Defining Life as a Semiotic Phenomenon
Cybernetics and Human Knowing
vol.5, Nr. 1 S.3
Abstract: The paper investigates a semiotic conception of life. As a notion or general idea of life it is seen as a member of a set of definitions bordering science proper and philosophy of nature, here called ontodefinitions. The received view of definitions in science (according to which definitions of life are virtually non-existent or meaningless to pursue) is criticised, and the semiotic notion of life is related to the emergent character of a simple living system. Defining life as biosemiotic processes seems to imply the emergence of functionality as a kind of 'biological meaning' in the physical world. The relevance of definitions is context- dependent, and one such context is Artificial Life (AL) research. A 'strong version' of Artificial Life claims it possible to synthesize and thus realize life computationally or by other means. If life should be defined in terms of semiotic processes intrinsic to nature, then semiosis must be required to take place in any system that realizes life.
Introduction: Life and every thing
"Can biology explain life?"— One should hope so if one believes in the very programme of that science. "But what does it mean to explain? Can life really be explained?" — Well, not really, I think. Let me explain what I mean, though it may take some time. Biology has not monopoly over the concept of life. No way. There is a tension between the following four statements that I hold (with some qualifications) to be true:
1. Science is rooted in everyday practice and knowledge, and is a refinement and development of that form of knowledge. There is continuity between scientific and non-scientific everyday forms of knowledge (this was for instance Niels Bohr's point about physics).
2. Science should make us able better to understand the world we live in. That world is complex, and, as a pragmatic necessity, we need division of work between various sciences. A complex world is explained (partly, incompletely, and fallible) by a complex of sciences. In the biology section of natural science, life is explained as a natural phenomenon.
3. Life is something good, something we as human beings prefer for the dead state of things. Life is not simply biochemistry, life is also what could be a good life for you and me. A normative concept.
4. Biologic life just happen to be there, as a causal evolutionary product; it was not created for the joy of mankind or the good of Gaia, it simply is.
The tension is made by abstracting from the normative dimension of life, taken as a methodological necessity in the natural sciences. Something is left out. What is left out is the fact that the good and the bad things are just as much a part of nature as are the heavy and light things, or the living and dead things, or even the 'dull' inert and the experiencing things .
What is left out is the fact that even though biology in the 20th century has been extremely successful in explaining the chemical machinery of life, that very machinery is not just purely 'mechanical' in nature. And even if we consider life—or let s say just a single living cell—to be a machine, this has not in any deeper sense explained the nature of biologic life, because the very notion of a machine—that artefact or product of human intentional work by which we extend not only our arms and legs but also our mental capacities—is not in itself a guarantee for achieving a reduction of the complex and contingent to the simple and lawful.
There are many forms of explanation. If explanation is a way to make one's knowledge of the causes of things manifest, then the various forms of explanation correspond to various forms of knowledge (and power) in relation to things in nature, things in the mind, and things in the social realm which are not 'things' at all, but relations between minds, signs and things.
By 'explaining life', we transform life as a vague, phenomenological concept of man’s life-world into a scientific concept, because in contrast to everyday language and its manifold meanings of the word 'life' with all their ambiguities, metaphoric connotations and complex significations, life in the natural sciences has become categorized as either social life (which is more often spoken of as social relations, power relations, etc.), psychic life (studied as consciousness, cognition, emotion, perception, and mental or representational concepts) or biologic life. To educated people in a modern society, the biologic category is the main locus of meaning of the term life, probably because of the widespread acceptance that biology is the central science of life in the most general and original sense of that phenomenon.
The fact that an everyday concept of life is richer than the biologic concept of life (in the sense of a greater semantic flexibility and its encompassing character of embracing normative, emotional, sacred, and other aspects of life) may lead us to pose a contra-factual question: Could other notions of life have become basic for biology had it not been developed in the shadow of a hegemony of a mechanicist ideal of science during the l9th and 20th centuries; i.e., could life have become conceived of as something different from merely complex organizations of material particles and their energetic relations?
Contra-factual questions in history may be pursued through thought experiments, and we can offer a philosophical experiment by looking at biologic life in way that is quite unusual, at least if one's preferred paradigm is molecular biology.
So we shall ask: Can life be defined as a semiotic phenomenon, that is, as something which is strongly connected with the subject matter of the science of signs? That science, semiotics, was once considered to deal exclusively with linguistic systems of signification used by humans in their social and psychic life. But if life—in a biologic sense as 'organic life, or organisms, or cells and systems of cells and systems of systems of cells, etc.—is a semiotic phenomenon from its very start, then biosemiosis (biologic production, transmission and interpretation of signs) was here from the very start of life on Earth from at least 3800 millions year ago. No matter whether a preferred general notion of life is a molecular, a functional, an evolutionary, or a semiotic one, let us first ask: What does it really mean to have a general scientific notion (or idea, definition, paradigmatic understanding) of such a general phenomenon as life? What work do such notions do within a scientific paradigm?
We need a broader view of the specific cognitive role of various kinds of general conceps in science, encompassing how scientists interact with and comprehend the objects of their field, including objects of the most general kind. Even though science and metaphysics are distinct enterprises, there is definitions of the most general kinds of objects of the special sciences, e.g. definitions of matter life, psyche, consciousness, culture, sociality etc. I have invented the word ontodefinition as a term for the integrative but often vague and implicit character of these notions within a given scientific paradigm—and for the theoretical attempts to descrlbe more explicitly these very broad ontological categories. The explanatory role of ontodefinitions is often only implicit.
Ontodefinitions are certain very broad categories—such as matter, life, mind, or society — which are not simply denoting huge phenomenologies in a vague manner; in addition they refer to the categories of the so-called modern scientific world picture. The ontodefinitions of which I shall only consider the concept of life, are very basic for the paradigmatic character of the scientific activity. They belong to the metaphysical component of a disciplinary matrix in Thomas Kuhn’s sense. They are somehow mixed explanations and definitions. They define what scientists are looking for. Thus they constitute what is relevant and what entities experiments should deal with. At the same time, they provide a basic scheme of understanding of the very nature of these objects, i.e., they convey an explanatory story of some kind, even an implicit one.
The ontodefinitions, if explicated, are not considered by the scientists to be important or to have anything to do with everyday experimental research. Biologists are typically reluctant to define life in explicit terms; nonetheless, distinct notions of life exist within distinct paradigms of contemporary biology. They have a role in the quest to understand life as a coherent emergent phenomenon within the evolutionary world picture, as pursued in traditional biology or within one of the 'sciences of complexity': the interdisciplinary field of Artificial Life, which has brought some attention to the idea that life is an intrinsically semiotic phenomenon (even though instead of 'semiotic', the term 'informational' is more often used).
Within Artificial Life, with its agenda of trying to study 'life-as-it-could-be' (not simply life-as-we-know-it in its Earthly instances), focus is put on the 'natural' generation (or computer simulation) of complex objects. The field emphasizes emergent phenomena. Typically, one can identify two levels of interpretation of an AL model, the lower level's pre-specified rules for local interactions (the generalized genotype, or G-TYPE, and the global level which exhibits a structural or behavioral P-TYPE (generalized phenotype) that emerges as a result of non-linear interactions, and thus, one may even study the "important feedback mechanism between levels in such systems".
The basic promise of Artificial Life research is to construct completely new and bona fide forms of life (software, hardware and wetware forms) in order to overcome the fundamental handicap of biologists. The handicap is that they basically know only one particular instance of life, life on earth, which is fundamentally "the same” form of life on the biochemical level, governed by the same mechanisms of inheritance, the same types of metabolic patterns, etc. (Langton 1989).
By constructing new instances of life, AL research promise to be able to explain or understand what is universally true about life and what is simply contingent upon the particular way life evolved on Earth (e g, we might extend the notion that all life require cells with DNA and RNA to a notion of life as component systems containing partial self-descriptions which may or may not be based on an organic chemistry of carbon chain molecules).
However, the presupposition that traditional biology has failed in giving a universally definition of life, seemingly accepted by a majority of biologists, is misleading, based on wrong premises. Biologists have taken the Aristotelian notion of a definition for given, in which something is defined ('by genus and species') as a member of a class (here: living beings) if and only if it shares with the other members a permanent set of essential (necessary and sufficient) properties that can be listed and checked (e.g., organization, nutrition, growth, development, reproduction, irritability, susceptibility to illness and death).
Such a conception of a definition of life leads to problems, and these problems (vagueness, special exceptions, etc.) have led biologists to think that in biology, we cannot generally define life. This is in conflict with the intuition that all life (on Earth) do share fundamental properties. This intuition is well grounded in biochemistry. The problem is not just to define life; this has already been done implicitly by 20th century biology. One must grasp the nature of such a definition, its cognitive role, and its relation to the notion of emergence.
The standard view
The view that defining life is a futile endeavour is very common among biologists. Most scientists are very sceptical toward attempts to make clear definitions of living beings They simply assert (with some justification) that a definition is of no use in solving the experimental puzzles of normal research. Definitions of life are seldom discussed in depth or even mentioned in biology textbooks or dictionaries, a reflection of the general sceptical and empiricist attitude toward what is taken as merely thoretical or metaphysical speculation in contrast with the "facts" of experimental research. A remark made by Ernst Mayr is representative for this attitude: "Attempts have been made again and again to define 'life'. These endeavours are rather firtile since it is now quite clear that there is no special substance, object, or force that can be identified with life.
This reflects the typical stance among biologists. The central assumptions "the standard view of the definition of life” (SVDL), which is 'the received view' most branches of biology, are the following:
I . Life as such cannot be defined, thus a clear definition is missing.
II. The question of defining life is not important for biology.
III.However, living processes may be defined, or at least approximately demarcated from inorganic processes through a list of characteristic properties (non-essentialism)
IV.Difficulties in delimiting such a set of properties are recognized, but are not considered to be serious. Particular living beings may not hold all properties given, so the list may not be a list of necessary and sufficient properties; it may be more vague or redundant.
V. Even though life is a physical phenomenon, biology deals with systems of such a vast complexity that we cannot in practice hope to reduce it to physics. Should we list the crucial properties of living processes, then complexity, organization, and genuine biological ones such as self-reproduction and metabolism would be inevitable.
The central claims are (I) and (II), and most biologists will usually not feel committed to make further elaboration of the consequences of this stance. One can also say that the attitude of subscribers to the SVDL is this: "Don't talk too much of definitions, enough has been said”. The neo-darwinian philosopher Michel Ruse provides a clear example of the SVDL: 'Life. This, the distinguishing feature of organisms, is best thought of as involving some kind of complex organization, giving an ability to use energy sources for self-maintenance and reproduction. Efforts to find some distinctive substance characterizing life have proven as futile as they have been heroic. The one thing which is clear is that any analysis of life must accept and appreciate that there will be many borderline instances, like viruses. Inconvenient as this may be for the lexicographer, this is precisely what evolutionary theory would lead us to expect." (Ruse 1995, p 487).
The attitudes of the SVDL are never followed by clear statements of what would be the requirements of a possible set of acceptable valid definitions of life. What requirements should a general notion of life meet?
First, one could list the requirement in an attempt to make explicit the paradigmatic nature of any specific ontodefinition of life, in order to advance our understanding of organisms as material, informational, and semiotic phenomena.
Second, one could use this explicitation to remove some false presuppositions about the role of definitions in science; that is, to improve our understanding of the sciencific process. The requirements of a definition of life can be given as the following demands that can be justified on theoretical and pragmatic reasons: generality; coherence; comprehensive elegance; and specificity:
a) A valid definition of life should be general so as to encompass all possible forms of life, not just the contingent products of darwinistic evolution on this planet. Life may not on other planets have its genetic material stored in DNA molecules or it may not have a metabolism based on proteins with enzymatic function, but it will probably have both a metabolism of some kind and genetic memory of some kind. Even though we do not know for sure, it is very hard to imagine (at least for 20th century biologists) forms of life which do not have (or, which are not parasitic on other forms with) a kind of genotype-phenotype duality, where the genotype is the genetic code or memory, and the phenotype is the manifest organism belonging to some general type.
b) A definition of life should not involve notions which stand in opposition to what we already know of living things and their inorganic components, i.e., it should be coherent with the general understanding of living systems based on biological research, and also with modern physics and chemistry. Based on this tradition it should be non-vitalistic in having no reference to occult powers of life, supernatural directing forces or whatever.
c) A definition of life should have what we might call a conceptual organizing elegance, i.e., it can organise a large part of the field of knowledge within biology and crystallize our experience with living systems into a clear structure, a kind of schematic representation that summarizes and gives further structure to the field. The role of an ontodefinition of life is not simply the role of definitions of more or less technical terms within specific sub-fields (e.g. what defines "the peptidyl-tRNA binding site of the ribosome); rather, its role is to give the general object of study within biology a clear profile, to organize our cognitive models and theories of living systems in a unifying and coherent way (as a kind of rational root metaphor) It should give a comprehensive view of life compared with matter, mind, and society, and it should enable us to comprehend the internal unity in the biologic diversity of life.
d) Though able to give an idea about any kind of system that does have the ability to live, metabolize, replicate its own kind (or other features of life considered as relevant) a definition should be specific enough to distinguish life from obviously non-living systems. A pragmatic view of science takes for granted that there are real things (and real differences between specific real categories of things), whose characters are entirely independent of our opinions about them, and that we can come to know these realities through the methods of science. Our understanding of living systems is based on fallible scientific knowledge of the distinctive characteristics of living cells and organisms.
Such a set of requirements are not demanded for definitions of every scientific term; most terms represent much more specific kinds of objects or processes. For instance, in biological classification. we wish to define every species, genus,order, class, etc., and we demand more confined criteria that specify an organism's potential class-membership of a biological taxon (e.g., a species based on a set of 'essential (necessary and sufficient) characteristics. However, when defining life, we wish to demarcate a very broad class of processes, a very general and organised mode of physical systems (different from culture, society, mind or matter). The cognitive function of the concept is of another kind, so it would be a fallacy to demand the same level of operational or conceptual concreteness of such a definition. One has to be careful taking the second step, i.e. to reform our view of the role of definition in science. On the one hand, we should emphasize that a lot of technical and theoretical terms in science still have to be defined according to what Lakoff and Johnson (1980) criticize as "the objectivist account of definition", whereby a category is defined (in terms of set theory) as a set of inherent essential properties of the entities in the category.' On the other hand, as noted above, we need a broader view of the roles of various kinds of definitions in science and how scientists comprehend their objects, including objects of a very general kind. Ontodefinitions are integrative concepts, they are often vague and form an implicit part of a paradigm. However, they may have acquired an explicit surface, made visible in theoretical attempts to define more explicitly these very broad ontological categories. When dealing primarily with science (and scientist's grasp of the most general kinds of objects), we can observe that 'defining a term' is not a question of one single methodological procedure or one specific game of language, and in matters where science and ontology meet, we should cross between the Schylla of rigorism and the Charybdis of murky vapourings.
Life as a semiotic phenomenon.
Now let's take a closer look on a candidate for paradigm-specific
ontodefinition of life. Biosemiotics can, as a first approximation, be presented as new and promising paradigm of theoretical biology (or philosophy of biology), allowing us another way to perceive life, not as based on the organisation of molecules, but as based on the communication of signs in nature.
In biosemiotics, the focus of attention it is not the natural selection of replicating molecules or genotypes as in the traditional neodarwinian paradigm, but the sign-links and interpretants of various semiotic agents on all biological scales; from molecular recognition to cellular self/non-self-distinction; from the molecular semantics of gene expression and regulation to the semantics of inter-organism communication from butterflies to elephants; from individual cognition to the swarm intelligence of ants and humans. We may even think of a major recasting of our view of life within the next decade from this sign-theoretical perspective. However, before we can glimpse this development, some fundamental issues have to be resolved and the first set of questions is concerned with the nature of the biosemiotic 'paradigm' itself: Will biosemiotics be a new paradigm for theoretical biology—just like the modern synthetic theory of evolution—that can guide experimental research in specific sub-disciplines and provide a coherent framework for the study of life? Or will it rather be a meta-theoretical reflection about the conditions of possibility for doing biological research (e.g., implying that the nature of biological knowledge is dependent upon the semiotic character of the object of study)? Or will it be a kind of new philosophy of nature, in which the world is seen from the very beginning as a meaningful living universe with inborn potential for creative generation of new signification? We cannot yet answer these questions. The second issue concerns implications of viewing life as a semiotic phenomenon. If we for instance define life as biosemiotic processes, these have to be specified in terms of organisms (i.e., sign-interpreters) and their functions. Lets us say that life is defined as functional interpretation of signs in self-organized material code-systems making their own umwelts.
Life is defined as functional interpretation of signs in self-organized material code-systems making their own umwelts
This definition seems to imply that information (signs, or meaning) is conceptually primary; while organisms, metabolism and evolutionary replication are secondary with respect to the semiotical processes. When we apply the semiotical concepts to natural systems, this is often taken for granted. However, in order to bridge the gap between (physical) nature and (semiotical) culture'', we have to develop a theory of the causal nature of sign-interpretation that can account for the generation of the so-called original meaning (not just ascribed observer-dependent meaning) as part of the natural activity of physical systems under specific boundary conditions.
A similar search for such a theory is going on in cognitive science and the neurosciences. As we have not yet seen convincing accounts of the emergence of sign-functions in a purely physical system, such a theory will probably be very dependent on a future biological understanding of the origin of life (living cells, metabolism and the semiotical machinery of the genetic memory ), as it is precisely here we can detect the first primitive semiotic systems. As biological life is functional—i.e., dependent upon system-maintaining relations between parts which are not living (such as a single molecule of sugar or a protein) and wholes which are living (such an amoeba or a cat)—it remains to be seen precisely how the causal nature of the part-whole relations is constituted
If the cell (e.g., the flrst cell in the primordial soup) is an emergent entity, or has emergent properties (such as metabolism, self-reproduction), this entails a kind of "upward causation” from the physical collection of individual macromolecules (lacking such properties) to a functional whole. One has to answer if this process entails just the emergence of functionality, as many biologists would be inclined to say, or if functionality is an inherently semiotical phenomenon. so that for any kind of complex system (above the von Neumann threshold) this kind of part-whole relation can only be realized by being based upon a sign-interpretation capacity of the very system itself. In case of the cell, its metabolism is based on proteins, and these are partly specified semiotically by the genome (the primary sequence of amino acids), partly being self-assembled in the folding process following the protein synthesis. Here, functionality, as revealed by molecular biology, is not 'purely physical'; it is biological, and in that respect, also semiotical:
In the genome of an eukaryotic cell there is sequence information
specifying a set of roughly 50,000 - 100,000 specific species of protein
molecules of which maybe 10,000 may be in use in a given cell type. The cell's DNA-based selective construction of one specific protein for synthesis—out of the astronomically huge number of possible proteins of a given size—is really the original meaning of 'biological specificity' as the term for the distinctive character of biochemical reactions, which was later identified as being based upon the 'biological information' in the genome.
The secret of biological complexity lies in that 'right' semiotically specified selection. The biosemiotical claim is that by casting molecular biology as just 'biology with chemical and physical methods, we tend to forget the intrinsically biological meaningfulness in the cell as the basic semiotical unit. The cell as a semiotical whole causes (by a kind of 'downward causation') another much more ordered distribution of materials and kinds of molecules than what would have existed without this emergent semiotical unit. This downward causation should not be interpreted in a certain strong sense; it does not necessarily mean that the 'causal closure' of the physical universe is disturbed 'from without (as if we are invoking a semiotic analogy to a vitalistic 'life force') or that physical laws are violated or something of that sort. However, to talk about the causal closure of the physical universe is somehow to take a transcendental 'God’s eye view' on the whole of nature. We cannot attach much pragmatic scientific meaning to such a proposition as 'the whole nature is causally closed'. As finite semiotical beings we should not invoke such demons of traditional physics as a complete micro-determinism. A more modest stance will emphasize the necessity of choosing a particular frame of description and particular observables in the quest for understanding life, and here we are forced to surpass the purely micro-deterministic stance. Downward causation is just a problem for an ontology that allows only strictly efficient causation, because efficient downward causation surely leads to contradictions. But semiotical causation is different. It involves other causal modes (or modes of explanation), almost forgotten but still helpful to us, from the Aristotelian tradition, namely material, formal and 'final' [functional] causation.
Many philosophers and biologists have believed that it is a simple fact that all attempts to formulate a satisfactory definition of life have failed. Some biologists would even add that this is completely insignificant for research, and one should simply study concrete organisms and give particular molecular, functional and evolutionary explanations of these systems; any attempt to define life would result in overly general concepts. I have argued that this opinion can be contended for several reasons.
First, definitions of scientific terms cannot be restrained to one single type of definition (e.g.. operational, mathematical, ostensive, Aristotelian, ontological or whatever) because of the manifold character of research. Talking about biological life is talking about a very general set of objects—in fact the whole subject matter of the biosciences—and we should not be too rigid in our demands for precise definitions, especially where the cognitive and theoretical function of a definition serves as a root-metaphor for the whole field (which may motivate
further inquiry to make it more specific and general). This is the case for what I tentatively have termed ontodefinitions. In contrast to the standard view (including the idea of a of a fuzzy' borderline between living and non-living processes), I claim that life can be defined or comprehended with rather good precision.
Second, biology in the 20th century has not only been empiricist and "fact"- oriented, but has given us rich conceptual tools to construct a coherent picture of at least some of the universal properties of living systems (cells, multicellular organisms, and systems of such organisms), conceived within an evolutionary frame as evolved, highly organized, adaptive systems with some autonomy and specific informational properties, i.e., with properties that are emergent, but no less material than chemical and physical properties. In this sense, organisms are genuine ontological units, and well-defined as objects of biology.
Third, even though it is controversial how to interpret the results of Artificial Life research gained so far—with respect to (a) clarifying how life indeed could- be, i.e., distinguish the contingently shared common properties of life on Earth from the universal generic properties of life in any form, and (b) deciding if some simulations may be considered as realizations — this field represent a set of inspiring approaches and methods not only to synthesize vehicles, animats, new kinds of self-replicating molecules, and new virtual universes of complex informational forms, but also to win a more general understanding of the
principles of complexity that is alive, and perhaps a general feeling for the laws of form that universally constrain the biological process of living.
When we investigate the possibility of defining life as a semiotic phenomenon, as a system of signs mediated by interpreting organisms, we should remember that only as abstracted and isolated from the practice of biology will definitions of life fail to give us insight. However, good theoretical notions of life do exist and enjoy a life of their own. Definitions should be used, and a definition of life can be used as a condensed paradigmatic expression for a whole view of living beings.
In this sense, the biosemiotic ontodefinition of life is a very general explanation of what kind of physical systems the living ones are. With ontodefinitions there is built-in, so to speak, a certain understanding or explanation of life. In this sense ontodefinitions are paradigmatic: they provide the biologist with a way to 'see' and explain particular instances of life.
It may appear to some as a contradictio in adjecto to speak of living phenomena as specified in the ontodefinition as 'implicitly well-defined general objects' of biology. Let me stress that by well-defined I do not suggest that for instance the problem of borderline cases will not appear (as cases of conceptual vaguenesS may reflect the existence of vague boundaries in Nature); they are well-defined only relative to the criteria for adequacy given above. This does not mean that such objects cannot be more clearly defined if we untangle some of their implicit properties.
If concepts of life as a general phenomenon are in use in biology, as argued above, can this be taken as a vindication of the principle of unity of knowledge? According to a one interpretation, the attempt to achieve general understanding in science cannot be dispensed with. For instance, Artificial Life was by its founders viewed as a contribution to reform and universalize theoretical biology to explain life in any kind, form, and medium, and to discover the general principles of evolution, adaptability, growth, development, behavior and learning (however, unsolved philosophical problems is involved in the idea of life as a medium- independent formal, or computational phenomenon).
Biosemiotics suggests to consider life from a quite different perspective, the semiotic notion of sign-interpretation, where the sign vehicle may be a physical thing (such as a molecule, or a complex of molecules), but where the important property of a living system is that this vehicle stands for something in some respect or capacity so as to determine an interpretant to enter into the same triadic relation thereby establish a link between the sign's object and the living interpretant.
The analysis of the implicit and general definition of life (as functional interpretation of signs in self-organized material code-systems making their own umwelts) supports the claim that biology as a science of general processes of life can profit from interdisciplinarity and search for universal principles. Informational and computational modelling, as well as semiotic approaches to biology may prove to be very important in this process.
The origin of order in the universe and the emergence of biological organization on Earth and on other planets cannot yet be understood in a single (causal, historical, and physical) coherent frame, although one should strive for such an understanding. The emergence of special principles of organization (e.g., a genetic code, and thus, of biological information) may grant biology conceptual autonomy, and may grant organisms a special ontology and mode of being—but the evolution of the universe, life, and mind should ultimately be explained in a grand narrative provided by science and informed by semiotics and philosophy.
Discovery of new laws of self-organization and evolution may eventually reform our picture of cosmos in a more 'organic' direction, in which our perception of the world may be reenchanted. But we should not give up a search for single unified world picture in science. However, as noticed in the introduction, the notion of life is still split between a normative and a non-normative conception.
Is semiotic a normative science? The quest for understanding the world in a unified sense is surely a norrnative pursuit. If a coherent world picture has to be an evolutionary one, as most of us would like to believe, then an understanding of the emergence of normativity itself and of the norrnative conceptions of life among human beings should be within reach, even as imperfect and fallible such an understanding might be.
HOME BOE SAL TEXTE