From time to time, the very foundation of the concepts by which whole societies and cultures consciously or unconsciously conceptualize and structure their picture of the world is revolutionized.
What was considered good and true in one century may after such changes very well become evil and wrong in the next. E.g. the religious norm and civilized behaviour in the Antiquity, was during the Middle Ages often considered to be pagan perversity and crude barbarism; what in one age represents evident faith and obvious virture, can in the following century perhaps characterize primitive superstition and world-renouncing death.
The world has seen many major system changes by which not only political world history changed its course, but by which more or less all foundations of religion, philosophy, science and convention were changed to such an extent that the way in which the world was experienced cannot be said to have been the same afterwards.
One needs only consider the extent of the activities of e.g. Buddha, Christ and Muhammed, or the implications of the frames of reference which through the philosophers of the Antiquity, the fathers of the Church or the reformers in the 16th century dispersed and left an indelible mark on most of the world.
Since the Reformation, no major religious paradigm changes have occurred, and especially in our latitudes religion has quietly run out like a tired clockwork not even Kierkegaard managed to rewind. Nothing lasts forever, and today it is no longer the old theology but primarily the young science that fathers the current picture of the world.
In the 17th century, this still heretical discipline definitively finished off that last part of scholasticism which the Renaissance had not already eliminated. Not least the three "Copernicans" Galilei, Descartes and Newton changed science and philosophy so radically, that the scientific as well as the philosophical concepts were turned upside down during the centuries that followed.
The paradigm they announced replaced the Churchs canonized authorities, Ptolemy and Aristotle. Nevertheless, we refer to this "new" materialistic paradigm as "classic science", for in science the kings do not reign forever either.
Due to a strong church, Ptolemy and Aristotle managed to get a couple of thousand years on the throne - subordinate to the Bible of course. Galilei and Newton had to settle with 2-3 centuries, before not least Einstein and Bohr effectuated a new and perhaps even more radical change of paradigms.
After the arrival of the Theory of Relativity and quantum mechanics in the beginning of the 20th century, the cornerstones of the picture of the world have been rearranged once more.
The question is, whether more than just the picture of the world has changed? Is it not alone theoretical explanation of the world, but also empirical experience, that is changeable?
The classical scientific paradigm had to answer no to such a question. The modern one, on the other hand, cannot unambiguously reject a yes!
The end of metaphysical objectivity
When Einstein demonstrated that the introduction of the aether "wird sich insofern als überflüssig erweisen" (Zur Elektrodynamik bewegter Körper, p. 892), classical science got its first crippling blow, and during a relatively short period of time not only the aether disappeared, but also basic concepts like time and space, atom and universe, and general notions of causality, objectivity and simultaneousness, got fundamental new meanings.
Moreover, in 1905 the Special Theory of Relativity rejected that mass, length, position and velocity were absolute quantities; instead, they were shown to be relative to the reference system of the observer. At the end of the Twenties the changes were further accelerated by the quantum mechanics of Bohr and Heisenberg, by virtue of which these qualities also had to be looked upon as relative to the method of observation and - what was even more spectacular - even determined by the fact that they were observed.
However, Einstein claimed that this was to go much too far and refused to give up the existence of an observation-independent world.
For decades the discussion was purely theoretical until Alain Aspect in 1982 performed his historical experiment which undeniably settled the debate in favour of Bohr. As N. D. Mermin notes, the foundation of quantum mechanics ceased - in contrast to Einsteins criticism of it - to be metaphysical: "Thirty years after Einstein's challenge a fact - not a metaphysical doctrine - was provided to refute him." (Is the moon there when nobody looks?).
The interaction between the observer and the observed has proven inevitable and has once and for all eliminated objectivity in the traditional sense where it implies a reality independent of the act of observation. In contrast to the modern paradigm, Heisenberg characterizes the classical one as the idealisation "… bei der wir über die Welt als etwas von uns selbst völlig Unabhängiges sprechen". (Physik und Philosophie, p. 95).
This interaction is so fundamental that it is impossible to sustain the notion that any phenomenon exists in some unobserved, uninfluenced condition, since the interaction as Bohr notes, is an "integrated part of the phenomena" (my emphasis).
This is a scientifically well-documented way of thinking today, but in the Thirties it was an idea even the scientific community was very unaccustomed to, dominated as it still was by classical materialism. To Heisenberg this materialism perhaps defined the core of the opposition against the quantum theory: "Es könnte sein, daß man sich leichter an den quantentheoretischen Wirklichkeitsbegriff gewöhnen kann, wenn man nicht durch die naive materialistische Denkweise hindurchgegangen ist, die noch in den ersten Jahrzehnten dieses Jahrhunderts in Europa vorherrschend war." (Physik und Philosophie, p. 197).
The observation-dependence is vital to one of the indispensable pillars of quantum physics - Heisenbergs Uncertainty Relation. It is impossible to determine simultaneously both the exact position and the exact impulse of a particle; the observation of an accurately localized particle results in the impossibility of determining its exact impulse; likewise, establishing the exact impulse makes it impossible to determine its exact localization - "it" is in many places, or as Hawking expresses it, it is "smeared out". (A Brief History of Time, p. 56).
The objective, observation-independent world of Einstein has simply been refuted, regardless of how romantic he made it sound: "Out yonder there was this huge world, which exists independently of us human beings and which stands before us like a great, eternal riddle, at least partially accessible to our inspection." (Albert Einstein: Philosopher-scientist, p. 5).
No metaphysical objectivity out yonder there can be upheld anymore, since is has been verified experimentally, that the phenomena as we observe them simply aren't those phenomena abstracted of our observation.
But what does that imply?
"Tendenz zum Sein"
In modern physics, a phenomenon is undefinable in principle before its being observed. Its ontological status can at most be characterized as potential.
We can determine experimentally that a photon, given one set of observational modes must be conceptualized as a wave, given another, as a particle. It is simply meaningless to ask what the photon really is, because it is neither-nor until it is registred by an observer - it is not even correct to apply the word "is", rather it's a mere tendency, "Tendenz zum Sein", as Heisenberg puts it.
But the description of the photon as a wave and a particle respectively, is evidently a contradiction. It cannot be both, and yet it is not fully described as either one.
Bohr tried to get around this paradox by introducing the concept of complementarity. The possibilities of definition and observation must be weighed against each other; the particle- and wave nature of the "same" phenomenon are inconsistent, if, according to the classical paradigm, we look upon that photon independently of the observational situation, but not if we join Bohr and accept the solution that the wave- and particle nature represent complementary, mutually supplementary descriptions which depend on mutually excluding observational situations.
Both descriptions are equally important to a full understanding of the phenomenon even though they cannot be used about the phenomenon simultaneously: "Within the scope of classical physics all characteristical qualities of an object can in principle be determined by one single experimental setup, although different setups in practice will be convenient in the study of the different aspects of the phenomena. The informations hereby gained supplement each other in a simple way, and can be put together to form an uncontradictory picture of the behaviour of the experimental object. In quantum physics however, the informations that can be established about atomic objects by means of various experimental setups reveals a new complementary relation to each other. One must realize that such seemingly contradictory informations when put together to make up a simple picture, defines all possible knowledge about the object. Far from limiting our attempts to ask Nature questions by using experiments, the concept of complementarity rather characterizes the answers we can get from these investigations, as soon as the interaction between the instruments and the objects comprises an inseparable part of the phenomena." (Atomer, naturbeskrivelse og menneskelig erkendelse, pp. 44f).
The settings of the observation is ontologically inseparable from the observed phenomenon so fundamentally, that for instance the present observation of a photon determines even the past of that photon - it simply determines what we could call its preobserved "condition" as well as its preobserved "path".
The pillars of the modern scientific picture of the world comprise such paradoxes; present quantum-choices do in fact determine the past quantum events retrospectively, as John Wheeler notes in an analysis of the so-called delayed choice experiment: "In this sense, we have a strange inversion of the normal order of time. We (…) have an unavoidable effect on what we have a right to say about the already past history of that photon. The dependence of what is observed upon the choice of experimental arrangement made Einstein unhappy. It conflicts with the view that the universe exists 'out there' independent of all acts of observation." (Quantum Theory and Measurement, p. 184).
It is just as meaningles to ask what the photon was, as it is to aks what it is in itself, if we thereby mean what is was and is independently of the act of observation. To describe this non-observed condition is only used a mathematical construction - the so-called wave-function, which prior to the observation theoretically incorporates the probability of the condition of the phenomenon during the observation. This theoretical "objectivity" is characterized by Heisenberg as: "… eine Welle in einem vieldimensionalen Konfigurationsraum, die man erst durch die Schrödingerschen Untersuchungen kennengelernt hatte, also um eine ziemlich abstrakte mathematische Größe." (Physik und Philosophie, p. 24).
This "quite abstract mathematical quantity" has no ontological value whatsoever. It is of course in principle unobservable because it collapses at the exact moment where the act of observation takes place - it cannot even be said to be.
It is still very unambiguously the act of observation that conceptualizes the phenomenon as a phenomenon or, as Wheeler puts it: "until the act of detection the phenomenon-to-be is not yet a phenomenon." (Quantum Theory and Measurement, p. 189).
There is nothing that exists objectively, in inself. At most one can speak of a hypothetical tendency, a Tendenz zum Sein - only the act of observation itself brings phenomena into existence.
The nervous system as a generator of reality
Physics has put Man (qua observer) in the centre of events, and it would be interesting to see how another science, for example neurology, sfrom its perspective describes the relation between the observer and the observed.
In Principles of Neural Science Irving Kupfermann writes: "We do not perceive the world precisely as it is but rather as a modified version that is altered on the basis of experience as well as the principles and limits of our perceptual analysis system." (p. 1003).
Again we meet the unsatisfactory ontological dualism: The world as we perceive it, and a (metaphysical) world as it really is ( - out there).
In scientific literature this problem far too often passes quite unnoticed, e.g. in Christopher C. Widnell & K. H. Pfenningers (ed.) Essential Cell Biology: "Features of the envoronment (…) are converted to an electrical signal by the receptor cell" (p. 231), and in Arthur C. Guytons Textbook of Medical Physiology which distinguished between the "outer" phenomenon and the "inner" information of the nervous system (nerve impulses): "The term information, as it applies to the nervous system, means a variety of different things, such as knowledge, facts, quantitative values, intensity of pain, intensity of light, temperature, and any other aspect of the body or its immediate surroundings that has meaning. (…) However, information cannot be transmitted in its original form but only in the form of action potentials, also called nerve impulses. Thus, a part of the body that is subjected to pain must first convert this information into nerve impulses; specific areas of the brain convert abstract thoughts also into nerve impulses that are then transmitted either elsewhere in the brain or into peripheral nerves to motor effectors throughout the body." (p. 562).
In fact, there seems to be nothing left of the original stimulus after the nervous system has "converted" and transmitted it. The "outer" stimulus (the preobserved "phenomenon") which is transformed into nerve impulses by the receptor cell and is transmitted to secondary cells and through their axons transported over numerous intermediate stations, e.g. to the cortex, has simply undergone so many ratifications in the subcortical structures that the original stimulus is completely unrecognizable when it finally arrives as the actual phenomenon we experience as such.
In other words, our perception does not work like a passively copying camera, as Kandel points out in Principles of Neural Science: "It [the visual system] does not simply record images passively, like a camera. Instead, the visual system transforms transient light stimuli on the retina into mental constructs of a stable three-dimensional world." (Principles of Neural Science, p. 441).
Kupfermann's modified version of the world, Widnell & Pfenninger's converted fearures, Guyton's unoriginal form and Kandel's transformation are just a new version of the "two" worlds, the preobserved out there and the observation's in here.
Considered philosophically, this preobserved "potential" is related to Kant's Ding an sich.
But such a fundamentally unverifiable X which should be able to affect our sensory apparatus one way or the other, is evidently a redundancy all the way through. If the only world we will ever be able to observe is the very same world that the nervous system and the brain construct during the act of observation, then the assumption of something else, an sich, is undeniably quite superfluous - at least as any kind of "objective outer world".
And even if one should deny to let go of this metaphysical objectivity, it is nevertheless unquestionably unavoidable that the world of sensations as it is experienced by the human brain is only conceptualized as such as a result of human observation.
"How can the brain be in the head, when the head is in the brain?"
But if the brain in some way actually constructs reality, how can it itself be a part of this reality?
Smythies formulates this paradox enigmatically but incisively in The Temporal Lobes and the Limbic System: "'Where in the world of my direct experience is located my physical brain?'. Most people would instinctively locate it in the head of the experienced body, that is the head of the phenomenological body image. But, of course, this is quite wrong, as the head of the somatic sensory field is itself in the brain. So how can the brain be in the 'head' when the 'head' is in the brain?" (p. 273).
In order to find a solution we must return to physics.
Is the photon a particle or a wave? That depends on the circumstances of the observation: sometimes the most adequate description, the most appropriate model, defines it as a wave, sometimes as a particle. We cannot get any closer than the model by which we conceptualize the phenomenon, and this model cannot be more true than it is "true" to the extent to which this model is appropriate - to the extent that it works.
Hawking remarks: "… a scientific theory is just a mathematical model we make to describe our observations: it exists only in our minds. So it is meaningless to ask: Which is real (…) It is simply a matter of which is the more useful description." (A Brief History of Time, p. 139).
It is not a question whether the photon in reality is a wave. This question is quite meaningless because the phenomenon is defined by the observational situation and the model(s) we apply to it.
It is a question of the more useful description. Not because we can get any closer to the "real reality", but because there is no reality but the reality the model in our minds enables us to react to. Therefore, it is impossible to demand any kind of correspondence between theory and theory-independent reality - there is no theory-indepencent reality as Hawking emphasizes: "A theory is a good theory if it is an elegant model, if it describes a wide class of observations, and if it predicts the results of new observations. Beyond that, it makes no sense to ask if it corresponds to reality, because we do not know what reality is independent of a theory." (Black Holes and Baby Universes, p. 44).
Every model is an interaction between what we refer to as the observer and what we refer to as the observed - and according to Heisenberg this dethrones the Cartesian objectivism: "Die Naturwissenschaft beschreibt und erklärt die Natur nicht einfach, so wie sie 'an sich' ist. Sie ist vielmehr ein Teil des Wechselspiels zwischen der Natur und uns selbst. Sie beschreibt die Natur, die unserer Fragestellung und unseren Methoden ausgesetzt ist. An diese Möglichkeit konnte Descartes noch nicht denken, aber dadurch wird eine scharfe Trennung zwischen der Welt und dem Ich unmöglich." (Physik und Philosophie, p. 66).
In other words, to the scientific community the consequence is as radical, as the fact that a model-independent conception of reality simply is impossible; every time we describe reality it is determined by the conscious or unconscious use of models.
At times, we will even have to make use of mutually conflicting models if we want to get an exhaustive clarification of a phenomenon, since both models can be verified (although in different situations) - they are complementary.
In neurobiology, there are already examples of such legitimate model-changes. E.g. Maturana and Varela conclude, that the two extremes when accounting for the functions of the nervous system (the conception of an "inner" nervous system which reacts to an "outer" world, and on the other hand the claim that the nervous system is a closed whole to which something "outer" is irrelevant) are in fact isolatedly viewed as both appropriate, and even though they contrast each other, both are necessary in order to get a full understanding.
"As observers we can see a unity in different domains, depending on the distinctions we make. Thus, on the one hand, we can consider a system in that domain where its components operate, in the domain of its internal states and its structural changes. Thus considered, for the internal dynamics of the system, the environment does not exist; it is irrelevant. On the other hand, we can consider a unity that also interacts with its environment and describes its history of interactions with it. From this perspective in which the observer can establish relations between certain features of the environment and the behavior of the unity, the internal dynamics of that unity are irrelevant. Neither of these two possible descriptions is a problem per se: both are necessary to complete our understanding of a unity." (The Biological Roots of Human Understanding, p. 135).
There is no alternative to the conclusion that to certain problems it is appropriate to consider the nervous system as an independent, closed system, where the distinction between input and output is meaningless; and that it in different situations makes better sense to use a model that looks upon the connection between the observer and the observed as a relationship where sensory input is "transformed" by the nervous system into the electrochemical output we experience as being the world.
But is the nervous system and the brain thus in reality a "reality-projector" or a "reality-screen"? Is the photon in reality a wave or a particle? The answer is yes and no. The models are complementary.
This takes us back to the main issue of this passage: "how can the brain be in the 'head', when the 'head' is in the brain?", and Smythies sees no other way out than resorting to complementarity - allthough reluctantly: "I believe that, (…) there is only one even remotely possible current theory of mind-brain relation and that is Niels Bohr's complementarity theory. In a famous speech in 1932 he suggested that the mind/brain relation might be similar to the particle/wave complementarity of the electron i quantum mechanics. (…) Thus one entity, the mind/brain, could present one set of properties when observed by a neurosurgeon and a different set of properties when observed by itself." (The Temporal Lobes and the Limbic System, p. 274).
The principle of complementarity is not only unavoidable, furthermore it has the pleasant side-effect that it rids us of the last leftovers of metaphysics: The rock-solid an sich, the observation-independent objectivity out there.
Not because metaphysics cannot present good models, and not because Ding an sich cannot be a useful model, but because as an implicit or explicit starting point it is a misleading redundancy, and because all neurology and physics in the end are based on the experimentally verifable fact, that it is Man's act of observation that conceptualizes the world he observes.
However, we shall hereby neither claim that reality nor science become purely subjective matters, but rather emphasize that objectivity must now be defined in a different manner than was the case in classical science. "The description of atomic phenomena has in these respects a completely objective character in the sense that it does not contain a reference to an individual observer", Bohr writes (my emphasis, Atomer, naturbeskrivelse og menneskelig erkendelse, p. 43).
Man has not become a creator if we by "creator" mean somebody who freely chooses and manufactures his own reality. But it cannot be denied that there is no reality where there is not one or more observers to conceptualize such a reality, and that the reality which is conceptualized depends on the situation of observation. Man's observation is not passively registering, but actively constructing.
By stating this, we do of course by no means advocate that anything goes. We have just suggested that the frames of reference (theories, paradigms, norms, language etc.) which are the foundation of observation, structure the basic experience of reality.
We started by asking whether it is not only theoretical explanation but also empirical experience that change when the concepts of the world change? We can now sum up the answer: The classical scientific paradigm had to answer unambiguously no to such a question - the modern on the other hand cannot unambiguously reject a yes!
With reference to science or epistemology we can no longer reject that every detail of reality not necessarily has to be the same to all people. The fact that we are able to agree with most people on by far the most common features, only testifies that the neurologically based human perceptual apparatus to a wide extent correlates perception between individuals in a relatively unanimous way. But when this correlation seems to be lacking we must be more reluctant to judge another person's reality unreal, just as we must be more reluctant to judge his or her truth untrue.
Where culture, language and habit only differ superficially, there is hardly any major deviation in the way in which each person experiences, i.e. conceptualizes the world of sensations. But on the other hand there is no reason to doubt that to the extent to which these factors deviate between individuals, the very reality that each one is surrounded by will also deviate.
Such a pragmatical concept of reality may perhaps seem somewhat unusual to anyone who consciously or unconsciously subscribes to the rock-solid objectivity. But considering the development especially within neurobiology and physics it is under no circumstances an unplausible position.
Likewise, there is no longer any reason to reject an ontological relativism, at least as a tentative foundation of all kinds of studies of cultural history. A pragmatic obliging approach to the concepts and realities of other cultures rather than an objectively rejective one is simply the only appropriate approach in the light of science.
Published in Faklen (The Torch), 1996
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