedes actuality because those entities need to be possible in order to exist. But, we need some restrictions for this, and this is something that came up yesterday. I think that a candidate restriction is law and order of addiction. I think it might be one as I've written there. You know, I'm open to debate about it, but I've defended the validity of law and order of addiction as a metaphysical constraint on existence, rather than on just a logical principle. And as I said, the category of structural reality, whatever you think it is exactly, would be a constraint on this because that's where you would get the dependencies between the various categories. And indeed, you can use the essential dependence relations to formulate those restrictions. So, you might think that if there's something like the principle of the satiation that holds, then those universals must always be instantiated. It's the Aristotelian principle here, and that gives you a type of a type of dependence relation between the categories. And you might think that, well, the natural kind must always be connected with certain properties because the properties make the natural kind what it is. So, a natural kind would always depend on certain properties, even rigidly, so you don't have the natural kind without those properties of existence. And the property universals, you might think, have some sort of dependence of the kind as well, depending on what your views are. So, whatever your views about the category of structural reality are, that would give you the sort of base dependence relations that you'd have to follow in setting this type of picture up. I've mentioned laws of nature there as well. Of course, on this type of view, you might think that the laws of nature are metaphysically necessary because if all the actual things exist, then the moral saves of laws better be connected to those things. So, it should appeal to a dispossessional essentialist, but whatever you want to say about laws of nature will probably apply to those pictures as well. Sorry, one question by actuality. Did you just mean the actual things? Yeah, the things that actually exist. Not something that is the property of being actual? No, yeah, good. No, just the actual things. So, whatever properties do actually exist, not the property of being actual, the actually existing entities. So, be them properties, and if you think substances, whatever the entities are that the ontology consists of. Well, if they exist, then they should give us to this type of structure. Good. So, we could discuss the constraints further, but whatever the constraints are, there's still going to be obviously a lot of these entities, candidate essences. So, I always think that monologues is very hard because of this. So, it's not easy to know which things actually exist because we don't have the full set of... Existence conditions for all the things and full evidence for the existence. But, I think we could make some progress, and here's why I mentioned this case study. So, law has mentioned in passing the case of traceric elements is a nice case of where essence precedes existence because it turns out a lot of the traceric elements that don't exist in nature were predicted before they were synthesized. So, take something like Einsteinium, if we hadn't synthesized it it doesn't seem that it would ever have existed. But, we already knew its properties to decent level accuracy before we ever synthesized it because we can make these predictions based on the period of development. So, very nice case. But, I didn't say very much about the details. I've looked into it in much more detail later on. So, I'd be sort of happy to talk about it, but maybe I shouldn't spend too much time on it. So, I've got some content on that in the possibility to proceed. Actually, I do pay for it, but I've got a lot of piece on the moral basis of scientific modeling and having synthesized it where I discuss this. We can talk about this in more detail in discussion if that interests you. But, the core of the matter is basically this. If we can make true claims about those transuranic elements that perhaps once that haven't been synthesized yet perhaps once that we ever will even synthesize then that would seem to be Pimafakia problem for the type of view because there needs to be some actual entities that act as truth makers for those moral claims. So, I've got, just to give you one example take the element 1-2-6 Umbi haksu doesn't exist. It hasn't been synthesized. It's been hypothesized as a sort of island of stability. The heaviest element that has to be synthesized is Organasum element 1-1-8. But, if 1-2-6 exists it would have certain properties presumably. So, we might state a counterfactual. If Umbi haksu existed it would have a longer half-life than Organasum that has been synthesized. Now, is that counterfactual true? Or if it's true it can't be made true by the entity Umbi haksu because it doesn't exist, right? And it might be they never will exist if we never synthesize it. So, even my four-dimensional view about natural kinds wouldn't help in that case. But I still think that there might be a way to analyze the truth makers for such statements. And the answer lies in the ways that we are able to predict the half-life of something like Umbi haksu element 1-2-6. And, well, we can go into a little bit of I'm aware of Peter right from my normal but the answer basically has something to do with the so-called magic numbers. So, this is something like Eugene Wiener coined back in the day. So, magic numbers are numbers such as 2, 8, 20, 28, 50, 82 and 126. So, they will be haksu. Now, that last one corresponds to the hybrid element. Now, what are these magic numbers? Well, they're effectively combinations of protons and neutrons that appear to produce a higher stability in the nucleus. So, combinations of protons and neutrons that are arranged to complete shells within the atomic nucleus. And that's what gives us the highest stability of these cases. So, we know of the existing cases, you know, the other elements 2, 8, 20, 28, 50, you know that those are those elements that isotopes of elements that correspond to those magic numbers have a higher level of stability. So, that's what gives us some confidence in postulating that 126 is an island of stability and indeed, that might give you a reason to think that if we didn't manage to synthesize it that element would have a higher half-life than organism. Not to mention some other properties, but put those aside. So, it would be something about the properties that these sort of elements have, the properties of or any existing entities that we have observed and know to have higher half-lives that would act as a truth-makers of these types of counterfactuals. So, the proposal is simply that those sort of counterfactuals are true and of course they might be meaningless or they might turn out to be not true in some cases. So, I'm not saying that this goes across the board, but there are cases such as this where I think we've got good reasons to think that even though those counterfactuals may seem to have a non-actual target on the axiom, actually the target is something that we can identify in the actual world based on these sort of partially structural features of existing elements. And if that's the right way to proceed here, then we do have kind of a general pattern of tracking the truth-makers for moral claims, really actually existing entities. And I think that we do a lot of this in science, actually. Not just in the case of traceric elements, but that's kind of a neat case because there are predictions that we make about non-existing entities. Now, I mentioned earlier one example, dark matter. We can use that example just as well, in fact. We could even talk about high level kinds of social groupings made by biological species and so on. So I don't think that these examples are just limited to fundamental physics but if you think that they are just fundamental natural kinds then of course the case would be limited to fundamental physics for a good reason or would look that way. But I just wanted to highlight that in case you were worried that we could normally do more like Mr. Marchie in theoretical physics. I don't think that's the case, but those are nice examples. Good. So that's the case that I'm happy to talk more about it if you're interested in it. That was a second point, so let me finish and I will be done in the hour. So the third point was that only the entities that can exist together can inhabit actuality and that's something I've mentioned already in passing, but I think it's important to emphasise it because this is not a typical feature of an essentialist picture or not a feature that is mentioned very often. So I think that we should look at essences certainly if we use them as a basis for model epistemology or model ontology as a holistic picture. So you can't really consider an essence of the identity and existence of conditions of an entity in isolation and the reason is obvious by now because there could be dependence on entities that conserve the identity and existence condition of that entity. Now, it could even be that there are sort of overarching dependencies among the actually existing entities. I'm thinking of some interpretation of quantum mechanics that might suggest entanglement across the board, de-coherence and so on. Now that would be an interesting result because you would have to consider the identity and existence conditions of all the existing entities together in some sort of way it seems. But maybe that's a fairly trivial kind of dependence that would come out of this. The details depend on the empirical results, right? But nevertheless, we have very clear cases where there are dependence relations between actually existing entities and we can't consider those in isolation. And that also goes for restricting the existence of some of these candidate entities that are ruled out because of the actual existing entities. Okay, good. Well, the rest of that I've pretty much sorted out. The fourth one is funny and irrelevant because I know you've been reading about Matt Tykeby today. On this type of view, on the Aristotelian type of view where the actual existence is the base of modality, platonic or unrealised possibilities, alien properties, all this has to be ruled out, sorry Matt. Now, that's not to say that you couldn't build something very similar to this in a platonic ontology, right? But in some cases the answers to a lot of the questions that I mentioned are super easy in that case because you can say that the truth-makers for those small truths are just the platonic universal states there. So you don't have to go looking for them in the act. You know, Umbihexium case, well, easy. Umbihexium is there with platonic evidence, universal. And that's the truth-maker. But the problem with that is that we don't seem to have any direct epistemic access, you know, classic problem with platonic class to these things. So I think that this is perhaps a slightly more interesting challenge to try to find the truth-makers in the actual world and if we can pull that off, which I think we might be able to do, that would be perhaps the result of speaking favourites to Umbihexium. But you know, we had a good discussion about this with Matt, sometimes girls I think we are on the same page about a lot of the things that you can build in terms of the ontology but just have a different starting point to it. Good. Now there we have it, I think. Once we've got all these conditions in place we've got a limited space of metaphysical possibility, if you like. And I should say that you can reconstruct the possible worlds semantics out of this if you want to. I haven't talked about possible worlds because I don't need to. But if you want to talk about possible worlds just take any of the viable combinations of the identity and existence conditions of entities you get a complete possible world. But I should say that I'd like to think of those possible worlds as maximal in the sense that you have to consider all the entities that exist in those not in the sort of way that we'll consider a possible world with just these two entities. That seems odd especially if you have a view of laws of nature which emerges from the kind of universe or something like this because what would govern the existence of a world which just has duality or something like that. But either way you can construct possible worlds out of this if you so want to. Good. Sure, yeah, I'm happy. Do you want to comment? This is super one of the strong questions Yeah, thanks a lot for the great talk. So, I guess my question is about the relation between the ordinary existence model of the human and its essentialistic nature and so you say what would be each viable combination of possible worlds okay with possible worlds more than just like coherence without it has to do some work but it's not very interesting and so we need an accessibility relation and so on and all these things and in general I mean what I find I guess most interesting in the in that difference for the photo picture and standards for the photo picture is that we are open to more interventional notions getting that introduced more I'm not forced to accept that well, if something is possible then also everything that would be would be possible as long and in some cases this is very attractive and especially if it's about essence it seems to be and nature seems to be unavoidable because some I mean it's essential for me to be self-identical I guess but it's not essential for me to be that God is self-identical so there are a few technologies that should be well, I think the same possible worlds but for essence it seems to quite intuitive I think fine in this point in some instances it seems to be full of parts I think it's quite easy to go against non hyperidentical intuitions that people have as soon as you introduce essence that's right, you can build the notion of modality based on essence maybe you can inherit this natural hyperidentiality and I'd be very interested in how that works and whether or whether you would like to have a picture of hyperidentical modality in this very traditional in the sense of no hyperidential distinctions being in there or whether you are also open to this more visionist sort of ideal modality as soon as it's based on when you have this ability to ground it to the essence in some way yeah, good thanks I certainly hope to inherit the benefits of a hyperidential model here and I think it is built into this I just express it I think even more precisely in terms of the identity and existence conditions because then we can model the dependencies there, so that's effectively on the background of even those classic finding and examples so if we talk about the Singleton Socrates case well, I mean you can express it in terms of just dependence relations that are in place so sets necessarily depend on the members for their existence and Socrates is necessarily a member of the Singleton Socrates but Socrates does not depend for his existence on the Singleton Socrates so you can finesse those hyperintentional relations if you like based on this type of talk as well so I think we can do that there's work to be done here to show that you could reconstruct the type of classic possible world semantics from this picture I suppose I'd be more tempted to start building it from finding a logic of essence but that work isn't completed because some like Habris Korea has done a lot of progress on that side as well but you know this so I just want to acknowledge that there's certainly work to be done to bring this talk to be equivalent with the type of typical use of possible world semantics but I think it probably can be done I mean there might be some difference I don't know if you might know this better than I do but if you want to recover it or if you want to destroy it it might be a project of useful ideas after it happens they have community we have been able to think clearly about some innovations about modality but maybe it's time for a new idea and so maybe we should not want to desire to recover everything yeah well right I mean there will be differences right so I mean Lo developed his own logic for counterfactuals but that work wasn't quite completed and you know someone like Timothy Williams would take issue with that because you get different results for the marketing formulas and so so there's debate to be had there and yes you would end up destroying something now of course Tim Willison is just resisting any kind of hyper intentional moves very strongly so yes obviously you can't reconcile those two pictures entirely and you know it's not going to come as a surprise that I'm on the hyper intentional account because I do think that the expressive wow that we get from this is beneficial but I mean that said you still want to be able to do all the work that you need to do whatever you've got there yeah so you want to have a picture of counterfactuals that's long but there are so many debatable things about the traditional picture of a counterfactual that we don't necessarily want to have the same theory of a counterfactual so that's Lo is with the sweets that's true I mean well the case where you possibly are deceived and it's been well yeah of course that's like but yeah yeah good so yeah I think I agree with all that now I haven't done all the work myself I should say on kind of working out what we might be able to retain and what we might need to throw away I think yeah other people have done some of it I should actually know that now that we talk about this I should go back to Lo's theory of counterfactuals which some people have taken issue with and see whether what I've said here is fully compatible with that picture because then I can just adopt that and maybe give it a bit of a more of a basis but I haven't checked that actually so I'll make a note to do that because of course ultimately it would be nice if we can the formal tools back that we need to you know need to do formal model logic so thank you for the question and some whole work for me I'd be very interested in the good stuff thank you for the talk I think I can guess your answer but I will come back on the biological kinds and dualism because the dominant view in philosophy of biology is that for biological individuals for all kinds of stuff but for biological individuals they have two categories unit of selection and some kind of generalization of organism and they say that some things are both some things valid the criteria of identity and existence for both and what would you say could you lose one and state the same for example you are a unit selection and you are an organism but for x y reason you are not a unit selection you lose some properties that are necessary for the criteria to be a unit of selection are you still the same individuals if you stay an organism because the purists would like to say yes and I don't understand how it's possible with that in your kind of view well I haven't thought of that specific question but in general kinds that superpose but they are not hierarchical at the same level that's the difficulty yeah good I mean I have thought of some of those examples which I can't quite remember by heart but yeah as I mentioned earlier Emma Tobin has some nice discussion well let me put all my cards on the table because I don't usually sometimes I have footnotes on this but now I think I am more committed that I think that there is just one there is just one biological kind as it were and that's to be a living organism yeah so that's maybe what you anticipated from what I said yesterday because I have been kind of on the fence on this and I often write about the biological examples as if they are generating different kinds but I am inclined to think now that there is just one there is just one biological kind and it is to be a living organism and we are all part of that same general kind indeed every living thing is part of that same general kind and that requires taking that four dimensional picture of the kind but if we have that singular origin of life we can all sort of be traced back to that same thing I think it's kind of a nice neat picture now then you ask well what about obvious differences between all the biological you might ask but some of my what about all the obvious differences between the biological class we need to be able to store it by different species anyway well yes but we are already able to and we already have all the competing species concepts of course some of them based on historical properties some of them based on partially intrinsic properties it just turns out that all of these are accidental properties you know the only essential property for the kind is to be a living organism or something like whatever it is that the essence of it but it's going to be something very general and all the other things are accidental properties and it's not a huge surprise that we get such a variety of them but it does mean that we can carve up species spaces you like which is useful because people are already having a say if you look at different species concepts now I mean this is a slightly more general answer than the specific one can I do a flow yeah because I think your answer is quite good with that kind of metaphysics because it's a criteria of existence also so it's not just a criteria of classification it's existence it's part of what to be what you are like Jonathan Lo was defending so you cannot be a real pluralist because you cannot it's forbidding if the identity of the thing is also some properties are part of the criteria of existence pluralism is out at least in a metaphysical strong sense yeah can't you be an electron infirming but that's hierarchical that's something to say yeah if you've got so the electron firming case is easier but it's the cross cutting cases I wish I could remember a good example so simple example from platypus platypus they all be paris they lay eggs and birds lay eggs as well but the platypus can't be classified as a bird obviously but the platypus is a mammal but mammals don't lay eggs generally so you get this it's a silly example really but it just shows how these biological categorisations are cross cutting because you can't classify the platypus nicely together with all the mammals as being not a glane because it doesn't have all the other shared properties the birds have platypus is a nice example anyway because they're so weird so you can find these some of the better examples that I can't remember now are trickier in explaining how the cross cutting should be understood there some of the chemical cases could touch on this as well actually when you get to bigger or maybe it's raw material some of the chemical metals it can be cross cutting I agree on the detail you need to work out the details so those cases are interesting but the general answer of course that I can have here is you're right some of those cases turn out to be one of them is now real kind so there isn't generally in cross cutting the cross cutting is sort of more epistemic in nature or there's just fundamental natural kinds so you don't get the interesting thing about philosophy of biology is that for decades there was a discussion what is the real part of biological individuals of selection, physiological of selection and finally now everybody's happy since they end up the pluralism I don't understand how because clearly they change the criteria of identity or the criteria of existence anymore yeah well that's true if you're a genuine pluralist that would be a cost there you don't know how to quantify something must give you the unit of quantification some criteria so I thought that the popular way to look at it is to look at the lineage and just identify the species purely on that basis I mean it's not going to solve all the cases but it's going to give you a pretty good criteria but of course I'm trying to be compatible with that sort of view because if you look at the lineage and you look at the entire lineage you're going to end up in the same place every time there's just one lineage good because I think it's an interesting question about how your natural character may be automatically defined but they may be still natural in the sense that there are a lot of properties that are natural in the sense that they are very natural bunch so the way you do your taxonomy may be pragmatic but they are still metaphysically something like this natural in the way of the term so I'm going to try to answer all the way to this question yeah I'm a bit uncomfortable with that line unless we're clear about what the ontology is on the background so on the type of robustly realist picture that I'm having here the pragmatic stuff better not influence the ontology now that doesn't mean that we can't make a schedule back to my turnout that we do them in a lot of cases but the ontology doesn't need to suffer from that necessarily I don't know the reason why I'm hesitating a little bit is because Strakowarty goes towards the type of anti-realist picture and these most recent workers at least one for us and stands to have a picture that way he ends up and then the criteria must be for mine he was a person from a resistance yeah but I don't necessarily accept the stance approach here so I have to try to be careful thank you questions? thanks for the report I hope I got them I hope I got them I'm very surprised and I want to get them I would argue that the chemistry is maybe the ideal size for these kind of examples because chemistry is pretty much the size that creates the ontological study most of the animals such as the serenity and the pertinence of that which is both pertinence and pertinence true, you don't have to trust your elements indeed I guess the very center of chemistry can be used there we can we can know about these substances that we are about to make for the very first time because of our knowledge of the other animal substances and the way we tend to react a lot so we can theorize about it right now that whenever I look at the substances and the specifications bound to happen or I will have such mistakes to be interpreted that's really the way to treat them I guess it depends on the cases but I'm just thinking some of those cases would depend quite heavily as I'm sure you can tell me more about the type of bond in effect and we know if the chemicals were ending up it's going to be covered by a certain type of bond structure then it will have certain type of properties so we've got existing cases of those bonds effectively those are a kind of dependence relation you only have a very common problem there and you can get to some of the properties there now whether you can get to all of the properties it's sort of easily is another matter but I think that would be a good way to go I mean I like Robin talks about the nuclear charge often in these cases that even in components the nuclear charge still has a key role in predicting and determining the chemical properties that might be controversial in some more complex cases but in some cases might be the nuclear charge is part of the truth so the answer is well let's do some empirical work and find a big rush where we can locate those truth makers and sometimes it might be epistemically quite difficult of course I mean I imagine that this is going to be very tricky in sort of macro molecule space and of course things like protein folding we are not very good at predicting those things at all I mean there's a context for AIs to predict protein structure based on the primary structure so that's an interesting case of what could possibly be the truth makers for this for some sort of yet to be synthesized for an eventual structure but you know I think these are interesting puzzles but they're mainly scientific or empirical questions so we can hopefully do some more work for this I mean I've got more detail on the Transurain case in the paper I've published but maybe I should think about those, I haven't really thought about those cases of just coming up with substances I mean part of the reason is that they're more complicated of course so it's much more difficult to trace those but you know you could be encouraged that this type of solution is the right way to go just by the fact that we are really good at predicting properties of yet to be synthesized compounds in many cases I mean we might already have in mind the property that we want from a compound when we start that work but I have good examples from the top line but what is the case of the troop maker then for some of the Transurain case but what do you take to be the troop maker of the other elements 1 to 6 so is it the other elements with magic numbers is it the theory about them so the example the specific example of the specific manufacturer stated to kind of was the longer half life right and so that seems to be made true by the properties of the electron shell configuration I suppose so I mean which property is it exactly I mean the way we arrive this is by this theory of magic numbers of course but it's the it's the electron shell structure that gives you the detailed answers to the energy levels of that structure so I'm just trying to cheat here to remember what I said about this exactly so so this is what I said that the truth maker for that sort of kind of factual so if it would have existed it would have a longer half life than organism would be the actual energy states of the nucleus and the positions and their positions in the potential well so that would give the higher stability in cases where we have the closed shells and you know the theory comes from the magic magic numbers of the nucleus of course but because the actual nuclear structure of that of course also doesn't exist no no that nuclear shell structure doesn't exist but the dependencies can be can be modeled already so the dependencies are the same in all of those cases so that's the idea so we know that that the nucleus which are you know it all consists of the same subatomic particles so that ultimately by talking about the dependencies between those subatomic particles that get more and more complicated of course as the elements get bigger but it's not like there's a fundamental difference in those cases and that's exactly why the magic numbers build up then we can model them accurately you know going beyond the actual cases so I guess I guess what I need to emphasise in these cases because I nearly tripped myself here is that you really can't consider the cases in isolation but rather you have to consider the entire dependence structure that gets that emerges from the dependencies between the various particles and this is a good example because it's of course now a single entity that gives you gives you truth make that access of truth maker for any of these cases you know but rather the interplay between the various entities that participate in the given element so and those dependencies are the same in all of these cases it could be argued because they all consist of the same subatomic particles so once we have that dependence interplay to where we can extrapolate into cases where the same dependence structure emerges but there's just more players in a way good I hope I got that wrong but but it makes those compound cases even more complicated because there's so many things playing together so you have to resolve those cases well that's all for me too I was going to head in that direction because a similar letter actually I think a really nice case for you because it's it's something just the Transuranian case on steroids people in synthetic biology do this all the time so you can walk up to a there are people working in drug development who start out by just walking up to a chalkboard and thinking about what they wish a protein would do they sketch for a while and then they conjure the damn thing into existence and this is like a thing we can do now right and that's I mean there I think yeah I like where you landed because I think where you landed can support that now now that's a unfathomably complicated dependency network oh yeah something like we're building a protein because we think we want to interact with this this element in the cell at this point in this kind of cycle what it's going to take to to say justifiably I think that if we did this it would work it's going to be a network that's going to get really gross yeah but this is I've been playing with this I also know I've been playing with this in a project that we're going to do someday probably thinking about states based thinking in biology because I think it's everywhere and a a fellow friend around me interesting stuff about exactly this but he's one of like three people who's ever actually slowed down to think about what possibility in biology means that's a really cool question and I think you've given us some really neat tools that was really just a long one in common and maybe that synthetic biocase is a cool one to explore if you want to find like dial the complexity to 11 it might be helpful yeah thanks very much I've mentioned this I have thought about synthetic biology case but I I haven't got into these I'm familiar with Rami's work of course so I know that there's a lot of potential in that regard and yes I do think that this type of model works precisely in those sort of cases as well so I think that I should like to next go into that that work but I just haven't had the time to read up on synthetic biology enough but yeah now I mean just to say something more it's interesting because you know everyone knows you've just indicated that there's going to be a crazy amount of different dependencies going on there who could possibly think about them all at the same time well we don't really because we know that we kind of take shortcuts in that we've already discovered some things that work and some things that you know speculating how they actually do this work in the lab but some processes then that produce no results some chemical reactions that produce no results and we can rely on and build on all that work we have sort of actively considering all the dependencies that work on the background right because you know sometimes accidents happen and you're like oh well wow that worked out better than to spend but you know the technology of the background doesn't change from that you have the no structures, you have the no processes that are ultimately built up from these very complicated networks of dependencies I mean I don't know if they use AI a lot yet, this is synthetic biology but I'm sure they will but the idea of predicting protein structures based on the primary structure is an interesting case of what the AI is grasping there because I don't think that the cases where I know there have been research, I don't think that the AI is actually grasping the dependencies it's just extrapolating from the big data set like in large language models I don't think that the AI understands the language and in this case as well it's not doing quite the same work I feel but if we could feed in the dependencies of the AI model that would be more effective it's like building it from the parts that actually do the work so right now I guess again, I feel like the AI is based more on sort of lucky connections from the big data sets rather than our first principles good but yeah, really great you mentioned that again it's homework for me because I should read out much more on the synthetic barge but it's good to hear that you guys are working on it one day I have an interesting idea you should like it I'll get you to do the work that's great, thanks nobody else this is kind of technical the idea that they are not empty themselves especially because of the kind of you said it's not a set it's not a problem entities in a very broad sense it's not even that then you say I propose to read as an identity and existence conditions of an entity so conditions is plural suggests maybe a set kind of thing well so it's a book of life and it's a request argument I'm not sure whether it's so problematic I mean a request is problematic it's a definition but maybe there's a characterization possible I don't know and I mean there's a whole kind of language that suggests that it would be entities given the essence of essences a dull linguistic the grammar of it the whole notes, the whole talk suggests that they would be entities of some sort maybe a weird sort but and then I wonder like could I maybe read this differently and see it more as a sort of a connector an operator like something that we call an essence that actually the thing is it's essential for X to something like that yeah it has a functional purpose in the framework and the logician would like try to but the function is also an entity right, it's kind of sad but to avoid that just add there in the language like necessarily is you don't have to buy into necessities as entities can just talk about necessarily and define the rules of necessarily maybe essentially could also be something like that and its function would be what is important about it I mean in that proposal that would be for me a way out I mean the idea that it's really not an entity as old, there's no reification of it nothing like that, it's just it's just not great but if that suggestion I hope that's a question for the logician yeah good there's definitely more to be said about that so you're right to raise that question and I'm not opposed to that sort of operator kind of thinking of this, I mean it works it works if you think of logical lessons as well it just works it works as a sort of operator so you can do the work and kind of think of it in this way and there are people not many people but there are a couple of people Nicholas Spinelli I think has a paper on this which responds to low on this infinite regress case and suggests that kind of a way out which may or may not work but a few people have suggested that that regress issue is not necessarily as serious as it might turn out to be but so here's a question so if we did think of, if we think that there's a you know the regress isn't problematic or regress we're still going to have to say well if the essences are entities then presumably they're entities that belong to some category of being right, if we're doing this sort of category of ontology anyway which is definitely a side point here so which category do they belong to are they properties and one of the fundamental ontological categories but the essences of the other categories of entities would then have as their essence an entity from another fundamental ontological category so you know the essence of a substance would be a property which belongs to the other formal ontological category that would mess up the formal ontological relations of the type of ontological picture that these lawyers I think so would be a key coherent I mean it would be a weird picture of things hiding together rather than this fundamentalist idea of some basic categories and all the rest from there but as long as it hangs together and you have a nice factorization I'm happy so yeah, I mean at least maybe you then have to say that whatever category those essences of entities belong to has to be the more fundamental category than the others because all the other categories depend on that category in some sense on this type of picture or maybe you'd have to say well there's a further fundamental ontological category category of essence and that's where everything's linked to well but it doesn't mean that you have to postulate a further ontological category so it's not that the most conservative approach so I mean if you can understand what's happening here just based on this non-entity conception of essence then I think it is more promising because you'd have to work out the logic of this and I mean notoriously people who do sort of verify essences they don't necessarily say much about that very question so you might just say well it's just a bundle of properties you know so the essence of an electron just is to have you know it's mass and charge and happy to get spin and the essence is just that set or bundle of the properties or the proposition expressing whatever each way of going here ends up in the same sort of area but then the question is well what unifies those properties into that essence exactly so what's exactly doing the work here David Otterberg has kind of an answer to this type of view but it's very much based on how you know how amorphism which is not something that I necessarily accept here so look I mean there are ways to go here but I am not convinced by any of the obvious alternatives here I mean one way which I suppose hinted towards as well would be to take them as kind of a linguistic entity I mean that could work up to a point but it seems unnecessary to think about them but yeah precisely it's not like that right an operator is not an entity it's not something it's something you work with that's right because if you're into everything you don't have to have an object that corresponds yeah yeah I agree so that could work but you better not think about it in the same way as maybe I mean some people might think of logical constants as entities as well and they would have a nature as well that could find talks about the essence of conjunction and if conjunction has an essence can you return that to the operator maybe you can no I don't think there's any the fact that we use conjunctions doesn't mean that we have to have them in our own quality right it's not because it's yeah yeah you can say that the constants aren't entities of any kind they're just similar to the operator they're just something we work with so that is as possible well look to finish my answer as I wear I think that that operator view probably becomes closest to what I have in mind of the kind of options that are on the table here because then you don't have to re-find the essences and as you see the essences for me at least are just something that you work with that's something that I and yeah I mean that's the conservative choice as well you don't add things that you don't need in the ontology you just have the things you have in the ontology and those things have some relations and that's what gives you good thanks but that's helpful and maybe it helps to specify the operator view actually as a sort of example of well what could they be well think of operators also entities so I keep this in mind you know that Brian thinks the essences to be crazy universal that are instantiated by electrons for example electron which you point to this word which is the essence of electrons is not instantiated in an electron so it's not a property like negative charge or spin it's a super generous universal which he calls a quasi universal and it's I think it belongs to the same category of properties but it's very special kind of property as he says how do you think do you agree with that you know I just want you to have your that thing on that yeah I don't remember the details of that is on this at all but that rings a bell we have another look at that so I always just at least as a sixth category of ontology right he's got two kinds of universal but there's a further quasi universal which is the essence but it's something maybe in the property category it's almost property it's crazy yeah I don't this kind of has a strange ring to it but I don't remember how he details this but it seems not necessary what you said you just said how I have my same favourite of a property we get to do it with the physics of laws without the senses without natural guidance because of powers but ok that's a lot of problem should not on religion he said well we need senses kind of according to this because of explanations requirements so it's like a difference to the and then what you explain you will hold these properties like spin one half negative charge a specific mass all those properties here there is a necessity link between those properties and a sense explains you know I think it's very mischievous but he explains why those properties are always found together yeah well I don't I mean it's passing to me that at least would say that as well because I think he also has substantial kind universals in the ontology and to my mind the explanation for why these properties go together is very simple it's because the substantial kind universal electron is rigidly dependent on those properties so there's a dependence relation there between that kind and the properties that characterise it and that's where you've got the explanation it's that there's behind every explanation there's a dependence relation and the dependence relation here is a formal dependence relation between the kind and the properties that characterise it really in which case you don't need to verify the essence of that it's essentially dependence yes but it's basically the essence of two different kinds of entities property universal and the kind universe but people do talk about I mean Martin Glacier for instance talked about the explanatory essences I think I can understand that talk and even agree with it if I can return or reduce that talk to not postulate the essence as the explanatory entity there but the essential dependence relations between various entities as being the basis of the explanation so you know explanation is track dependencies in this case they track essential dependencies so yeah I think I can get by with less I mean obviously I still need all these categories since essence precedes existence could you could you elaborate about what you see out as some constraints on the demand of essences or any or you so what kind of stuff can be there so are you talking about what I maybe what I talk mentioned as these I guess candidate essences because all the things here we seems to talk about natural properties as or measurable at least measurable properties as constituting the domain but do you see that as a restriction do you see it bigger what kind of things could be in a criteria identity in existence good yeah so I think that the first question is if we're I mean it's good to be in a place where we can talk in this sort of way some sort of a category or ontology so your first restriction is probably going to be well how many fundamental ontological categories there are what are they so you start out with I mean almost everyone accepts properties or tropes you know if you like a trope bundle theorist I suppose so at least there's some sort of starting point here and you well there are people who try to get by with one category right a trope bundle theorist might be one but then you have all sorts of issues with that but what you need to do is build those dependencies based on that category of structure that's why a one category ontology seems very problematic to me actually because you don't seem to have dependencies between the categories so you don't have the formal ontological structure and necessary richness to build up you know all the things that we need in our ontology but that's I think that's the first constraint and then there's the question of whether there are things like the law of contradiction perhaps that govern those relations themselves that they have to follow some sort of some sort of logical principles about which kind of entities can exist together in this first place so could contradictory properties be established in the same entity at the same time maybe you want to pull that out but yeah so I mean that's the starting point you know to be able to agree that starting point does require us to make some make some sacrifices perhaps but I think that's you know that's life yeah well I haven't worked this out I mean I only thought of this as a potential example of the way of the train over here so yeah I thought that maybe maybe the reason is that there's some sort of normal app between the supposed identity and existence conditions of Fludgeston and what we now know is Oxygen and maybe other things as well so I'm not saying that there's a perfect old app there and it seems that in the in the same actual case it would be very odd to have both of those those things because they do seem to do some of the same things as well so that you know in chemical reactions where Oxygen participates it seems like there would be some violation if there's both Oxygen and Fludgeston acting together or something like that so I mean so it's because they're playing the same role or at least supposed to play the same role because I mean you could say taking the electoral it has a certain pass it's in a half and a negative charge what if you change the negative charge into a positive charge well I mean positive but of course they do also play different roles so if you would have those two into the same role but if you explain conversion by in Oxygen which is captured from the atmosphere whereas the Fludgeston is something which is released those are two contradictory entities I mean so if one exists the other one doesn't exist that's the thought but I mean I haven't worked out a detailed example but the other hand you know the philosophy of science there's Oxygen refers to the same thing as what is really called the different differentiated air the differentiated air it's a gas without register and of course it's without register so it seems I mean well the identity existence conditions for Fludgeston are even well well formed or something like that but I mean it was pretty well formed as I understand the history of chemistry as a concept as a candidate but then when we found out the other stuff that does exist namely Oxygen and well we understood some combustion processes better anyway then it seems like some sort of a contradiction could be derived if they're both well there I mean one with a negative weight they all would have a positive weight so there were many things different I would say that's one of the reasons they had to assume if we had a negative weight because as people must mentally it gets heavier that's a good point yeah so that would have some sort of property probably a negative weight I mean well yeah you know in the history of physics yeah so yeah we virtual exchange particles that don't have any weight I still don't know how to understand them really so so do they have career identity of existence conditions I'm not sure so if anyone has any ideas for what could exclude the existence of some other entity then I'm all there yeah if that is the case then that does seem to be you know at least if we accept that contradictory something that we want to have you know yeah yeah that's what I mean always having to have it good thank you anyway thanks for being here