 So our next speaker is Cecilia Bolion-Cous, who is a post-doc at the, this is an English translation, the Institute for the History and Philosophy of Science and Technology, and the lab acts, who am I? She is most recently a co-editor with Charles Wolfe of the volume, Philosophy of Biology, Before Biology, published by Rutledge, where she examined biological and protobiological writings from the mid-18th century forward. She has written on how nutrition shaped viadal organization in the late 18th century and forward. In her talk, The Concept of Metabolism, Biological Identity, and the Challenges for Microbiome Research, Dr. Bolion-Cous will build a theoretical framework for thinking about biological identity to connect a metabolism-based notion of identity with recent findings about the relevance of microbiota for all functions of life. So the floor is now yours. Thank you very much. Thank you very much, Chris. OK, so thank you very much to the organizers for inviting me today. What I'm going to present is a kind of work-in-progress material, so please be indulgent. And I look forward to your suggestions to improve it. It's part of a new postdoctoral project that I just submitted and that will start in next September in Louvain-Lenevin, Belgium. OK, so for a few decades, we have come to realize the extent of the intertwining between symbiotic bacteria and organisms. Various functions in animals and plants are carried on by symbionts or mutualists of different species. For example, termites rely on bacteria to digest cellulose. The cicatrization processes in mammals are due to symbiotes. And very probably the origin of placenta in mammals is due to symbiosis with a virus. And even though the acknowledgement of the microbiome's role in physiology and development is widespread, no consensus yet is rich about the impact it should have on our conceptions of biological identity and its maintenance. So in my doctoral dissertation, I have shown that the concept of metabolism had since the mid-19th century, I would say, has played a key role in elaborating the notions of organismic individuality and identity, sketching a view of organisms as self-organized, bounded, and autonomous entities. And therefore, I think that there appears to be a strong contradiction between this inherited metabolism-based notion of identity, which I will elaborate a bit in a moment, and the recent idea that heterogeneous elements can participate to the organism's identity. So any account of biological identity now faces a tension between the traditional reference to metabolism and the recent realization of the extent of the involvement of microbiota within vital functions. So metabolism, indeed, concerned processes through which the alien matter is made into matter homogeneous to the organism itself. But inversely, the contribution of the microbiota to the maintenance of the organism is precisely due to the bacteria as remaining themselves, therefore as remaining somehow heterogeneous to the organism. So this contrast between the two concepts through which biological identity has to be explained is a key philosophical issue that an updated account of biological identity should address today. And such attention needs to be solved if we want to make sense of the concept of biological identity in this so-called revolution in today's biology. So the goal pursued by the current project is to build a theoretical framework for thinking about biological identity able to connect a metabolism-based notion of identity with recent findings about the relevance of microbiota for all functions of life. The project draws on the historical and conceptual analysis of metabolism that I undertook in my doctoral dissertation. And it will contextualize the current problems raised by microbiome research for the notion of biological identity in the light of the inherited complex conceptual structure of the notion of metabolism. OK, so about biological identity. Making sense of the concept of biological identity means mainly two things. First, accounting for how an X is identical in the sense that it is X and not Y, and therefore is discriminable from any Y, hence distinct as X from Y. Second, accounting for how X is likely to be re-identified as X in many contexts and time intervals, especially how can X endure as X, right? So I have chosen to name the first question, the individuation question, and the second one, the enduration question of identity. Regarding biological identity, the individuation question often revolves around the general concept of information and has in the last decade often be centered on accounts that put genes and genomes on the foreground, whereas the enduration question arguably involves the concept of metabolism as metabolism captures the processes through which individual organisms maintain their identity through time and change. It has indeed often been noticed that general question about life and models of what life is are divided between two families, the ones that put replicators, gene and information and heredity first, and the ones that privilege metabolism. As to the enduration question, namely the maintenance of identity and the endurance through time, so this question is frequently framed either in terms of multilevel selection processes, that is, how is the collective of cells buffered against selfish mutants, for example, or in terms of self-organization in what is now called the Varellian tradition, which involves investigation of metabolism at any levels. However, as I have shown in my dissertation, metabolism arguably bridges those two identity questions, namely individuation and enduration. So metabolism is indeed a process through which a living body integrates external matter and possibly inorganic matter and makes it into matter akin to itself. And in the same way, metabolism, metabolizing means turning input substrates into the living matter proper to an individual with a given genetic identity. Yet, the notion of metabolism, because it's instantiated at various scales and combines an idea of specific chemical processes and a notion of biological functioning, is multilayered and complex. And most of the time, the philosophical users of this concept overlooks such a complexity. Philosophical accounts of identity that mention metabolism indeed mostly stem from the formal self-organization perspective or from research on origin of life so that authors hastily subsumed this concept under their favorite philosophical scheme or issue, that is, for example, self-organization, chemotone, origin of life protocells, and forget other aspects of the concept that would be relevant to the identity issue. In contrast, an approach that would be attentive to the conceptual genealogy of the concept of metabolism would allow us to capture those complexities and layers of sense. So that is why I now turn to the late 18th century just to give you a quick overlook of not the emergence of the concept of metabolism, but more the problem space of metabolism. Because as Hannah said earlier, it was Théodore Schwann, who, in the context of the cell theory, first coined the term metabolism. So in the late 18th century, just a quick overlook of the chemical and biological context, so it is well known that Lavoisier defended the conception of animal respiration as a combustion. And at the time, so that's the first part of the puzzle that I'm just trying to sketch here. This work by Lavoisier and Seguin was done in the context of the search for the physical chemical conditions of life in the late 18th century by means of chemical analysis of organic substances. People were looking for the composition of organic substances that would constitute the living organisms, namely carbon, hydrogen, oxygen, and nitrogen, each of which was characterized by the proportion of the elements they would contain. So in the late 18th century, the chemical theories of biological processes mainly relied on the elementary composition of organic substances and were then conditioned by the state of the ideas about these compounds. After the Lavoisier theory of respiration as a general combustion, there was this beautiful picture of nature that divided life into two rains and that would distribute the chemical works to the plant and the animal. The plant would be responsible for any organic synthesis in nature, whereas the animals would only be responsible for chemical analysis, that is combustion in Lavoisier's terms. So life in a certain way was kind of alienated because it was divided into, so the chemical work of life was distributed in two rains or divided in two rains, the plant on one side and the animal on the other side. In parallel to this great depiction of the chemical work of nature and this division of life in two rains, the knowledge of the elementary composition of organic compounds started to grow, for example, with the work of Bertollet and Fourcroix in the late 18th century. The main point here is that slowly nitrogen was considered as the main characteristic element of animal substances. So one puzzling question at the time was how on earth, well, why would animal substances contain as much nitrogen since animals could not be responsible for any kind of organic synthesis? Where do these great quantities of nitrogen originated? Where do they come from? Because animal could not synthesize anything. So the response to this question was that these great quantities of nitrogen had to originate in nutrition. So that at the end of the 18th century, early 19th century, you started to have this growing theory of nutrition as direct assimilation. Animal nutrition was a matter of direct assimilation. So identity maintenance for animal organisms was depicted as a direct nutrition. That is, the absorption of a nutritive matter had to be already identical to that of the organism that would assimilate it. In a way that a substance would be nutritive if and only if it was chemically identical to that of the assimilating organism. And that is why albumin and fibrin would be considered as paradigmatic foodstuff at the time. So for example, in the works of Jean-Baptiste Boussaint-Gault and Jean-Baptiste Dumas in their essay de statique chimique des êtres organisées published in 1941, they both write an animal constitutes in effect a combustion apparatus from which carbonic acid is continuously disengaged and in which consequently carbon continuously burns. So I forgot here to quote Holmes from his lectures on intermediary metabolism, where I take the quote. So Holmes says that Boussaint-Gault and Dumas held a vision of the combustion of foodstuffs in animals that was derived not from direct evidence of the processes occurring in animals, but from a general understanding of the elementary composition and chemical properties of the three basic categories of substances, namely carbohydrates, fats, and nitrogenous albuminoid bodies. And that the near identical character of each of these three types in plants and animals had made it appear self-evident to Dumas and Boussaint-Gault that plants would create all the substances necessary for animals and that the latter, the animals, therefore, did not need to create any themselves. They would directly assimilate them. So that is what I have called a pre-formist theory of nutrition because in that conceptual framework, the histochemical elements that compose an animal are a mere aggregate of the ingested foodstuffs, which immediate principles are only selected and separated during digestion. Moreover, there is a clear focus on blood rather than on tissues, and blood here is depicted as a dissolution of the elements already present in foodstuffs that are isolated, selected, and extracted during digestion. Blood is a kind of dissolution of the elements that compose the organism. So in the end, animals do not synthesize any original organic compound, and they are chemically passive, that is to say, they only destroy or directly assimilate what the plants produce. So they're right. It is in the plants that lies the true laboratory of organic life. In the same way, Justus von Liebig wrote, I like these two quotes because it's so about the general, about what Hannah just said about stov-vexel. I think it's not so clear that it's well, what kind of change from the plant to the animal Liebig refers to. So I think that there is a change, but it's not so clear that there is no synthesis from the animal part, at least. So Liebig writes, herbivorous received from the plant the components of the blood, albumin and fibrid. They feed from the flesh, the blood, and the cheese that are created by the plant. From the viewpoint of chemistry, a carnivorous eats itself because its food is identical with the constituent parts of its organism. And the herbivorous eats itself because its food is identical with its blood. So we'd like to contrast that with Claude Bernard's theory of indirect nutrition. So interestingly, Claude Bernard never uses the word metabolism, nor does he really use the word stov-vexel. In his carnet, he uses the word stov-vexel once, but to criticize it and to say that it's a kind of metempsicosis. I think maybe because it's, to him, stov-vexel keeps the soul of the substance that it assimilates. There is no genuine chemical change in the German stov-vexel for Claude Bernard. And maybe we will see why in a minute. So on his work on the origin of sugar in animal economy, Claude Bernard shows that it is mistaken to believe that the sugar in the blood derives from the digestion of sugar of starch. And he looks for the source of sugar within the animal. So he writes, it was evident that it was the liver from which the sugar arose. And it is clear that in the face of these facts that law that animal cannot create any immediate principle but only destroy what is furnished into them by plants cannot be true since animal in a physiological state, like plants, in fact, create and destroy sugar. So and after that in 1857, he showed that the substance that the liver was making sugar off was, well, he called it the glycogenic matter. So sugar was not made from the blood, but rather from something within the tissues. And the liver could generate both external secretions, such as the bile and internal secretions, such as the glycogenic matter. Those works led Claude Bernard to separate, and again Hannah said that earlier, nutrition and digestion. Digestion would occur in the stomach where nutrition is a more general process occurring through the body. So digestion is the process by which food comes into the body and undergoes a first series of transformation. But nutrition refers to the processes, a series of processes of change and of genuine chemical change occurring in the internal foods, tissues and organs. And this is why Claude Bernard defines nutrition as a general characteristic of living beings, even more fundamental than reproduction in some sense, because it's the constant reproduction of one's own organism, or rather the constant production of one organism by itself. Sorry. So I just want to read this quote from the lectures on the phenomenon of life common to animals and plants to contrast it with the views that were held by Juman Boussango. So Claude Bernard writes, nutrition is the continuous mutation of the particles which constitute the living being. The organic edifice is the site of a perpetual nutritive movement which leaves no part of trust. Each one, without seeds or respite, takes its food from the medium that surrounds it and into it. It rejects its weights and products. This molecular renovation, which is a top of the time, is impercitable to the site, but as we see it's beginning and its rest, the intake and output of substances we conceive of its intermediate phases and we represent to ourselves a flow of material which passes incessantly through the organism and renovates it in its substance and maintain it in its form. The universality of such a phenomenon in the plant, in the animal and in all their parts and its consistency which suffers no interruption makes it a general sign of life. So the animal for Claude Bernard, he says, creates fat instead of finding it fully formed. The dog does not get fat on mutton fat, it makes dog fat. So in such a way, what Claude Bernard says here is that nutrition is not a direct assimilation process, it's rather a genuine process of changing what you eat. So it's an indirect process of organic synthesis, organic and organizing synthesis. He writes that animals must have within themselves mechanisms that drive similar materials from this very diet and regulate the proportion of them that must enter the blood. Finally, I like this one, the living organism is made for itself and it has its own intrinsic laws, it works for itself and not for others. Okay, so there is nothing, for example, in the law of evolution of grass that implied that it should be cropped by a herbivore. So just a detail here, when Claude Bernard speaks of evolution, this has nothing to do with Darwinian evolution, rather it's a synonym for individual development. Nothing in the law of growth of the cane that announces its sugar must sweet man's coffee. The sugar from in the beet is not distinct either to maintain the respiratory combustion of the animal that feed upon it, it is reserved for consumption by the beet itself in the second year of its growth when it flowers and fructifies. So the organism through this indirect nutrition makes its own substance for himself. So initially, the concept of metabolism emerged in the mid-19th century in a position to a view of identity maintenance as direct assimilation, namely a process through which organisms directly integrate the elementary organic building blocks that would compose the foodstuff they absorb. The emergence of this problem space of metabolism therefore provided biology with the view of organism as bounded individuals and autonomous entities. This is the individuation side of the problem. It likely to self-organize and to self-maintain this is the enduration side of the problem in a wide variety of contexts. So ultimately, metabolism had to integrate the mechanisms to support the regulation activity and the maintenance of identity through time at various integrated levels. And metabolism thus made it possible in a sense to link the specificity of organism to their chemical conditions of existence and determine the scheme from which the specificity of organisms, namely the soft production and self-preservation, could be understood in a naturalistic way. There is therefore a clear sense in which metabolism has underpinned organismic individuality and biological maintenance. So however, as I said in the introduction, the last two decades have witnessed theoretical breakthrough that have affected these two paradigmatic answers to the identity questions, namely information and metabolism. First, epigenetic phenomena, possibly transgenerational mitigate the assumption that the answer to the question of the distinctive identity lies in genes. Even the inherited identity may not be purely genetic and thus multilevel selection accounts of identity which assume a traditional gene center, which assume a traditional gene center in view of inheritance are challenged. Second, the acknowledgement of the extent of the turn-twinning between symbiotic bacteria and organisms led to new insights such as the Holobion concept, namely the set of host and microbes, supposed to be a unit of evolutionary processes and of physiological functioning. Regarding identity, this means that the genome of an organism while essential for its life, as it has been often claimed, is not only the genes of the host. Moreover, the microbiota and especially the gut microbiota is involved in many metabolic processes, including assimilation functions. So those challenges stemming from epigenetic and microbiome sciences, suggest that the individuation and duration questions of identity are more intertwined than generally assumed. And this new development in the understanding of identity is the context of the current project. So in this recent context of the acknowledgement of the constitutive role of heterogeneous symbiotic bacteria within organisms, some philosophers have suggested that biological identity is in need for conceptual clarification. I especially refer to the paper by Scott Gilbert who claims that we have never been individuals. Such a challenge is the major motivation for this project where I would like to tackle the issues raised to a metabolism-based understanding of organismic individuality and biological maintenance by recent microbiome studies on the basis of a historically informed notion of metabolism and its various layers of sense. So the project can be decomposed into three interrelated objectives as listed below. The first objective would be to reassess the self-centered view of identity. That is to say to determine the role, the concept of metabolism should play in any account of the maintenance of biological identity according to physiology and cell theory. This would entail to decipher the individuation and duration aspect embedded in the metabolism-based notion of identity. So second objective is to map the challenges raised by microbiota studies to the self-centered view of identity. That is to say to identify and tackle the obstacles that the implicit use of a metabolism-based notion of identity raise regarding the integration of microbiome science in a renewed theory of biological identity as both individuation and duration. So that would mean to undertake the revisions of the concept of metabolism required to supersede those obstacles. Thirdly, so the third objective of the project is to integrate a theory of the microbiome's contribution to identity within a renewed account of biological identity. And it implies to specify the conditions according to which a renewed metabolism-based notion of biological identity could integrate the contributions of the microbiota to the biological identity. So the first objective concentrates on what I will call the self-centered view of identity, where identity relies on metabolism as a process warranting a constitutive homogeneity of the organism while integrating alien substances. There I would discuss the consequences of focusing on metabolism at distinct levels of the organism, which will define several ways to develop the theory. So I can skip this. So the systematic examination of meanings and roles of metabolism in the self-centered views of biological identity will pave the way for the objective number two, that is the mapping of the challenges raised by microbiome science. So to what extent does each of those views prevent making room for processes in which heterogeneous elements, namely other species organisms, such as bacteria or fungi, fulfill or contribute to fulfilling a vital function. And especially which aspect of the complex meanings of the metabolism concept are most problematic for integrating the role played by heterogeneous elements within an inclusive account of biological identity. And with regard to this question, the difference between organism integration, regulation and self-maintenance of the cell will be explored. And inversely, what specific aspect of the role played by various bacteria species in the microbiota are most challenging for the self-centered view of identity. So I will especially investigate how the concept of metabolism underpins the received and now challenged view of organism as bounded and autonomous individual, which contrasts with the emphasis put by microbiota research on the contribution of specifically and genetically heterogeneous elements to organisms' function and endurance. On this basis, the objective three will lead to sketch an account of identity alternative to the metabolic self-centered views that were exposed in objective one. The objective here consists in suggesting how the aspects of the complex meaning of metabolism identified as most antagonistic to the idea of a key role of heterogeneous elements within identity could be modified in order to make sense of such a key role. So the fulfillment of this project should provide the elements for a future discussion of the immunological views of identity, held, for example, by Pradeux, that explicitly distanced themselves from a self-centered view of identity because, ultimately, the project should lead to a general map of alternatives to self-centered views of biological identity. So I would like to finish with some concluding remarks. So metabolism has indeed appeared to us as the process by which a living body ingests an external matter, possibly inorganic, and transforms it into its own substance. Conversely, metabolizing implies transforming foreign substances into a living matter specific to an individual with a given genetic identity. I have determined that the conceptual space of metabolism emerged in the mid-19th century in contrast to a conception of identity maintenance as direct assimilation, that is, the process by which organism directly integrate into their organic texture the elementary constituents of the foods they absorb. The emergence of this conceptual space seemed to me to have provided biology with a conception of organisms as autonomous individuals capable of self-organization and maintenance in a wide variety of contexts. However, the last two decades have been marked by theoretical advances that have shaken profoundly this pattern. We're now realizing the extent of the interweaving between symbiotic bacteria and organisms. And therefore, any account of biological identity now faces a tension between the traditional reference to metabolism and the recent awareness of the importance of microbiota involvement in vital functions. Okay. So, if we were now to map the stakes of a philosophical reflection on biological identity informed by a genealogical study of the constitution of the conceptual space of metabolism in which this problem crystallized for general physiology and therefore post-Bernardian biology, we would have to distinguish what we would call the traditional self-centered vision of identity where identity is based on metabolism as a process justifying a constitutive homogeneity of the organism while integrating foreign substances. And there are, of course, theoretically varieties of this egocentric vision, depending on whether they focus on thermodynamics, organic chemistry, as frameworks for formulating the requirements required by any metabolism. And whether they focus on integration into the body or self-maintenance as key objectives of the metabolic process. To this selfish vision or self-centered vision, we would oppose an alternative vision in which identity is the result of the cooperation and conflict of organisms of different species that compose an organism. What the concept of olobion tries to name, but perhaps by posing more problems than it solves. Such a vision would integrate the theoretical contribution of the evolutionary biology of symbiosis or the metagenomics of cellular activity, but it is clear that it would struggle to accurately reflect the limits of identity, namely the distinction between all those myocrobes, viruses, and possibly insects that contribute to the identity of a given living organism. It seems to contradict the traditional equation between metabolism and biological identity, but at the same time, it probably requires a renewed understanding of metabolism. So to what extent does each aspect of the selfish vision prevent the development of processes in which heterogeneous elements, or organisms of other species, perform or contribute to perform a vital function? In particular, which aspect of the complex meaning of metabolism are most problematic in integrating the role played by those elements into an inclusive account of biological activity, identity? Probably the difference between the integration and regulation of the organism, the self-care of the cell should play a major role here. And conversely, what specific aspects of the role played by various species of bacteria are most difficult to reconcile with the egocentric view of identity? These are questions that would probably emerge from taking into account this new frontier of the metabolic space that is being built today by the renewed knowledge of heterospecific contributions to the biological construction of identity and understanding where this history of nutrition, which was a kind of preformation of the history of metabolism could extend, is a philosophical challenge of perceiving this new frontier. And I thank you very much for your attention. Questions, comments? Let's go ahead. So I'm really, thank you so much. Really rich and thought-provoking. And I'm kind of struck at this level of kind of philosophical analysis at how recursive the problem is and what metabolism is doing in terms of trying to grapple with the problem of unity. So I mean Aristotle is really coming up with a notion of soul to solve the problem of nutrition as the assimilation of like to like and saying actually that's insufficient to account for how you actually get an emergent organism. So in a way it's a recursion of the philosophical problem. And so I'm wondering, so I kept thinking in terms of the question you pose about the challenge of these symbiotes. And I'm wondering I guess the question of how like or unlike is your problem to the broader question of parts and whole. So I mean that's the, maybe that is the million dollar question if everyone is nodding. But I mean the two soul problem is in a way to say, well on the one hand you have a kind of commitment to total eminence and total unity everywhere and on the other you have a directorial one but nevertheless all the parts are working together with the whole. And so I guess I wanted to ask you more about the kind of specific function of heterogeneity and how the kind of figure of the bacterium is functioning to shift the challenge and whether you think that's productive, whether you think in fact symbiosis asks us to think I mean the whole biome is maybe a concept which would change the way we think about organism that may not be so different from other part whole formulations. Thank you very much for your question. I don't have an answer to that question but definitely I think, so I think that probably microbiome research raises more question that it solves problems at least today and because well one interesting thing is that it clearly changes our received conception of biological identity and biological individuality as a bounded autonomous closed image of what is a biological organism. It does not really tell us what would be an organism, I mean it opens the frontiers. So in such a way that for example Chadeau's work on immunology has contributed also to open the boundaries of the organism and to say that the self and the non-self view of immunology is not right, is not a good theoretical framework for thinking about what is a biological organism and what is the self and the non-self, what is a biological self. But still that does not tell us so what kind of integration must be achieved so to speak of an individual like we know we have to open those boundaries in order to integrate those symbiotes but still any cluster of heterogeneous organism is not an organism per se so that leaves the question open to regarding the metabolism what I found interesting in that context is that so if you go back to the 18th century you also had these old ancient theories of direct nutrition where the quality of the food would pass directly to the eater and that the qualities of the food stuff would not be transformed into a genuine organic substance that would be proper to the assimilating organism and interestingly the conception that Claude Bernard developed in the mid 19th century of indirect nutrition challenged this view so that the living organism would not dissolve itself in the environment that metabolism, this constant exchange with external matter would be a necessary condition for the construction of or the elaboration of its own identity and autonomy in regards to the environment, its environment or the cosmic condition as Claude Bernard say. So metabolism and this is not often acknowledged that so for example in the Scott Gilbert paper we have never been individuals, he lists a number of individual properties that substance our conception of organism as an individual and but he doesn't really speak of metabolism so this is often metabolism is overlooked in the contemporary debates on biological identity and what's interesting with the microbiome is that it challenges this received view of metabolism that contributed to shape this view of organism as an autonomous entity different from any other entities. It's not just that the gene-centered view that contributed to shape this view of biological identity. I saw Charles but as we say in Croatian, Kratka-Pitan, small question, short, okay. Because we're running out of time. Okay, okay, I won't be long. It's just to push, to sort of push you on your framework, although I guess you're, because there was a lot of conclusions in this talk and so I was trying to digest it halfway through and thinking what's the methodological message in a way and I was thinking this idea and I didn't get the exact phrase down from Claude Bernard that the organism does what it does for itself, it doesn't obey kind of foreign external laws, that kind of idea, that kind of intuition. People take that and do different things with it, meaning that this kind of material, so Dennis Noble and people like that who are into systems biology, they take that and they say, ah-ha, we have here uniquely vital laws and processes, therefore we need it. Moreno and Mosho, right now, right? We'll take that kind of material just to insist on the uniqueness of the biological. Others like Tobias Chung will take this kind of material and say here's an interesting episode in a long history of negotiations of inner outer relations and physiology or whatever. Duprey can stick a processional label on to it as you mentioned and others with their internalist methodologies will want to make this a chapter in the history of vitalism. What do you, what flavor, what method, it's not really a question of methodology but what would you like to do with it or what do you do with it in that sense given, I just gave some examples that speak to me in their perspective. I mean, with Scott Bernhard? Well, what would be the example about that? What would this kind of material be? I don't have a, I mean, if, yeah, there's, I mean, would that fit in the frame? Yeah, like, but I don't, to me, it's more problems that we open than questions we answer or it's, so what Claude Bernhard, so it's not like a school or a label that would be process or vital laws or it's, I mean, it's a bit of every, of that there are processes, inner and outer relations, the relationship between chemical conditions of existence and specific vital realization of those chemical conditions like, so the intertwinning or the relationship between the chemical and the biological in Claude Bernhard, in Claude Bernhard's view. But mostly the fact that, well, Claude Bernhard explicitly challenges a view of life where, so you have a complementary processes, distriction and creation that were supposed to be distributed equally in nature for the plant and the animals. And ever since Stalin before those two complementary phases of chemical activities and vital processes were supposed to be exclusive of one another or to fight or to have an antagonist action between one another, what's interesting with Claude Bernhard is that Claude Bernhard at the best of my knowledge is the first to say that there is, so the living is not about fighting the chemical forces of dissolution, the living is not about a harmonious distribution of complementary chemical tasks in nature, but living is about fulfilling in cycles those complementary chemical works. So each living does the work of synthesis and analysis. So to me, that's the, so if I were to speak in terms of framework and this dialectical history of the relationship between the vital and the chemical, that would probably be the most interesting part in Claude Bernhard, but to me, that's, thank you very much. In the interest of time, we're going to break but if you have questions, you can email me and I can email the author. Thank you very much. Thank you to all of our presenters and to the audience.