ISIS-Symmetry / SEMA Congress „Forma y simetria", Buenos Aires 2007

PETER KLEIN

Name: Peter Klein, Prof. Dr. phil. Dipl. Phys. Physicist, Educator (b. Breslau / Germany, 1940)
Address: Universität Hamburg, Faculty of Education, von-Melle-Park 8, D-20146 Hamburg
Priv. address: Babendiekstr. 13, D-22587 Hamburg, Tel. +49-(0)40-862266
Email: klein@erzwiss.uni-hamburg.de
Fields of interest: Philosophy, Physics, Education

I IN SEARCH FOR INTERMEDIATE MATTER AS ESSENCE OF LIFE AND MIND

Physicists when contributing to interdisciplinary science on whatever subject, from atoms to the philosophy of mind, are always in a privileged situation: first, they can declare themselves as professionals in the basic science of „physicalism", in my opinion inevitable background program of any reliable interdisciplinarity; second, they are convinced to act on the firm fundament of undoubtable empirical facts. In this article I will try to undermine the latter standpoint by speaking about concepts of matter which in history of physics played the role of though constitutive, yet quite uncertain if not imaginative „facts" – not intending, however, to undermine now also physics, but rather: to increase its reliability by giving insight into its methods and to develop criteria to discriminate sense from non-sense.

Speaking at a congress in Latin America, it appears as an adequate reverence to mention first the meritorious patron of the continent´s cultural identity, Alexander von Humboldt!

In fact, when Humboldt prepared for his famous journey to the „Äquinoctialgegenden des Neuen Kontinents", he focused attention, seemingly „by the way" and far from his „geographic" intentions, also on the phenomena of electricity in animals, a recent discovery that was to cause a radical change in the understanding of the basis of the „materialistic monism" that was common in science and philosophy of the enlightenment area. For it immediately raised hope that electricity might be the long searched link between bold „normal" matter (defined as impenetrable (qua Descartes) and heavy (qua Newton)) and those sophisticated manifestations of „matter" (this assumption of course remained undoubted!), namely life and mind, that hitherto had resisted simple „mechanistic" explanations.

Humboldts friend Friedrich Schiller, well known as a poet, yet by profession a physician, had given a survey and some tentative categories of the problem some years before in his two dissertations about the „relations between the animalistic and mental nature of Man"; so in 1795 he published Humboldts „Vom Rhodischen Genius" as fitting well into his periodical „die Horen" (reprinted in „Ansichten der Natur" from 2^nd ed.). In this programmatical article Humboldt declared, merely metaphorically and at that time against common opinion, electricity to be the very essence of „force of life", valid for life and mind, with both understood as having emerged from and still being a unity with matter, "just physics, yet in a higher order", as Herder had postulated ten years before („Ideen zur Philosophie der Geschichte der Menschheit" 1784).

However, when Humboldt prepared his journey in concreto, he turned the merely symbolic idea into hard empirical science. The results, published 1797 as „Untersuchungen über die gereizte Muskelfaser", combined with the meanwhile detected relation of electricity to chemistry, made him withdraw his too universal thesis about the underlying principles: he now reserves electricity only for explaining life, but assigns the mind to a principially different category. Fifty years later, now based on the advanced categories rendered by the experiences of half a century, he reaffirms the distinction between the (supposed as) material bases of life and of mind, respectively, in „Kosmos" (I (1845) 386), the famous and influential „sum of his life". As this book applied to a wide public, this distinction became something like a basical cultural axiom, that soon also boasted the dramatic style of the advanced „pompous age", when Humboldts friend Emil DuBois-Reymond proclaimed his categorical „Ignorabimus" on that point – an exclusive view, that quite surprisingly has regained reputation, even dignity in our times.

It seems to me that it fits well into the frame of this congress to scrutinize this stupefying approach (which in my opinion is wrong) by tracing some of the various streams of hypotheses and experiments about intermediate matter from 18^th through 19^th to 20^th ct., because these ideas not only represent the core, the internal logic of the historical development of modern science, but are also widely based on key concepts of interdisciplinary symmetry studies, like e.g. unification, balance, polarity, (ir-)reversibility, complementarity, correspondence and equilibrium, like structure, order and selforganisation.

The question for the general structure and ontological status of the relation between mind and matter arised not earlier than in the 17^th ct., as a consequence of „post-Galilean" „sciencia nuova". As is well known (cf. Schütt 1987, 59ff), this „new science" substituted the old Aristotelian „impetus"-theory (that each thing has its „natural place" which it aspires to reach by means of teleological principles) by Galilean/Newtonian mechanics. Consequently

-- all the Aristotelian „causae", esp. the teleological, expired, leaving only one left, the „causa efficiens" (identical with our contemporary, „the" very „causality"), and

-- all movements and changes of matter now were to explain as caused by mechanical forces.

Less present in historical conscience is the fact that the new paradigm was extended also on the human mind: Before, the human „soul" was believed as created and laid into Man by God, and as motivated and moved by the spiritual destination of divine providence („Unruhevoll ist mein Herz, bis es ruht in Dir!"), ontologically situated on top of the hierarchy of „soul"-levels which Thomas Aquinas had described. Now, the mind counted as a secular part of matter, motivated by mechanical stimuli, guided by the same causal laws, as are valid for matter and taken for granted also for the relation between matter and the mind. This relation, however, could not sufficiently be understood (esp. for intended technical manipulations on the mind), unless the ontology of matter and mind was clarified – a task, however, up to now successfully or satisfying done neither for mind nor matter.

Not even was it self-evident any longer that the mind exists at all. Yet the mind insisted to exist by revealing empirically several definitory qualities which hardly could be denied, like spontaneity and (more or less) free will power. However, once the existence conceded, the question immediately arised how a probable impact of mind on matter should be characterized, an impact, that was empirically obvious!

The problems that coincide with that question have something in common for both principal ontological dogmas, the „monistic" one (that postulates that only matter exists as a substance, including, as an epiphenomenon, and more or less an illusion, that spurious entity „mind"), and the „dualistic" (defined by the postulate that matter and mind are two different, autonomous substances): Both, in fact, have to explain how the mind, whom we experience as an im-material entity inaccessible by our senses, may nevertheless influence matter, so that Man is able to „act" in the world. Boldly speaking: how is this mind able to make stupid atoms transform merely imaginated motives into true actions by (some kind of) rational use of those natural laws that guide the interactions of the atoms themselves.

Schiller had, as mentioned, briefly reviewed the three main traditional arguments from a „dualistic" standpoint; being merely a student at that time, he had simply referred the state of the art by listing up:

• the „materialistic" view: that mind is just a, though more delicate, kind of matter, so that there was no need of special laws for their relation,
• the argument of Leibniz: that there exists a „pre-stabilized harmony" between them, and
• „Occasionalism": that God himself coordinates mind and matter directly at suitable „occasions".

Now, all these arguments could be demonstrated as insufficient for various reasons. Instead, Schiller (resp: the science of his time) tentatively postulated an additional substance possessing an ontological status of its own and determined to nothing more than to mediate between mind and matter.

Of course, one might say that this was not really ingenious, but simply an old trick: Postulates are patient, one may always postulate whatever one may want or need, but should never forget to confirm them afterwards by experience. Also in this case the mediator was conceived so that it possessed just the qualities needed: It had to exist (because he obviously caused something), and it should be some kind of matter (because it influenced matter), yet (like the mind itself) it could not be sensually conceived, as experience showed. Summing up: Different from „ordinary" matter (which we will have to define!) this new substance was imponderous and spurious, but able to incent and to influence matter by means of mechanical force (because matter would only react on force), and these forces must follow causal laws. Summing up: science was in search for a special kind of real, intermediate matter able to insert force on ordinary matter on behalf of causal laws; consequently it was called „Mittelkraft", or also „Nervengeist", because mental activities and incentives ("Geist" = spirit) were linked to matter by nerves.

At first view one might suppose that a monistic, mechanistic approach would not suffer from these problems, because then only one singular substance would exist, and the mind when conceived as a manifestation of matter that would not demand a special ontological status. But it cannot escape similar problems on an even simpler level, because the mind (if conceded to exist) differs considerably from ordinary matter. At least now it´s time to define what we mean by „ordinary matter", or how scientists, following Descartes, in 18^th ct. defined it. First of all, matter is „open to the eyes", i.e can be experienced by the senses as possessing the following universal qualities: to be compact, i.e. more specific, impenetrable for other matter, and to be heavy, i.e. tend to fall down to the earth; the latter quality, since Newtons „principia", is always combined with „inertia", i.e. matter is substancially inert against accelerations, which to their side, if happening, are indicators of actually impressing forces.

Now, the problem is that the mind, though in the materialistic view is „nothing but" a kind of matter, possesses none of these qualities (but "is" a substance of ist own character, as we pointed out), yet shows interactions with ordinary matter – so the postulated mediator most likely would participate in the character of both!

But that was by far not all! Ordinary matter, that became clear in course of research, under the modern mechanistic paradigm needed a mediating entity, too, because without such a mediator the contemporary concepts about processes in nature, the changes and causal interactions of matter could not suitably be explained. This dilemma was not new; it had slept for a long time. For instance, the materialistic Greek atomists had explained the world as consisting of eternal atoms, whilst the manifold qualities, the movements and changes of the objects, that appear in the sensual world, were conceived as changing arrangements of atoms in empty space. Change was supposed as being caused by the interactions of the atoms with each other, and these were thought of as mechanical kicks between the atoms.

This explanation failed not only when applied to the mind, what Descartes had tried to overcome by suggesting his theory of specific whirls as the mechanism of mental processes, an idea, immediately and directly refuted by the Danish anatome Nils Stensen on the basis of his anatomical brain studies (As Stensens arguments were adequately esteemed not earlier than in our time, they had no concrete influence, and we will not go into details here!).

We need not do so, anyway, because at the same time the entire simple traditional model of kicking atoms became in toto obsolete, namely as a direct consequence of Newtons theory of general gravitation, - what indirectly also changed the image of the matter-mind-relation. Moreover: not only the law of universal gravitation made the simple ball-and-kick model dysfunctional, but Newtons first law (about inertia) was sufficient for that consequence, as well. For without the existence of any attractive forces the kicks of the atoms would make a systems of atoms alltogether fly asunder. On the other hand, Newtons new universal gravitation would end in a catastrophe, either, because it would make the world collapse. Consequently, Kant (1786, A 34f) had postulated the existence of a repulsive force, that together with gravitation would hold the world together and in stable equilibrium. So far so good (at least until W. de Sitter examined the stability of the universe under these conditions and found it unstable).

Undetermined for both forces (and for possible further, hitherto undetected ones) remained the question how they could influence matter, or otherwise: how forces that originate from one thing may impress another. Obviously, it was impossible that the universal gravitation at distance (at unbelievable huge distances, as astronomers soon found out!) happened via direct contact, e.g. as the classical mechanical kicks between atoms. Strange enough: the question for a mediator of gravitation in fact did not arise for a long time: the image of a direct and immediate impact of gravitation at distance was doubtlessly valid till 20^th ct.!

But for other impacts of forces at distance this image was not accepted, neither for classical ones, as light or heat, nor for the newly detected like electricity or magnetism. For all of them the mediatorship of matter was postulated, either in the sense of direct mechanical contact (like that of the kicking atoms) or as the emanation of specific particles. For all of them the existence was simply proclaimed, in spite that nobody had „seen" them (or perceived them otherwise), and none had the attributes of classical (Cartesian) matter: namely to be massive, impenetrable, heavy („ponderous").

In fact, nearly all branches of physics at that time were literally defined by the specific characteristic intermediate „imponderous" matter they exhibited. That was not so stupid as it sounds! Heinrich Hertz (whom we will meet later as the „Terminator" of the „Ether"-concept in Ch. IV) reminds us (Hertz 1884, 29) that the idea of matter as the source of gravitation and heavyness was only a very recent one: „200 years ago, nobody knew that all material bodies attract each other. So let us admit that there might exist kinds of matter that do not underly gravitation, and thus are not detectable by means of weight. ... The old physic in fact supposed a great number of them. In fact she was a „physic of imponderabilia". The source of heat was an imponderous matter called „caloric", light consisted of emanated light-particles, electricity was a tender, imponderous fluid, that was filled in bottles, and magnetism was also a tender fluid, that could not leave the atoms of iron („phlogiston")." Furthermore, recently detected "serious" effects had made scientists used to accept as subjects of experiental science "facts" that could not be sensually experienced: like ultraviolett and ultrared light, detected in 1800/01 by Herschel resp. Ritter. Only chemistry, as it seems, made an exception, because Lavoisier had essentially connected it with exactly the defining quality of ordinary matter, gravity, namely the constance of weight of the reaction partners. (But silence! - chemistry had its own esoteric concept, the "Wahlverwandtschaften") –

Alltogether, I think we get the impression of a world of ghosts, of numerous „imponderous" matters, undetectable for the senses and postulated for no other reason than to mediate between „true" matter by transporting the impact of forces.

Happy enough, soon hope arised for the necessary restoration of rationality! The last word, „forces", became the key concept to banish again this ghostly world, or better said: to transform the ghosts into serious scientific concepts. But, irony of history: whilst those scientific ghosts were imaginations of the „enlightenment" movement, their metamorphosis into serious science was executed by a period of science that is (ill-)famous for its exuberant flourish of fantastic hypotheses, of wild speculations and impertinent performance, namely the notorious „Romantische Naturphilosophie", which thus gains a fascinating ambivalence.

The method we described above how the various kinds of imponderous matter were invented, namely: to postulate just what you need (though you cannot find in empirical reality, but instead affirm us that this is impossible, and welcome that it is) – a method like this seems completely foolish, esp. for an „empirical" science. But no and on the contrary! it is in fact one (emphasis lies on „one") wellfounded phase in the methodology of scientific progress: namely to set (even to simulate) hypotheses that seem apt to explain single experiences, and to connect them with each other and with the system of knowledge. These hypotheses afterwards of course must be tested experimentally, thus proving that they fit into the systematic context of science as a whole.

Now, the representative philosophy of the time, German „Absolute Idealism", and its scientific counterpart, „Romantische Naturphilosophie" (RNP), were perfectly appropriate (some people say: by their perfect absurdity) to fullfill the actual task of interpreting the newly detected „forces". I have exposed the main ideas in more detail at our ISIS-S Hiroshima meeting (Klein 1992), with emphasis on their close connection with basic principles of symmetry, as mentioned above.

Specific extensions of Kants philosophy played a threefold part in the development of RNP:

1. Kants postulate of attractive and repulsive forces, whose equilibrium stabilizes the universe, had installed a „dynamical" view of nature, that had given forces an at least equal ontological importance as matter had possessed before. But what for Kant was just a formal parameter needing experimental verification, gained priority for the Idealists and their romantic follower-scientists, who understood those heuristic postulates as general metaphysical principles transcending mere empiricism. The facts and laws of nature were thought of as already hidden in the mind itself, so that they could be deduced from its structures, and in the last consequence empirical verification seemed to be unnecessary at all. The scientific style based on that conviction, and the sometimes purely phantastic results can easily be imagined. Yet, on the other hand it was an important turn in scientific method to draw attention on the strategies of scientific labor and to emphasize the role of the underlying general principles.
2. In the „Critique of Judgement" (1790) Kant had explained the well organized character of „organisms", their obvious ability to run their lives by well adapted behavior as seemingly teleologically organized structures by the „idea of suitability", as a merely „guiding idea" of our power of judgement (as part of critical reason determined to relate general laws of cognition to specific single objects of experience). According to Kant, the necessity of causal explanation in the sense of modern science remained. But RNP changed and widened this organismic view of nature from a structural quality of reason to a universal axiom about nature, which was now understood as a well ordered unit of a whole, that generated itself in an unexhaustable productive process. The great comprehensive principle was to understand nature as a great unity of a whole, with matter and the manifold forces conceived as interacting components of a universal system, that generated the overarching task of science to examine (hard to translate!) „das Zusammen- und Ineinanderweben der Naturkräfte" (A.v.Humboldt).
3. As a derivation (or „deviation") of Kants „practical" postulate that the laws of nature and the moral law must be compatible postulates because of their postulated common origin in God as their creator, the romantic concept of the unity of nature and mind was completed by the idea, that both because being created by God must be coordinated as facts; in the words of Oerstedt, discoverer of the magnetic effect of electricity (Oerstedt 1850,8): „All the natural laws together thus are a unit of a whole, which, considered in its efficacy, is the essence of the entire world. ... and the whole world is the expression of an infinite comprehensive idea, that is identical with an infinite reason that lives and works in everything. In other words: The world is nothing else but the revelation (manifestation) of the united reason and creative power of the Deity. ... So we can understand now, why we are able to perceive nature by reason: because cognition is nothing but the self-recognition of reason through perception of the things."

We stated above, that the mechanistic „New Science" had reduced the Aristotelian ontology to the only valid causa efficiens; that was sufficient for scientific purpose, because in that paradigm the only object of science were the laws of the movements of the otherwise invariable matter. In RNP now, the organismic understanding of nature to the one side, to the other side the enormously grown importance of forces (compared with their target, i.e. with that what they influenced and moved, namely matter, that essentially remained as before) – these characteristics of RNP had the paradox effect that in a certain sense the Aristotelian quartett of „causae" was reinstalled:

• matter remained to be the, so to speak: passive, building material of the universe, the „causa materialis";
• it became the object of the enormously differentiated impact of forces, as the agents of productive nature, with nature as the instrument in the hand of the eternal creator – exactly the role of „causa formalis";
• and I think it needs no intense persuasion to understand that the organismic view on nature, as a well-ordered unit of a whole that fullfilled its own essential destination by an internal plan, is nearly perfectly identical with the teleological „causa finalis".

I emphasize this point, because the (up to now) last historical step in modelling intermediate matter will be the far-reaching and problematic identification of causa materialis and causa formalis in modern atomic physics.

But first we will go back to RNP! Different from the philosophical „idealists" and their naive pseudo-scientific adherents, Oerstedt and most of the other earnest romantic scientists understood very well that the revelation of the identity of mind, matter and God cannot be gained by self-satisfactory introspection, but requires hard, disciplined empirical and theoretical labor. The set of methodical principles, invented or developed to more precision and successfully applied by the romantic scientists in fact became representative for modern science. This counted for favored principles like

• unification of isolated facts,
• mutual conversion of different objects, material or immaterial, into each other,
• search for conservative laws as factors of balance in these processes,
• comparison of structures and their equivalence,
• dialectics of polar or complementary magnitudes.

The history of the conceptual unification and theoretical systematisation of chemistry, electricity and magnetism in 19^th ct. has clearly demonstrated the fruitfullness of the approach, if only it was supervized by critical empirical control and adequate translation of traditional qualitative philosophical principles into measurable physical magnitudes (as an important example: to change the vague (yet inspiring!) principle „causa aequat effectum" into the law of energy preservation).

We may discriminate three phases of clarifying the ontological status of the different forces and kinds of imponderous matter suggested to explain the newly discovered effects, esp. those of electricity and magnetism, which may count as paradigmatic in structure and importance:

-- There was, first, a phase of enrichment, i.e the detection of even more new effects of non-mechanical origin, that called for intermediate transfer. This is marked esp. by the sensational discovery of „animal electricity" by Galvani and his dispute with Volta, which was immediately felt as crucial for the problems connected with possible explanations of life and mind (and of course was abused soon by charlatans like Mesmer). Galvanis supposition 1791: that Galvanism, seemingly a spontanuous vivid reaction of frogs legs were a discharge of the power of life itself, was controversial because at that time galvanism was not by far clearly identified with „electricity", the long known outdoor phenomenon,that was familiar for every civilized person from Leiden bottles via lightning-rods to entertainment on the marketplace. The discusssion on that point still endured at the end of 18^th ct. in a more technical sense by Volta. It gained scientio-philosophical brisance when the romanticists intervened in the international research. The first, however, Alexander v. Humboldt was not really a romanticist when one considers his experiments „in vivo" (i.e., a precious detail, on his own body, that afterwards, as his friends reported, often looked like tortured – by the way and also rarely known, assisted by his brother Wilhelm, who then also „lebt und webt in Kadavern", as Alexander reports). As mentioned, his voluminous book had interpreted his findings very cautious, if not sceptical. The young Johann W. Ritter, however, pursuing Humboldts research, 1798 published a „Proof that the life process in animals is accompanied by a continuous Galvanism". He thus seemed to take decision in Galvanis view. Yet, immediately the next year he published a symmetrical „Proof that Galvanism exists also in anorganic nature". The consequence of both views, of course, was to identify the "old" electricity and the new Galvanism as essentially the same. So what was really new was the important insight of the chemical origin of Galvanism, culminating in the thesis that chemical processes were essentially electrical processes – comprizing life!

-- Ritter, as a true romanticist, immediately made the next step: to postulate reciprocal relations between all electric, chemical and biological (including mental) phenomena, but that was a too ambicious program for his time, so within the few years he had to live was captured by esoterical side-paths, and his scientific credit diminished. His friend and disciple Christian Oerstedt, however, was more successfull in verifying the program of reciprocal relations. Applying it on electricity and magnetism, he discovered (in 1820) the circular magnetic field (in Oerstedt´s "dynamic" terms: the „conflictus electrici") of electric circuits. Expressing their reciprocity, he concludes that „all non-magnetic bodies seem to be penetrable for the electric conflict, the magnetical bodies, however, or their magnetic particles, seem to resist transition of conflict. They move by pushes that originate from the fighting forces, and our observations show, that the conflict moves in circles (around the wire)". Now, given this impact of electric current on „magnetic particles", the program of reciprocity immediately demands the „reciprocal" effect, in fact discovered by Faraday, and during the next decades, as is well known, many reciprocal effects between electricity and magnetism were detected, as also to different „forces" like light and heat, and finally also between these.

-- Now, when reciprocal relations were discovered to exist between nearly all regions in nature having become subjects of scientific research, the inspiring allembracing idea, that they all were created by the one universal productíve force of nature, nearly stringently implied the hypothesis that they all were only different manifestations of just one central essence. This seemingly convincing idea resulted the third phase of the romantic program, to try the theoretical and experimental unification of them all. Should this be a scientific program, however, this implied to find a measurable magnitude, that could count as the balancing reference factor of this unity. For ordinary, "ponderable" matter this factor was the classical measure of gravity, weight. For this, Lavoisier had formulated a conservational law – an adequate choice, because, as according to Kant "conservation" was the definitory quality of "substances", for scientific purposes a measurable magnitude had to be found, that follows a conservational law.

Unfortunately, the intermediate matter of the many forces was "imponderous"; so "weight" was not really an adequate magnitude. On the other hand, when really unified, there should exist only one conservational magnitude, valid for all and as imponderous as they all. So it was convincing to understand the law of energy conservation (tentatively expressed by J.R. Mayer, quantitatively measured by Joule and exactly formulated by Helmholtz, all this within 5 years at exactly the same time when Humboldt published the 1^st vol. of his final holistic concept, "Kosmos") as the final key-stone of the romantic Program of Unification.

Even chemistry could not resist the unifying power of the energy concept, when the esoteric "Wahlverwandtschaften" were now interpreted in physical terms as "mechanical" forces between different elements: "polar" ("ionic") bond was understood as caused by exchange of electric charge already by Faraday (thus he gained the merit to keep atomistic models alive through 19^th ct.), whilst "atomic" and "metallic" bond had to wait for quantum-mechanical explanation till the 20^th ct. (Lewis/Langmuir 1916 resp. Born 1920es).

A survey of the state of the art in interpreting the interdependent system of manifestations of forces between (cf. top >> down) formal fields of force, intermediating imponderabilia and ordinary matter in the mid 19^th ct. was given by J. R. Mayer in Fig. 1 (cf. Klein 1992).

Energy was to become the crucial point in concepts about the relation between forces and matter. Thus the importance of imponderabilia grew the more they became the favorite objects of research, whilst the ponderable matter widely came out of focus for ca. 100 years. In some respect they only survived because they offered traditional "mechanical" models, how to imagine the impact of (inter)mediating "matter", whilst the new mathematical models about impact merely by exchange of energy (without exchange of matter, i.e. as a wave-like interaction) remained formal; but because of the mechanistic associations which the minds of scientists were used to, they did not count as true explanations. So now for each kind of interaction two possible "mechanisms" of impact had to be considered, via "particles" or via "waves", and the surviving mechanistic tradition even went so far that the new dynamical effects required mechanistic models for both types of explanation.

Happy enough, the scene became simpler, when, as the final result of the unification program, only electrodynamical force was left, after Faraday, Maxwell and Hertz had demonstrated also the last resisting, light, as electromagnetic waves.

But now, when only this one kind of imponderous matter, electromagnetic force, remained, the psychological wish for mechanical models insisted in the existence of at least one final and universal material substance as mediator of it into far distances, ending up with the postulate of a subtle substance called "ether", spread all over space, indetectable to the senses and without resistance against the motion of stars and planets. In the course of the growing importance of fields of force compared with classical matter, the investigation of this ether became focus of research during the 2^nd half of 19^th ct., so that classical matter (atomistic, heavy) and hypothetical ether (universal, imponderous, yet unperceivable) at times gained equivalent extension: a recently detected manuscript of young Hertz (1884) on "The constitution of matter" renders exactly the same number of pages to each.

Ether in fact was the very meeting point of physics in the 1880es; its ontology was still uncertain, and each of the many newly discovered effects, esp. each new kind of "radiation", was immediately checked for whether being particles or radiation!?! by the standard crucial experiments for Reflection? Refraction? Dispersion? Interference? Polarisation? Magnetic Deflection? Photoeffect? asf. (cf. Gerlach 1970). Esp. longitudinal el.magn. waves (possible in theory and searched for long time) were tentatively attributed to cathode rays (by nobody less than Helmholtz!), to X-rays, radioactivity and black-body heat-radiation. "Radiation" then always meant "Ether", and all that effort would seem as labor on a pure illusion, had it not clarified the problems so as to finally make accessible the very structure of atoms.

The insuitability of the ether concept is usually (e.g. in school) demonstrated by the absurd qualities which the ether must have if electromagnetic waves were considered the same way as mechanical waves: Ether then should be a solid body (to enable transversal waves) of extreme elastic density (... waves of light velocity), which the planets nevertheless may pass without any observable resistence. But Hertz` arguments were much more subtle: Instead of fighting with the oddities of an exotic solid state, he confines himself to analyse only those qualities which Maxwell´s theory unescapably demands: so merely attributes to ether certain states of polarisation, and after reformulating Maxwells equations in a throughout symmetrical form and harshly postulating as an axiom, that „„Maxwells Theory" is simply identical with Maxwells equations", Maxwell´s theory (including the el.magn. waves) becomes independent from all mechanistic or whatever models. Hertz explicitely declares all speaking about ether (as a necessary mediating substance) as just a „fancy dress" of performance, serving the human weekness to be inclined to accept only illustrations he is accustomed to as satisfactory "explanations". Thus, Hertz already in 1891 comes to the conclusion to expel any ether concept as basically „unnecessary".

When Einstein made the same step in the Special Theory of Relativity in 1905, he obviously took the idea directly from Hertz, as his first expression to ban ether (in his letter to Mileva Maric from Sept. 1899) indicates, that nearly verbally coincides with Hertz´ considerations 1891. Those historians who see Hertz merely under the auspicies of the ether hypothese miss the historical situation and neglect the results Hertz gained through his scientific work.

It was an enormous step, that Einstein valued this way (quote Pauli 1959, 242): "The emancipation of the field concept from the statement of mediating matter ("Setzung eines materiellen Trägers") (added: "by Hertz" (P.K.)) belongs to the psychologically most interesting events in the development of physical thought". Cassirers interpretation (1954, p. 544) is even more essential, yet also simplifies the historical situation and truly speaks about Hertz (without being conscious of it), when he describes the final outcome of the ether debate: As a very good idea he first reminds the "classical" (Newton vs. Huyghens) wave-particle-„dualism" of light (this is in fact – but rarely seen that way – an analogon of the Quantum-mechanical dualism of light!). Then he turns to the concepts of the light-ether-relation, that became "the more paradox, the more subtle became the descriptions of its constitution." But all problems vanished, Cassirer writes, „when only, as in Maxwells theory, light was defined as an electrodynamical process. For this was the most important principal step: to transcend from physics of matter to pure physics of fields. Because, those realities whom we give the name „fields" then are no longer thought of as a complex of physical things, but they are merely the expression of a concept of physical relations."

Exactly this was Hertz´ methological program, and his manuscript from 1884 shows us that he perhaps was the only physicist who verified it strictly, systematically, step by step, and with stupendous sensitivity, so that, had he survived, in my opinion would have yielded some kind of theory of relativity at about 1897 (at least after appearance of the Lorentz-transformations).

On the other hand it´s amusing, how Einstein in 1920 (!), when it comes to explain the structure of space in the General Theory of Relativity (GTR 1915), argues in favor of an Ether-concept that reminds strongly to what was state of the art about 1890. In „Äther und Relativitätstheorie" he says (Einstein 1920, Abs. 13): „The special theory of relativity does not compel us to deny ether. We may assume the existence of an ether; only we must give up ascribing a definite state of motion to it, i.e. we must by abstraction take from it the last mechanical characteristic Lorentz had left." Why? Hertz´ considerations on the process of physical measurements in his „Prinzipien der Mechanik" (1894) (that went farther than Einsteins prolongation and preliminary completion in the „Special Theory of Relativity" (Unsöld 1970)) caused Einstein in the GTR to re-introduce an Ether concept similar to that of Ernst Mach, when he attributes to empty space certain physical qualities, esp. the metric structure of space as determined by the gravitational matter distributed in it (l.c. Abs 21). Einsteins comment: (l.c. Abs 18): „(So) there are weighty arguments to be adduced in favor of the ether hypothesis. To deny the ether means to assume ultimately that empty space has no physical qualities whatever. The fundamental facts of mechanics do not harmonize with this view. For the mechanical behavior of a corporal system hovering freely in empty space depends not only on relative positions (distances) and relative velocities, but also on its state of rotation, which physically may be taken as a characteristic not appertaining to the system itself. ... asf" – that is exactly the structure of the "official" arguments from Newton to Mach.

But it is, frankly speaking, a less general standpoint than that Hertz had already taken in the „Prinzipien". But even long before, Kant had given the perhaps „weightiest" of „arguments in favor of the ether hypothesis": „Any experience of empty space is impossible, also any conclusion on its object, because experience needs impact of matter on my senses. Thus, the statement „empty spaces exist" can never be a neither direct nor indirect empirical statement." (op. posth., zit Lange 1961, p.328) – because, we may add in summarizing the "Critique of pure reason", space is only the form of order of sensual intuitions, but needs the impact of matter in order to construct real objects of experience. This is, I concede, a discrimination, that in contemporary physics is usually neglected and is substituted (though merely formally) by an arbitrary mixture of formal and material parameters – perhaps a "Zeitgeist" phenomenon parallel to the final elimination of classical matter in todays atomic physics, that we have to study now.

In fact we must ask, what we mean any longer by speaking of "matter", considered that in modern atomic physics matter in the classical sense does not exist any more: That classical image of matter as bold, massive portions of unpenetrable and indivisible bodies has radically changed; atoms (provided they exist) now have become centers of fields of force, possessing specific forms and symmetries, soft surfaces and internal structure; they can be divided or composed, and penetrated by even smaller, more "elementary" particles. The universe now appears as an accumulation of „matter as field" (F.Hund), that is regulated by the interaction of four basic forces. This change commenced in 17^th ct., when Niels Stensen explained the specific plane angles of crystals as caused by "oriented forces" of the crystalizing matter during crystal growth (Stensen 1669). About 1800, the Coulomb fields of ions rendered the spherical symmetry of particles that became so important for RNP. Then, since 1900, QM interaction of the electron shells of atoms resulted the orbitals that destinate molecular structures, whilst their dynamical equilibrium with the atomic nucleus causes the stability (thus the "existence") of atoms at all. Kant had justified, even required this shift of meaning in "Metaphysische Anfangsgründe" by his "dynamical" understanding of matter, when he states (Kant 1786, A 31ff): "Matter is what is movable insofar it fills space. To fill space means to resist any movable entities that try to penetrate space by means of their movement. ... (But) matter fills space not by its mere existence, but by its specific driving force."

Nevertheless, in this "dynamical" concept of matter at least the second classical indication of matter, „gravity", is preserved. But it could not resist the attacks of the perhaps most radical 20^th ct. physicist, Einstein, who just draw the consequences of Hertz´ formalistic program, when he simply states ontological identity for entities that are only formally identical (namely by their equal dimensions) – or the other way round: when he attributes the classical universal material quality, gravitation ("mass"), to such a spurious and artificial (i.e. not directly sensually conceivable) magnitude like „energy" through his fa mous E = m x c²

But in the same "annus mirabilis", 1905, Einstein went even further, when, following his strict paradigm to combine Quantum Theory with Theory of Relativity (Pauli 1959, 242), he eliminated any remaining differences between matter and fields by field quantization, first for the electrodynamical field by the photon hypothese – a step, which then was generalized in contemporary solid state physics (first Max Born) by the various concepts of "quasi-particles", i.e. by the conception of just geometrical disturbances of particle systems as virtual "quasi-particles" like phonons, excitons asf., as also by the deliberate variations of formerly stable qualities (that defined particles as such, like "mass" or "charge") as "effective" masses or "effective" charge (who in fact tells us that free "electrons" are the same kind of "particles" as the "electrons" that constitute the "electron gas" in metals – and what does this mean?)

Finally: that even the most characteristic classical defining quality of matter, gravity, can be given to any fields, and that these interact by exchange of „gravitons", perhaps remains the (last?) unsolved problem in particle physics, which is expected to be solved by the „Great Unification of Interactions", the „Theory of Everything". Ironically, this "solution" seems not possible without a rebirth of matter, even as a kind of "imponderabilium", when we speak in science about a universe "filled with that mysterious Dark Matter resp. Dark Energy … which one cannot see nor experience, but which manifests itself merely by its effects." (Eckhardt 2005, 28) – Well, this had we before! My intention was to understand, why!

Let us now finally return to Humboldts declaration of the mind as a phenomenon that exists in a substancially different category as matter. As pointed out in Chap. II, this would mean to confess a dualistic understanding of the mind, and to state the necessity to introduce (at least) an additional substance, with all of Schillers problems to survive as follow-ups. Indeed, contemporary philosophers, but also neuroscientists, frequently tend to such a self-understanding, when they declare „physicalism", the characteristic program of modern science, as failed. „Physicalism" means the attempt to construct a scientific system apt to explain all objects of experience, natural or artificial, only by means of a hierarchically ordered system of scientific concepts and laws developed by continuous extension of physical laws adjusted to the hierarchical ontologic order of objects. This program, on the contrary, has been a stupendous success at any ontological level that is refuted only when based on ignorance of contemporary science as a whole and inadequate application of too simple concepts and laws that do not consider conceptual extension for „higher" ontological levels.

Within this program the explanation of „living systems" in terms of chemistry is rather simple: D. Nies (in a letter to Spektr.d.Wiss. 11/07, p.11) defines them as aquatic quasicells, isolated to the environment by semipermeable membrans, absorbing energy for synthetisation of carbonic macromolecules, thus increasing internal order by accumulated negentropy, that is thermodynamically compensated by external growth of entropy. This certainly is a correct chemical definition, that however hardly seems to express our ideas associated with life as a field of spontaneous, vivid self-experience. The intention, however, to characterize it more specifically soon shows us the limits of defining ontological borders and transitions, first: from non-living to living systems, then, as our primary interest, from „life" to „mind" as a specific quality of some living systems. Both have evolved from chemical systems by means of chemical laws, yet resulted specific „systems´ qualities".

In that respect, as a systems´ quality, the mind – or better: the „spirit" which we find as „product" of the organismic mind – is nothing substancially special. It certainly exists, for we experience it through our internal senses, and it is not, in the manner of orthodox materialism, „nothing but matter", but is in fact something new, which nevertheless needs no additional special „substance" (though perhaps, but also at most, a new „principle" for us when thinking about it). The mind is inseparably connected with matter, namely with the internally incented activity of matter, that is the defining quality of life. But it is obviously not found suddenly at whatever level of evolutionary diversification of life. Spirit expresses this activity, which to its side is signalized to the internal senses as output of mental activity that in fact is, as we showed, „nothing but" a result of specific states of order in matter. So this order is acquired merely by the qualities of matter itself, though favored by certain environmental conditions like suitable energies at suitable times and temperatures, which, if they happen, cause matter to organize itself in that evolutionary process that (at least on earth) created living beings.

Ergo: the spirit in mind is the result of a process of „self-organisation" (we may even concede to, however critical, „creationists": by means of laws laid into matter by an intelligent designer, as its creator commonly called „God"). It is the product of a process of emergence of new systems´ qualities, under the conditions of „variation" and „selection", a process that happens since some ten billion years in the uninterrupted continuity of evolution. It resulted the continuous chain of ascending manifestations of material organisation that we understand as „life" and „mind". This process generated e.g. (considered down >> up) the molecular protobionts / self-reduplication / sensitivity and specific reactions on stimuli from out- or in-side / fixed stimulus-response-chains of behavior („instincts") / evaluation and valuation of stimuli / combinations of evaluated circles of behavior / learning / expression of internal states / communication / thinking / rationality / reflection / consciousness and self-consc. (cf. Klein 1997) ... – Now, at what place, what level, which point of this continuum should suddenly appear that radically new substance, that could not be explained as just a normal phase emerging one from the other in that evolutionary continuum? – or, equivalently the other way round: how many different „substances" should we insert, if we find as unsatisfactory the principle of evolutionary continuity, that can be demonstrated, at least re-constructed, for any level and every step in the history of evolutionary development?

So we may now end our tour d´horizon by stating: Instead of adding specific intermediate substances to explain those basically new qualities of matter called „life" and „mind", it is the principle of evolutionary continuity alone that is sufficient to explain them. They simply emerged in evolution, requiring nothing else than the qualities of matter itself, and by means of nothing else than causal physical laws. The result is not some new kind of matter, but a new state of the structural order of matter (a relation perhaps best compared with the hardware - software relation in processing „information").

Cassirer, Ernst (1954); Philosophie der symbolischen Formen; vol. III, 2^nd ed.; Darmstadt

Eckhardt, Ulrich (2005); Wie kam Einstein auf die Relativitätstheorie?; www.aww.uni-hamburg.de/kse_vortragsarchiv.html

Einstein, Albert (1920); Äther und Relativitätstheorie (Rede Univ. Leiden, 5.5.1920); Berlin

Gerlach, Walter (1970); 75 Jahre Röntgenstrahlen; in: Physikal. Bl.; vol. 26, pp 490-497

Hertz, Heinrich (1884/1999); Die Constitution der Materie (Albrecht Fölsing, Ed.); Berlin

Hertz, Heinrich (1891, 1892); Untersuchungen über die Ausbreitung der elektrischen Kraft; (= Ges. WW II); Leipzig; pp 1– 31: Einleitende Übersicht

Hertz, Heinrich (1894); Prinzipien der Mechanik; (= Ges. WW III); Leipzig

Kant, Immanuel (1755); Allgemeine Naturgeschichte und Theorie des Himmels; Riga

Kant, Immanuel (1786); Metaphysische Anfangsgründe der Naturwissenschaft; Riga

Klein, Peter (1992); Symmetry Arguments in Romantic Naturphilosophy; in: Symmetry – Culture and Science; vol. 3, pp 401-420

Klein, Peter (1995); Zur Geschichte der Relativitätstheorie als Protophysik; in: E. Jelden (ed.), Prototheorien – Praxis und Erkenntnis? (Leipzig); pp. 91-102

Klein, Peter (1997); Self-consciousness as a Coherent Representation of Internal Signals in the Mind; in: „S" – European Journal of Semiotic Studies; vol.9, pp 623-640

Klein, Peter (2007); Revision of Mechanics – Heinrich Hertz Preparing the Theories of Relativity (in German); in: Gudrun Wolfschmidt (ed.); Proc. of the Internat. Symposium "Heinrich Hertz and the Development of Communication"; Hamburg Oct. 2007 (in print)

Lange, Heinrich (1961); Geschichte der Grundlagen der Physik; vol. II, Freiburg

Lorenz, Rüdiger (2004); Aspekte der Funktionsweise des Gehirns; in: H. Fischer (ed.); Individuum und Kosmos; Mainz (Abh. d. Humboldt-Ges. vol.19); pp 199-220

Oerstedt, Hans Christian (1850); Der Geist in der Natur; Leipzig; vol. II, pp 1-24: Der allgemeinen Naturlehre Geist und Wesen

Pauli, Wolfgang (1959); Albert Einstein in der Entwicklung der Physik; in: Physikal. Bl.; vol. 15, pp 241-245

Schütt, Hans-Werner (1987); Galilei, die Technik und die Römische Kirche; in: C. Hünemörder (Ed.); Wissenschaftsgeschichte heute; Stuttgart, pp 47-68

Steno, Nicolai (1669); De solido intra solidum naturaliter contento dissertationis prodromus; (engl. ed.: G. Scherz (Ed.); Steno Geological Papers; Odense 1969)

Unsöld, Albrecht (1970); H. Hertz, Prinzipien der Mechanik – Versuch einer historischen Klärung; in: Physikal. Bl.; vol. 26, pp 337-342

For valuable comments I am obliged to G. Lugosi, D. Nagy, A. v. d. Schoon and P. Toschek.