Lithbea, a new domain outside the tree of life

Vol.:(0123456789) Global Philosophy (2023) 33:4 https://doi.org/10.1007/s10516-023-09654-6 1 3 ORIGINAL PAPER Lithbea, aNew Domain Outside theTree ofLife JaimeGómez‑Márquez1 Received: 3 June 2022 / Accepted: 22 November 2022 / Published online: 24 January 2023 © The Author(s) 2023 Abstract At this time when the development of synthetic biology and artificial intelligence are changing the world around us, philosophers and scientists, first of all, must converge to analyze the present and predict the ethical-social consequences and biological dangers associated with new “living entities” that are not the result of the natural evolutionary process. As synthetic/artificial life forms (xenobots, robots, transgenic organisms, etc.) become more and more abundant and sophisticated, it seems first of all necessary to bring some order to all this new biodiversity, establishing what is alive and what is not, and analyzing the consequences of this incessant creative activity. Here I intend to organize all these human-made entities and clarify their status as living beings or artificial elements, leaving the door open to an uncertain future in which we will be able to see how “the artificial” and “the natural” could merge to originate something different from everything known. Accordingly, I propose the creation of a new domain, Lithbea, which includes all synthetic and artificial entities within a new kingdom called Humade (derived from human-made). I have also included viruses in a new realm, the Viral kingdom, because they were excluded from the classical three-domain tree of life despite playing a fundamental role in the evolution of biodiversity on Earth. Finally, I make a brief comment on the unpredictability of the unknown, the implications of this new landscape of biodiversity, and the uncertain future of all these advances. Keywords Viruses· Synthetic organisms· Artificial life· Life domains· Lithbea 1 Introduction The biodiversity that exists on our planet is grouped into three domains: Archaea, Bacteria and Eukarya (hereafter woesian domains) as established by Woese etal. (1990). This classification has, in my opinion, two major drawbacks: (i) it separates * Jaime Gómez-Márquez jaime.gomez.marq[email protected] 1 Department ofBiochemistry andMolecular Biology, CIBUS – Faculty ofBiology, University ofSantiago de Compostela, SantiagodeCompostela, Galicia, Spain Global Philosophy (2023) 33:4 1 3 4 Page 2 of 19 prokaryotes into archaea and bacteria, making a molecular criterion such as the comparison of RNA sequences prevail over the absence of a cell nucleus, and (ii) it excludes viruses because they lack cellular structure and are not considered living beings by the scientific community (Moreira and López-García 2009). In addition to these natural life forms arising from the evolutionary process, more and more artificial life (hereafter A-life) forms and synthetic organisms, are being engineered. This new landscape, in which natural biodiversity, synthetic organisms and A-life entities are increasingly intermingled, raises some important questions for the present and future of the biodiversity in our planet with significant implications in science, biomedicine, economy and philosophy. Synthetic biology and A-life are two branches of science that blend our knowledge of biology with engineering and artificial intelligence technologies. Scientists build hybrid entities, synthetic organisms and living machines, robots, or computer algorithms to better understand the process of life (Deplazes and Huppenbauer 2009; Bongard and Levin 2021). In this context, the terms “artificial” and “synthetic” have closely related meanings because both words refer to entities manufactured by humans and, consequently, are not the result of a natural evolutionary process. Sometimes they are even used interchangeably even though they are not the same thing. A-life is more related to artificial intelligence, to the computer design of entities that pretend to imitate the living, such as, for example, some computer programs (software A-life or soft A-life) or physical robots (hardware A-life or hard A-life) (Gershenson etal. 2020). There is a third type of A-life (wet A-life) that aims to synthesize living systems from biochemical manipulations (Aguilar etal. 2014). Wet A-life, unlike the two previous ones, is based on organic matter and therefore falls within the field of synthetic biology. Synthetic Biology was defined as “the design and construction of new biological parts, devices, and systems and the redesign of existing, natural biological systems for useful purposes” (Calvert 2010). The advances in this branch of biology opens up new and uncertain biological possibilities with a wide range of applications and implications, generating significant scientific and philosophical debate (Ijäs and Koskinen 2021). In addition, synthetic biology expands the biodiversity of the planet by constructing new synthetic organisms with structural and/or functional elements that are different from natural ones and, therefore, are not the result of the evolutionary process (Fernau etal. 2020; Garner 2021). As synthetic/artificial life forms become more abundant and ever more sophisticated, a growing number of bizarre organisms—xenobots, soft and hard A-life entities, genetically modified organisms, etc.—are beginning to populate laboratories, computers, natural spaces, etc. In this work, I intend to order all these human-made entities and clarify their status with reference to their consideration or not as living beings. In this new organization of the non-woesian biodiversity, I have also included the viruses because they straddle the line between living and non-living. In this sense, we could say that viruses are alive when they infect a cell, as they control the production of new viruses and fulfil the fundamental objective of all living beings, which is none other than to perpetuate the species, but when they are outside the host, they behave as infectious inert entities (Dupré and O’Malley 2009; Gómez- Márquez 2021). It is this dichotomy between living and inert that makes me think 1 3 Global Philosophy (2023) 33:4 Page 3 of 19 4 that we should consider a new category to include viruses within the living things that inhabit our cells, bodies, and ecosystems. Not forgetting that some viruses could also become part of the synthetic organisms world because they can be also created in the laboratory. 2 Life andLiving Beings Where is the borderline between the genuinely living and artificial or synthetic entities? Can viruses be considered as living beings? Is life the A-life? Are synthetic organisms new entities with their own individuality? To find the answers to these and other questions, we first need to have an answer to the fundamental question of biology “what is life”. When we have a working definition of life, we will be able to establish more easily whether this or that entity is really a living being or not. What is life? This is a question without a clear answer because life is a very difficult concept to define. In fact, there is a great controversy among scientists and philosophers of science on this question. There have been many attempts to define life from very different perspectives (obviously a comparative study of this enormous variety of definitions of life is beyond the scope of this article), yet none of the proposed definitions have been universally accepted (Benner 2010; Gómez-Márquez 2021; Mariscal 2021). Some scientists and philosophers of science even argue that life cannot be defined (Cleland 2019) or that seeking a definition is a futile task to understand the origin of life (Szostak 2012). In this context, the comment that E. Koonin (2012) wrote about the complexity of defining life seems to me to be very appropriate: “… although life definitions are metaphysical rather than strictly scientific propositions, they are far from being pointless and have potential to yield genuine biological insights”. On the other hand, we have general theories in physics and chemistry that help us understand the universe, but as far as biology is concerned, there are still no theories of our own that, together with the laws of science and philosophical thinking, help us explain nature. The lack of a general theory underpinning biological knowledge makes more difficult to understand life phenomena and to define what life is. Reflecting on this, it was recently proposed a set of principles, named as the commandments of life, to explain the vital phenomena (Gómez-Márquez 2020). From this theoretical approach, it was proposed a definition of life based on the characteristics common to all living beings. Thus, life is defined as a process that takes place in highly organized organic structures that is characterized by being preprogrammed, interactive, adaptative and evolutionary (Gómez-Márquez 2021). Accordingly, living beings are the system where this vital process takes place. I want to highlight two important points because they are key to determining whether synthetic organisms or artificial life entities are something we can consider as living or not: (i) the consideration of life as a pre-programmed process, with adaptive capacity and the potential to evolve, and (ii) the realization that every living thing is a system of organic nature and, therefore, based on carbon chemistry (whether there is an alternative life form to carbon chemistry is not a fact, it is only a speculation). Global Philosophy (2023) 33:4 1 3 4 Page 4 of 19 3 Natural Versus Non‑natural (Synthetic orArtificial) Life Philosophers debate on the ontological differences between artifacts (an algorithm, a robot, or a genetically modified organism) and natural objects (a living organism). There is one obvious difference between them: their origin. Natural objects come into being without human intervention, whereas so-called artifacts are human-made. In addition, there are other differences between them related to their structure, functionality, and composition. L. Baker defines artifact as “objects intentionally made to serve a given purpose” (Baker 2008) giving importance exclusively to the creator but ignoring something as important as the composition of the object and its structure. From that definition, a robot would be the same as a transgenic organism because both are “objects” constructed for a specific purpose. However, this is not true because a robot is an artificial entity and a transgenic organism is a living being. Adding a different perspective, philosopher Symons (2010) asks if there is any difference between organisms and artifacts and concluded that there is a meaningful difference between both entities, and that this difference involves the character of their individuality. Moreover, he asks whether genetically engineered animals will have different persistence conditions than their wild cousins and concluded that genetically engineered animals are still individuals (Symons 2010). In my opinion, genetically modified organisms do not lose their vital essence, their character as a biological species (a transgenic mouse or tomato remains a mouse or a tomato) even if it has been modified in its genome. However, one fundamental question should be considered in this analysis: When does a genetically modified living being become a synthetic organism different from the one that was initially given its new identity by its creator? Symons examines the paradox of the Ship of Theseus, which raises the question of whether an object that has had all its components replaced remains fundamentally the same object, to resolve the problem of the individuality of artifacts and organisms (Symons 2010). In my opinion, which is not that of a philosopher stricto sensu but that of a professor of Biochemistry and Molecular Biology, the solution to this metaphysical problem is that the artificial object will remain the same. Let us take a photographic camera as an example. When we change the batteries in a camera, it is still the same camera. When we change the memory card or even put in a different lens, it is still the same camera. With all these changes, the inanimate artifact known as a camera has not lost its identity as that camera. In the case of A-life entities such as, for example, a robot, this artifact will remain the same robot, even if all its components are changed, as long as the new components are the same: the robot will look the same (identical structure) and do the same functions; like Theseus’ Ship, the robot is just an inanimate object and does not lose its “artifactual individuality” as long as the replacements are identical. The entities belonging to A-life cannot lose their individuality, their vital essence, because they have never had it. They never were and never will be living beings because they lack all the necessary requirements for it. Any entity belonging to A-life (computer programs or robots) can be massproduced. However, synthetic organisms, being organic in nature, with a functional 1 3 Global Philosophy (2023) 33:4 Page 5 of 19 4 genome, can mutate and generate individuals different from the original specimen. A robot can be an artificially organized, pre-programmed and interactive system, but it is not alive because it is neither organic, nor does it reproduce, adapt, or evolve on its own, without the intervention of its designer, it will always need to be built or programmed by an engineer to do so. On the contrary, in the case of a synthetic organism, when we alter its genetic material, we are altering the heart of its identity as a living being, which is its genome and, therefore, it will no longer be the same organism, although it will still be the same species or the same type of synthetic organism. In other words, a transgenic mouse or tomato will still be a mouse or tomato, but it will not be exactly the same as a wild mouse or tomato. Noteworthy, they will cease to be a mouse or a tomato when the modifications to their genome are so profound that they are unable to hybridize (reproduce) with their wild relatives. Then these organisms will seek a different individuality, giving rise to new species of synthetic organism. What happens to the individuality of organisms that have been modified without manipulating their genome? Nothing would happen, these organisms continue to maintain their individuality. Let’s take the pacemaker as an example. I wear a pacemaker that keeps my heart in shape, but neither my genome nor my brain or other body parts have been altered; consequently, my individuality as a human being has not changed. Organisms that carry a pacemaker, contact lenses, a hip prosthesis, or any other inanimate object, cannot be considered synthetic organisms or members of the A-life world. They do not belong to the new Lithbea domain (see below). The philosopher M. Bedau wrote: “So, to the extent that the essential properties of living systems involve processes like self-organization and evolution, suitably programmed computers will actually be novel realizations of life” (Bedau 2007). However, from my point of view, as I mentioned before, A-life cannot be considered life (at least in the biological sense of the term) because A-life does not meet all the requirements to be considered alive, just as a flight simulator is not a plane or a toy dog is not a dog. An A-life entity is not organic, nor does it have anything equivalent to genetic material with the capacity to express, replicate, adapt, mutate, and evolve in response to environmental stimuli. Furthermore, the structures and functioning of living things can be explained from their evolutionary history, but such explanations are not available for the creatures of A-life because they have no evolutionary history, they always depend on their designer. My conclusion is that A-life entities are artificial and cannot be considered as true living organisms, whereas synthetic organisms are living beings that are not the fruit of the tree of life but the result of the will of their creator. 4 Life‑in‑the‑Border Entities (Lithbes) Lithbes, acronym of life-in-the-border entities, are beings, systems, or realities that we could place on the border between the living and the inert, between the natural and the artificial, between the organic and the inorganic, because they do not meet all the conditions necessary to be considered as truly living beings. Global Philosophy (2023) 33:4 1 3 4 Page 6 of 19 To identify and classify the lithbes, I take as the main criteria their origin (natural, synthetic, or artificial), and the characteristics shared by all living beings (organic nature, high degree of organization, pre-programming, interaction, adaptation, reproduction, and evolution) as defined elsewhere (Gómez-Márquez 2021). Naturally occurring lithbes are those entities that have arisen because of the evolutionary process and are not included within the three woesian tree of life. Artificial and synthetic lithbes are entities that have been manufactured, partially or totally, by humans and, therefore, they are not the consequence of a natural evolutionary process. Consequently, there are two types of lithbes: those of natural origin, which are represented by viruses, and those of synthetic/artificial origin, i.e. human-made, which include synthetic organisms, with all their variants, robots or hard A-life, and algorithms or soft A-life. It is important to note that, while viruses are the result of a natural, and therefore unintentional, evolutionary process, synthetic organisms and artificial life, robots and soft A-life are the total or partial result of the will of the creator who designs them according to a pre-established plan. In addition to their origin, the key distinction between synthetic organisms and representatives of A-life is that the former are cellular and organic entities, fulfilling almost all the characteristics of living beings, except their non-natural origin, while the latter are not organic and do not perform metabolic processes or gene expression, nor are they capable of evolving on their own, without the intervention of the designer. We can find biochemistry and genetics in a synthetic organism, but never, at least for the time being, in a computer program or a robot. 5 Viruses Viruses are acellular infectious agents, intracellular parasites, formed by a macromolecular complex of proteins and nucleic acids. They do not metabolize substances, nor can they reproduce by themselves, grow, or breathe. Outside the cell, viruses do not satisfy the seven characteristics of living things because they are inert particles without any vital activity. In contrast, when viruses infect a cell, they become a sort of living entity because they meet the characteristics common to all living things: in addition to being organic, highly organized and possessing a genetic program, they interact with the host, they reproduce, and they can adapt and evolve because they can mutate, they are alive! Some authors include viruses within the biological entities called biological replicators along with plasmids, organellar DNA, transposons, etc. (Koonin and Starokadomskyy 2016) whereas other scientists classify them as capsid-encoding organisms (Raoult and Forterre 2008). However, viruses differ from all these DNA elements in their ability to infect cells on their own, to interact with the host cellular machinery and to evolve. Their exclusion from the tree of life, even though they played a key role in the history of life most likely from its origins, should be somehow reevaluated. Today virtually no one questions the importance of the virosphere in the evolution of species and ecosystems (Agnati etal. 2022) as well as in shaping the tree of life (Villarreal and Witzany 2010). 1 3 Global Philosophy (2023) 33:4 Page 7 of 19 4 The reason for including viruses as lithbes lies in their live-inert duality and in the fact that they lack cellular structure and are therefore excluded from the woesian domains. They are the only lithbes of natural origin although they could also be created in the laboratory (artificial origin), and eventually be incorporated into any organism due to their infectious capacity. It is certainly a very high risk, with unforeseeable consequences, to release artificial viruses outside the laboratory. Noteworthy, it has been recently reported that the flu virus and the respiratory syncytial virus can fuse together to create a new hybrid virus that can evade human immune system (Haney et al. 2022). This finding shows that viruses from completely different families can combine generating a new pathogen. Is it possible that natural viruses could also be combined with viruses created in the laboratory? The most likely answer is yes, viable viral chimeras could be created with unpredictable ecological and human health consequences. 6 Synthetic Organisms There is no single definition of what a synthetic organism is and very different definitions can be found on the web. Three examples: (i) organisms for which a substantial portion of the genome or the entire genome has been designed or engineered (seen in “Nature portfolio”); (ii) organisms that produce a substance, such as a medicine or fuel, or gain a new ability, such as sensing something in the environment (NHGRI, National Institutes of Health); (iii) an organism that has been synthesized by the human beings (Deplazes and Huppenbauer 2009). They are probably all correct, even if they emphasize different nuances (the genome, industrial application, or the fact that they were created by us). We could add another definition for synthetic organisms: living entities that are not the result of a natural evolutionary process. Here, by synthetic organisms I mean human-made living entities that are based on carbon chemistry. Consequently, physical robots or computer programs are not synthetic organisms, they are entities that belong to A-life (see below). All types of synthetic organisms are organic in nature, highly ordered, have their own metabolism, their own genome, etc., but the fundamental difference with other living things is that they are human-made entities created by modifying other living things whose origin is in nature or by creating them from scratch. According to my proposal (Fig.1), synthetic organisms can be divided into three different types: 1) Genetically Engineered Organisms (GEO), 2) Living Programmable Organisms (LPO), and 3) Artificially Created Cells (ACC). 7 The GEO GEO are organisms whose genome or genetic code has been intentionally altered (engineered) in the laboratory to achieve a specific result. These genomic changes may be aimed at causing a physiological change, producing a specific substance, or altering the genome to investigate its function or to open up new genomic possibilities. Depending on the type of manipulation carried out to create the Global Philosophy (2023) 33:4 1 3 4 Page 8 of 19 synthetic organism, I find three main types of GEO: (i) Genetically Modified Organisms (GMO), (ii) Synthetic Genome Organisms (SGO), and (iii) Codon- Altered Organisms (CAO). GMO are organisms whose genome has been manipulated in the laboratory using recombinant DNA techniques either by the introduction of a foreign DNA from another species (transgenic organisms) or by genome editing (gene-edited organisms). Animals, plants, and bacteria have been used to generate transgenic organisms for purposes related to basic research, food or the production of substances of therapeutic interest (Cartwright 2009). Gene editing may involve deletions, insertions (gene knock-in), silencing (gene knock-out) or repression of specific genes (Khalil 2020). Key among gene-editing technologies is a molecular tool known as CRISPR-Cas9 that allows to remove and insert DNA in the desired locations (Anzalone etal. 2020). It should be noted that the difference between the knock-in organism and the transgenic organism is that in the former, the Fig. 1 Classification of synthetic organisms. If we consider the procedure for constructing synthetic organisms in the laboratory, we can distinguish three different types: (i) Genetically Engineered Organisms (GEO) have altered their natural genome or they have a new genome synthesized in the laboratory. There are three kinds of GEO: GMO, SGO, and CAO. The GMO have incorporated a gene (or genes) from other species becoming a transgenic organism; other GMO consist in organisms with the genome edited either by knock-in (insertion of a sequence in a specific region of the genome) or knockout (delete or inactivate a specific sequence of the genome). The SGO includes all organisms with a synthetic complete genome, i.e. designed and constructed in the laboratory. The CAO have their genetic code altered either because the number of triplets has been modified (taking advantage of the redundancy of the genetic code) or because new triplets have been introduced. (ii) Living Programmable Organisms (LPO) are new forms of life designed by the combination between biology techniques, robotics and artificial intelligence. The first member of this bizarre group of synthetic creatures are the xenobots designed by a special algorithm and constructed from embryonic cells of a frog. Other LPO includes all LPO that have not yet been born but are very likely to start being produced in the future. (iii) Artificial Created Cells (ACC) will include all cells and multicellular organisms synthesized in the laboratory following essentially a bottom-up approach. No cell has yet been made using this strategy, but it is very likely that in the not-too-distant future the goal of making a cell from its components will become a reality 1 3 Global Philosophy (2023) 33:4 Page 9 of 19 4 insertion is directed to a specific locus in the genome, whereas in the transgenic organism, the insertion of the transgene is random. SGO are organisms that have a genome entirely synthesized in the laboratory. In 2010, researchers from the J. Craig Venter Institute (JCVI) announced the first self-replicating synthetic cell known as JCVI-syn1.0 (Gibson etal. 2010). For that purpose, they digitized the genome of the bacterium Mycoplasma mycoides and then synthesized and assembled it invitro. Later on, the JCVI team created the smallest synthetic cell up to that time, M. mycoides JCVI-syn3.0, a minimized version of JCVI-syn1.0 with only 473 genes (Hutchison III etal. 2016). However, this weird bacterium behaved strangely as it grew and divided producing cells with very different shapes and sizes. Interestingly, it was found that when they were added seven genes to JCVI-syn3.0, normal growth and cell division were restored (Pelletier etal. 2021). On the other hand, it was recently reported the creation of the first bacterial genome designed entirely by a computer from the essential genome of C. crescentus (Venetz etal. 2019), although a viable engineered bacterium, named as Caulobacter ethensis-2.0, does not yet exist. Basic research on minimal cells and synthetic genomes should be very useful to understand the evolutionary history of life as well as to bring about new biotechnological applications. CAO are synthetic entities in which the genetic code has been altered, either by changing the number of triplets or by introducing new codons that do not exist in nature. The generation of organisms with a reduced genetic code, avoiding redundancies without losing information, or the introduction of new variants from synthetic nucleotides, is one of the most important challenges for researchers in synthetic biology (Rennekamp 2019). Researchers at the MRC Laboratory of Molecular Biology (Cambridge), redesigned the DNA of Escherichia coli, creating an artificial genome that has an altered genetic code with 61 codons instead of 64 (Fredens etal. 2019), demonstrating that life can operate with a reduced number of synonymous sense codons. Scientists are now creating synthetic organisms with an expanded nucleotide alphabet by making DNA with unnatural nucleotides (Duffy etal. 2020; Nie etal. 2020); these modified DNAs are also called xeno nucleic acids. Remarkably, Romesberg and coworkers have been able to engineer E. coli and create a semisynthetic organism with an expanded genetic code (Zhang etal. 2017). Subsequently, Hoshika etal. (2019) presented the hachimoji DNA and RNA, an eight (hachi-) letter (-moji) genetic system, demonstrating the power of synthetic biology research for developing new synthetic organisms and biotechnological applications alongside understanding how fundamental biological systems work. Researchers are aware of the enormous applications of modifying or expanding the genetic alphabet, although this is not without risk, especially if these organisms were to “escape” from the laboratory. Nature also experiments with variants of the ACGT alphabet. This is the case of the genome of certain phages in which adenine (A) has been replaced by 2-aminoadenine or diaminopurine (Z) generating a DNA with an alternative alphabet (ZTGC) that evades the attack of restriction enzymes (reviewed by Grome and Isaacs 2021). Discoveries like this one, besides showing us once again that nature is full of surprises, expand the possibilities of synthetic biology to design new organisms with modifications in their genetic code. Global Philosophy (2023) 33:4 1 3 4 Page 16 of 19 like because we have an ever-deepening understanding of biology and biotechnological tools are becoming more and more precise. However, we cannot be completely sure what the new organism will be like and, above all, how it will behave. The explanation for this uncertainty lies in the fact that we are creating something new, something that is neither a machine nor the consequence of the evolutionary process, something that while subject to the laws of nature is also subject to the unpredictability of chance or randomness. An example of this unpredictability is the case of xenobots. As I mentioned before, xenobots are very special creatures because they are living machines produced by the combination of artificial intelligence with cellular techniques without genomic manipulation. They can self-assemble, move in groups and sense their environment, etc. and this behaviour was designed to happen more or less like this. What was a big surprise was to see that xenobots could reproduce in a completely new and different way to any animal or plant known to biological science (Kriegman etal. 2021). What would happen if organisms with an altered genetic code were released into the wild? What would happen if a pathogenic virus or bacterium made in a laboratory could infect human populations? Could a pandemic occur with millions of deaths? Could the massive cultivation of GM crops eventually displace wild species or have negative consequences for the environment? What would happen if xenobots or other similar organic entities with the ability to reproduce were to invade our environment? and so on and so forth. We do not really know the answer to these and other questions and therefore we have to balance scientific progress with safety and prudence, without forgetting the ethical aspects that we as civilized societies should never forget. The research and analyses of the new advances related to synthetic biology and artificial life offers a new perspective on life, poses intriguing new challenges, and opens new avenues of thought with important philosophical implications. For the first time we are playing God, creating new species, and altering the natural course of the evolutionary process. Beyond generating new organisms in the laboratory for purposes related to industry, health or basic research, there is no overarching goal in this whole biological revolution. Perhaps we should reflect on where we want to go and whether we should set limits that prevent us from making abnormal organisms or go beyond the limits of more traditional ethics. The unpredictability of the unknown should make us cautious about making new synthetic organism, especially if these new entities are released (or “escape”) into the outside world. Acknowledgements I would like to thank Dr. Miguel López (CIMUS-USC), Dr. Mariluz González (Faculty of Biology-USC) and Dr. Pepe Bella (Faculty of Sciences, Genetics-UAM) for their recognition and support. I dedicate this work to my beloved granddaughter Daniela. Funding Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature. Declarations Conflict of interest The author declares no conflict of interest. 1 3 Global Philosophy (2023) 33:4 Page 17 of 19 4 Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http:// creat iveco mmons. org/ licen ses/ by/4. 0/. 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