The development of form in living organisms continues to challenge biological research. The concept of biological information encoded in the genetic program that controls development forms a major part of the semiotic metaphor in biology. Development is here seen in analogy to an execution of a program, written in a formal language in the computer. Other versions of the semiotic or "nature-as-language" metaphor uses other formal or informal aspects of language to comprehend the specific structural relations in nature as explored by molecular and evolutionary biology. This intuitively appealing complex of related ideas, which has a long history in the philosophy of nature and biology, is critically reviewed. The general nature of metaphor in science is considered, and different levels of metaphorical transfer of signification is distinguished. It is argued, that the metaphors may be of considerable value, not only heuristically, but in order to comprehend the irreducible nature of living organisms. In arguing for a semiotic perspective on living nature, it makes a marked difference whether the departure is made from the tradition of F. de Saussure´s structural linguistics or from the tradition of general semiotics of C. S. Peirce. An agenda is made for a Peircean perspective on the semiotics of nature.
Examples of the nature-as language metaphor
The teleonomic character of living systems continues to challenge the conception of life prevailing among biologists. No matter how forcefully vitalistic or finalistic explanations have been defeated through developments in experimental biology such attitudes apparently never totally disappear, even among professional biologists. Rather they reappear in new guises for every new generation.
In the history of science controversies of this kind going on for centuries have rarely, if ever, been resolved through the unambiguous victory of one of the sides. In the first decades following the neo-Darwinistic synthesis of the 1940s, however, most biologists considered the matter settled once and for all. The purposeful character of living organisms was seen as an inevitable consequence of evolution to be causally explained by the mechanism of natural selection gradually favouring the spread of adaptive mutations within populations.
This provisional cease-fire, however, did not survive the 1970s. Severe criticism from areas ranging from paleontology to embryology and molecular biology succeeded in provoking a renewed theoretical debate on the role of natural selection in evolution, and thus the gradual and adaptive character of this process (Gould 1982, 1985, Vrba and Eldredge, 1984, Webster and Goodwin 1982, Goodwin 1984, Løvtrup 1987, Ho and Saunders 1979, Dover 1982).
At the deepest level, as we see it, this renewed criticism concerns the question of biological form. Is the development of form simply to be explained through the gradual improvement of function? Do organisms and parts of organisms develop their characteristic forms, just because such forms were the most functional (the most successful)?
This problem is an old one: What is the relation between substance and form? In reflecting over Korzybski's famous statement, Gregory Bateson traces the problem back to Pythagoras:
Opponents to this belief would claim that forms are not reducible to such a series of single steps. For instance a die of four cannot be obtained simply by adding an extra dot to a die of three. Rather quite a new pattern has to be constructed. And there would be no guarantee that the intermediate steps between two different patterns or forms would be functional at all - if anything, the opposite would seem plausible. Form, according to this view, must be considered an autonomous factor in evolution. Historical (i.e., phylogenetic), architectonical and embryological constraints would be reflected in the actual forms of living systems on this planet, and the rules governing such constraints would tell a lot more about evolution than natural selection, which can only modify the given patterns on which it works.
It is difficult to escape the feeling that much of the energy now invested in defending the functionalist image of evolution is in the end invested in order to defend a causal mechanism for evolution. Since the time of William Paley, the argument from form has always been associated with religious conceptions, whether the claim for Godly 'design' or only for the existence of vital forces or final forces. To give up natural selection as the prime mover in the world of living creatures seems identical to giving up the firm hold of science over this strange teleonomic aspect of life.
It is with this background that one must understand the temptation among biologists in recent years to consider life from the point of view of communication or information theory rather than from the point of view of classical physics and chemistry. After all, the only place to go for models of purposeful behaviour would be in the cultural sphere of the human being. And whatever the reasons for purposeful behaviour of living systems are, a more appropriate description of such behaviour might help formulating scientific explanation. The choice need not be between natural selection or vital force. Maybe a third route might be found.
This idea, of course, would probably not have been so attractive had it not been for the introduction into biology during the 1950s and 1960s of a whole set of terms borrowed from information theory. A meaningful description of the genetic processes going on at the molecular level of the cell seemed to require terms such as 'genetic code', 'messenger RNA', 'feedback', 'information', etc.
Unfortunately, in spite of their widespread use, these concepts are far from unambiguous. Thus in information theory (e.g., Shannon 1949) information is understood as an objective quantifiable entity. The information content of a message is equal to the improbability of that message. While this definition makes theory easy, it also removes the concept of information from any use in real life situations. In human communication statistical analysis of the probabilities to be ascribed to any definite statement is not only not feasible, it is impossible for theoretical reasons. Nobody would deny that totally unforeseen events are an essential part of life. The eventual appearance of such events obviously makes it impossible to ascribe distinct probabilities to any event. We strongly feel, nevertheless, that we often get informed through conversation. Mere improbability does not cover the real meaning of information.
In fact, most statements in human communication are only understandable at a semantic level of analysis. Evidently, the 'information' of the mathematical theory of information is a much less comprehensive category than the information exchanged between people talking.
When this concept of information is introduced into biology these sophisticated problems are imported as well. However, the tradition of biology is very unprepared to cope with such problems. Actually in the daily praxis in the laboratory information is simply identified with a substance, a piece of DNA, a gene. And in this way of confusing information with substance the new terminology of molecular genetics automatically reinforces the functionalist theory of neo-Darwinism.
We doubt that a scientific understanding of the teleonomic character of living systems will ever be possible based on this restricted concept of information. Rather we propose that biological information must be understood as embracing the semantic openness characteristic of information exchange in human communication. The cost of this, of course, is that we shall have to abandon the belief in information as an objective entity to be measured in units of bits (or genes). (For a more detailed discussion, see Hoffmeyer and Emmeche, in press).
In consequence, any theory which tries to describe the dynamics of living systems from the perspective of communication or exchange of signs, i.e. semiotics (from Greek: semeion = sign) would have to rely on a concept of information as a subjective category. Following Gregory Bateson we take information to mean: a difference that makes a difference to somebody (Bateson 1972, 1979). According to this definition, information is inseparable from a subject to whom this information makes sense. Our thesis is that living systems are real interpretants of information: They respond to selected differences in their surroundings. Only on this premiss, we claim, may analogies from the sphere of human communication serve as explanatory tools in the understanding of the purposeful behaviour of living systems.
A more detailed model for the application of these principles in the study of prebiotic and biotic evolution is forthcoming (Hoffmeyer and Emmeche, in press). In the present paper we analyse the requirements which must be met in order to use metaphors and analogies from such areas as linguistics and semiotics in biology.
This of course begs the question about the significance of metaphor in science. Therefore, we first consider the nature of metaphor in science in order to distinguish between the metaphorical transfer of signification at various levels in scientific theories. Second, we focus on the metaphor of nature as language in different versions, to give an impression of the very general character and the cognitive appeal of this metaphor, and to criticize some of the models. In fact, nature perceived as language, or a language-like system, constitutes a complex web of cognate ideas of various heuristic value. In arguing for a semiotic perspective on living nature, we have to consider the existence of at least two different semiotic traditions - the linguistic structuralism of Ferdinand de Saussure, and the theory of signs of Charles S. Peirce, both of which may inspire the new view of nature. We shall argue, however, third, that the Saussurean theory as applied to living systems, raises some decisive problems in relation to an account of the different coding processes of biological information in the evolution and development of living beings in ecosystems. To spell out these problems, we shall criticize Forti's analogy between language and living species. Fourth, in the last section we show that the basic concepts of the semiotics of C. S. Peirce fit very well into the requirements of a `subjective' category of biological information (here subjective should be taken in the epistemological sense, and not as equivalent to non-rational or non-scientific). Biological structures in general and the gene in particular may be understood as signs forming a network of triadic semiotic relations through space and time.
Darwin's metaphor. The theory of evolution by means of natural selection is a telling example of the role of metaphor in science, although the necessity of the central metaphor is still subject to controversy. In the 'interaction' view of metaphor (Black 1979), a metaphor can be thought of as effectively creating similarities; it suggests possible relations and analogies, many of which are neither clearly 'positive' nor 'negative', and hence open for further exploration. The analogy between nature and artificial selection grew out of Darwin's reflections on sporting dogs and other domestic breeds, which he increasingly saw as well adapted to nature, and not simply as monstrosities. As is well-known, he used the analogy to construct the new concept of the mechanism of evolution through 'natural' selection. This analogy was not an accidental circumstance in the contexts of discovery of the mechanism of evolution. On the contrary, it implies a hidden, 'technological' perspective towards nature (breeding is seldom conceived as a technology; but it certainly is). The analogy encourages us to look at the problem of evolution from a technological point of view, that makes nature both an external agent in the image of man, and at the same time the product of external forces, as in the case of the organisms under the breeder's control. The interest in ontogenesis, the internal causes of change and the exact causes of variations could then be abandoned. Thus, J. F. Cornell remarks that
The culture-as-nature analogy. Since the development of information theory and the rise of modern molecular biology there has been no shortage of theories based upon analogies between living nature and some communicative aspects of human culture. Concepts from the theory of evolution have often been transferred or 'translated' to the social field in an attempt to use them in models of socio-cultural evolution. Cultural development has been explained through the darwinian concepts of variation (in the organic world via mutation and recombination, in the socio-cultural context via innovation and discovery), selection ('natural' and intra- & intersocial selection, respectively), and transmission (of genetic information via reproduction, vs. of 'knowledge' and 'ideas' via upbringing, education etc.). An unfortunate consequence of such evolutionary analogies has been the frequent reduction of the very concepts of language, human being and culture. Thus language tends to become a mere instrument for communication, human beings are seen as essentially adaptive creatures, and culture reduces to cultural inheritance, which subsequently boils down to some notion of information processing. And the lack of positive analogies concerning the units and mechanisms of evolution in the two areas is totally disregarded (Schroll-Fleischer 1983). Hence, the implementation of analogies between two different subject areas should be done with great care to avoid what might be called the fallacy of misplaced reduction.
In the construction of the analogy between language and living nature - a 'semiotics of nature' - it is not our intention to advocate the application of biological concepts in theories of human, economic or social affairs (pace the evolutionary epistemology, e.g., Plotkin 1987). In order to understand the structure of a society, an institution or a political conflict, one needs the approaches from the social sciences and the humanities, without the importation of theories or methods from physics and biology as has so frequently been tried in the name of positivism and scientism. But do we recommend, then, the opposite strategy: To understand nature through concepts and metaphors borrowed from the humanities (putting us in danger of just the opposite kind of reductionism)?
To answer this question, we shall first discuss the nature of metaphors and analogies, then consider some other examples of the nature-as-language metaphor, especially Guido Forti's 1977 paper, the critique of which will serve to frame our own position on the status of metaphors.
The nature of metaphor and analogy. Etymologically, metaphor (the Greek metafora, 'carry over') means 'transfer', 'convey', the transference of an often figurative expression from one area to another, and analogy (Gr. analogia, 'relation', from ana, 'up' + logos, 'thought') means 'similarity', or 'accordance'. Both terms are found in Aristotle, with a sense fairly similar to the present use. It is hardly feasible in any unequivocal way to delimit the concepts of model, analogy and metaphor in science. Model, however, is the most general term, and analogy and metaphor can be defined as special kinds of models. Any theory can be seen as a model system. An analogy is a relation between two descriptions of objects (or subject areas) which allows inferences to be made about one on the basis of the other (e.g. studying cell membrane diffusion on artificial membranes), or one to be understood in terms of the other (e.g. the solar system model of atomic structure). The analogy may be formal or material, and complete or partial. In formal analogy there is similarity of form, logical or mathematical structure or syntax; in material analogy of content, substance, function or semantics as well.
Philosophers of science have discussed 1) if models or analogies are logically and epistemologically redundant and unnecessary, not explaining the phenomena (claiming that theory should bind together experimental laws), 2) or if to be intellectually satisfying, a theory must also consist in a (non-deductive) relation of analogy with some known field of phenomena (cf. Hesse 1966). The problem can hardly be settled in a general way, because different cases in the history of science exemplify both situations; analogies were either not meant to give the final explanation, or they were an essential part of the argument. It can be argued however, that in order to make a theory more comprehensible, to understand its structure, and to make the relation between the theory and related subject matters intelligible, it is often of great value to construct and use analogies as well as to understand their limits (Leatherdale 1974).
Drawing analogies between different phenomena has been interpreted by some to presuppose a commitment to the ontological claim that there are general structures underlying reality. Forti, making the analogy between nature and language, writes for instance: 'The exercise of constructing analogies between different systems (...) is justified when it is possible to show that analogy actually illuminates the roots of things and provide us with a key for understanding more fully fields that are related in their structural substance.' (Forti 1977: 69). In other words, the theoretical use of analogies presupposes the existence of general structures in reality which are discernible through our explorations and pursuit of 'the root of things'.
It is also possible, however, to consider analogy to be a part of the big map of nature we create in the process of exploration, thus projecting a conceptual order into the natural phenomena under study. Explanation can be understood (metaphorically!) as the mapping of a description onto a tautology (Bateson 1979), and this tautology always makes direct or indirect reference to some system of signification - e.g. ordinary human language, mathematics, general physics etc. - that is already known. Even the most 'closed', seemingly non-analogic, formal or mathematical theory makes reference to some implicitly known basic rules of language or praxis, not defined in the theory itself. Whether this non-deductive reference is called 'analogy' or not, there is a signification-transfer involved between the different areas. It should be noticed that Peirce's concept of abduction - the non-deductive and non-inductive process of inference by 'lateral extension of abstract components of description' (Bateson 1979) - captures this aspect of signification-transfer by analogy very well; and both metaphor, analogy, dream, the whole of art, the whole of science, the whole of poetry, etc. can be seen as instances or aggregates of instances of abduction within the human mental sphere. Without our capacity to relate two bodies of knowledge abductively, realizing them as both falling under the same rules, we would have no science at all. There seems to be a liaison between abduction, abstraction and analogy, and according to Buchanan (1962: 99), 'argument by analogy is the fundamental technique in the process of abstraction'.
A metaphor can either apply to a special term transformed from one subject matter to another (as the term information in the ordinary notion of genetic information in molecular biology) or more generally to a 'symbolic' term standing in relation to a whole field of knowledge, where the term signifies and unites the paradigmatic 'way of seeing' the subject matter, e.g., in mechanistic biology the organism as a machine. We can thus write the levels of metaphorical 'signification-transfer' in science as follows, reserving a 'medium-level' for analogies: Level 1: The transfer of single terms ('metaphors-1') to other contexts to create new meaning and signification in the field concerned. Level 2: Construction of analogies as part of a specific theory or a general and systematic inquiry to elucidate the phenomena under study. This may often include considerations of the positive as well as negative aspects of the analogies in question (Hesse 1966). The analogy may be a preliminary heuristic device or component of a seemingly final theory. Level 3: A uniting view ('metaphor-3', below plainly 'metaphor') on the area described by the paradigm, often symbolized by a specific term referring to the whole frame of understanding in the given paradigm.
The last level is of course most important in connection with paradigmatic changes in science. A new metaphor does not merely provide answers to new questions (as may be the case in level 2), rather, by recasting our perceptions, it creates new problems, concepts and eventually experimental strategies, in this way contributing to a new 'research program'. Thus Donna Haraway argues how the metaphors of organismic biology must be analysed as central to this whole paradigmatic undercurrent of 20th century biology, thereby tracing the change in metaphor from machine to organic system. When a science enters a revolutionary phase, when paradigms - in the sense of Thomas Kuhn - are changing, this involves metaphorical redescription. Haraway ascribes explanatory power to metaphor (i.e., 'metaphor-3'), describing it as 'the vital spirit of a paradigm (or perhaps its basic organizing relation)' (Haraway 1976: 9). This wider notion of paradigm includes techniques, examples, community values, and the central metaphor. A metaphor can be related to a sense object - such as a machine, crystal or organism - or an abstract object, such as language; and it can be thought of as an image that gives concrete coherence to even highly abstract thought. It is in this sense that 'the language (or semiotics) of nature' must be considered.
There is, finally, a fourth level of metaphorical signification-transfer in science, indeed the most comprehensive level, where science itself, or any scientific theory is a set of metaphors as suggested by Lacan (Wilden, 1980: 26). In this view, knowledge itself is irreducibly metaphorical, scientific knowledge included. For Buchanan (1962: 96)
Examples of the nature-as-language metaphor. Rather than giving a complete survey of the use of language-like phenomena as a metaphor for the biological realm or some aspects of it, let us give some examples of this traffic. These suggest that the 'nature-as-language metaphor' is an intuitively appealing complex of related ideas, an intellectual archetype rather than a single coherent concept of nature.
Nature as the Great Book. The complex of ideas about nature as language may be seen as the secularized descendant of the old prescientific metaphor of 'the great book of nature' - magnus liber naturae rerum (St. Augustine) - wherein one can read the eternal power and divinity of the Almighty God. This metaphor had its palmy days from the late Middle Ages to the Enlightenment, and a pre-history as old as the theology itself (Pedersen 1986). But also the Natural Theology of William Paley (1802) illustrates the concept of the book of nature as the sign of divinity in the Creation. The book of nature was often conceived as the visible sign of an otherwise invisible and transcendent God. It was readable by anyone, although the meaning of the book might be accessible only for the specially chosen. The book metaphor, however, was used in the most different contexts, and its relation to the present metaphor of a language of nature is rather spurious. Admittedly, it is a relation of analogy (cf. however, Blumenberg 1981). In the 20th Century, 'nature as language' can no longer be studied as the sign of a Supreme Lord, but it may help us more adequately to grasp the ecological and evolutionary complexity of the living beings on Earth. A link between the two metaphors may be derived from the perspective of Bateson, where the informational complexity of living systems (ecomental systems) points to some consciousness of the 'sacred' aspects of the immanent larger mind of nature (see below).
A historically more significant link between our past and present day concepts of nature is traced by Mayr, who indicates a connection between the natural theological tradition of reading nature as a text and evolutionary biology:
General uses. The old epistemological questions about how to understand the relation between the structure of Nature and the structure of Theory has frequently been addressed under some general notion of analogies (or structural isomorphies) between language and nature. This approach may be influenced by the appearance of information theory, the theory of automata and cybernetics (e.g., Hawkins 1964).
Often the metaphor is used in a very loose and unprecise way, pointing towards special and rather limited phenomena among living organisms, as for instance the very complex communication system of bees (von Frisch 1950). In an early attempt to specify the analogy, Kalmus (1962) maintained that the communication systems operating in life resemble language in so far as they both show the properties of symmetry (between sender and receptor in respect to message coding or reference system), meaning (or semantics), arbitrariness (in the symbol-object relation), and style. The latter refers to an analogy between literary style and 'biological type', i.e., the limited number of body plans that has developed through the geological epochs. These historical aspects of the isomorphism of language and life are emphasized by Kalmus, who also points to the methodological similarities of the two fields (see also Picardi 1977), illustrated by a scholar engaged in the genesis of a literary work and the phylogeneticist reconstructing the evolutionary history. (Actually, the reflected methodology of the 'cladist' phylogeny of biology has been used in textual criticism and linguistic reconstruction, see Platnick and Cameron 1977).
Life as learning and thought. Bateson acknowledged the imaginative and productive role of metaphors in science, and he himself used two kinds of metaphorical redescriptions of the phenomena of evolution and development, the first of which is learning. Bateson's hierarchical theory of learning (partly drawing on the Russell/Whitehead theory of logical types) (Bateson 1972) was developed in relation to his work on psychiatric diseases, but he also used the concepts of different levels of learning in analogy to evolutionary phenomena. Bateson was aware of the limits of this application. His theory assumed that logical types (or the learning categories zero to IV) can be ordered in a simple unbranching ladder; but as he stated, the world of action, experience, organization, and learning cannot be completely mapped onto a model which excludes propositions about the relations between classes of different logical types (Bateson 1972: 307). He realized that the complicated relation between context and content obtains in both the biological and the linguistic field. Thus he remarked that
We use the concept of analog/digital communication in the discussion of the Saussurean approach below, and in Hoffmeyer and Emmeche (in press). Coding is a ubiquitous phenomenon of communication; one is never faced with meaningful messages in 'pure' form, they are always coded in some specific way. Analog and digital coding are not the only modes of communication, but in this context they are the two most important ones (compare Bateson 1972, on iconic, metaphoric and ostensive coding). Though rather difficult to define formally (cf. Wilden 1980), communication is digital, if there is discontinuity between the primary signs (or 'signals') constituting the complex (i.e., composite) sign for the message in question. Communication is analogic when such discontinuities cannot be distinguished, that is, when a magnitude or quantity in the sign as a whole is representing some continuously variable quantity. The terms are borrowed and generalized from the analog and digital computer, which computes by means of real, physical, continuous quantities; or discrete elements and discontinuous scales. According to Bateson and Wilden, all natural systems of communication employ both analog and digital communication at some level in the system. One might add that the world in its immediate aspects that impinge upon us through active human praxis or perception is an analogic coded version of reality.
Several significant gains from this distinction are mentioned here: First and most obviously, it allows one to focus on the code-duality between analogic and digital codes in the evolution of life. In evolution, the phase of individual epigenetic development can be seen as a translation of the digital DNA-code to the structurally complex adult 'analogic' organism. Epigenesis resembles the development of a complex tautology, where one starts from the (digital) axioms and definitions and develops an analogic three-dimensional geometry: an instance of the morphology of life. The real life of organisms in their ecological niche constitutes the more explorative phase of evolution, where selective and stochastic processes are in action. Ideally, the termination of the life cycle through sexual reproduction corresponds to a 'back-translation' of the environmental experiences of the (analogic) population, to the digital level of the DNA inside the cohort of zygotes starting the next generation. Secondly, within this perspective one can speculate on the evolutionary origins and advantages of the analog/digital 'double-description', and its relation to sexually reproducing organisms. Thirdly, the Bateson/Wilden approach to analog and digital coding offers opportunity to consider the role of the hierarchy of contexts in evolving systems, and the existence of metacommunication; i.e., messages about messages in the digital mode of the genetic language as well as the human verbal language (for details, see Hoffmeyer and Emmeche, in press).
Life as memory systems. The molecular biologist François Jacob (1981) drew the analogy between the genetic, the immunological and the nervous systems on one hand, and the memory of human beings on the other. Although memory has not the same extension by definition as human language, the two are highly interdependent, the analogy is thus connected to the nature-as-language metaphor complex. The basic evolutionary principle of all three systems is the creation of diversity and difference by the bricolage or recombination of an historically constrained finite number of elements. Through this analogy, Jacob implicitly generalized the concept of memory to cover not only the electronic 'memory' of computers, but also the biochemically based genetic systems, albeit he maintains the qualitative differences between the three systems mentioned.
Organisms as cognitive systems. Before entering into the 'structuralistic' phase of his radical critique of traditional biology, the embryologist Brian C. Goodwin devised an agenda for a 'cognitive biology'. In this theory, the organism should be seen as a cognitive system, i.e., operating on the basis of knowledge of itself and its environment (Goodwin 1978, which contains additional references). This knowledge is expressed in the form of rules or constraints which generate structure/behaviour useful to the organism for survival, reproduction and evolution. The view is based on an explicit extension of Chomsky's theory of linguistic competence. According to Chomsky the 'innate', unlearned capacity for generating correct sentence structure emerges in the course of child development. It is constituted by rules/constraints that define the processes that generate the surface structure of sentences from their deep structure. These in Chomsky's theory rather contentious innate structures (endowing the individual with linguistic competence) were seen as a kind of inherited knowledge. Goodwin extends this proposition and claims that 'the basic attribute of living organisms is their possession of knowledge about aspects of the world'. Some of this knowledge is coded in the DNA and needs to be translated into active form before being 'tested'; a great deal, however, is 'tacit' knowledge in other structures.
The aim of Chomsky's theory was to explain the highly productive character of language: in principle, the unlimited series of sentences to be created by means of a finite number of words and rules of the 'generative grammar'. Other authors have seen this aspect of language as highly relevant to biological problems (see Campbell 1982 for a lengthy argument that `life, like language, remains "grammatical"'). Jerne (1985) made an analogy between language and the immune system. He compared the variable region of a given antibody molecule not to a word but to a sentence or a phrase. The immense repertoire of the immune system was then seen not as a vocabulary of words but as sentences, capable of responding to any sentence expressed by the multitude of antigens which the immune system may encounter. (The inheritable `deep structure' of the immune system is known as the DNA segments that encode the variable regions of antibody polypeptides, and its 'generative capacities' have been demonstrated as e.g. proliferating B lymfocytes undergoing somatic mutations which result in antibody-variable regions different from those of the stem cells). Jerne is astonished by the complexity of this 'cognitive system' that has evolved by itself and functions without the assistance of the human brain.
Some Chomskian linguists invert the signification transfer of the metaphor (i.e. 'language as a biological system') in that they stress the importance of biological organization as a key in understanding the deep structure of language. Thus, it is asserted that sentences exhibit the properties of biological systems because they only exist with the correlated activity of a literal biological system (McNeill 1971). Or it is asserted that the 'generative grammar', the basis of language competence, is coded in the genetic program, and that this claim rests on 'conservative operation with structural genes determining specific [central nervous system] tissue' (Hansen 1981).
Life/organisms/genetic systems as computers. The concept of life as a kind of computing or information processing machine derives from two (eventually interdependent) sources; one is the fuzzy area between neurobiology, logic and automata theory, and the other is molecular biology. The former is connected to the early developments of cybernetics, information and computer science, namely McCulluch and Pitt's use of mathematical logic to characterize the capabilities of neuron networks in the early 1940s and the von Neumann conception of machine self-reproduction (about 1950); posing the theoretical possibility of constructing a 'machine' containing a complete description of itself and capable of self-reproduction and assembly (for reviews, see Burks 1975, Langton 1984, Weisbuch 1986). Von Neumann was interested in the general question of what kind of logical organization is sufficient for an automaton (i.e., a formal, logical 'machine', that may exhibit dynamic, organism-like properties) to be able to reproduce itself. Observe, that he was not trying to simulate the self-reproduction of a natural system on the level of genetics or biochemistry (nobody has ever succeeded in that). He wished to abstract from the natural self-reproduction problem its logical form. Although the result was a specification of the sufficient conditions for self-reproduction for a logical structure, his logical 'machine' is an enormously complex and unhandy configuration that has never been run under 'real' computer simulations. Later on, more simple self-reproducing 'machines' were constructed (Langton 1984). Already C. S. Peirce, however, as early as 1883, recognized the relation between logic and biology, drawing the analogy between the informational aspects of a frog's response to an electrical stimulus and the process of conscious deductive reasoning. It illustrated his thesis that rationality was a matter of degree, rather than a unique property of man.
Whether it is the abstract logic of self-reproduction, the neural networks of higher animals, or some other cybernetic or generative system of the organism (hormonal control; morphogenesis), the central uniting view in these approaches must be called the 'nature-as-artificial-language metaphor' (a metaphor-3 in the above classification). The organism is understood in terms of some kind of artificial languages of logic or mathematics, often implemented by electronic computers allowing for simulation of complex behaviour. An intensified version of this view is the recent attempt to make `Artificial Life' a research programme for an extended perspective of theoretical biology, where `aliveness' is seen as a question of the `logical form' of an organism (i.e., a formal informational structure, just as a language system can be described formally) rather its material basis of construction (Langton 1989: 11; see also Rasmussen, in press). The philosophical problem in this stance seems to be similar to the claim of medium-independence in classical research in artificial intelligence: some aspects of the intelligent performance may depend crucially on non-formalizable variables of the human psyche. And some aspects of the logical form of an organism may not be separated from the properties of its material `wet-ware'.
One should note that the cybernetic idea is also rooted in the mechanistic tradition of biology. In the seventeenth and eighteenth centuries biology made systematic use of reference to mechanisms analogous to organs, inspired by the Galilean and Cartesian science (for examples, see Canguilhem, 1963). In this way, the notion of the organism as an information processing machine may represent a crossing or coalescence of two metaphors: life as a machine and life as a language.
The other source of the view of life as a computer is molecular biology itself. In a review of 'the molecular biology that was', Gunther Stent calls attention to the differences between the structural and the informational school of molecular biology in their respective interests and conceptions of subject matter. It was the latter line of thought that brought into biology the idea that the genetic material must be organised like a 'code-script' (Schrödingers famous term) conveying biological information about the inheritable characters of an organism (the idea of heritable information is certainly older and can be traced back to August Weismann, cf. Maynard Smith 1986). Scientists of the informational school were often motivated by the desire to discover hitherto unknown 'other laws of physics' by studying the molecular basis of inheritance. Although these expectations were not fulfilled, the concepts of information proved to be very fruitful, especially in relation to the deciphering of the DNA code. As George and Muriel Beadle remarked, this has
It was not so much the Shannon/Weaver concept of 'information content' that influenced the biological discussions (e.g., Quastler 1953) as the more informal concepts of information as (intentional) instructions or algorithms in artificial languages. When applied to developmental biology, information theory implies that the egg should be seen as a communication channel between parent and offspring adult organism. This, however, raises the apparent paradox of increasing 'information' during development. Criticizing this use of information theory Apter and Wolpert (1965) and Waddington (1961, 1968) made clear that in the transition from zygote to the adult
When one goes from the communication channel metaphor to the computer metaphor, one should note the disanalogies between the organism (or cell) and the computer. Although 'genetic strings', according to Burks (1975, p.307) can be treated like formulae of a deductive formal language, this approach has some serious limitations. In the cell, we find a level mixing of which no counterpart exists in the yet known computersystems. As the computer scientist Hofstadter remarks, not only are programs and data intricately woven together, but also the interpreter of programs, the physical processor, and even the language are included in this intimate fusion (Hofstadter 1979: 547). He considers in detail how the DNA, the proteins, the ribosomes, tRNA etc. can be classified in various ways in computer science terms. E.g., the
C.I.J.M. Stuart has criticized in detail the metaphorical use of the term information in biology (Stuart 1985a, 1985b). He introduces the concept of 'the bio-informational equivalence' denoting the equation of biological process with 'information transaction', and identifies three kinds of such equivalence. The first and the second kind consist of an analogic application of mathematical information theory to biology, namely the theories advanced by Shannon and by Brillouin. According to Stuart the application of these theories raises serious epistemological problems. It is not clear what should be the physical interpretation of the order measure in statistical mechanics. The third form of the equivalence amounts to the idea that biological information is a central concept for modern biology, though a concept different from the physical or mathematical concepts of information. Thus, the informational metaphor in biology has to do not with the quantity of information, but with its value, quality, or role within the biological process. As noted above, it is often incorporated as an intrinsic concept of modern molecular biological theory. The bio-informational equivalence absorbs, from our experience with ordinary language, the idea of referential information: information about something. Stuart (1985b) attempts to eliminate the anthropological basis of the equivalence in all three forms by eliminating the notion of reference 'in favour of concepts that fit into the conceptual-analytical framework of classical mechanics' (1985b: 442). The bio-informational equivalence is a 'conceptual stumbling block' (1985a: 612) for biological theory because it introduces an epistemological confounding of the observer's information about a given system and 'properties intrinsic to the system itself' (1985b: 444). Thus, the informational metaphor, according to Stuart, attributes to phenomena of biological organization 'properties (such as cognition, reference, and intensionality ) which (...) would not exist in the absence of human observers' (1985a: 614).
This last statement, one should add, seems to be the central undiscussed conviction in the stance of Stuart. At this point, the implicit Cartesian, or dualistic epistemology of his approach comes up against what might be termed the natural history of information, signs, and meaning. We agree with the necessity to distinguish analytically between the observer's information about biological systems (of any kind) and the attribution of information processing to the biological systems themselves (Stuart 1985b: 444). The question is if this epistemologically important distinction forces us to delimit intentional aspects of the world exclusively to the Homo sapiens. After all, human beings have also quite physical aspects of their bodies and actions, so should the mechanics of Newton be anthropomorphic in this sense too?
We shall not go into detail with Stuart's own alternative (a 'non-anthropomorphic' treatment of adaptive phenomena in terms of variational principles, Stuart 1985b) in which he introduces a concept of colligatory information, which substitutes statements of the form 'x is influenced by y' for (the metaphorical) statements of the form 'x has information about y'. The alternative goes beyond the analytical reduction of the metaphor; it eliminates it, and this is the price that 'must be paid if biological theory is to be analytically and also scientifically viable' (1985b: 445).
We consider Stuart's critique important and cannot here render full credit to all his arguments. It is, we think, unfortunate that it is produced from the point of view of a declared 'methodological canon of natural science ever since Galileo and Newton', accepting only effective causes in explanations. This seems to result in an a priori exclusion of intentional higher-order phenomena from the subject matter of science.
Stuart's critique is summarized in the claim that the term 'information' is borrowed from the human sphere of communication, thus being anthropomorphistic, 'quasitheoretical', and unfit for modern biology. The fact, however, that humans possess the ability to communicate or 'inform' each other in various ways does not make this general capacity a unique human characteristic. There are various levels of communication, of which the written and spoken language may be a prime characteristic of Homo sapiens, but that does not commit us to antropomorphism in the naive sense when talking about information transfer between animals or genetic systems. In the study of animal behaviour we should seek to avoid the projections of the human observer of specific human ways of language- and concept-mediated communication on to the animals under study. And the same critique of human projections should be applied to the computer metaphor of molecular biology. In the deeper, epistemological sense, however, we can only get rid of the human observer in the theories of nature through a process of abstraction that leaves the subsystem of the observer unspecified. This epistemological condition holds for the description of non-living as well as living nature (Emmeche 1988). Stuart seems to assert that we can draw sharp lines between how natural systems are 'in themselves' and how they appear to us, as if real scientific theories were about Nature as some 'Ding an sich' matter. The critical reflective specification of the role of the human observer in the scientific description of natural systems is crucial (to the understanding of nature, epistemology and the semiotics of nature), but this do not logically force us to abstain from the use of different points of view or levels of description in science, such as the ascription of intensional properties to non-human living systems. Without demarcating between 'theory' and 'quasitheory' as Stuart does, we consider the 'nature-as-artificial-language metaphor' to be a part of a basic frame of a scientific research programme, even if it has problematic status.
Of course, nature conceived as a computational system, the organism as an information processor, steered by a program in an artificial (or genetic) language, may seem to be far from the notion of a 'semiotics of nature' or looking at nature as a natural language. Yet, language itself is a complex, many-level system that can be approached in various ways. The natural language of human beings is a constantly changing, dynamic system, that cannot be said to be fully formularizable or to have a well-defined semantics. It is heavily loaded with self-references. One should remember, therefore, that an artificial language can only model some aspects of natural language by reducing other aspects, thus being less complex in semantic structure than natural language. The risk of relying too confidently on the 'nature-as-artificial language metaphor' as offered by the Cognitive Science is that certain properties of living nature are lost from the perspective of the analysis, namely the self-referential and self-organizing aspects (e.g., the self-assembly of a molecule without any explicit 'instructions'), the tangled-hierarchy or 'level-mixing' structure of which we understand so little. (On the basis of the relation between evolution and the 'linguistic complementarity' Löfgren (1981a) in a similar vein has argued that evolution is a concept that cannot be formally described.) It is exactly these aspects where living nature and the natural language of humans show some very interesting isomorphies (not identities, please), which should be investigated under the perspective of a new paradigm of biology, a semiotic paradigm, yet to be established.
Life as a linguistic/semiotic system. Instead of looking at life as a parallel to the artificial languages of computer science and logic or as 'programmed' by a system of genes or genetic algorithms, several authors have searched for structural similarities between the informal everyday natural language and life. However, in the biological literature, linguistics and philosophy, explicate comparisons between the phenomena of linguistics and the genetical or evolutionary aspects of life are rather seldom (for a critique, see Shanon 1978), but we shall give some examples.
Roman Jakobson, one of the founders of the Prague school of linguistics, was struck by the formal similarities of language (the phonological structure of speech) and life, as revealed by modern genetics.
One of the most ambitious attempts to integrate a view of nature as a sign-producing system into an elaborated theoretical frame of one of the life sciences has been done by Marcel Florkin. In his treatise from 1974, 'Concepts of molecular biosemiotics and molecular evolution', Florkin reviews the molecular/biochemical evolution and sets up a new perspective on synchronic and in particular what he calls 'diachronic molecular epigenesis', i.e., the diachronic (in the phylogeny of organisms) epigenesis of the synchronic (limited to life span) epigenesis, resulting in biomolecular changes along the branches of phylogeny. He places the accent on 'the biosemiotic aspects' of molecular evolution, i.e., the intensive aspects of information involved in the impact of natural selection acting at the level of the organism. It is emphasized that if information, as understood in thermodynamics as an extensive property, should have any significance for the feasibility of living process, it is to be modulated by an intensive property, which indicates the biological relevance or purposefulness of that information (cf. Johnson 1970):
In constructing a whole new terminology, Florkin partly draws on the linguistic theory of F. de Saussure, using the general terms of this theory, but 'with the special meaning they have in molecular biosemiotics'; e.g., significant (signifiant) and signified (signifié) for the aspect of molecular configuration and the aspect of biological activity, respectively, this doublet forming a bioseme. One should note, however, that Florkin does not associate his approach with the information theoretical 'extensive' one; nor does he try to consider an organism plainly by analogy to language: it is advisable to 'avoid the application of the specific concepts of linguistics (word, phrase, etc.) to biosemiotics' (p.13, ibid.). Linguistic signs are, according to Florkin, 'psychological entities', and the association between a significant and a signified is arbitrary: 'A bioseme carries no Bedeutung or Sinn. Its significant consists of an aspect of molecular configuration and its signified of an aspect of biological activity' (p.15, ibid.).
Florkin claims that in molecular biosemiotics the significant and signified are in a necessary relation, imposed by the natural relations of material entities. Semiotics is the denomination he (along with Peirce) apply to the general science of signs of which biosemiotics forms a special section. General semiology, on the other hand, refers to the study of systems of signs in relation to the structure of language framed in the social reality.
Florkin recognizes the signified of biomolecules as being involved at levels of integration higher than the molecular one, for instance the level of self-assembly in supramolecular structures, and the physiological and ecological levels. Thus he designates as ecomones the non-trophic molecules contributing to insure, in an ecosystem, a 'flux of information' between organisms. His emphasis, however, is the pattern of changes accomplished through diachronic molecular epigenesis along the phylogeny of organisms; in ordinary terms, biochemical evolution. Natural selection is not considered as being exerted on specific biomolecules, but on organisms, which he consider as the biomolecular order expressed in the structure and nature of the whole collection of biomolecules of which the organism is made (p.57, 116, ibid.). He proposes that
We shall not go into a further critique of Florkin's paper, but we hope to have conveyed some of its impressive flavour. One could ask if the ambitions were yet commensurate with the results, or if the semiotic concepts have a tendency to degenerate into blank expressions superimposed upon the descriptions of comparative biochemistry. It is, however, too early and too easy to pass judgment, and Florkin's treatise still provides insight in the molecular aspects of the semiotics of nature.
One cannot accuse Florkin of unreflected application of some general 'nature-as-language metaphor'; on the contrary, he made explicit conceptual demarcations to the linguistic field. His treatment falls under the heading of this section because he shares some of the conceptual background and assumptions with the other communicative or 'linguistic' approaches dealt with here, and because there is still some deep associations or thought-figures connected to a semiotic approach to some part of reality, always connoting the functions and behaviour of a complex system like language. Thus, in spite of these demarcations, his contribution can be understood as part of a general shift in the leading metaphors (level 3) of biology.
The same holds for the writings of Kergosien (1985), Sebeok (1972, 1986), and Krampen (1981). Y.L.Kergosien (1985) advocates a semiotics of nature in an epistemological sense of analysing interacting biological systems, in order to increase the precision of terms such as 'signal', and to develop new themes of inquiry into the nature of biological signification. Interestingly, besides the epistemological analysis of the sign in the field of scientific inquiry and experiment, Kergosien allows for a concept of natural signification. Adaptations for example, of an animal to a new, specific function, are perceived as the realization of a natural metaphor: The signification of some biological structure is transposed, i.e., its value is changed, when it acquires another environmental context, as in the process of metaphorical signification in language. Martin Krampen (1981) seeks to establish phytosemiotics as an area of inquiry into sign processes occurring within and between species of plants, parallel with the zoosemiotics of Thomas A. Sebeok (1972). The later term was coined in 1963 by Sebeok to identify the rapidly expanding discipline within which the science of signs intersects with ethology, the study of animal behaviour. As an analytical tool, Sebeok combined a linguistic theory of acts of speech (Bühler's theory) and the information theoretical model into a hexagonal model of animal communication involving the dimensions of (a) the source, (b) the destination, (c) a channel, (d) a code or set of transformation rules, (e) a message, (f) a context referred to. In this scheme, 'zoopragmatics' deals with the origin, propagation and effects of signs, i.e. (a), (b) and (c); zoosemantics with the signification of signs, in brief (f); and zoosyntactics deals with combination of signs, in brief (d) and (e) (Sebeok, 1972: 124). The perspectives of both Krampen and Sebeok are influenced by the concepts of Charles S. Peirce as well as by Jakob von Uexküll and Thure von Uexküll, the founders of a biological Bedeutungslehre (Anderson et al. 1984, Uexküll 1982, for references and introduction). We cannot, however, give a detailed review of these traditions here; for general accounts of biosemiotics, see Hoffmeyer (in press), Schult (1990) and Bentele (1984). Sebeok (1986) sketches how physics, biology, psychology, and sociology each embodies its own peculiar level of semiosis, or sign-action (yet the immune system and the nervous system are 'intimately interwreathed by a dense flow of two-way message traffic'); thus the irreducibility of semiosis on a superior level in the hierarchy of organization to that on a lower level.
This irreducible character of sign-action on any level of integration raises the question fundamental to biology (and in particular the attempts to construct a semiotic approach to evolution) about how to give a scientific explanation of the origin of life - as well as the origin of language. The physicist Howard H. Pattee and the computer scientist Lars Löfgren have given interesting hints at a possible solution. As regards the first question, it has been a central idea to Pattee in dealing with these problems during the past two decades, that the essence of the matter-symbol problem and the measurement or recording problem must appear at the origin of life (see, e.g., Pattee 1969, 1977, 1981). Here arises the basic epistemological duality of all symbolic systems, which by definition require both a subject and an object; reflected in what is called the complementarity between the dynamic, continuous and rate-dependent mode of description of the living system, and the 'linguistic', or discrete, rate-independent mode. There is not then any single complete description possible. This approach implies still some metatheoretical presuppositions (namely 'the insertion of a self-like entity just at this very point [the origin]', as pointed out by Locker (1973: 48, cf. Locker 1981), and should not be taken as an explanation of how life could originate 'by itself'. Lars Löfgren (1981a, 1981b) outlines a self-referential linguistic model of evolution. Life itself is considered a linguistic phenomenon with language broadly conceived as a complementary pair of description and interpretation processes, hierarchically ordered with respect to expressibility. On the basis of the truth-theoretical achievements of logicians such as Tarski and others, Löfgren mounts an argument for the non-formalizability of the concept of evolution.
The idea that life comprises a language-like system is called, by David Berlinski, 'a controlling metaphor' in his aim to explore the ramifications of theories of information and complexity in evolutionary biology. Among the topics he touches on is the question of different measures of complexity/simplicity, e.g., the Kolmogorov measure (randomness in a simple string measured by the degree to which such strings admit of a simpler description). For instance if a mammal or a mollusc could be represented as a binary string, these would, he maintains, be low in Kolmogorov complexity.
Conclusion on examples. In most cases of the 'nature-as-language metaphor' discussed here, we have seen analogies between restricted aspects of the fields of biology and linguistics (level 2) rather than proper level 3 metaphors, although it is difficult to make a sharp distinction between the different levels of signification transfer in the use of metaphors in science. This is due to the different connotations which a single metaphor may convey in different contexts, some relating to specific topics, others to very broad areas, as in the case of Goodwin's cognitive metaphor. The nature/language isomorphies observed and treated under different viewpoints by Goodwin, Bateson, Berlinski, Löfgren and Pattee - and Forti, as we shall see - were conceived as rather fundamental, perhaps even paradigmatic. It is tempting to see these suggestions as part of a general trend in the life sciences towards a new view of living nature, where, according to the metaphorical view of science, metaphorical redescription (Hesse 1980) enters as a phenomenon of central importance to the creative change of scientific order. Florkin and Sebeok however, did not consider their contributions as metaphors or analogies, but as the establishment of some special sections (molecular biosemiotics, zoosemiotics) under the general science of signs.
To conclude these examples we shall cite Turbayne, who himself, in 1961 invented an instance of the nature-as-language metaphor, although in a more specific context, namely in a concrete test of the 'machine' model of vision (and its father, the 'geometrical' model) against what he called the language model:
In an attempt to develop a new synthetic concept of 'evolving organic structures', Guido Forti starts from the structural linguistics of Ferdinand de Saussure and a version of neo-Darwinism, which is taken for granted as the theory of evolution.
Evolving organic structures, encompassing, according to Forti, bioevolution and language, share common properties in that they are evolutionarily open, innovatory and transcendent: The results of the processes of language and evolution are not predictable. This is because of the arbitrariness between signifiant structure and signifié structure (see below) and the randomness of mutations. Starting off from the existing structures, the results of both processes are alien to the systemic nature of the structure considered synchronically, and are thus always synthetic and innovatory; they transcend the existing structures.
It was argued above that one should not uncritically accept the version of the theory of evolution to which Forti adheres. Neither do we endorse the linguistics of Saussure, because of its dubious or, rather, missing conception of the relationship between language and reality. We shall first schematically present some of Forti's own points on the life-as-language analogy before we move on to the critique.
Forti's illustration of the analogy between 'language' and 'living beings' includes several items, which may be summarized in a list of analogical structures (A) and similarities (S) between the two fields (the A/S distinction is ours): see scheme 1.
In order to comprehend Forti's analogies, one has to understand the concept of structure in the Saussurean tradition of linguistics. Forti describes language and species as abstract concepts. The language actually spoken among people in a language-community may well be the empirical point of departure for the linguist, but it is not the ultimate object of a structural linguistics. The spoken word (parole) is the individual's situation-embedded use of the language-system. This language system, la langue, is the underlying deeper structure, which has to be explored in the analysis. Actually, it is through a kind of methodological abstraction, separating the language system as such from the concrete act of speech performed by the individual, that the linguist can reveal the general, but immediately hidden, structure that makes up the language system. The elaboration of this structure requires a careful analysis of the component language signs and their mutual relations, to, on the one hand the acoustic image, the 'expression'- or signifiant-aspect and, on the other, their 'element of content', i.e., conceptual or signifié-aspect. The separate signifié's and signifiant's are only determined (identified) through their differential relationships to other signifié's and signifiant's. The whole language system is therefore a huge net of relations, in which a position in the network is determined by its difference from other positions. This language system always already exists, when individuals are speaking. That is, the language system structures the language use. There is, however, a feed back (or 'dialectical') relation between language system and language usage, since the language system itself is changed through the process in which it is used, thus evolving.
Language usage is not (even in Saussure) a simple effect of `la langue': the system is not changed by the individual usage as such, but through the community, which the language as an institution helps to form. However, this concept of social praxis, which becomes crucial if one wants to understand the proper establishment and change of the language system, is missing in Saussure. Social praxis is obviously a part of the larger reality that language is embedded in, but which structuralism seldom deals with in its methodological closure around the always already existing structure.
The missing conceptualization of the relation between language and 'reality' in the structural linguistics has as a consequence that the concepts of 'language' and 'species' assume a very dissimilar status. Language is a tool for communication about life in a world, but it cannot exist in itself without human beings of flesh and blood; language is not - in the immediate sense of the word - a fleshy part of the world (though it may certainly be very carnal). As a network of relations of significations it is to be found between things, between the human beings, between the meanings. This, however, does not apply to the species. A species is most definitely a part of a larger ecological system, but a very corporeal part, which exists as a subcomponent of the system, and not as a communication about the ecosystem. Thus, the relation between the species and the ecosystem is non-analogous to the relation between the language and reality.
But isn't it, one might object, the 'genetic communication' as such, which Forti is referring to, rather than ecological existence? Isn't it the structure of species that is analogous to the (linguistic) structure of language (though not its pragmatic structure)? But if so the analogy implies an unspecific switching or sliding between the species concept, the genetic gene pool concept and the concept of evolution. If the species is like a language, so are the gene pool and the evolutionary history of the species as well. On the basis of the analogy, one cannot distinguish. This unfortunate consequence we see as an effect of Forti's choice of biological framework (as well as the linguistic), namely the synthetic theory of evolution, with its tendential identification of evolution with changes of frequencies of genes in the population pool and its incomplete theory of the genotype/phenotype connection. (In terms of the idea developed in Hoffmeyer and Emmeche (in press), neo-Darwinism cannot account for the role of code-duality between analogic and digital codes in evolution).
Forti admits that the analogy is not a perfect one, because language is less well defined than species. The possibility of communication between different language areas is not so rigorously delimited as in the case of species, where 'interfertility either exists or it does not' (Forti 1977: 70). However, the species as a genetic lineage is less well-defined than Forti asserts (e.g., hybridization among plants; transduction in microorganisms; the unstable species/subspecies distinction). Although this seems to strengthen his analogy, it does not invalidate our principal objection against it.
The difficulties in the whole approach are shown by the next analogy he sets up. The distinction between langue and parole in Saussure is compared by Forti to the distinction in biology between genotype and phenotype. As parole is the concrete and situation-bound speech act, which presupposes the proper system (la langue) of oppositions and distinctions, so the phenotype is realized through a basic system with a supposed inner structure, i.e. the genotype.
Drawing the analogy in this way, however, Forti misses the whole point of introducing the language-metaphor into biology. Certainly, life has its own 'language'. This language, furthermore, resembles human language in one very essential characteristic: it is built upon a digital code, the code of DNA. Now, the Saussurean distinction of parole and langue is a distinction inside language, i.e., both parole and langue belong to the linguistic sphere of the digital code of words. Yet, the phenotype - like the species - is of blood and flesh, and as such its eventual communication belongs to the universe of the analog code (excepting the human phenotype with its characteristic voice). Thus, identifying parole with phenotype is a confusion of digital and analog communication or, in fact, a confusion of language and 'reality'.
Still, there is in biology an obvious counterpart to the parole/language distinction of structural linguistics. This is the distinction between on the one hand the genome of a single individual and on the other hand the organized gene pool of the species, which we termed the genomorf (Hoffmeyer and Emmeche, in press). According to this view sexual reproduction takes on the same role in the life sphere as does linguistic communication in the cultural sphere. And fertilized eggcells interpret the messages of genomes in much the same way that persons interpret the messages of single utterances.
There is also an analogy between la langue and genotype (or the system of genotypes) in a more critical and epistemological sense. Both the gene-concept in biology and the language-concept in structural linguistics are subject to similar debates between ontological realistic interpretations versus more methodological/pragmatic ones:
The concept of language system in Saussure has an ambiguous ontological status. On the one hand, it signifies the system that the linguist reveals through the mentioned methodological abstraction, from the concrete speech acts through the network of relations of distinctions on the expression- and content-sides of the language. On the other hand, Saussure has a tendency to treat the language system as an object as concrete as the language use, i.e. as an autonomous reality (he even claims an actual material existence for this system in the brain of the individual, cf. Forti 1977: 72). This conceptual confusion can be observed also in philosophical structuralism: from being a methodological principle about exploring the structure of the theoretical object (language) as something self-contained, not determined by relations external to the system (the principle of immanence), structuralism can inadvertently lead to a concept of structure as an independent reality. What is going on, in fact, is an ontologization of the concept of structure. In broad outline a similar development may be observed in genetics. The genetic structures, 'anlage' or 'factors', were from the beginning hypothetical relations, whose material counterpart had a highly uncertain status. The genotype of Mendelian genetics was a concept defined with reference to a specific constant relationship between observable characters at the level of the phenotype. As a result of the intensive search for the molecular correlate to the conceptual abstractions, the gene finally emerged as a concrete spatial entity of heredity buried in the structure of the DNA. The 'hereditary structure' seemed to be reducible to what was perceived as concrete entities at the molecular level.
But this strategy cannot be generalized, and the reduction of the Mendelian gene to the molecular gene is attended only with great theoretical and practical difficulties. Even those who embrace reductionism must conclude that 'there cannot be actual derivation or deduction of some regularity about the transmission and distribution of phenotypes, say their segregation and independent assortment, from any complete statement of molecular genetics.' (Rosenberg 1985: 106). This is in part because the leap between genotype and phenotype includes several levels involving a multitude of factors of which a simple simile might be the biochemical flow-chart of the basic metabolism.
The structure of the genome is itself complex. Since the discovery of the highly redundant DNA of the eukaryotic chromosomes, it has become increasingly evident that reference to 'the gene' as a discrete and concrete entity of the DNA could not be maintained. The attempt to individuate in time and space the material correlate to the language system would come up against the same kind of epistemological difficulties, as the controversy in AI (and functionalism in philosophy of mind) concerning natural language and thought simulations suggests. Talking about the material existence of the language system in the brains of individual persons is just as confusing as postulating the genotype to be located as a chemical substance in the nucleus of the individual cells in the organism. Such inadvertent reifications are, in fact, contraintentional to a structuralistic or systemic perspective.
Forti extends the genotype-langue analogy by juxtaposing the linguistic phoneme and the triplet of DNA bases, while the equivalent of the linguistic morpheme (the minimal meaning-bearing elements: basically words) is the sequence of bases codifying for a protein, i.e. a gene. It is a reasonable analogy, although it is not self-evident what is to be the 'minimum amount' of signification in genetics. François Jacob and Roman Jakobson (see above) equivalated the single bases in the DNA to the phonemes and concluded that the genetic and the linguistic code were the only known codes to be based upon the use of discrete components without any inherent signification as building blocks for the minimal signification-bearing units.
What then are the mutual relationships between the components of Forti's analogy? We are told that the equivalent of the field of signifiés in biology is the field of organic functions. Furthermore, the field of signifiants equivalates that of genetic structures (compare the list of scheme 1, #6). For both systems, the relation between the expression and content, (signifiant and signifié, the genetic and the functional) is arbitrary (p.74). In respect to the signs 'contingent' relationship between the signifying and the significated, it makes good sense to talk about analogy between the two systems. But what is the relationship between the organic functions/signifié and the phenotype/parole? Something halts in the analogy. The phenotype, we suppose, is the unity of organic structure and function, and the genotype is the unity of genetic structure and function. We can model Forti's suggestions as follows:
Parole----phenotype/field of organic functions----signifié
Langue----genotype/field of genetic structures---signifiant
By drawing these analogies Forti has brought in some inconsistency in the theory of language: the distinction parole/langue is in no way to be put on the same footing as the distinction signifié/signifiant. The analogies cannot both be right.
The confusion above indicates some problems with the metaphorical signification-transfer on this level of single concepts. The analogical mapping of concepts in one area (linguistics) on to other concepts in another area (genetics) may seem appropriate, but if we believe that we have mapped, by the same stroke, the relations of significations between the different concepts from one area to the other, we are likely to have become the victims of our own metaphor.
Take, for instance, the metaphorical statement 'society is a sea'. A word or concept (sea) is transferred from the area in which it is normally applied (the 'secondary' or 'subsidiary' subject, cf. Black (1979), i.e. the area of shipping, navigation or shipwrecks, etc.) to the 'primary subject' (society). In the process the metaphor acquires a new context - a new similarity is created - while at the same time it is loosened from some parts of its original context, i.e., its content is changed. Thus, the transfer of signification via the metaphor is only partial, and the result is that the metaphor denotes a different content than the original concept. In the process of signification transfer we are in danger of making the concepts more palpable and tangible than they are, hypostatize or reify them, forgetting that we created the metaphor ourselves and that it does not signify the same as the original concept. Society is a sea, economic crisis is a solar eclipse, and mass unemployment a shipwreck - but should a shipwreck indicate the eclipse of the sun? In genetics the tendency to hypostatize concepts is exemplified in the original methodological distinction between genotype and phenotype that has become part of the basic language of biology. Implicitly this implies the notion of the genotype as the 'essence' or guiding principle of the phenotype, the organism is thus understood as a dual entity, as the Cartesian duality between res cogitans and res extensa. In a similar sense the langue is an abstraction in danger of being perceived as a 'hidden structure' in the cranium of the talking person steering his or her speech.
The organic functions of the organism can certainly be compared to the signifié to the extent that one means signification, content or, vaguely, 'meaning'. The purpose of the genetic information is exactly to assure biological functionality. But then we fall back to the naive view that the individual sign has an already defined reference - the individual functions in the organism - prior to its contextual actualization. But what is a genetic sign? It is well known from classical genetics that genes can show incomplete penetrance and variable expressivity due to differences in genetic background (and environmental noise). 'Genetic background' relates to the fact that an individual does not inherit a single gene, but a whole genotype. The gene makes a part of an organized genome, and a gene product operates in concert with a multitude of combinations of other gene products. The function and effect of a gene (product) can be sensitive to the presence of other proteins in the cell, thus varying from one individual to another (with other genotype). Thus the 'meaning' of a gene is highly context-sensitive, not a priori given in isolation from the other genes in the epigenotype.
If the gene is a sign, and living nature is to be perceived as language or a semiotic system parallel with language, one should take advantage of the basic insights of the linguistic sciences about the difference between the sensuous, acoustic aspect of the language signs and that to which they refer, or point to. As signs they are precisely such relationships between different elements, and this feature is not restricted to the human language system. According to C.S. Peirce, the founder of modern general semiotics, a sign is a genuine triadic relation between 'a First', the primary sign or 'the sign vehicle' (corresponding to the sound, or the signifiant in speech), and 'a Second', its Object (i.e., a thing, a process, a concept or a set of concepts - that the sign refers to), 'determining a Third', its Interpretant (which mediates the reference of the primary sign to the object, i.e., the interpretant is the very meaning) (Peirce 1955). We can thus interpret the gene as a triadic sign: it has a 'primary side', the chemical structure or the 'chemical sensuality' of the DNA molecules, the signifiant of the gene. Furthermore this piece of DNA enters into a relation which mediates its signification as a code for a specific sequence of aminoacids. That is, the DNA piece as gene (i.e., as sign) is a relation to another object, the protein, symbolized by the genetic code in this gene. Finally, this relationship between the primary sign (the chemical DNA) and the protein (the object) is mediated by a complex mechanism of transcription, RNA-processing and translation, that interprets the DNA sequence in the cell: ultimately it is the whole cell itself that participates in the network necessary for such an interpretation. The interpretation thus depends on the actual state of the cell, being specified by a range of other parameters that share relations back to other genes.
Seen in this perspective the signifié is dissolved further in a relation that mediates something substantial (a concept, a protein) to a concrete interpretation. Instead of the opposition between 'organic function---signifié versus genetic structure---signifiant', we get the triadic relation, shown in figure 1.
The knowledge gained by the inspiration from the semiotics of Peirce is the emphasis that the field of genetic structures, or a single gene, cannot be seen in isolation from the larger system in which it is interpreted. The meaning of the gene resides outside the entity that is normally identified as gene: a DNA-sequence on a chromosome. This identification expresses a reduction of the gene (as a triadic sign-relation) to a physical/chemical structure. The meaning of the gene is defined by its effects on the organism, i.e. the role of the proteins in the totality of the other relations that make up the biochemical network of the organism (or its cells). A given DNA sequence can change signifié depending on the state of the cell: when the interpretant changes, the signification of the gene does too - the relations have shifted, and in this way we have a new gene. There is no such thing as a gene in isolation, every gene being a constituent of a sequential set of genes or other cellular signs, so that apart from membership of this set, a piece of DNA has no meaning - or is not a sign.
The triadic scheme, furthermore, accentuates another point: it is only by being used that the gene - as something other than just a molecular structure - is a sign (a signifié, if you like). If the gene is not actually interpreted in the cell, it is only existing as a silent, potential sign; precisely as the words in a yet unread book on my table are signs only to the extent that they are brought into a relation with an interpretant. When a gene is turned off, its meaning or relation to the interpretant is only potentially existing in the future. It thus shares the characteristics of the 'degenerate' type of sign that Peirce called an index. In the active state the genetic sign is a symbol; the relation between the object and the interpretant is predominant.
As Wittgenstein rejected the existence of prior given mental states which lie behind or under our actions (or speech acts), we can reject the existence of 'genetic states' or a distinct inheritable 'meaning', which should be immanent in the very DNA-sequences of the genome. As chemical structures these sequences have meaning - and thus constitute genes - only to the extent that they are used in a concrete organismic context. Therefore the pronouncement of Wittgenstein, that 'if we had to name anything which is the life of a sign, we should have to say that it was its use' (in Bloor 1983: 19ff) is a precise comment even to the signification of the signifié.
The intuition that the biochemical 'message' of the cell is like a sign-relation network can be tightened up and formulated as a claim concerning the epistemological status of living systems as opposed to 'dead' physical/chemical matter. The teleonomic project character of living systems is not due to the circumstance that certain elements play the role of signs for the human observer - this is a general feature in all physical and non-physical systems to which we ascribe indices; nor to the fact that the idea of purposiveness must guide our knowledge of these systems based on reason (as Kant maintained; though he may be right in respect to a systemic overall 'Ganzheitserkenntnis', but the separate components can easily be described without the teleological idea of purpose or intention (Zweckmässigkeit)); rather, it is due to the condition of living systems that they themselves constitute interpretants for the signs they contain as their subcomponents (the genetic systems).
Thus looking at the gene as a sign, it is a piece of information, which makes a difference to the organism. The organism itself is a system of signs. Abstaining from any attempt to give a non-circular definition or non-self-referential concept of life, life can be characterized in a general way that makes sense without being a particularly operational concept as the following: Life is basically a difference in the sense of 'distinction from sameness', a kind of deferment of the immediate uniform presence, the sameness of which implies the entropic flow towards death as non-discriminate being in itself. Living being arises as a distinction in being between permanent non-informational being, that is, death, and a temporary postponed death, i.e. a difference, or drive, in matter, that makes a difference between dead and living matter, that is, life.
Let us now sumarize our discussion of different versions of the language-as-life metaphor. Although we have seen several problems in the contribution of Forti, his approach has one major advantage in contrast to the metaphor of nature as an information processing machine or artificial language: the picture of life as a sign-relation network draws attention to overall, systemic, and dynamic aspects of natural history. In the normal 'information processing' paradigm of molecular biology as well as cognitive science there is a tendency to see the information (in the genes or in the written text) as the passive substance, being actively 'processed' or 'interpreted' by an organism or brain/computer which then restructures the message originally contained in the genetic or literary 'memory' of the system. However, in the context of the natural language of the spoken word or in books, it is obvious that this picture is a distortion, or half-truth: the 'original' information is not given, there is no stable 'code' that once and for all can translate the 'real' information content in a text to its actual meaning to a person or a cultural epoch; rather, meaning is a still-floating transformative principle, not found in the text or in the mind of the beholder, but in the dynamic process of interaction between communicating persons interpreting signs: other persons' thoughts, their own thoughts and texts. Reading is an active process of creating new meaning. It is not unlikely that one should look at the 'information content' of the DNA in the same way; i.e., not as a fixed blueprint or even a program with some 'instructions' containing information telling the cell what to do, not as an inherent biological meaning processed by the cell and translated from the potential information to actual information (although this is a much better metaphor than the static 'blueprint'), but as a relational determined part of a whole developmental system. The information of this developmental system is not 'inherent' in the DNA, but is being created in a continuous flow of events of interactions between the DNA and other parts of the cell. Therefore, the 'meaning' of the genetic 'message' is only discernible in the concrete process of development at the biochemical, the cellular, the organismic, and even higher levels.
Anderson, Myrdene, Deely, John, Krampen, Martin, Ransdell, Joseph, Sebeok, Thomas A. and Uexküll, Thure von (1984). "A semiotic perspective on the sciences: Steps toward a new paradigm." Semiotica 52(1/2), 7-47.
Apter, M.J. and Wolpert, Lewis (1965). "Cybernetics and development. I. Information theory." Journal of theoretical Biology 8, 244-257.
Barnes, Barry (1974). Scientific knowledge and sociological theory. London: Routledge & Kegan Paul.
Bateson, Gregory (1972). Steps to an Ecology of Mind. New York: Ballantine Books.
Bateson, Gregory (1979). Mind and Nature, a necessary unity. New York: Elsevier- Dutton Publ.Co.
Beadle, George and Beadle, Muriel (1966). The Language of Life. An Introduction to the Science of Genetics. New York: Doubleday & Co.
Bentele, Günter (1984): Zeichen und Entwicklung. Vorüberlegungen zu einer genetischen Semiotik. Tübingen: Gunter Narr Verlag.
Berlinski, David (1986). "The language of life." In Complexity, Language, and Life: mathematical approaches (= Biomathematics vol.16), John L. Casti and Anders Karlqvist (eds.), 231-267. Berlin: Springer-Verlag.
Black, Max (1979). "More about metaphor." In Metaphor and Thought. Andrew Orthony (ed.), 19-43. Cambridge: Cambridge University Press.
Bloor, David (1983). Wittgenstein. A social theory of knowledge. London: Macmillan.
Blumenberg, Hans (1981). Die Lesbarkeit der Welt. Frankfurt a.M.: Suhrkamp Verlag.
Buchanan, S. (1962). Poetry and Mathematics. New York.
Burks, A.W. (1975). "Logic, biology and automata - some historical reflections." Int. J. Man-Machine Studies 7, 297-312.
Campbell, Jeremy (1982). Grammatical Man. Information, Entropy, Language and Life. New York: Penguin.
Canguilhem, Georges (1963). "The role of analogies and models in biological discovery." In Scientific Change. A. C. Crombie (ed.), 507-520. London: Heinemann.
Cornell, John F. (1984). "Analogy and technology in Darwin's vision of nature." Journal of the History of Biology 17(3), 303-344.
Crick, F.H.C. (1966). "The genetic code, III." Scient.Amer. 215(4), 55-62.
Dover, Gabriel (1982). "A molecular drive through evolution." BioScience 32(6) 526-533.
Emmeche, Claus (1988). "Metaphors in biocommunication theory." (unpubl.)
Florkin, Marcel (1974). "Concepts of molecular biosemiotics and molecular evolution." In Comprehensive Biochemistry, vol.29 part A (Comparative Biochemistry, Molecular Evolution), Marcel Florkin and Elmer H. Stotz (eds.), 1-124. Amsterdam: Elsevier Scientific Publ. Co.
Forti, Guido (1977). "Structure and evolution in language and in living beings." Scientia 112, 69-79.
Frisch, Karl von (1950). Bees: their vision, chemical senses and language. (revised ed. 1971). Ithaca: Cornell University Press.
Goodwin, Brian C. (1978). "A cognitive view of biological process." Journal of Social and Biological Structures 1, 117-125.
Goodwin, Brian C. (1984). "Changing from an evolutionary to a generative paradigm in biology." In Evolutionary Theory: Path into the Future, J. W. Pollard (ed.), 99-120. London: John Wiley & Sons.
Gould, Stephen Jay (1982). "Darwinism and the expansion of evolutionary theory". Science 216, 380-387.
Gould, Stephen Jay (1985). "The paradox of the first tier: an agenda for paleobiology." Paleobiology 11(1), 2-12.
Hanna, Joseph F. (1985). "Sociobiology and the information metaphor." In Sociobiology and Epistemology, James H. Fetzer, (ed.), 31-55. Dordrecht: D. Reidel Publ. Co.
Hansen, Otto (1981). "Are the genes of universal grammar more than structural?" Hereditas 95, 213-218.
Haraway, Donna Jeanne (1976). Crystals, Fabrics, and Fields; Metaphors of Organicism in Twentieth-Century Developmental Biology. New Haven: Yale University Press.
Hawkins, David (1964). The Language of Life. An essay in the philosophy of science. San Francisco: W.H.Freeman & Co.
Hesse, Mary B. (1966). Models and Analogies in Science. Notre Dame, Indiana: University of Notre Dame Press.
Hesse, Mary (1980). Revolutions and Reconstructions in the Philosophy of Science. Brighton, Sussex: The Harvester Press.
Hoffmeyer, Jesper (in press), "Semiotic aspects of biology: Biosemiotics." In Semiotics. A Handbook on the Sign-Theoretic Foundations of Nature and Culture, Roland Posner, Klaus Robering and Thomas A. Sebeok (eds.). Berlin/New York: Walter de Gruyter.
Hoffmeyer, Jesper and Emmeche, Claus (in press). "Code-duality and the semiotics of nature". pp. 117-166 in: On Semiotic Modelling , Myrdene Anderson and Floyd Merrell, (eds.). Mouton de Gryter, Berlin.[was published 1991, look here!]
Hofstadter, Douglas R.(1979). Gödel, Escher, Bach: an Eternal Golden Braid. London: The Harvester Press.
Ho, Mae-Wan and Saunders, Peter T. (1979). Beyond neo-Darwinism - an epigenetic approach to evolution." Journal of theoretical Biology 78, 573-591.
Ho, Mae-Wan and Saunders, Peter T. (1984). "Pluralism and convergence in evolutionary theory." In Beyond neo-Darwinism, Mae-Wan Ho and Peter T. Saunders, (eds.), 3-12. London: Academic Press.
Jacob, François (1981). Le jeu des possibles. Paris: Libraire Arthème Fayard.
Jacob, François, Jacobson, Roman, Lévi-Strauss, Claude and L´Héritier, Philippe (1968). "Vivre et parler". Les Lettres françaises N° 1221-1222.
Jakobson, Roman (1973). Main Trends in the Science and Language. London: George Allen & Unwin (in danish in R. Jakobson (1979). Elementer, funktioner og strukturer i sproget. Udvalgte artikler om sprogvidenskab og semiotik, p. 19-70, Copenhagen: Nyt Nordisk Forlag).
Jerne, Niels K. (1985). "The generative grammar of the immune system." Science 229, 1057-1059.
Johnson, Horton A. (1970). "Information theory in biology after 18 years." Science 168, 1545-1550.
Kalmus, H. (1962). "Analogies of language to life." Language and Speech 5(1), 15-25.
Kergosien, Y. L. (1985). "Sémiotique de la nature." In IVe Séminaire de l'École de Biologie Theorique, Solignac 4-7 juin 1984, 11-26. Paris: Editions du CNRS.
Krampen, Martin (1981). "Phytosemiotics". Semiotica 36(3/4), 187-209.
Langton, Christopher G. (1984). "Self-reproduction in cellular automata." Physica 10 D, 135-144.
Langton, Christopher G. (1989): "Artificial life." In Artificial Life , (= Santa Fe Institute Studies in the Sciences of Complexity, vol.6), C.G.Langton, (ed.), 1-47. Redwood City, Calif.: Addison-Wesley Publ. Co.
Leatherdale, W.H. (1974). The Role of Analogy, Model and Metaphor in Science . Amsterdam: North-Holland Publishing Company.
Lewontin, R.C. (1982). "Organism and environment." In Learning, Development, and Culture, H.C. Plotkin, (ed.), 151-170. New York: John Wiley & Sons.
Locker, A. (1973). "Discussion". In Biogenesis, Evolution, Homeostasis. A symposium by correspondance, A.Locker, (ed.), 47-48. Berlin: Springer.
Locker, A. (1981). "Metatheoretical presuppositions for autopoiesis." In Autopoiesis. A theory of living organization, Milan Zeleny, (ed.), 211-233. Amsterdam: North Holland.
Löfgren, Lars (1981a). "Knowledge of evolution and evolution of knowledge." In The Evolutionary Vision. (AAAS Selected Symposium 61), Erich Jantsch, (ed.), 129-151. Boulder, Colorado: Westview Press.
Löfgren, Lars (1981b). "Life as an autolinguistic phenomenon." In Autopoiesis, a Theory of Living Organization, Milan Zeleny, (ed.), 236-249. Amsterdam: North Holland,.
Løvtrup, Søren (1987). Darwinism - The refutation of a myth. London: Croom Helm.
Maynard Smith, John (1986). The problems of biology. Oxford: Oxford University Press.
Mayr, Ernst (1982). The Growth of Biological Thought. Cambridge, Mass.: The Belknap Press of Harvard University Press.
McNeill, David (1971). "Sentences as biological systems." In Hierarchically Organized Systems in Theory and Practice, P. A. Weiss, (ed.), 59-68. New York: Hafner Publishing Company.
Milgram, M. and Atlan, H. (1983). "Probabilistic automata as a model for epigenesis of cellular networks." Journal of theoretical Biology 103, 523-547.
Oyama, Susan (1985). The Ontogeny of Information. Developmental Systems and Evolution. Cambridge: Cambridge University Press.
Paley, W. (1802). Natural Theology. London: R. Fauldner.
Pattee, H.H.(1969). "How does a molecule become a message?" Developmental Biol. Suppl. 3, 1-16.
Pattee, H.H. (1977). "Dynamic and linguistic modes of complex systems." Int.J.General Systems 3, 259-266.
Pattee, H.H. (1981). "Symbol-structure complementarity in biological evolution." In The Evolutionary Vision. (AAAS Selected Symposium 61), Erich Jantsch, (ed.), 117-128. Boulder, Colorado: Westview Press.
Pedersen, Olaf (1986). Naturens bog - streftog omkring et metafor. In Naturens bog, Svend Andersen, (ed.), 12-32. Århus: Forlaget Anis.
Peirce, C.S. (1883 ). Collected Papers of Charles Sanders Peirce. Vol.2, par.711. Cambridge: Harvard University Press.
Peirce, C.S. (1955). "Logic as semiotic: the theory of signs." In Philosophical Writings of Peirce, Justus Buchler, (ed.), 98-119. New York: Dover Publ.
Picardi, Eva (1977): "Some problems of the classification in linguistics and biology, 1800-1830". Historiographia Linguistica 4(1), 31-57.
Platnick, Norman I. and Cameron, H. Don (1977). "Cladistic methods in textual, linguistic, and phylogenetic analysis." Systematic Zoology 26, 380-385.
Plotkin, H. C. (1987): "Evolutionary epistemology as a science." Biology and Philosophy 2, 295-313.
Quastler, Henry, ed. (1953): Information Theory in Biology. Urbana: University of Illinois Press.
Rasmussen, Steen (in press): "The Coreworld: emergence and evolution of cooperative structures in a computational chemistry." Physica D, Stephanie Forrest (ed.).
Rosenberg, Alexander (1985). The Structure of Biological Science. Cambridge: Cambridge University Press.
Saussure, Ferdinand de (1916 [1906-11]). Cours de linguistique générale. Payot, Paris.
Schroll-Fleischer, Erik (1983). "Evolutionære modeller i kulturvidenskaberne." ['Evolutionary models in the humanities'; in danish]. In Evolution, Kultur og Samfund, Erik Schroll-Fleischer, (ed.), 50-146. Herning: Systime.
Schult, Joachim (1990): "Biosemiotik - Gegenstandsbereiche und Anwendungsmöglichkeiten." (to appear in June 1990 in Semiotik Interdisziplinär II (= Reihe Angewandte Semiotik, Bd.7)).
Sebeok, Thomas A. (1972). Perspectives in Zoosemiotics. (= Janua Linguarum, Series Minor, 122). The Hague: Mouton.
Sebeok, Thomas A. (1986). "The doctrine of signs." Journal of Social and Biological Structures 9, 345-352.
Shannon, Claude E. (1949). "The Mathematical Theory of Communication"  In The Mathematical Theory of Communication, Claude E. Shannon and Warren Weaver, 3-91. Urbana: The University of Illinois Press.
Shanon, Benny (1978). "The genetic code and human language." Synthese 39, 401-415.
Stent, Gunther S. (1968). "That was the molecular biology that was." Science 160, 390-395.
Stuart, C.I.J.M. (1985a). "Bio-informationel equivalence." Journal of theoretical Biology 113, 611-636.
Stuart, C.I.J.M. (1985b). "Physical models of biological information and adaptation." Journal of theoretical Biology 113, 441-454.
Turbayne, Colin Murray (1970). The Myth of Metaphor. (revised ed., 1st ed.:1962). Columbia, South Carolina: University of South Caroline Press.
Uexküll, Thure von, ed. (1982). "Jakob von Uexküll's `The Theory of Meaning'." (=Semiotica 42(1), special issue). Amsterdam: Mouton Publ.
Vrba, E.S. and Eldredge, N. (1984). "Individuals, hierarchies and processes: towards a more complete evolutionary theory." Paleobiology 10, 146-171.
Waddington, C.H. (1961). "Architecture and information in cellular differentiation." In The Cell and the Organism, J.A.Ramsay and V.B.Wigglesworth, (eds), 117-126. Cambridge: Cambridge University Press.
Waddington, C.H. (1968): "The basic ideas of biology." In Towards a Theoretical Biology. vol.1: Prolegonema, C.H.Waddington, (ed.), 1-32. Edinburgh: Edinburgh University Press,.
Waddington, C.H. (1972). "Form and information." In Towards a Theoretical Biology, vol.4: Essays, C.H.Waddington, (ed.), 109-141. Edinburgh: Edinburgh University Press,.
Wagner, G.P. (1988). "The gene and its phenotype." Biology and Philosophy 3(1), 105-115.
Webster, G. and Goodwin, B.C. (1982). "The origin of species: a structuralist approach." Journal of Social and Biological Structures 5, 15-47.
Weisbuch, G. (1986). "Networks of automata and biological organization." Journal of theoretical Biology 121, 255-267.
Wilden, Anthony (1980). System and Structure. Essays in Communication and Exchange. 2nd ed. New York: Tavistock Publications.
Zwick, Martin (1978). "Some analogies of hierarchical order in biology and linguistics." In Applied General Systems Research. (Nato Conference Series II:5), George J. Klir, (ed.), 521-529. New York: Plenum Press.