Annotationen:The Control of Perception and the Construction of Reality: Epistemological Aspects of the Feedback-Control System
Philosophy has struggled with the spectre of scepticism for over 2000 years. The strongest arguments in the sceptic’s arsenal have centered on problems of perception. Yet it is perception that perpetually seems to reinforce common sense in its rejection of scepticism: The world looks and feels real, and even if it becomes more and more difficult to prove that it is, common sense agrees with Descartes and refuses to believe that God could have been so mean as to equip us with untrustworthy senses.[2] But does common sense have to hide its head in the sand? The Pyrrhonist’s suspension of belief, after all, springs from a simple kind of reasoning that might well be adopted by common sense. Sextus argues:
Each of the phenomena perceived by the senses seems to be a complex: the apple, for example, seems smooth, odorous, sweet and yellow. But it is non-evident whether it really possesses these qualities only; or whether it has but one quality but appears varied owing to the varying structure of the sense-organs; or whether, again, it has more qualities than are apparent, some of which elude our perceptions. (Sextus Empiricus 1933 p. 57, I 94-5)
The argument is effective because it becomes obvious to anyone who stops to ponder the act of perceiving. There is no good reason to believe that our senses somehow provide a one-to- one correspondence with something which we do not perceive.Today’s common sense is based on the realism of 19th century empiricists, and the sceptical arguments about perception are particularly effective against the realist empiricist. Since he wants to be able to rely on science as the most solid form of human knowledge, he must have certainty at the foundation. For the empiricist this has led to asserting the incorrigibility of sense-data statements, or some reasonable facsimile. But there need be no fundamental connection between empiricism and a requirement of certitude. Recent writers have accepted sceptical arguments and incorporated them into an empirical framework. This is done explicitly by Paul K. Feyerabend 1965, 1970 and 1970a and Arne Naess 1972, and is at least implicit in the work of Thomas Kuhn 1962, Norwood Russell Hanson 1958, and others. The seminal work was contained in Ludwig Wittgenstein 1953 and, to a certain extent, in Sir Karl Popper 1934. The position is straightforward. Human knowledge in general, and science in particular, is not engaged in uncovering certainty, truth, or reality, or any of the bugbears of dogmatic science.
Modified scepticism requires that we view any epistemological system as a hypothetical framework or “model,” in the sense that it is a tentative conceptual arrangement that may help to make experience more comprehensible and more manageable. In this context we are using the term “model” as it is used in cybernetics. That is to say, a model is not intended to depict or replicate a physical structure, but merely to illustrate one possible way of carrying out a function that leads to a given result. The hypothetical framework or model, thus, must allow us to map one possible way to perceive a common-sense world, but at the same time it must remain ontologically uncommitted and abstain, in the Pyrrhonist tradition, from postulating or denying correspondence to an external reality. This can be attained if we make it explicit that the fundamental question is not ontological: What is the structure of the real world? but cognitive: What is the structure of our experiental world? The key point is that we may be able to analyze the structure of our experience without making the unwarranted assumption that to perceive must be a process of passive reception rather than a process of construction
Only the part above the dashed line corresponds to what an observer would consider to be an organism, for instance a frog. The area below the line represents that part of an observer’s experiential field that remains as “environment” or “background” from which the observer has perceptually or conceptually separated the organism. Hence, the observer may see (and speak of) the frog as interacting with its environment. The frog, that is the organism itself, as we shall argue in what follows, has no possible cognitive access to its environment. And, if we apply the model to ourselves as organisms, we too cannot have access to our own environment because our experience, whatever it may be, lies on this side of the dashed line and can be composed only of the signals within our neural network.
The diagram represents an organism in which the connections between error signals and effector function are fixed connections, not learned ones that would be modifiable by further learning; and the fact that they have “environmental feedback,” i.e. the fact that they actually affect the sensor function, is taken for granted. From the epistemological point of view, therefore, we can say that the diagram represents an organism with built-in “knowledge,” because “knowledge” in a control system is knowing which effector function will be successful in eliminating the error signal created by a particular sensory signal. For an observer of the organism, the observed “output quantity” is an effect of the “effector function” and, in turn, the cause of a change in the “input quantity” which then causes a modified sensory signal within the organism. This part of the loop, however, is not accessible to the organism itself, because, as Powers has said, the organism can perceive nothing but its own sensory signals
Behavior in this model refers to an activity, rather than to the result of an activity. With a rat in a Skinner box, for instance, it will no longer be sufficient to ask why the rat’s bar-presses become more or less frequent; we also have to ask how the rat succeeds in pressing the bar when it may have to start toward it from different places in the box. In other words, how is it that the rat – or ourselves, for that matter – ever manage to hit a target or attain a goal? The answer suggested by the feedback model is that “targets” or “goals” are simply reference signals, i.e. specific values of sensory signals (or constellations of such signals) in the form of an internal representation to which actual sensory signals can be compared. If the comparison shows a discrepancy, an error signal is generated and triggers an activity which modifies the actual sensory signal until it no longer shows a discrepancy from the reference value. The feedback model, moreover, accounts also for a somewhat different situation that stimulus- response theory finds difficult to explain: there can be a “response” (i.e. activity) without a stimulus. Activity is triggered by an error signal, and an error signal is generated not only when there is a change in the sensory signal but also when there is a change in the reference value.
The environment which, in Powers’ terms, is “emitted” by the first-order input functions of a perceiving organism can in no way be equated with what an observer of such a control system or organism would call the system’s environment. The observer makes the distinction between an organism and that organism’s environment as a distinction in his own field of experience. In terms of visual experience it is equivalent to any figure/ground distinction. For the organism itself, however, the first-order perceptual signals are “environment,” but only in the purely metaphorical sense that they constitute the raw material for all further neural computation. Seen from inside that organism – the organism we are observing – the dichotomy between it and its environment cannot possibly be made. “Environment” is not something such an organism can in any way derive from its proximal neural signals, it can be posited only by an observer of the organism
“Knowledge” is the construction and maintenance of invariances; and “learning” is an increase in the system’s ability to control sensory signals and to adjust reference signals to do that. Knowledge is not the recognition or awareness of these invariances and learning is not passive recording. This would encumber the model with some form of representational theory and would lead to an infinite regression, i.e. how do we know that we know, etc. This misconception arises from the view that signals, within a control system, usually imply “information” and perhaps knowledge. As D. C. Dennett argues:
Any time a theory builder proposes to call any event, state, structure, etc., in any system (say the brain of an organism) a signal or message or command (or otherwise endows it with content) he takes out a loan of intelligence. He implicitly posits along with his signals, messages, or commands, something that can serve as a signal-reader, message- understander, or commander (else his “signals” will be for naught, will decay unreceived, uncomprehended). (1971, p. 96, italics in the original)[7]
If we try to apply this to Powers’ model, one thing immediately becomes clear: Though he says that the signal emitted by the first-order input function “is an analogue of an external quantity” (1973, p. 148), this analogical correspondence can be posited only by an observer – the control model has the signal and nothing but the signal. “What we experience is a set of outputs of perceptual functions, and we have no way to detect the true nature of the inputs” (Powers 1974 p. 6). That is to say, for the model itself, the sensory signal can have no “content” and cannot be decoded – it is what it is, a neural current travelling to a certain point in a network, where it arrives and functions as a neural current. As far as the system’s sensory signals are concerned, no “loan of intelligence” has to be taken out and in themselves they cannot constitute “knowledge.”In the hierarchical network as Powers has projected it, this kind of learning to select the “right” activity in the first-order loops, becomes “learning to choose the right reference value” in the higher-order loops, where all signals and values are composites of elements from the lower levels.[8] That is to say, we can now consider it a learning process resulting in “knowledge” when the organism construct and maintains invariant, for instance, as a “permanent object,” a reference signal that is composed of several sensory signals from below. Constructed invariances of that kind correspond exactly to what Piaget has called “operative schemas,” and we believe we are justified in considering them “knowledge” because they are acquired determinants of activity regardless of whether or not the organism is consciously aware of them. It is these invariances that give the apparent stability and durability to our representations and enable us to recognize and to know. Conversely, maintaining already established constructs invariant inevitably creates constraints for any further construction. There is a parallel with the empiricist construction of scientific theories.
Traditionally, observations were taken as data to support or refute scientific theories. Similarly, perceptions were taken as data for supporting or refuting our view of the world. Contemporary scientific empiricism has reversed the role of observation and theory. A scientific theory establishes criteria which define what is to count as data or evidence. A global scientific; theory establishes a metaphysical system.
Such a system will, of course, be very “successful,” not, however, because it agrees so well with the facts, but because no facts have been specified that would constitute a test and because some such facts have even been removed. Its “success” is entirely man-made: it was decided to stick to some ideas, and the result was, quite naturally, the survival of these ideas. (Paul K. Feyerabend 1965, p. 178)
Thus within the framework of a scientific theory there are indeed facts. But these facts and the related scientific knowledge are theory-laden. They are incorrigible (in whatever sense of the word you want to adopt) only within the framework of the theory. They must stand or fall with the criterion for accepting or rejecting the theory. Insofar as that criterion is arbitrary, so are the facts of the scientific theory. Similarly, we reverse the roles of perception and the organization of the world. The higher-level organizing principles establish criteria which define what is to count as data or evidence. It is in this very sense that we decide to “stick to some ideas.” Within the framework of the organizing principles there are indeed veridical perceptions. But these veridical perceptions, and knowledge in general, are bound by our commitments – they are “organization-laden.”Let us now examine several of the traditional issues from the perspective of Powers’ model. What would it mean for perceptual statements to be incorrigible? In the framework of our model this question needs to be more explicit. We must specify the level of the model to which we are directing our analysis. Is there a level which provides the data for incorrigible statements? In what sense would any levels’ input be grounds for incorrigibility – from the perspective of the model?
If the first-order sensory signals are “the only environment that higher systems can respond to” (Powers 1973, p. 95), and if these signals represent no more than the intensity of some basic physical effect, then it is clear that no amount of summation, transformation, or computation of these signals can reveal to the perceiving system what has caused the physical effects that constitute its input. The system acts on the lowest level to keep these signals’ intensity close to a certain reference value, which is to say, it acts to keep them invariant. On the higher levels, the input signals are compounded and so are the reference values. What is being kept invariant there (and in that sense constructed out of simpler invariances) are permanent objects, permanent concepts and, finally, a relatively permanent and reliable world. The reference values that constitute these invariances are set and adjusted from the top. From level to level they are sent down to the bottom level of sensory functions. And since it is these reference values that control the activities that can modify the sensory signals, one can say that, in principle, what the system perceives is controlled from the top of the system’s hierarchy. We now apply this model to ourselves, as organisms.
Within the framework of each level, particularly the lower levels, what we perceive cannot be doubted. We do not doubt because what we perceive is modified by our own activities. This successfully precludes any attribution of ontological significance to what we perceive. There is no “given.” There is no lowest level which is free from the organizing principles. If “the given” is really (in some sense of the word) the disturbance of level one, then it is not discriminable within the structure of the model. The disturbance is modified in order to produce the input to level one. It is modified by our behavior and the modification is an analog process. Epistemologically this is of paramount importance: The disturbance, whatever it may really be, is never sensed discretely but merely creates a fluctuation in the total sensory signal. Hence the organism can never discern to what extent a fluctuation is due to disturbance and to what extent it is due to its own activity. Thus there is no level which is organization-free perception. There is no dichotomy between perceiving and interpreting. The act of perceiving is the act of interpreting. The activity of perceiving consists in constructing an invariance. Isolating, selecting, focusing, attending, are all a part of this process.Norwood Hanson argues, “People, not their eyes, see. Cameras and eyeballs, are blind” (1958, p. 9). Seeing requires organization. It is not possible to isolate the process, or to identify it with the activity of any particular level. It is systematically ambiguous. “To perceive” is equally systematically ambiguous. This ambiguity is precisely what is responsible for positing a “given” in sensation which is then “seen” or “perceived.”
We are not able to recover what is typically referred to as the given in sensation. In particular, we are not able to recover the original disturbance to level one, what the proverbial naive realist would try to refer to as the “physical quantities in the environment.” The neural computation at the input of level one permanently confounds the disturbance.
What is difficult, of course, is getting used to the idea that what we see indicates the existence of a perceptual transformation and only secondarily and hypothetically something actually occurring in an external reality. (William T. Powers 1973, p. 24)
The world, as we see it, is always just that, the world, as we see it. As in Piaget’s developmental model, we are not starting out with a clearly well defined world, rather we construct the world by “assimilating” all input to already formed conceptual structures.Given this active construction, it is an equivocation to speak of external objects in a real world. Objects and the world are both complex products of the organism’s system. The notion of an object is imposed upon the system by its own doing. Whatever may be the source of the lowest-level disturbance, without the organism’s combinatory effort they arc not “objects.” The world of middle-sized objects is constructed at the third levd and organized, by sequencing and establishing relations at the fourth and fifth levels. Hence, from the system’s point of view, there can not even be a conceptualization of causality below these levels, and that means that whatever we isolate as a “cause” or as an “effect” must be a construct of the third level or above and cannot represent an independent entity that “exists” outside the operations of the network. The system builds the notion of permanent object. The degree to which this is matched in some external environment is, by definition, not perceivable.
This means that we would be much safer in general to speak of sensation creating input functions rather than sensation recognizing functions. To speak of recognition implies tacitly that the environment contains an entity to be recognized, and that all we have to do is to learn to detect it. It seems far more realistic to me to speak instead of functions that construct perceptions. (William T. Powers 1973, p. 114)
For an organism, strictly speaking, there is no environment. This is only definable for an observer who within his field of experience constructs an organism and constructs an environment for that organism. It is senseless (literally) to place ourselves and our experiential world within an environment, i.e. to postulate a mysterious realm beyond our own signals into which we may project a noumenal origin of the invariances we compute.How does it come about that we all seem to be bound by remarkably rigid constraints in the construction of our worlds and why, if our construction of a world requires no more than a certain internal consistency of subjective invariances, do we all end up with worlds that seem so very much the same?
The constraints of our construction are sometimes explained by referring to the individual’s cognitive development and in particular to the fact that the construction of objects,’ of the categories of space and time, and of the concepts of motion, change, and causality takes place at a very early stage in the individual organism’s cognitive career. These constructs become immediately involved in every one of the organism’s cognitive activities, most subsequent constructs are in some way based on them, and it therefore becomes almost impossible to “undo” them at a later stage. With most of us these basic concepts lead to a highly successful construction, if success is measured by the stability rather than the logical coherence of the world we achieve.
From our very childhood we are subjected to an education which gives a definite direction to our way of looking at things and acting in the world, and which suppresses, or relegates to the realm of fantasy, all other possibilities. This is how our notion of reality comes into being, ... (Feyerabend 1967, p. 304)[9]
The argument can be simplified and presented on the most general level without any reference to actual ontogenic development. It seems inevitable that, in any structure that uses specific building blocks, the character of these building blocks will entail certain limits and constraints of construction. In Power’s hierarchical model, for instance, it should not surprise us that the construction of higher-order invariances will be to some extent constrained by the number and kinds of invariances that can be maintained on the first level.[10] The question concerning the similarity of construction in a plurality of individuals raises an altogether different problem. What has to be answered is not really the question as to how we come to have “objective” or “intersubjective” knowledge (a secondary consideration), but rather the more elementary one: How do we come to have other people in our subjective construction of a world? It is certainly possible to provide a plausible analysis of the construction program that a control system would have to carry out in order to install in its network invariances of permanent objects that belong to a special class with “other-people properties” (comprising for instance an invariant and therefore predictable margin of unpredictability). Such construction leads to a solipsistically generated society of fellow humans, and that is intuitively quite unsatisfactory. But then, intuitively, the denial of any knowledge of an ontological reality is also unsatisfactory. Berkeley, in his efforts to escape the solipsistic loneliness into which his unwavering and, it seems, irrefutable reasoning had landed him, opted for an imaginative but wholly irrational way out. His attempt to recover an objective reality through the introduction of God’s perceptual prowess has for us, today, the air of a gimmick.[11] But the Empiricist who resorts to a real external object is doing the same thing. Consequently, it is subject to the same criticism. What, after all, is the real external object other than “that which preserves objectivity”? External structured reality is a hypothetical construct which serves this sole purpose. We have argued here that it is misleading since we cannot have access to any of its features. This is what Kant achieved by attributing space and time, as Anschauungsweisen (ways of apperception), to the process of experiencing. He irrevocably pushed ontological reality beyond the reach of human representation. No amount of transcendental effort can make our reason grasp a noumenal universe in which, by definition, none of the relations we are able to compute is applicable.
This is precisely the Pyrrhonist limitation we accepted in the beginning. The limits of our model represent only the limits of what we perceive. Knowledge is limited by the very methods we use to obtain knowledge.From the perspective of the cognitive model we must reject the deus ex machina solutions of Berkeley, as well as those of classical and logical empiricism that, albeit without the help of God, reify a structured external reality. Instead we turn to man. Man is both an organism and an observer/ constructor of organisms. In this dual role there is an inherent danger of confusion. An organism’s introspection, his awareness of his own constructive activity, leads to the realization that his representation of a world, his knowledge, must be of his own making. That is, it leads to what we should call epistemic solipsism. But this cannot be an insidious solipsism because it is ever present and pervades all and every awareness of ourselves. We do, in fact, live with it. Perhaps it is the source of that intimate sense of loneliness that is endemic to human beings. It is the inescapable consequence of the Pyrrhonist’s arguments, of the ultimate limits of reason, and of our perpetual effort to segment, order, and comprehend experience. As the observer/constructor of organisms, on the other hand, we are led to believe in the objects, the other people, and the whole world which we actively create in the act of perceiving. They are “real” in the sense that we do organize our experience in that way. Ontological solipsism, which would be insidious, can get no foothold in this construction of ours, as long as we remain aware of the basic assumption that our constructive activity operates with the proximal signals within our experience and results in an experiential model. It is only when we confound our roles that we mistake the nature of reality. As observers we can h ave our real world, as organisms we must remain aware of the fact that it is our construction.[12]
Once we adopt this position, we can put the ontological questions into their place – which is not to say that we answer them. In our role as observers/constructors of organisms it should not surprise us that “several people can perceive or act or be affected by the same object at one time” (Hirst 1964, p. 259). Since we have constructed “other people” by crediting certain permanent objects within our experience with goal-directed behavior and goal structures similar to those we attribute to ourselves, it would indeed be surprising if these “others” did not act and were not affected by objects in ways which in principle, we could attribute to ourselves. And since, in constructing the object, we have given it “permanence” by projecting it into an external world, it should not surprise us that we now expect it “to persist even when it is unobserved” (ibid.). We are constantly striving to achieve a homogeneous, consistent, non- contradictory construction of our experiential world. We are constantly looking for invariances and assimilating experiences by disregarding individual differences. Hence we should not be surprised when we perceive things to be similar, recurrent, and invariant . But, as we have tried to show, similarity, recurrence, and invariance pertain to the way in which we organize our experience, and nothing in our experience could warrant the assumption that they are characteristic of an ontological reality. That such a reality exists, that it contains permanent objects and other people may be our profound intuitive belief, but if we restrict “knowledge” to what we can rationally demonstrate, we have no way of knowing such a reality.
From our very childhood we are subjected to an education which gives a definite direction to our way of looking at things and acting in the world, and which suppresses, or relegates to the realm of fantasy, all other possibilities. This is how our notion of reality comes into being, ... (Feyerabend 1967, p. 304)[9]
Such a system will, of course, be very “successful,” not, however, because it agrees so well with the facts, but because no facts have been specified that would constitute a test and because some such facts have even been removed. Its “success” is entirely man-made: it was decided to stick to some ideas, and the result was, quite naturally, the survival of these ideas. (Paul K. Feyerabend 1965, p. 178)
Each of the phenomena perceived by the senses seems to be a complex: the apple, for example, seems smooth, odorous, sweet and yellow. But it is non-evident whether it really possesses these qualities only; or whether it has but one quality but appears varied owing to the varying structure of the sense-organs; or whether, again, it has more qualities than are apparent, some of which elude our perceptions. (Sextus Empiricus 1933 p. 57, I 94-5)
The senses wherein lie the greatest source and proof of our ignorance. Every thing that is known is unquestionably known by the ability of the knowers; for, since the judgment is derived from the mental activity [De !’operation] of him who judges, it is right that he should perfect that activity by his resources and will, not by outside constraint, as would be the case if we know things by the force, and from the l aw, of their essential being. (Michel de Montaigne 1925, p. 382)
A first-order perceptual signal reflects only what happens at the sensory ending: the source of the stimulation is completely undefined and unsensed. .. . There is no information in any one first-order visual signal to indicate the origin of the light which the input function absorbs; the source can be fluorescence inside the eyeball or an exploding star a hundred million years removed in space and time, with no change in the character of the perceptual signal. (Powers 1973, pp. 95-96)
Science is not a search for a set of facts which are incorrigible. For Naess, “Anything is possible,” (1972, p. 88) and for Feyerabend, “Any idea can become plausible” (1970, p. 301). The point of their work has been to examine the structure of human knowledge, after acknowledging its limitations.
There are clear precedents for this approach in, what Richard Popkin refers to as “constructive or mitigated scepticism” (1964, Ch. VII). Pierre Gassendi tries to hold the middle of the road.
For the dogmatists do not really know everything they think they know, nor do they have the appropriate criterions to determine it; but neither does everything that the sceptics turn into the subject of debate seem to be so completely unknown that no criterion can be found for determining it. (Pierre Gassendi 1658, p. 326)Powers’ model of the cognitive functioning of the brain abstains from these additional assumptions and proposes a provocative alternative for the epistemologist. Powers assumes that our picture of the world is a construct. The degree to which this construct corresponds to an “external reality” is, from the point of view of the organism, not knowable. Powers explains, “The brain’s model of reality, as far as consciousness is concerned, is reality – there is nothing else to perceive” (William T. Powers 1973, p. 24 and again p. 152).[4]
The model is essentially an unpacking of a single claim: Behavior controls perceptions. Although we shall make an effort to sketch the outline of Power’s model, our main concern is to draw attention to and expand the epistemological implications of his work. Where Pavers refers to issues in epistemology his comments are compatible with classical scepticism. There is, however, one point where we diverge from Powers’ model, and that is with regard to “learning.” While Powers describes a complex system of learning involving integral reorganization, we merely refer to the very basic process of inferential learning as it was mapped out by Craik 1966, Ashby 1967, 1970 and Maturana 1970 (see footnote 8).
It is a generally accepted axiom of behavioral models[5] that the objects of perception (stimuli) control behavior (responses). Powers explicitly rejects this. “Behavior is the process by which organisms control their input sensory data. For human beings, behavior is the control of perception” (1973, p. xi). An act of perception is not neutral or passive, it does not just happen. Rather, what is perceived is a function of the organism’s own behavior. The behavior is altered in order to modify what is perceived. Actions serve to keep the experiential world stable and intelligible.
The diagram illustrates a homeostat, i.e. a system designed to maintain constant a specific condition which is represented by the signal emanating from the “sensor function” (cf. Cannon 1932; Ashby 1952).
“The central fact that needs explanation is the mysterious fashion in which actions vary in just the way needed to keep the behavioral result constant” (Powers 1973a, p. 352).
Rosenblueth, Wiener, and Bigelow pointed out: When we perform a voluntary action what we select voluntarily is a specific purpose, not a specific movement. Thus, if we decide to take a glass containing water and carry it to our mouth we do not command certain muscles to contract a certain degree and in a certain sequence; we merely trip the purpose and the reaction follows automatically. (Rosenblueth, Wiener, and Bigelow 1943 p. 19)
The principle which Powers proposes for the structure of more complex systems is that of hierarchical arrangement. “The entire hierarchy is organized around a single concept: control by means of adjusting reference signals for lower-order systems” (1973, p. 78).
“The set of all first-order perceptual signals emitted by first-order input functions is the only environment that higher systems can respond to” (Powers 1973, p. 95).[6]
There are no stars, no fluorescence, no space and time, and certainly no organism and environment on that first level – there are only elementary sensory signals, and what the first- order systems control is the intensity of these signals. In Powers’ words, they can be thought of “as an analogue of some basic physical effect” (1973, p. 101). But the organism has no way of telling where that effect comes from – for all it knows it might originate in its own eyeball. As the signals enter the second level (second-order input function) they are combined and constitute “qualitative vectors.” As an example Powers uses the taste of lemonade, which
Contains an easily recognizable vector, derived from the intensity signals generated by sugar and acid (together with some oil smells). However unitary and real this vector seems, there is no physical entity corresponding to it. The juxtaposition of sugars, acids, and oils in one common volume does not create any special entity there. (1973, p. 113)
The third level again groups and coordinates signals as they emerge, modified by the second-order loops, and some of the resulting compounds are what we call “objects.” As it happens, process and results of this third level correspond to the beginning of what Piaget has mapped as the “construction of permanent objects” (1973, pp. 1-85).If we try to apply this to Powers’ model, one thing immediately becomes clear: Though he says that the signal emitted by the first-order input function “is an analogue of an external quantity” (1973, p. 148), this analogical correspondence can be posited only by an observer – the control model has the signal and nothing but the signal. “What we experience is a set of outputs of perceptual functions, and we have no way to detect the true nature of the inputs” (Powers 1974 p. 6).
Humberto Maturana 1970 and Ross Ashby 1967, 1970 both assumed that living systems are essentially inductive systems in a strictly Humean sense in that they function “in a predictive manner: What happened once will occur again” (Maturana, 1970, p. 39).
If the first-order sensory signals are “the only environment that higher systems can respond to” (Powers 1973, p. 95),
Norwood Hanson argues, “People, not their eyes, see. Cameras and eyeballs, are blind” (1958, p. 9).
Once we adopt this position, we can put the ontological questions into their place – which is not to say that we answer them. In our role as observers/constructors of organisms it should not surprise us that “several people can perceive or act or be affected by the same object at one time” (Hirst 1964, p. 259).
And since, in constructing the object, we have given it “permanence” by projecting it into an external world, it should not surprise us that we now expect it “to persist even when it is unobserved” (ibid.).
