Gottfried Wilhelm Leibniz (1646-1716), esprit universel et promoteur des sciences, est à la fois philosophe, mathématicien et diplomate. Passionné par le langage et le monde, il cherche en encyclopédiste à rendre compte de toutes les inventions et de tous les savoirs. Lors de son séjour à Paris - quatre années pendant lesquelles il rencontre Huygens et étudie Pascal -, il conçoit, en 1675, un projet original de création d'académies, plusieurs spectacles de divertissement. Imaginant des mises en scène ou cherchant à (...) régler la direction des casinos, le philosophe raisonne toujours en stratège. Pour lui, tout dans le monde est combinatoire. D'où son amour pour les jeux, qui associent signes et réseaux. Ainsi se dévoile une Europe savante et inventive qui anticipe notre monde relationnel et numérique. (shrink)

Although researchers studying human speech recognition (HSR) and automatic speech recognition (ASR) share a common interest in how information processing systems (human or machine) recognize spoken language, there is little communication between the two disciplines. We suggest that this lack of communication follows largely from the fact that research in these related fields has focused on the mechanics of how speech can be recognized. In Marr's (1982) terms, emphasis has been on the algorithmic and implementational levels rather than on the (...) computational level. In this article, we provide a computational-level analysis of the task of speech recognition, which reveals the close parallels between research concerned with HSR and ASR. We illustrate this relation by presenting a new computational model of human spoken-word recognition, built using techniques from the field of ASR that, in contrast to current existing models of HSR, recognizes words from real speech input. (shrink)

Although researchers studying human speech recognition (HSR) and automatic speech recognition (ASR) share a common interest in how information processing systems (human or machine) recognize spoken language, there is little communication between the two disciplines. We suggest that this lack of communication follows largely from the fact that research in these related fields has focused on the mechanics of how speech can be recognized. In Marr's (1982) terms, emphasis has been on the algorithmic and implementational levels rather than on the (...) computational level. In this article, we provide a computational-level analysis of the task of speech recognition, which reveals the close parallels between research concerned with HSR and ASR. We illustrate this relation by presenting a new computational model of human spoken-word recognition, built using techniques from the field of ASR that, in contrast to current existing models of HSR, recognizes words from real speech input. (shrink)

We argue that artificial networks are explainable and offer a novel theory of interpretability. Two sets of conceptual questions are prominent in theoretical engagements with artificial neural networks, especially in the context of medical artificial intelligence: Are networks explainable, and if so, what does it mean to explain the output of a network? And what does it mean for a network to be interpretable? We argue that accounts of “explanation” tailored specifically to neural networks have ineffectively reinvented the wheel. In (...) response to, we show how four familiar accounts of explanation apply to neural networks as they would to any scientific phenomenon. We diagnose the confusion about explaining neural networks within the machine learning literature as an equivocation on “explainability,” “understandability” and “interpretability.” To remedy this, we distinguish between these notions, and answer by offering a theory and typology of interpretation in machine learning. Interpretation is something one does to an explanation with the aim of producing another, more understandable, explanation. As with explanation, there are various concepts and methods involved in interpretation: Total or Partial, Global or Local, and Approximative or Isomorphic. Our account of “interpretability” is consistent with uses in the machine learning literature, in keeping with the philosophy of explanation and understanding, and pays special attention to medical artificial intelligence systems. (shrink)

Computational modelling has proven to be a valuable approach in developing theories of spoken-word processing. In this paper, we focus on a particular class of theories in which it is assumed that the spoken-word recognition process consists of two consecutive stages, with an `abstract' discrete symbolic representation at the interface between the stages. In evaluating computational models, it is important to bring in independent arguments for the cognitive plausibility of the algorithms that are selected to compute the processes in a (...) theory. This paper discusses the relation between behavioural studies, theories, and computational models of spoken-word recognition. We explain how computational models can be assessed in terms of the goodness of fit with the behavioural data and the cognitive plausibility of the algorithms. An in-depth analysis of several models provides insights into how computational modelling has led to improved theories and to a better understanding of the human spoken-word recognition process. (shrink)

(2013). Open Access Digital Data Sharing: Principles, Policies and Practices☆. Social Epistemology: Vol. 27, No. 1, pp. 47-67. doi: 10.1080/02691728.2012.760663.

Constructive Neutral Evolution is an evolutionary mechanism that can explain much molecular inter-dependence and organismal complexity without assuming positive selection favoring such dependency or complexity, either directly or as a byproduct of adaptation. It differs from but complements other non-selective explanations for complexity, such as genetic drift and the Zero Force Evolutionary Law, by being ratchet-like in character. With CNE, purifying selection maintains dependencies or complexities that were neutrally evolved. Preliminary treatments use it to explain specific genetic and molecular structures (...) or processes, such as retained gene duplications, the spliceosome, and RNA editing. Here we aim to expand the scope of such explanation beyond the molecular level, integrating CNE with Multi-Level Selection theory, and arguing that several popular higher-level selection scenarios are in fact instances of CNE. Suitably contextualized, CNE occurs at any level in the biological hierarchy at which natural selection as normally construed occurs. As examples, we focus on modularity in protein–protein interaction networks or “interactomes,” the origin of eukaryotic cells and the evolution of co-dependence in microbial communities—a variant of the “Black Queen Hypothesis” which we call the “Gray Queen Hypothesis”. (shrink)

Several approaches to clinical ethics consultation (CEC) exist in medical practice and are widely discussed in the clinical ethics literature; different models of CECs are classified according to their methods, goals, and consultant’s attitude. Although the “facilitation” model has been endorsed by the American Society for Bioethics and Humanities (ASBH) and is described in an influential manual, alternative approaches, such as advocacy, moral expertise, mediation, and engagement are practiced and defended in the clinical ethics field. Our Clinical Ethics Center in (...) Paris was founded in 2002 in the wake of the Patients’ Rights Act, and to date it is the largest center that provides consultation services in France. In this article we shall describe and defend our own approach to clinical ethics consultation, which we call the “Commitment Model,” in comparison with other existing models. Indeed commitment implies, among other meanings, continuity through time, a series of coherent actions, and the realization of important social goals. By drawing on a recent consultation case, we shall describe the main steps of our consultation procedure: interviews with major stakeholders, including patients and proxies; case conferences; and follow up. We shall show why we have chosen the term “commitment” to represent our approach at three different but interrelated levels: commitment towards patients, within the case conference group, and towards society as a whole. (shrink)

The counterfactual and regularity theories are universal accounts of causation. I argue that these should be generalized to produce local accounts of causation. A hallmark of universal accounts of causation is the assumption that apparent variation in causation between locations must be explained by differences in background causal conditions, by features of the causal-nexus or causing-complex. The local account of causation presented here rejects this assumption, allowing for genuine variation in causation to be explained by differences in location. I argue (...) that local accounts of causation are plausible, and have pragmatic, empirical and theoretical advantages over universal accounts. I then report on the use of presheaves as models of local causation. The use of presheaves as models of local variation has precedents in algebraic geometry, category theory and physics; they are here used as models of local causal variation. The paper presents this idea as stemming from an approach using presheaves as models of local truth. Finally, I argue that a proper balance between universal and local causation can be assuaged by moving from presheaves to fully-fledged sheaf models. (shrink)

Νέα ανάγνωση των επιγραφών που αφορούν τις ιερές αγροικίες του Απόλλωνα στη Δήλο και τη Ρήνεια. Α. Το είδος των επιγραφών επιβάλλει περιορισμούς στην ερμηνεία τους : δεν μπορούν να μας πληροφορήσουν ούτε για τη θέση των αγροικιών αλλά ούτε και για τη μορφή τους. Το γεγονός ότι υπάρχουν δεν πρέπει να μας κάνει να υποτιμήσουμε την σπουδαιότητα των ιδιωτικών αγροκτημάτων για τα οποία δεν διαθέτουμε κανένα παρόμοιο αρχείο. Β. Το έδαφος της Δήλου δεν ήταν λιγότερο πλούσιο από αυτό της (...) Ρήνειας και δεν είχε αποκλειστικό προορισμό την κτηνοτροφία : η αποκατάσταση της ID 452, 16-32 σε σχέση με την ID 467 βεβαιώνει την ύπαρξη ενός αμπελώνα στα Επισθένεια. Η έλλειψη μυλώνα στις αγροικίες της Δήλου δεν αποδεικνύει με κανένα τρόπο την απουσία καλλιέργειας δημητριακών αλλά πρέπει να συσχετισθεί με τον αριθμό των ατόμων που ζούσαν στις αγροικίες. Ενα μικρό ομοιογενές σύνολο κιστοφόρων τετραδράχμων της εποχής των Ατταλιδών είχε αποδοθεί, σε ένα πρόσφατα δημοσιευμένο corpus, στις Σάρδεις και τα Σύνναδα. Προσπαθούμε να αποδείξουμε ότι θα έπρεπε να ακολουθήσουμε ένα διαφορετικό συλλογισμό και τα νομίσματα αυτά να αποδοθούν σε τέσσερεις διαφορετικές πόλεις. Οι πόλεις αυτές θα μπορούσαν να είναι η Διονυσούπολις, η Βλαύνδος, η Λυσιάς ή τα Συννάδα και μία τέταρτη της οποίας η ταυτότητα παραμένει αβέβαιη. Βρισκόμαστε στη Φρυγία και προβληματιζόμαστε για τους λόγους ύπαρξης αυτών των σύντομων νομισματοκοπών. (shrink)

Withdrawing Artificial Nutrition and Hydration in the neonatal intensive care units has long been controversial. In France, the practice has become a legal option since 2005. But even though, the question remains as to what the stakeholders’ experience is, and whether they consider it ethically appropriate. In order to contribute to the debate, we initiated a study in 2009 to evaluate parental and health care professionals perspectives, after they experienced WAHN for a newborn. The study included 25 cases from 5 (...) different clinical neonatology departments. We interviewed both the parents and some of the HCP who cared for the baby, at least 6 months after this latter deceased. We proceeded through in-depth individual qualitative interviews. Content was analyzed for themes and patterns that emerged from the data. Some parents expressed that WANH offered an opportunity to the family to spend a few demedicalized days with the baby before she dies, without any tubes and machines, and to be well supported by the HCP during this palliative stage. But others evaluated the practice in retrospect as a terrible ordeal. All said that, at least, the time of waiting for death to ensue should not last too long. After a few days, it becomes unbearable because of the transformation of the baby’s appearance and because they, as parents, began to wonder if she was not dying from starvation rather than from her initial disease. An important proportion of HCP also expressed some kind of ethical unease. This was due to the psychological violence involved in the decision for a human being to stop feeding a little one, and also to the difficulty to deal with the fundamental intention behind the decision of WANH: indeed, could it be claim that it does not presuppose the intention of provoking the infant’s death? The discussion focuses on the point to know if WANH can be considered as a source of progress from an ethical point of view, particularly in comparison with earlier practices—that in France could involve active euthanasia by lethal injection. We argue that when HCP are merely focused on avoiding that WAHN could be construed as a way of intending to hasten the baby’s death, the practice is at risk to be implemented in a way that becomes ethically counterproductive. Focusing on this intention easily distract the clinical teams from what should be their ultimate concern, namely the baby’s comfort during the dying process, as well as the support owned to her parents. To conclude, we suggest that the ethical priorities, when WANH is decided, should be the support due to the patient and her family on the one hand, and, on the other hand to implement it in such a way that at least the baby seems to have died of her initial disease and never of starvation. This means that HCP have a duty to control the timing of death, even though this might be incompatible with the worry to avoid the intention of hastening the baby’s death. (shrink)

Comment l’art vient-il aux personnes, aux objets, aux activités? Comment passe-t-on d’une activité quelconque à un art, d’un simple artefact à une oœuvre et d’un praticien à un artiste? C’est cette opération qu’explore ce livre, sous le nom d’« artification » : un déplacement durable et collectivement assumé de la frontière entre art et non-art. Conditions pratiques, techniques, sémantiques, juridiques, institutionnelles, organisationnelles... Les enquêtes réunies ici explorent ces différentes dimensions avec les outils de la sociologie pragmatique, attentive à la matérialité (...) des actions observées en situation. Le lecteur circulera ainsi de la danse hip-hop à la photographie, du graf aux métiers d’art, de l’art naïf à l’art brut, des arts primitifs au théâtre, du cirque à la magie, de la typographie au cinéma, de la mode aux objets de culte et de la bande dessinée au patrimoine. Et c’est au terme de ce petit voyage en artification qu’il aura enfin réponse, précisément, à la question : quand y a-t-il art? (shrink)

This article reports on the methodology for setting the Mexican User Satisfaction Index for Social Programs as tested in seven national social programs. The evaluation is based on Structural Equation Modeling. How satisfaction takes the central place of the SEM, which postulates its causes and effects, contributes to the increased validity and reliability of satisfaction indicators that allow benchmarking between social programs. The MUSI model is an adaptation of the American Customer Satisfaction Index model. The MUSI methodology includes qualitative and (...) quantitative techniques. The estimation model is by the Partial Least Squares. In each of the seven social programs, no statistical evidence was found to reject the main relationships postulated by the ACSI’s model: that Perceived Quality impacts Satisfaction, and Satisfaction impacts Trust. The improvement opportunity areas were also identified for each program. These results give valid and reliable feedback to public policies. (shrink)

The French bioethics laws of 1994 contain the principles of the anonymity and non commodification of all donations of body parts and products including gametes in medically assisted reproduction. The two revisions of the law, in 2004 and 2011 have upheld the rule. In view of the latest revision process, the French government organized a large public consultation in 2009. Within the event a “consensus conference” was held in Rennes about different aspects of assisted reproduction. In what follows we shall (...) first describe the anonymity clause for gamete donations in the French law and the debates surrounding it. We shall then analyse the procedure used for the 2009 public consultation and the related consensus conference, as well as its upshot concerning the anonymity doctrine. In this respect we shall compare the citizens’ own recommendations on the gamete anonymity issue and its translation in the consultation’s final report drafted by a philosopher mandated by the organizing committee. Whereas the final report cited some fundamental ethical arguments as reason for upholding the provisions of the law—most notably the refusal of the ‘all biological’ approach to reproductive issues—citizens were more careful and tentative in their position although they also concluded that for pragmatic reasons the anonymity rule should continue to hold. We shall argue that the conservative upshot of the public consultation is due to some main underlying presuppositions concerning the citizens’ role and expertise as well as to the specific design of the consensus conference. Our conclusion will be that public consultations and consensus conferences can only serve as an empirical support for devising suitable bioethics norms by using second-order normative assumptions. (shrink)

La question des productions agricoles à Délos a fait l'objet d'un intérêt renouvelé ces dernières années : les vestiges d'aménagements agricoles, les fermes et les inscriptions ont été réétudiés. Une des questions en suspens concernait la destination des pressoirs situés dans la ville : produisaient-ils du vin ou de l'huile? En 1997, la fouille d'une installation de pressurage située dans le Quartier du théâtre a permis de démontrer qu'il s'agissait d'une huilerie. Aménagée au début du Ier s. av. J.-G, elle (...) comportait deux pressoirs à levier, trois récipients de décantation et six pithoi de stockage. Elle était installée dans une maison dont les origines remontaient au Ve s. av. J.-C. et qui, depuis lors, avait connu plusieurs remaniements. Outre des données nouvelles sur l'histoire du quartier, cette fouille apporte des éclaircissements sur la végétation des îles proches, sur les variétés d'olives cultivées et sur l'économie de la fin de la période hellénistique. Ces realia rééquilibrent la documentation tirée des inscriptions en faisant une certaine place à l'oléiculture au moins aux IIe et Ier s. av. J.-C. (shrink)

Traditional epistemic and doxastic logics cannot deal with inconsistent beliefs nor do they represent the evidence an agent possesses. So-called ‘evidence logics’ have been introduced to deal with both of those issues. The semantics of these logics are based on neighbourhood or hypergraph frames. The neighbourhoods of a world represent the basic evidence available to an agent. On one view, beliefs supported by evidence are propositions derived from all maximally consistent collections evidence. An alternative concept of beliefs takes them to (...) be propositions derivable from consistent partitions of one’s inconsistent evidence; this is known as Schotch-Jennings Forcing. This paper develops a modal logic based on the hypergraph semantics to represent Schotch-Jennings Forcing. The modal language includes an operator U(φ1,…,φn;ψ)\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$U(\varphi _1, \ldots, \varphi _n;\psi )$$\end{document} which is similar to one introduced in Instantial Neighbourhood Logic. It is of variable arity and the input formulas enjoy distinct roles. The U operator expresses that all evidence at a particular world that supports ψ\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\psi $$\end{document} can be supported by at least one of the φi\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\varphi _i$$\end{document}s. U can then be used to express that all the evidence available can be unified by the finite set of formulas φ1,…,φn\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\varphi _1,\ldots, \varphi _n$$\end{document} if ψ\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\psi $$\end{document} is taken to be ⊤\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\top $$\end{document}. Future developments will then use that semantics as the basis for a doxastic logic akin to evidence logics. (shrink)

A commentary on “The Ethics of Anonymous Gamete Donation: Is There a Right to Know One's Genetic Origins?” by Inmaculada de Melo‐Martín, in the March‐April 2014 issue.

Qu'est-ce qu'un enseignement? Une pensée? Qu'autorisent-ils? À la suite de Claire Brunet, Sandra Laugier et Frédérique Ildefonse qui dirigent ce volume, d'anciens étudiants, aujourd'hui chercheurs renommés ou plus discrets, creusent à travers le sillon de leur discipline ce que leur a permis l'enseignement de leur maître commune à l'École normale supérieure. Les amitiés intellectuelles s'y joignent. Ce que l'on appelle communément communication dans le monde académique devient texte. Tous, en creux, décrivent l'influence d'un enseignement, la liberté qu'il permet à (...) des esprits pour s'épanouir et nous laissent découvrir un portrait intellectuel d'une grande originalité. La pensée de Claude Imbert, philosophe, logicienne, longtemps directrice du département de philosophie de la rue d'Ulm, n'a pas les honneurs médiatiques français en sus des "académiques" d'usage. S'y prêterait-elle? Pourtant, la philosophe française est depuis plus de vingt ans lue, reçue et écoutée dans les universités du monde entier, des Etats-Unis à la Chine en passant par l'Amérique du Sud. Tous les textes rassemblés ici, comme autant de variations, sans jamais le dire, souhaitent contribuer à la reconnaissance de l'oeuvre. Un inédit "Ne rien oublier et tout apprendre" de la philosophe et un texte de Pascalle Monnier, écrivain, accompagnent le volume."--Page 4 of cover. (shrink)

Cette monumentale etude d'Olivier Brunet reste assurement la reference majeure concernant la philosophie esthetique de David Hume (1711-1776). Les questions et les problemes relatifs au "beau", au "jugement de gout" ne se presentent pas, dans l'oeuvre du penseur ecossais, de maniere detachee, isolee du reste de sa philosophie. C'est l'un des merites d'Olivier Brunet d'avoir montre que les reflexions de Hume sur l'esthetique sont inseparables de ses concepts essentiels. Ainsi, lorsque l'on recherche les racines conceptuelles de la definition (...) du "jugement de gout" chez Hume, on retrouve les memes jalons qui structurent son ethique. En morale comme en esthetique, les "passions" jouent un role central et sont liees - chacune a leur facon - a l'"utile"; celui-ci participe a la cause du "plaisir esthetique" qui est lui-meme etroitement lie a la fameuse "sympathie", sentiment desinteresse reglant le comportement moral tel que definit par Hume. La boucle est-elle bouclee? Loin de la, car l'esthetique humienne serait encore impossible a saisir, sans y considerer l'usage que le fondateur de l'empirisme moderne fait de ses concepts-phares : la croyance, le scepticisme, l'experience, l'habitude. Olivier Brunet, enfin, ne borne pas son etude a la philosophie esthetique de Hume. De tres belles pages sont consacrees a la relation personnelle que ce dernier entretenait avec l'art, ainsi qu'aux vertus sociales, psychologiques et morales que l'auteur du Traite de la nature humaine deduisait de la contemplation du Beau. (shrink)

Punctuated by joy, disappointments, and conflicts, research evaluation constitutes an intense, emotional moment in scientific life. Yet reviewers and research institutions often expect evaluations to be conducted objectively and dispassionately. Inspired by the scholarship describing the role of emotions in scientific practices, we argue instead, that reviewers actively define, display and manage their emotions in response to the structural organization of research evaluation. Our article examines reviewing practices used in the European Research Council’s (ERC) Starting and Consolidator grants and in (...) the Marie Skłodowska-Curie Action’s (MSCA) Individual Fellowships. These two European funding mechanisms offer different perspectives on the organization of grant evaluation. We conducted interviews with review panel members and analyzed various institutional documents. By drawing on the sociological concepts of feeling rules and emotional work, we demonstrate that reviewers define rules concerning how emotions should be experienced and expressed to ensure the proper functioning of evaluation, and that reviewers experience the need to actively regulate their emotions to comply with these rules. We present four feeling rules concerning the experience and expression of: (1) excitement for novelty during individual evaluation; (2) respect for others’ opinions and the absence of anger in review panels; (3) attentiveness and interest, which are seen as missing in online evaluations. Reviewers also expect ERC candidates to (4) avoid pride and manifest modesty during interviews. These rules demonstrate that proposal peer review is governed by emotional norms, and show the influence of organizational settings and moral requirements on research evaluation. (shrink)

In the 1970s, R.D. MacElroy coined the term ‘extremophile’ to describe microorganisms that thrive under extreme conditions (MacElroy 1974). This hybrid word transliterates to ‘love of extremes’ and has been studied as a straightforward concept for the past 40 years. In this paper, we discuss several ways the term has been understood in the scientific literature, each of which has different consequences for the distribution and importance of extremophiles. They are, briefly, Human-Centric, at the Edge of life’s habitation of Morphospace, (...) by appeal to Statistical Rarity, described by Objective Limits, and at the Limits of Impossibility for metabolic processes. Importantly, these concepts have co-existed, unacknowledged and conflated, for decades. Confusion and equivocation threaten to follow from the wildly varied inclusion or exclusion of organisms as extremophiles depending on the concept used. Under some conceptions, entire kinds of extremophiles become meaningless. Since our understanding of how life works is shaped by what we take to be its extremes, clarifying extremophily is key for many large-scale projects in biology, ecology, biotechnology and astrobiology. In what follows, we proceed as if a noncontroversial account of life is possible and that it is possible to find complex chemistry in the Universe that is similar enough to Life on Earth such that both may be considered instances of ‘life’ (but see Mariscal & Doolittle 2018). We raise, but do not address, the questions of whether the distribution of Life on Earth is representative of what we may find elsewhere in the Universe, whether the same kinds of extremophiles would exist given a replay of the tape of life. Additionally, each of these concepts assumes life based on some sort of biochemistry in this universe, effectively setting aside claims made by some artificial life proponents that their digital organisms are genuine examples of life (Langton 1989, Ray 1995). On the distinction between extremophilic and extremotolerant, we note that all accounts accept the latter as a broader category than the former, since ‘phily’ means love and tolerance is a prerequisite for love under any conception. Indeed, there will be many extremely impoverished environments where tolerance is the only option and thriving is precluded, e.g. Bacillus marismortui was extracted and grown from 250-million-year-old salt crystals in the Permian Salado Formation in an inactive yet persistent state (Vreeland et al., 2000). We also note that extremophily, as a functional category, is potentially applicable at many levels of the biological hierarchy. Extremophily at one level does not necessarily extend to higher and lower levels. For instance, a microorganism in isolation might be quite intolerant to certain environmental conditions yet flourish when subjected to the same conditions as a community or natural biofilm. Alternatively, a protein molecule might be quite stable or active under certain conditions even if the optimal environment for the organism containing it is far more mesophilic. There is an industry of artificially selecting organisms and proteins to adapt to extreme environments (see van den Burg & Eijsink 2002), providing some justification to consider ‘functioning at extremes’ as a worthwhile category of investigation. Finally, we also note certain physico-chemical ranges are rarely considered with respect to extremophily – timespan, size, nutrient availability (Hoehler & Jørgensen 2013), etc. – as well as some biological parameters – abundance, isolation, competition, etc. Perhaps scientific interest must also come into play as to the reason these criteria are not considered relevant. We return to this issue later. In the next section, we give five definitions of extremophily, show their benefits, drawbacks, and unintended yet unavoidable consequences. These arguments are summarized in Table 1 and represented visually in Figures 1 and 2. Given research on polyextremophiles, it seems Figure 2 is a more plausible representation of the state of current knowledge than Figure 1 (Harrison et al. 2013). Life is patchily distributed across various dimensions, which may reflect its contingent history, poor sampling, or (perhaps) fundamental limits. Figure 3 shows the conceptual flowchart for all of these views. In the following section, we take a step back to ask whether we should choose between these definitions and how such a judgment could be made. We argue for a limited pluralism, in which some, but not all, of the concepts are acceptable relative to certain practical and theoretical aims. (shrink)

Les auteurs "font le point sur des concepts fondamentaux: éducation, enseignement, connaissance, art, science, pédagogie".