the traditional model for perception and theory of knowledge: its metaphor and two recent...

THE TRADITIONAL MODEL FOR PERCEPTION AND THEORY OF KNOWLEDGE: ITS METAPHOR AND TWO RECENT ALTERNATIVES

by Gail R. Fleischaker University of Louisvilte

This paper provides 1) a description of what has historically become the traditional model for perception theory and the theory of knowledge, 2) a characterization of the assumptions underlying that model, and 3) a comparison of that traditional model to each of two recent models.

The two recent models are the “information-based” model of perception by the psychologist James J. Gibson, and the autopoietic or “organizational closure” model of perception by the biologists Humberto Maturana and Francisco Varela. A description of each model is presented, as are its underlying assumptions and conceptual viewpoint.

The author’s intent, in an examination of the two recent models, is to show 1) that problems attendant to the traditional model, and to Gibson’s model as a variant of it, result from definitions within the ocular metaphor which describes that model; 2) that once the metaphor is discarded, both the theory of perception and the theory of knowledge can be differently circumscribed altogether; and 3) that the autopoietic model of Maturana and Varela has done just that.

KEY WORDS: perception theory, theory of knowledge, ecological approach, holism.

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INTRODUCTION

HIS PAPER 1) describes what has his- T torically become the traditional model for perception theory and the theory of knowledge, 2) analyzes the assumptions underlying that model, and 3) compares the traditional model to each of two recent models. The two recent models, each of which claims explicitly to be an alternative to the traditional one, are those of the psychologist James J. Gibson and of the biologists Humberto Maturana and Fran- cisco Varela. A description of each model will be presented, as well as its underlying assumptions and conceptual viewpoint.

In his recent Philosophy and the Mirror of Nature (1979), Richard Rorty has presented a rich evaluation of the ocular metaphor-a metaphor which is forceful both in description of the traditional model and as a determinant of the statement of problems within that model. It is one of the assumptions of this paper that Rorty’s critique is a fruitful one both for theory of perception and for theory of knowledge. Another assumption is the importance of the role of societal consensus in the artic-

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ulation of any accepted scientific theory: If at any time an accepted scientific theory is consistent with a society’s own view of its doing business, that general view will be one which is already established, and an “acceptable” scientific theory will be defined within that limiting view (Kuhn, 1970). Rorty cautions that since a society’s general view, and the particular scientific theory framed within that view, are both capable of being metaphorically described, an additional bias is possible: A bias packed in the language of the metaphor itself and not necessarily present either in the general view or in the particular theory.

It is the intent in this paper to examine the two recent models, operating on Kuhn’s societal consensus as an assumption and Rorty’s cautionary remarks as a methodo- logical tool. It will be shown 1) that problems attendant to the traditional model, and to Gibson’s model as a variant of it, result from definitions within the ocular metaphor which describes that model; 2) that once the metaphor is discarded, both the theory of perception and the theory of knowledge may be differently circumscribed altogether; and 3) that the auto-

GAIL R. FLEISCHAKER 41

poietic model of Maturana and Varela has done just that.

THE TRADITIONAL MODEL

Since the recent models to be discussed here are offered as alternatives to what I shall call the “traditional” model of perception, I shall begin with a presentation of the traditional model itself and an indica- tion of some of the conceptual difficulties which emerge from its use. The presentation will consist, first, of a characterization of the model and its use within psychology and philosophy, and second, of a short historical development of the metaphor which describes the model.

Contemporary models for the perceiving and cognizing mind are traditional ones, derived from characterizations by Des- cartes and Locke, elaborated within philosophy by Kant and within psychology by von Helmholtz. Differences between the models are those of emphasis of inquiry rather than those of definition. Indeed, the characterizations differ so little that one can speak of a single model serving both traditional philosophy and traditional psychology. The various theories of perception within psychology and the theories of knowledge within philosophy are attempts to use that model to solve problems posed within each field (Kahl, 1972).

The traditional model is a causal one in which the properties of the external physical object affect the retina to generate an internal mental image of that object. The distinction is made between the “sensation” as within the external world and the “perception” as within the internal world. Whether one holds, with Kant, that the internal representation has been actively assembled or, with von Helmholtz, that it has been passively mirrored, the tradition- alist maintains both that the external object and the internal representation are nu- merically and temporally distinct and that the internal representation is the end product of a causal and unidirectional chain which starts with the external object (Hirst, 1972; Ben-Zeev, 1981).

The traditional model of mind, then, is found within a “representative” or “indi- rect” realism-it is one in which an exter-

nal world of objects is somehow represented as an internal world of images. Problems traditional both to psychology of perception and to philosophy involve a side-by- side comparison of the two worlds, exploring the accuracy of the internal representation compared to the external object itself. Specific problems typically formed within the model are “Where is knowledge/ information found?” “How does the perceiving mind receive it?” “How does the cognizing mind assemble it?” “How accurate is it?” Within this model it is the external world of objects which is independently real, and the internal world of images which is representative of external reality.

While both psychology and philosophy start with the same model of perception, each emphasizes a different part of the model in its own inquiry. Problems within traditional psychology encompass the ana- tomical mechanisms mediating the two worlds. This includes both the “normal graphics” of perception (i.e., an external form and its normally-caused internal image) and “abnormal graphics” of perception (i.e., illusions and other “tricks” of the mind). Psychology raises the questions “What is it to perceive?” “HOW is it that we see. . .?” Answers to such questions are stated as explanations in terms of anatom- ical architecture and physiological function.

Within philosophy, traditional problems are posed in our pronouncements or claims of knowledge which result from our comparing the two worlds-that is, in science as our description of the world. The question is no longer “How is i t that we see. . .?” but “What is it to know?” “Given that we see.. ., what can we claim from it?” It is this latter question which lifts the epistemological inquiry out of the foundations shared with the perceptual inquiry. It is this question which shifts the inquiry from questions of representation (with their answers in the form of explanation) to questions of knowledge claims (with their answers in the form of justification).

A conceptualization of the system in which this model will work at all is one in which the two worlds can be viewed di-

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42 PERCEPTION AND KNOWLEDGE

rectly, simultaneously, and separately. This can be accomplished only by an observer who is both independent of, and has direct access to, the two worlds. The traditional model requires, thus, a third position: the viewpoint of a system observer external both to the world of objects and to the world of images. In the modern tradition of Des- cartes, this viewpoint was occupied by God (Descartes, 1641/1961). Only from this viewpoint of system observer can both the world of objects and the world of images be distinguished and compared. Only from the viewpoint of the system observer can the truth of the traditional knowledge claims be ascertained. Belief in the possibility of such a viewpoint carries with it the implicit assurance that at the end of time our assembled images (our constructions of knowledge) can be compared to the external objects (the reality whose nature we struggle to determine and define).

These are the assumptions, then, which are inherent in the traditional model of perception and knowledge: 1) there is a duality of the external world and our internal representation of that world, and 2) there is the possibility of our comparing the two. Further, a comparison of the two rests ultimately upon the possibility of a system observer who is independent of worlds- the world external to the mind and the world internal to the mind.

The metaphor illustrative of the traditional model of mind is an ocular one: the mind acts as a mirror, reflecting the external object as an internal image. Rorty traces the development of that metaphor in fine philosophical and historical detail in the third chapter of his book. He notes that even in writers as early as Plato one finds use of the ocular metaphor. Yet in such references the emphasis is on the nature of the physical object, and the process of perception is construed simply as a passive reflection from the external to the internal through a medium which remains unques- tioned. It was not until Locke’s discussion of the qualities of “things” and of “ideas of things” that the distinction was made between the external and the internal (Locke, 1690/1961; Copleston, 1960a). Once that schism was created, the emphasis shifted to questions of comparison of the external

and the internal, to their differences and to the possibility of their accurate correspond- ence.

Kant reinforced such an inward turn with his distinction between phenomenon and noumenon, and with his definition of the Categories of the Understanding as the spontaneous and involuntary mediation from sensation to perception (Kant, 1787/ 1965; Hartnack, 1967). The phenomenon is that object which is sensually given and can be conceptually categorized. The noumenon is that which stands behind the phenomenal object, is incapable of being given to our senses, and, hence, is incapable of being conceptually categorized. Because of definitions internal to Kant’s system, there can be neither a denial of the noumenal nor a claim for its identity with the phenomenal. In requiring noumenal reality which is incapable of our perception, Kant came to a position which may be characterized thus: things mundane and seen are but mediated reflections of the divine and unseen.

Kant made it explicit first that we can have knowledge only of phenomenal reality-that our mirroring minds cannot show us noumenal reality. Further, he made it explicit that we have direct access only to our internal perceptions of phenomenal reality-that our mirroring minds can show us only mediated reality.

This Kantian framework undergrids the position from which contemporary philosophy begins its work on traditional problems. That framework defines 1) a systematic duality between the world external to the perceiving mind and the world internal to it, and 2) the impossibility of our direct access to the world external to the perceiving mind. Yet as shown above, the answers to the traditional questions must of neces- sity be made from the viewpoint of an observer who is independent of both worlds, who is external to that very duality. Clearly, with the denial of human perceptual access to that viewpoint, we are denied the possibility of ever knowing the truth of our own knowledge claims within the traditional system. One is in the position, then, either of maintaining the traditional framework and its metaphoric viewpoint, and saying with Hume “We will never know the answers” (Hume, 1748/1980; Copleston,

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1960b), or of changing systematic frame- works altogether-of discarding the metaphor as no longer illustrative and asking different questions.

THE GIBSON MODEL: INFORMATION- BASED PERCEPTION

The first alternative to the traditional model to be discussed here is that of the psychologist James J. Gibson. While much of Gibson’s earlier work dealt with the empirical aspects of perception, it is his final two books that explicate his mature theoretical model (Gibson, 1966, 1979).

The main thrust of The Senses Consid- ered As Perceptual Systems (1966) is based on the distinction between our sensual awareness and our perceiving. In dealing with the anatomy and physiology of the senses and with our conscious evaluation of sensation, perception theory has been traditionally considered to be dealing with perceiving. Yet in Gibson’s usage, “perceiving” is limited to the information gained through our senses and it is in no way to be confused with the awareness of sensation which may accompany that information gain.

When the senses are considered as channels of sensations they are curious and interesting, but they are not the instru- ments of our contact with the world. The impressions of sense are incidental ac- companiments of perceiving, not the data for perceiving. . . Sensations are not, as we have always taken for granted, the basis of perception. (Gibson, 1966, p. 319)

(Ben-Zeev, 1981, discusses the confusion which arises because of Gibson’s idiosyn- cratic use of a term which is so securely grounded in an established vocabulary.) The senses are defined as elements within a network, a closed perceptual system of overlap among individual senses. The ac- tivity of the perceptual network is that

. . . of orienting and that of exploring and selecting-the commonsense faculty of attending-[and] is seen to be one that extracts the external information from the stimulus flux while registering the change as subjective feeling.. . .

The puzzle of constant perception de- spite varying sensations disappears and a new question arises, how the invariant information is extracted. Perceptual development and perceptual learning are seen as a process of distinguishing the features in a rich input, not of enriching the data of a bare and meaningless input. (Gibson, 1966, p. 320)

By virtue of “training his attention,” the agent can make new discriminations and extract new meanings: the agent is “self- tuning,” a mobile and active explorer in an informing world (Gibson, 1966, p. 270).

There are two aspects of the model which are crucial to the present discussion, aspects which are characterized by two terms which Gibson himseli GLS to describe his model: 1) “information-based perception,” and 2) “direct realism.” With the first characterization, Gibson specifies his departure from the traditional view that stimulation by light is the basis of visual perception, that neural inputs from retinal receptors provide the data upon which the brain op- erates. Rather the senses operate as a uni- fied system, as a “closed network” of perception in which “centers of the nervous system, including the brain, resonate to information” (Gibson, 1966, p. 267). I t is the role of light to carry the stimulus information, not just to stimulate the receptors: we do not see light-we see because light illumines. It is a thing’s being struck by light which produces information, and it is the information which we perceive:

Visual perception can fail not only for lack of stimulation, but also for lack of stimulus information. In homogeneous ambient darkness, vision fails for lack of stimulation. In homogeneous ambient light, vision fails for lack of stimulus information, even with adequate stimulation and corresponding sensations. (Gibson, 1979, p. 54)

The information flow around us is contin- uous and forms an ecological environment for our perception. What we extract from that environment is the invariant relation- ships in the flow, the patterns within a changing optical array defined in the organized stimulus energies of ambient light

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(Gibson, 1966, pp. 156-163; 1979, pp. 50- 58).

The definition of patterned structure is a distinction, then, which is made external to the perceiving agent. It is that definition of information as externally distinct which brings us to Gibson’s characterization of his model as “direct realism.” Gibson maintains both that 1) discrimination of information is accomplished regardless of brain connections or distribution of brain processes, and 2) there is no transformation of signal to information through the neural processes. Clearly these statements do not make the same claim. If he wished simply to maintain the first, it would amount to his saying, “Whatever it is that the brain processes involve, the end-product is dis- criminated as information.” This might give an implicit invitation to examine the brain processes, but it leaves open the question of the relationship between the incoming signal and its perception. In that case, Gib- son would be either espousing the traditional cause-effect relationship between the two, or pleading for some form of biological reductionism. But by avowing the stronger of the two statements (that there is no transformation at all), Gibson negates the sensation-perception distinction altogether and asserts an identity between the already-organized invariant information and the neural input. It is with this identity, characterized in his “direct realism,” that Gibson claims both a collapse of the traditional duality between the external and the internal and, thereby, a guarantee of the accuracy of the internal representation. Thus the cognitive faculties of the perceiving agent are not constitutive of the internal representations: In the language of the ocular metaphor, the mirror has become irrelevant.

In describing his perceptual model, much of Gibson’s terminology seems to resemble that of contemporary information theory. In his classic The Mathematical Theory of Communication (19621, Claude Shannon carefully distinguishes the semantics of information from the engineering of information:

The fundamental problem of communication is that of reproducing at one point . . . a message selected at another point.

Frequently the messages have meaning; that is they refer to or are correlated according to some system with certain physical or conceptual entities. These semantic aspects of communication are irrelevant to the engineering problem.. . . (Shannon, 1962, p. 3)

Not only are they irrelevant to one another, their analyses require different viewpoints: Analysis of the engineering problem requires a viewpoint outside the total message system, while analysis of any semantic as- pect requires a viewpoint inside the message system. For Shannon, it is the engineering problem which is of interest-the matter of transmitters, channels, and re- ceivers. However, for all of Gibson’s discussion of the properties of the physical perceptual system (what amounts to the “engineering problems” of perception), his concern is with the message and its meaning-the useful ‘functioning of the perceiving agent within an ecology of invariant patterns. Gibson may use the language of information theory, but in so doing he takes Shannon’s distinction and stands it on its head It is the engineering problems which have become irrelevant to the semantics.

Let is set up an illustration of Gibson’s information-based perception with the fol- lowing elements: ambient light, information (moving shadow of a fly), and a perceiving agent (frog). Given that frog vision is limited to motion, and that of only certain-sized objects, it would be Gibson’s point that it is the motion of the fly’s shadow in ambient light which constitutes information. But information to whom? Certainly not to us as observers of the entire system, for any “information” here would include not only the moving shadow, but the fly and the frog as well. Gibson’s limited definition of information as shadow-in-motion holds only from a viewpoint within the frog’s perceptual system- and that amounts to equating external information with internal meaning. Gibson’s model appears to work as long as he is discussing such things as frogs and moving shadows-that is, as long as he is discussing things which are clearly external to us as observers. Gibson is bound to fail, however, when he uses the same model to describe human perception, for we have no access to

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the world external to our own internal perceptual world-there is no way we can ob- jectively define external “information” for human perception in Gibson’s terms.

By defining his model as “direct realism,” Gibson sought to collapse the duality of external and internal. In defining his model as “information-based perception,’’ however, Gibson requires that same duality: Information is defined external to the perceiving agent and meaning is defined internal to the perceiving agent. As in the traditional model of perception, the underlying assumption is that the external world and the internal world are capable of observation and comparison from a single viewpoint independent of both worlds- that of the system observer. What Gibson has accomplished with his model is merely the substitution of “information” for external object and of “meaning” for internal representation. The ocular metaphor still applies.

The source of Gibson’s failure is a confusion of the particular system being observed at any given time, and hence, the viewpoint required for any human observer of an internal-external dualist system. Is the observed system limited to the world external to the perceiving agent? The description of that system would produce the model found within information theory or its variant, stimulus-response behaviorism. Is the observed system limited to the world internal to the perceiving agent? The description of that system would produce the model found within biological reductionism. Is the observed system one which requires independent definition within both worlds? The description of that system would produce the traditional model, the very one from which Gibson has declared himself liberated.

THE MATURANAFARELA MODEL: OPERATIONAL CLOSURE

While the initial work of Humberto Ma- turana and Francisco Varela was in the neurobiology of vision, it soon expanded for Maturana into the cognitive processes, the biology of language, and the neurophysiology of cognition. Varela’s work expanded into the logico-mathematics of cybernetics,

the principles of biological systems, and the evolution of biological processes. Both men are published in the standard technical biological journals, but it is in the journals of broad spectrum, interdisciplinary studies or of the theoretical structure of scientific systems that one finds their model for perception and for theory of knowledge. That model was developed from empirical studies of the nervous system and the immune system, systems which serve as chief illus- trations of the model.

Maturana and Varela predicate that model on their characterization of living systems in general, clearly described in Ma- turana’s words:

Living systems as they exist on the earth today are characterized by exer- gonic metabolism, growth, and replication (reproduction), all organized in a closed causal circular process. . . . (Ma- turana, 1970, p. 5 )

Such a characterization is produced by the application of the general concept of closure to the specific realm of living systems. Within such an application, one can describe the ongoing business of a single cell, for instance, as those transactions deter- mined by the pattern of organization within that cell and productive of those materials required in the operation of the cell itself. Thus, the characteristic “metabolism, growth, and replication” all take place within the bounds of the cell and according to the pattern of organization that charac- terizes that particular cell (a pattern of organization that would distinguish an ep- ithelial cell from a retinal cell, for example). This process thus establishes a self-perpet- uating circularity which is dependent upon the presence of the intact cellular membrane: it is the cell membrane which both marks the unit of closure (that is, which defines the particular system) and within which its operations take place.

Note that closure in Maturana’s and Var- ela’s sense does not refer to the physical structures or components required in the processes of living systems, but to the organization by which those components are put to use within the enclosed system. Such systems are not closed for interaction with

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matter or energy-they are operationally closed, that is, closed for “information.” To continue Maturana’s characterization:

Living systems as they exist on the earth today are characterized by exer- gonic metabolism, growth, and replication (reproduction), all organized in a closed causal circular process that allows for evolutionary changes in the way the circularity is maintained, . . . This circular organization determines that the components that specify it be those whose synthesis it secures. Hence, its circular nature is essential for its main- tenance and its operation as a unit. That which is not in it is external to it or does not exist. This circular organization is the living organization. (Maturana, 1970, p. 5)

While Maturana designates the function of living systems in “operational closure,” Varela designates it as autopoiesis (literally, “self-forming”). The two designations are synonymous and refer to the display of these characteristics of the living system itself: 1) its identity (that is, what distinguishes it from what lies about it); 2) the circularity of its internal organization; and 3 ) its integrity (that is, its stability as the product of those interactions). Yet inas- much as

[a] living system defines through its organization the domain of all the interactions into which it can possibly enter without losing its identity; its identity is maintained as long as the basic circularity that defines the system as a unit of interactions remains unbroken,. . . (Ma- turana, 1970, p. 5),

it becomes apparent that these three characteristics amount to the same thing, and the circular organization marking the nature of the living system emerges:

. . . the condition for being a unit of interactions of a living system is maintained, for its organization has functional significance only in relation to the main- tenance of its circularity. (Maturana, 1970, pp. 5-6)

By choosing the parameters for units of interaction within any description, one can speak equally well of an entire species (as a system) as one can of the immune system, respiratory system, and so on. This is to say that the principle of operational closure is applicable at different levels within natural systems. Varela begins with a characterization of whole systems in general:

. . . wholes, or whole systems, are ar- ranged like Chinese boxes. One whole contains another whole and every whole is contained in another whole. There’s a recursion principle there. But that doesn’t mean that you cannot stop your unwinding at some point and consider a system. (Varela & Johnson, 1976, p. 26)

Such a characterization is then applied specifically to living systems where it is used to discriminate among levels of whole systems. It can be used, incidentally, to iden- tify any level which may be a source of newly emergent properties: Elements which enter into the organization at one level may not appear in a previous level. Properties may emerge at any level, char- acterizing the nature of the system at that level:

We recognize wholes because they have certain stable properties, and the stable properties arise from the closure of the organization, and the closure of the organization is the key to the appearance of new properties, which is the characteristic of a whole that has new emergent properties. . . . I would say something like ‘the whole is more than the sum of its parts, it is the organizational closure of its parts.’ (Varela & Johnson, 1976, p. 29)

Whether the particular whole being described is bounded at the level of a cell, of a neural network, of an organism, or of a specific ecological niche, each system has its own integrity within its operational closure.

A crucial epistemological shift in this theory is that the so-called environment, and the organism’s performance in it, are considered at a level of description which

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is distinct from, and cannot be confused with, the level of the description of the nervous system as a closed network. Thus, for the nervous system there can be perturbations from the environment which are compensated via recursive interactions between neurons. When the observer expands his vision to a larger domain, those perturbations can be treated as stimuli . . ., the compensation can be construed as meaningful behavior . . ., and the whole performance can be viewed as adaptation. But in no sense is there environmental “information” being “processed” by the nervous system; such an analysis is faulty by confusing levels of description that must be kept distinct. (Varela, May 1977, p. 66)

Taken one at a time, then, the different boundaries mark different levels of explanation, different levels of conceptualization within an expanding domain.

Yet while the scope of view has been enlarged, the point of view has not changed the observation of the living system, at whatever level, is still within a specified and bounded domain relative to the observer.

Living systems are units of interactions; they exist in an environment. From a purely biological point of view they cannot be understood independently of the part of the environment with which they interact, the niche; nor can the niche be defined independently of the living system that occupies it.

For every living system, its niche is represented in its organization as the domain of its possible interactions, and this domain constitutes its entire cognitive reality.

The niche is, then, to the observer, part of the environment; to the living system, all that with which it can interact without losing its identity. For the observer the environment in which the organism lies is larger than the niche, but this environment lies in the domain of interactions (cognition) of the observer, not of the organism. (Maturana, 1970, p. 5 )

The role of the observer, then, cannot be overemphasized, for all descriptions arise from within the view of the observer as a living system, i.e., from within the human cognitive domain. In examining any system, the observer can point out the possible levels capable of different description; and in so doing he is able to characterize those levels of the system itself which are observer-dependent and separate them from those which are system-dependent.

In the model of operational closure, it is the stable pattern of response or repeated behavior of the whole system in interaction with other systems, or with its niche, that defines the nature of any particular living system. The nervous system is seen as cen- tral to that definition,

. . . not as an input-output information processing device as is the current understanding in neurophysiology, but rather as a closed unit of perception and action to maintain internally generated refer- ence levels. In other words, the idea is that the organisms’s stability produces certain levels to be maintained, and all the nervous system does is to maintain those internally generated levels in the face of perturbations. So behavior becomes the compensation for those perturbations.

Now, “compensation” and “perturbation” are very different things from “input” and “output,” although they might work in a similar way. “Input” and “output” carry the connotation of being something arising in the design of a system. . . The basic difference between input-output and perturbation-compensation is that one puts emphasis on the design of a thing, and the other puts emphasis on the stability arising from the closure of its organization . . . (Varela & Johnson, 1976, p. 28)

This characterization of organization in which the Maturana/Varela model finds its definition is what distinguishes natural systems from designed systems. The two system types are contrasted in their difference of operation: natural or nondesigned systems are characterized by an internal circular organization which accounts for the

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nature of the system; designed systems are characterized by an internal hierarchical organization which results in the product for which the system was intended. With the distinction between natural systems as circular and nonteleological and designed systems as hierarchical and teleological, one can make clear the fallacy in applying information theory to any natural system, e.g., the nervous system. Information theory would have it that in the nervous system there is a particular input and a specific output with the system functioning as the receiver of one and the producer of the other-that there is, in other words, a marked beginning and end. By contrast, operational closure has it that

. . . once the boundary of the sensors is passed, the nervous system, as a mode of organization, seems to begin at any ar- bitrary point that [the observer] may choose to consider: the answer to the questions “What is an input to the nervous system?” depends entirely on the chosen point of observation. (Maturana, 1970, p. 13)

So Maturana and Varela have it that in the nervous system, as in any natural system, the end is circled on the beginning.

The conceptualization of the Maturana/ Varela model can now be compared to that of the traditional model. With the definition of all descriptions as arising within the human cognitive view, Maturana and Var- ela render impossible the position of the system observer external to the human mind, an element required within the traditional model. With the definition and operation of the principle of operational closure, the traditional duality of external object and reflected internal representation is denied. Indeed, the concept of reflection is itself denied since all observations origi- nate within the world of human cognition: One cannot properly speak of any “mirror” since there is no “mirroring.” Clearly the ocular metaphor is in no way illustrative of the autopoietic model of perception.

CONCLUSION

To be an effective explanatory tool, a metaphoric model must be both specific

enough to apply to particular empirical cases and broad enough to provide only a framework in which general cases may be tested for fit-that is, its definition must be both detailed and general. But if the metaphor is defined generally enough to be lifted from the detail of the actual cases, there is the possibility of defining in elements that were not required in the particular cases. One is entitled to ask from time to time, then: What is required in the actual case? What is required in the metaphorical case? What in the actual case does the metaphor legitimately capture? What does the metaphor itself unnecessarily contrib- ute?

Richard Rorty has asked those very questions of the ocular metaphor in its illustration of the traditional model for perception and for theory of knowledge. While the ocular metaphor was intended to describe the actual cases in schematic terms, the very act of schematizing built in logical requirements at the conceptual level which were not present at the practical level of particular empirical cases. Specifically, the process of neural transformation of external stimuli into internal images does not require an observer external to the transformation, yet the conceptualization of a system or a metaphorical model in which such a process is seen as taking place has just such a logical requirement: reflecting logi- cally demands an observer both of the object and of the image.

Historically, the ocular metaphor and its logical requirements were consistent with the scientific and philosophical thought of the times in which they arose and were used. And so, too, were the problems and their various solutions within perception theory-and they were cast in terms of that metaphor. The development of scientific and philosophical thought in our own time has been away from the tenability of the objective observer and from the logical con- sequences of its incorporation into any system. Thus we find contemporary alternatives which deal explicitly with the disman- tling of the metaphorical traditional model (i.e., the definition of the objective external observer, or the duality of external object and internal representation) and explore altogether new understanding of the cog-



nitive processes. It is to be expected that such contemporary alternatives will produce new metaphors and new logical requirements consistent with our scientific and philosophical time.

In fashioning his model of information- based perception, Gibson took elements from two current alternative models: ecological theory and information-system theory. Gibson claimed that his “ecological approach” to perception constituted a rev- olution in perception theory, that his point of view was radically different from the traditional view. It has been shown here that such a claim is unwarranted-that Gibson’s view is still one of traditional ocular reflection. While Gibson may have intended a radical alternative to the traditional model, his attack is not radical (as one launched at the systematic view would have been). His result is not an alternative to the traditional model but a substitution for its individual elements.

By contrast, Maturana and Varela begin with a holistic view: in seeking to describe a system in which the details of the immune and nervous systems might fit, they leap the bounds of the ocular metaphor altogether. They are among those who attack reductionist theories of living systems-an attack which serves as a critique of Gib- son’s “ecological approach” as well as those of the biological reductionists and information or systems theorists in general:

The behavioral view reduces a system to its input-output performance or behavior, and reduces the environment to inputs to the system. The effects of outputs on environment is not taken into account in this model of the system. The recursive view of a system emphasizes the mutual interconnectedness of its components. That is, the behavioral view arises when emphasis is placed on the environment, and the recursive view arises when emphasis is placed on the system’s internal structure. (Goguen & Varela, 1979, p. 34)

Maturana and Varela have created a model which is not constrained within the same bounds as the traditional model: Because they inhabit an entirely different point of view, they have constructed a new framework for an entirely different model.

In the broad principles of “operational closure,” Maturana and Varela give us the tools to distinguish exactly what operational domain we are a t any moment describing and at what level. With scrupulous application of these tools, we are able to avoid the confusion of contexts as Gibson was not. The definition of living systems as “units of interactions,” coupled with the distinction between levels of description, make apparent the role of the human observer-as capable of interacting with all that he describes. Additionally, with the cautionary note as to the human omnipres- ence in the role of system observer, we are made aware of the possibility of his inten- tional stance as he assumes that role of descriptive observer.

Because of the conceptual confusion within the traditional model of perception, the endeavors of traditional psychology and traditional philosophy which grew out of its use were confused on the same ground. By applying the principle of operational closure to the traditional conceptualization of mind, the confusion within the traditional model and the confusion between the two endeavors can be seen for what they are: a confusion of levels of description.

Where does this leave the theory of perception? The theory of knowledge? It means that a clear distinction can be made between the two endeavors, that the psy- chological enterprise can be pursued on one level and that the philosophical enterprise can be pursued on another level. With such a distinction made, the two enterprises need not compete for a definition of what “legitimately” comprises the single domain of cognition; they can instead cooperate in deriving the description of a single domain from two different levels.

In closing, we can do no better than to use Varela’s words as he bemusedly compares his model to the traditional one from which it is so markedly different, indicating some directions for future development as he does so.

For an observer [it] is necessarily the case that whatever he describes (sees, perceives, understands) is a reflection of his actions (perceptions, properties, organization). There is a mutual reflection between described and describer. They



are mutually revealing. (Varela, 1976, p. 65 )

This means that the contents of our reality are truly a reflection of the recursive biological and cognitive computations, in contradistinction to the more commonsense view that our knowledge is a map of the out-there. From this point of view, there is more a construction than a map. These are tantalizing possibilities for a cross-connection between epistemology and science . . . (Varela, 197713, p. 82)

With a theory of perception, we can pursue questions within the context of the physical-in terms of explanation for visual and cognitive phenomena as perceptual processes. With a theory of knowledge, we can pursue questions within the context of the conceptual-in terms of justification for statements in the social and linguistic do- mains.

REFERENCES Ben-Zeev, A. J. J. Gibson and the ecological approach

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Gibson, J. J. The senses considered as perceptual systems. Boston: Houghton Mifflin, 1966.

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Journal of General Systems, 1979,5,31-43. Hartnack, J. Kant’s theory of knowledge. M. Holmes

Hartshorne, [Tram. ] . New York: Harcourt, Brace & World, 1967.

Hirst, R. J. Perception and realism. In P. Edwards, (Ed.), Encyclopedia of philosophy (Reprint edition). New York: Macmillan, 1972, Volume 6: 79-84 and Volume 7: 77-83.

Hume, D. An inquiry concerning human understanding. [1748]. Chas. W. Hendel, (Ed.). Indiana- polis: Bobbs-Merrill Educational Publishing, 1980.

Kahl, R. Helmholtz, Ludwig von. In P. Edwards, (Ed.), Encyclopedia of philosophy (Reprint edition). New York: Macmillan, 1972, Volume 3: 469- 470.

Kant, I. Critigue ofpure reason, (2nd Ed.). Unabridged [1787]. Norman Kemp Smith [Trans.]. New York: St. Martin’s Press, 1965.

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Locke, J. Essay concerning human understanding. [1690] In W. Kaufman, (Ed.), Philosophic C h - sics- Vol. II: Bacon to Kant. Englewood Cliffs, New Jersey: Prentice-Hall, 1961, pp. 164-202.

Maturana, H. The neurophysiology of cognition. In P. Garvin, (Ed.), Cognition. New York Spartan Books, 1970.

Rorty, R. Philosophy and the mirror of nature. Prince- ton, New Jersey: Princeton University Press, 1979.

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Varela, F. J. The nervous system as closed network. Brain Theory Newsletter, 1977,2,66-68. ( a )

Varela, F. J. On being autonomous: The lessons of natural history for systems theory. In G. Klir, (Ed.), Applied geneml systems research: Recent deoelopments and trends. New York: Plenum Press, 1977. ( b )

Varela, F. J. & Johnson, D. On observing natural systems. CoEoolution Quarterly, 1976 (Sum- mer), 26-31.

(Manuscript received April 2, 1982)


the traditional model for perception and theory of knowledge: its metaphor and two recent...

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