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1. INTRODUCTION - THE SITUATION OF COGNITION

There are no guarantees for man that everything will happen according to his understanding of everyday life, an understanding which has evolved in his confrontation with his mesocosmic environment. In early stages, either as a hunter, or as a potential victim, it was vital for his survival for him to be able to distinguish from the general background a prey, or a predator, and to figure out its spatial as well as its temporal behaviour. This can be compared with our present-day attempts to avoid accidents in traffic. Stereoscopic vision and hearing are, of course, helpful for judging surrounding events. However, beyond this, would it not be possible, without the usual emphasis on the need for survival to contemplate the existence of holistic, comprehensive spatio-temporal states? To exclude these states a priori would surely be a dogmatic act! It, seems to me, therefore, much more appropriate for the purposes of philosophy to understand holistic phenomena, such as "instantaneous action at a distance", by rationally enlarging our inherited view, in the manner of the great natural philosophers of the past. We may recall that physics was once a division of "natural philosophy", and that the price of its gaining independence was a loss of cognitive or philosophical objectivity, for which physicists have tried to compensate by developing physics around the central role of the observer, as in relativity and quantum mechanics. In Definition III of his Principia, Newton had already analysed the origin of our concept of motion, before formulating the "axioms, or laws, of motion".
     The concept of space and time evolved together with the parallel functioning of the human brain, so that static and dynamic aspects became separately ordered. This testifies to their separate but equally vital, importance. The temporal judgement of events relies upon our ability to remember and to compare. From none of this, however, does it follow that everything is unambiguously localisable in space and time, that all forces can act only locally, or that their action spreads out with an upper-limited velocity. The transmission of forces through direct pulls and pushes, with which we are accustomed from early childhood, is no guarantee of their exclusiveness. The children of our times learn, however, to pay attention also to indirect forces, such as those of electricity and magnetism. So if, in spite of our greatest efforts, there is no explanation of gravity either through these direct pull and push forces or through indirect influences such as those of electromagnetism, this should be no reason to doubt our intellect. The impossibility of an intuitive, mechanical explanation of phenomena suggests to the epistemologist that our way of understanding, acquired in childhood, may have reached its limits and that the time is no w ripe to seek new patterns of explanation.
      The meaning of science ("WISSENschaft" in German) is to create knowledge ("Wissen SCHAFFEN"), rather than to consume it! To the ancient hunter within us, accustomed to appropriating to itself things which can be caught in space and time and devoured, the only importance of knowledge of things as they are in themselves is in their value to him as prey. Present-day science and technology encourage us in this way to dominate nature, to reduce it to a product-reservoir, without knowing its essence. The negative consequences of this predatory treatment of nature, to the extent even of risking ecological destruction, are thus unavoidable. There are, also, however, attempts to understand nature, free from any predatory interest, thus broadening our customary way of understanding towards a deeper humanism. This need not require a devaluation of the established space-time and local-mechanical treatment of phenomena. It would simply prompt us to question the dogmatic belief that this customary treatment is the only kind that is possible.
     Any dependence on pure dogma is harmful to the free development of the human spirit, especially in philosophy and science. However, I think that physicists involved in gravity research now have sufficient arguments in favour of the holistic approach to free us from the mechanistic dogmas of the past. There are, for example, those "timeless tunnelling" experiments of the Nimtz-group in Cologne. Till now such phenomena have escaped our understanding and are considered a problem, because the hunter within us obstinately insists that everything is appropriable to him in his habitual predatory manner, so that any suggestion of limitations on this conditioned grasp on things may cause existential fears. Perhaps this is why physicists tend to be driven by their professional anxieties, rather than by purely rational thinking, to impute to nature maxims which are no more than human expedients, a problem which was already recognised in classical antiquity.

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In his famous (but, to many people obscure) teachings, Parmenides of Elea (540 - 480 B.C.) tried to analyse what he saw as our failure to grasp the essential unity and the wholeness of Being. In his opinion, the fault lay with the human way of thinking, itself, which characteristically divides and separates things.[1] Although, as a sceptic, he was deeply aware of the fallibility of human thought, he did not exclude the possibility, that opinions (in Greek, "doxa") generated in human experience can be surmounted by infallible logic, thus allowing men to make more rational judgements. He therefore sought to convince with logical arguments alone, freed from the influence of subjective, "opinion". The first theorem of logic is that of identity, which requires that in all judgements A has to remain A. This theorem is extended to epistemology, provided we assume that the realm of our scientific judgements is governed by logical necessity, rather than by human arbitrariness, "that the Moira (Goddess of fate) weaved it" - as Parmenides expressed it, in the words of a nameless Goddess. Thus, in that early phase of natural philosophy, the preconditions of logical judgements were formulated. In the same way, this non-arbitrariness of procedure makes mathematics so suitable for science. In my view,we have to understand Parmenides in the sense that only in appearance do the various separations, classifications and divisions within the one and the same reality (the Eleatic One, or Being) exist. This seems not to contradict Heraclitus, whose basic teaching was that "everything is in flux", because everything can be in flux only lf that everything is continuous in the sense of Parmenides. This idea of something in eternal flux does not, however, stem from Parmenides. His statement is therefore timeless, thus valid in our days, too. He trusted that: "Nor is it divisible, since it is all alike and not more or less in any degree or any respect which might keep it from uniting, but, it is all full of Being. Therefore, it is all united, for Being is adjacent to Being." [2].
     Here Parmenides makes explicit the idea that no gaps can exist between objects, since "the non-existing doesn't exist". This gapless "existing" is paralleled by the "spacetime continuum" of relativistic physics. The modern idea of continuum makes it easier to understand Parmenides' description of gravity which, for the Greeks was a manifestation of the love-affair between "Gaia" (the Earth) and "Uranos" (the sky), which physically connected both. These cosmological considerations of Parmenides' reinforce one's impression that his ideas may lead directly to the Newtonian concept of "centripetal force" which, exerted by all particles on one another creates whole spherical conglomerates of objects. Such consequences were anticipated by Parmenides, whilst comparing "the existing" with "a well rounded sphere, around the centre of which there is always of the same force". In Newton's gravitational formula, also around the centre, of an object, at the surface of a sphere of any radius, the sum of gravitational forces is always the same.
     Without this sphere-generating property of particles, there would be no stars, no planets, no moons and no galaxies, hence, no heat, no light and no life. In view, then, of a sky full of evidence, it seems ridiculous to deny the existence of the necessary holistic force, as when talking about "forbidden distant forces" or, as is fashionable, to consider pure description instead of causal chains as more appropriate, which takes us back to Newton. On the other hand, causality is a favourite argument against the existence of supraluminal velocities, the logical impossibility of which makes us question the reliability of the claimed "measurements". Theories have to be fitted to the facts and not the other way round, otherwise the whole purpose of experimentation is futile.
     Without wanting to over-interpret Parmenides, it seems to me decisive that through him gravity is presented as a force of the wholeness which does not tolerate gaps, or voids, holding all Being (all things) together. All parts of the whole contribute to this force, in direct proportion to their mass and inversely according to their relative distance. According to this view, an object isolated from all the rest is just a construct of imagination, not an experimental fact. Relying upon the Parmenidean heritage, aided by our present-day knowledge, I would like to include in mechanics the following theorem:

All existing things, have two complementary attributes: one of its own and the other of the whole. Its own attribute force is that of inertia and the holistic attribute shows as its share of the centripetal force of the whole. As two attributes of the same thing, their measures are proportional.

These two forces, then, are irreducible, albeit complementary, attributes of a single reality which, in its passive aspect shows as inertia and in its active aspect, as centripetal acceleration. These two aspects are indissolubly interconnected, without either one being the cause of the other! That both aspects are complementary and constant appearances of the one, single reality, is already expressed in Newton's profound but till now, perhaps, not properly understood idea of the constant of proportionality G. This makes it unnecessary to look for reasons for the equality of inert and gravitational mass. The different but complementary nature of inertia and gravity makes unnecessary the need for mechanistic space-time explanations of the holistic model based upon inertia, since wholeness is an aspect which "intrinsically fulfiles" Being (Parmenides). This means that the holistic effect differs qualitatively from the inertia of a thing, which can be experienced only by actions external to it. Newton, who postulated gravitation as an universal force governing the behaviour of astronomical bodies, wisely refused to offer mechanical explanations regarding its nature, "without considering their physical causes and seats". He also says that "the accelerative force to the place of the body (is) a certain power diffused from the centre to all places around to move the bodies that are in them." [3].
     His purely spatial law of gravity is isotropic in space. This is his only non-arbitrary assumption. The permanent ability to act, mentioned previously, makes superfluous any question of a temporal factor and can be considered as the description of a "field". The repeatedly expressed opinion that the great Newton believed in distant action (of inert masses), just unmasks convictions that gravity needs a causal factor. This false understanding of gravity, as if it were "being created"' by inert masses, according to Steven Weinberg, shows up when one claims, in the context of Einstein's General Relativity, that "masses are curving the spacetime". For me this is the description of nothing more nor less than an "active action at a distance", even if one adds that it is "mediated", thus requiring a third entity in addition to the object and its gravity, namely a mediator. To Newton the centripetal force of an object is just as constantly present at the place where it acts, as is the inertia - the two faces of the same thing, which provide its measure. The place of an object, or, better, the places of every particle constituting an object, is the mathematical centre-of-gravity. Einstein's metric fulfils a similar role, even though he believed that he had to depict spacetime as a physical entity which mediates effects.[4]
     However, the, question of our discussion remains that of whether the gravity field manifests itself as an object, i.e. a whole, in space and time or whether a sudden shifting of a source can propagate energy with a finite velocity only. Only experimental research can have the last word on this and, so far as the tunnelling microwave experiments are concerned, electromagnetic waves seem to be able to tunnel in zero time! So long as Einstein's gravity waves propagating in space and time are not definitely confirmed, we have to leave open the possibility of overall-simultaneous (i.e., holistic) displacements of fields, giving Parmenides' idea of wholeness a chance. Since the nature of any action-transmitting medium is unknown, we cannot say that an overall-simultaneous shift in such a medium amounts to a violation of causality. The velocity of light is in this context no factual criterion, since the velocity of light is not the velocity of anything but light. It need not be, for instance, the speed of the shock-waves from a supernova. Only the manifestation of an effect before the cause would be, a violation of causality. On rational grounds, then, the argument identifying the gravitational field with spacetime curvature requires the instantaneous, or velocity-less displacement of gravity fields, and only the discovery of gravity waves propagating with finite velocity would dispose of that rational argument for the necessity of instantaneous effects. Unfortunately, the continued absence of any proof of finite-speed gravity-waves will not prevent supporters of mechanistic models from remaining convinced of their existence. Such evolutionary entrenched attitudes have blocked our understanding of Newton's profound philosophical wisdom, which prompted him to present a mathematical concept, based on detached principles, with the aim of producing an objective handling of facts in which, as in the method of Parmenides, interpretation plays no part because, as we say, every interpretation of facts depends on the subjective opinion of the observer and reflects no more than the zeitgeist. A complete exposition of the reasons for the validation of the Newtonian concepts in practice would require a much more detailed discussion than is possible in this contribution.
     So let me simply point out, consistently with Newton's "hypotheses non fingo", that my argument is by no means speculative but is based on rationalist principles, since only statements relying upon carefully elucidated logical principles can be a guarantee of rationality. The main principle in this argument is therefore Parmenides' cognitively clarified idea of the unity and wholeness of all Being. This idea, together with simple, incontrovertible facts and logic, has led me to this view, which any physicist should be able to follow, provided that he is free from prejudice. My way of thinking does not allow me to deal in pure speculations, or questions related to the possible existence of "curved spacetimes", "strings", "wormholes in spacetime" and suchlike. I consider these popularity-chasing depictions, borrowed as they are from everyday life, doubtful, especially since journalists - and through them the public at large - become accustomed to treat metaphors as facts and thus become prisoners of their own metaphorics. During crises they cannot avoid compromising themselves by trying to retract previous statements made in public. "As-if" models can sometimes be useful in developing mathematical concepts, but their usefulness, depends on whether there is a proof, or even a hint, that something is indeed like that, remembering, of course, that during another zeitgeist, things may be interpreted very differently. Superfluous interpretations and assumptions should therefore be avoided. Nothing new in that! The advance on it , however, is the view, presented here, of the need for indisputable criteria as being indispensable for the validity of judgements.

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According to Parmenides, the Existent "as a whole is an identity". That which is for all things the same, cannot be prevented by "a more ... or a less" from remaining an "equal". The falling of an object has to do with the gravitational field alone, not with ist content. This was discovered by Galileo, while ascertaining that objects fall equally fast, independently of their form and their mass. Since "a more ... or a less" (with respect to mass) has no influence on the falling object, it follows that anti-matter, light and electromagnetic energy generally, as well as "massless" particles are all equally falling. The calculations of John Michell (1783) and Laplace (1796) for estimating the mass of a star which would not allow light to escape its gravity field (in Wheeler's wording, a "black hole"), are based on Galileo's experience and the idea of wholeness. So, also, are the calculations of Soldner (1801) and Einstein (1911; 1915) regarding "light deflection" by the gravity field of the sun. The question of whether the nature of light is wavular, or corpuscular is irrelevant. The effects that masses have upon one another are merely what we are used to observing, without this implying that those observations are absolute. Moreover, if mass is just "condensed energy", and if gravity is a property of mass, then the energy has to have that inert gravitational property also. As soon as we realise that everything is subordinated to gravity and that everything is the centre of a gravitational field, it should be clear that, by virtue of the mass-energy equivalence, everything partakes of the gravitational constant G. Therefore the centripetal force of gravity is not just one force among others but is, rather, a universal complement of all forces, as expressed in my above-proposed theorem. Newton's gravitational constant G, connecting gravitation with inertia, is thus extended to include also the "gravity of energy" through the equivalence formula E = mc². This was Einstein's first and, in my opinion, correct interpretation of his equation. However, a property of something cannot derive from something which derives from that property! So the later interpretation of E = mc², as telling us how much energy a mass converts into originates, again in my opinion, in magical/alchemistic thinking. In the real world there are no magical transformations like that of a frog turning into a prince when kissed by a princess. Structures are, of course, built and destroyed by energy. During atomic fission a structure is destroyed and binding-energy is released. The fairy-tale, however, does contain a grain of truth insofar as nothing happens without cause or motive (the frog remains a frog so long as no princess kisses him). Moreover, small causes can have large effects. Also, if inert mass is taken as the only source of gravity, then what seems to be a deficit of gravitational sources, in the case of the missing "dark matter", should come as no surprise.
     Gravity, then, as a complementary aspect of all forces, makes it understandable that:
1, anti-gravity cannot exist: objects can possess complementary characteristics, but no contradictory ones! In particular, there are no centripetal and centrifugal actions at the same time;
2, all attempts to put gravity on a par with the other fundamental forces have so far failed;
3, no real "gravity quantisation" problem exists, since gravity itself belongs to quanta;
4, in my view there is no fundamental difficulty on the way to a Grand Unified Theory.
     The counterpart of gravity is represented by various kinds of explosions, from "supernovae" to the "Big Bang", which are reactions of matter to self-condensation. This reaction, opposing gravity during the "Big Bang" was supposedly initiated by the production of anti-matter, so defining its cosmological role.
     The universal existence of a centripetal gravity, supports the idea that the known, structured universe, originated necessarily in an common "Big Bang", which created the centrifugal forces that enable the cosmological division.
     The undifferentiated state preceding the "Big Bang" means "the whole in one" and, afterwards, "the one is in the state of the whole", as soon as the universe starts to differentiate through cooling down. But in both states, "it is now altogether, one, indivisible" (Parmenides) [5]. The alternately attractive and repulsive forces within the wholeness would be the basis of a "pulsating Universe". In Parmenides' wording, "With your mind, gaze on even absent things with as present and do so steadfastly. For it will not serve Being from clearing to Being as either dispersing or gathering in every direction in every way in regular use." [6] This idea of their ancient predecessor lies behind the search of modern cosmologists for the missing critical mass which should prevent the dispersion of the known cosmos. Since the centripetal force, acting against, the expansion of the universe, decreases with the square of the distance, the presently observed red-shift of galactic light applies only for the moment of observation. This bears upon estimations of the "age of the universe". Since the expansion was slower in earlier times, the age of the universe has to be older than is calculated on the basis of the now observed expansion-velocity. lf, before the Big Bang. the universe had a predecessor which had terminated in a Big Crash, then the Big Bang probably occurred before the plasma had become completely homogeneous (and had a finite radius). Therefore new galaxies emerge from similar structures which had existed before.
     The universe originating in a common "Big Bang" could, of course, be only a "partial universe", which has developed within "a more complex universe". Its receding parts could, at some time, collide with other "partial universes", thus causing new "Big Bangs". Highly energetic phenomena, like gamma-ray bursts and quasars, not accountable by standard physics and cosmology, could possibly indicate such collisions of fragments of universes" I mention the possibilitv of a complex universe only as a warning against the old error of considering just the part of the universe that, is known to us as the whole "world system". Such a conclusion has always proved wrong! Nor does the finite velocity of light, considering the age of astronomical objects, imply an optical horizon not, an objective boundary to the universe. Moreover, a universe, having man and his earth in its centre would be a miracle, in a world larger and more complex than ever imagined by a simple human being, who is still conditioned by his predatory instincts. This narrowness belongs the fixedness of our stance in respect of knowledge, a limitation on our thinking, against which scientists have to struggle, over and over again.

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In order to secure contradiction-free facts and knowledge, it is necessary - in my opinion - to accept, unreservedly, the idea of wholeness. Boldness is required to consider the implicit, instantaneous effects - even if we find difficulty in imagining them. Our human capacity, of imagination, developed in the mesocosmos, as already stated, is no safe and sufficient, criterion to judge problems in macro- and microcosmic domains. Such human judgements cannot, therefore, be taken as the last word on the subject. It is our philosophical task to adopt and to deepen new ideas, which is the main purpose of this present paper. In this connection I would like to remind the reader of the enfolded, or entangled particles (in German: verschränkte Quanten) which react instantaneously when one of them is polarised. For me, this is another aspect, of wholeness which is worth pursuing further. This kind of wholeness, called today "non-locality", successfully investigated by Anton Zeilinger at Innsbruck (Austria) University, was described in a recent publication. "One may formulate enfolding as the fact that two or more particles possess qualities in a manner that only common but not individual qualities of the particles are defined". In my opinion, synchronism also belongs necessarily to this non-locality and non-differentiability.
     At a time when Man has detached himself from nature in such a dangerous way, more thought must be given to these holistic interconnections, as C. F. v. Weizsäcker agreedduring a detailed discussion with this author. As has been argued, there can be no physical macro- and micro-objects, which exist all by themselves. This is particularly true of living matter, which depends on other living and inert matter. For the sake of our common future, this has to be understood. We have to learn to understand to live this perception. Therefore even physics is obliged to contribute its share to the idea of the wholeness, without reservation.
     There are also holistic approaches in cosmology. According to the anthropic principle there has to be a correlation between the present state of the universe and the existence of man. That, is to say, if the universe were not in its presently ascertainably complex state, we would not exist at all. Under the flag of self-orientation and vanity, some have drawn from this correct insight the crazy conclusion that Man was the purpose of the evolving universe, which has therefore to be his servant. This is called "the strong anthropic principle". Of course, the dinosaurs, one hundred million years ago, as they dominated the earth, could have assumed this with equal justification. It is, however, more reasonable to conclude that only by respecting and preserving the complex and delicately balanced conditions of our existence, can mankind survive. One may call this the, "holistic anthropic principle". I think, nevertheless, that the anthropic principle expresses this indissoluble interdependence between the state of the universe and the existence of homo sapiens, an interdependence which has to be taken seriously. The wise Laotse (604 - 520 B.C.), almost a contemporary of Parmenides (540 - 480 B.C.) said: "Who doesn't take life seriously, will be shown life's cruel seriousness."

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Correct as the consistency of thinking for a scientist must be, openness to alternative ways of thinking is no less important. Nobody can guarantee that, even a well proven view, like reductionism, represents the only possible one. Only calmness and tolerance of alternative arguments can keep the scientist open to the truth, which should be a guide for all his thinking and doing. Only this allows the scientist to exemplify a love of truth and enables science to be an advanced guard of an open, future-oriented society, attempting to solve its problems in harmony with nature. Ideological cramp, prejudice and superficiality hamper recognition of doing right and becoming truly humane. This responsibility for the ethically oriented progress of humanity is now needed more than ever. At the present time, the question is whether science should remain the servant of vested technological/commercial interests and anxieties, or whether to commit itself unconditionally to truth - to regain its leading position of enlightenment. It seems tome absolutely necessary that science approaches nature respectfully and with love. This is the only way natural philosophy may retain its meaning and understanding and that, wisdom can prevail.
     What we need in physics is not, a new theory beyond quantum mechanics and relativity theory, but rather a deeper understanding of the role of the observer, thus making further theorising superfluous. A deeper self-understanding will enable us to differentiate clearly between ourselves and things; for example, between data and information. While data belong to a material structure and can be processed by material means, information is something purely spiritual, interpreted by us on the basis of our life-experience and previous knowledge. All experience and knowledge is a mixture of objective data and subjective judgements, with which man makes the universe sensually and spiritually his own. Only by recognising the subjective components can knowledge become objective. Only somebody who realises this and takes into account his own share in perception, really perceives. Otherwise, he will remain a blind victim of his sensory and mental heritage. Now in my opinion it is the task of philosophy and science to understand the relation between observer and observed better than has been done so far. A final consequence would be the emergence of an inter-disciplinary science of the "Relation of Everything", inclusive of the observer and his cognitive structures.
     It is appropriate, here, to repeat the words of Carl Friedrich von Weizsäcker at, the 49-th congress of DPG (German Physical Society) in 1985 in Munich, on the occasion of the Niels Bohr centenary, regarding the relationship between relativity theory and quantum theory:
        "I would say, reversing Einstein's hope, that this (future) theory (beyond the present day quantum theory) would be gained not by a reduction of the quantum theory to the spacetime-continuum, but rather by a derivation of the spacetime-continuum as a classical borderline case of a pure quantum theory." [7]
Attractive as it sounds, the simple reversal of the Einsteinian reductionism will, to my mind, still be in the spirit of reductionism and we should not look for the easiest way. It would be in the very spirit of Bohr to dispense with any dogmatic "either-or" thinking, about the particle and the field approach and to consider the two as complementary, within a structured universe and to apply whichever description is most useful in the circumstances.
    Only usefulness allows us to test methods and theories. When an experience requires that we need descriptions of different kinds, we have to respect that experience. The scientist should reflect on the reason why this is so. It is because reality always surpasses the imaginable, so that our thinking and speaking allows us to approach reality only in an imperfect and tentative way. For this reason, one should argue in terms of logical principles, rather than words, because words are no more than our means of communication, whereas logical reason transcends purely verbal argument. I am convinced that, by broadening the scope of science in this rational way, through acceptance of a holistic view with instantaneous effects as a logical consequence, gravity will cease to be a stumbling block for physicists on the way to a unified theory of the four fundamental forces. In such a view the events in micro- and macrocosmos elegantly bind into a Whole, which the Ancient Greeks had seen as united "by a band of love". Gravity is no more "occult," than its complementary, non-derivable, inertia, with which physicists also have their problems. However, it is always the pre-scientific "doxa", the convictions and ways of thinking, rather than the facts, which generate these avoidable problems. The goal of scientists has to be the transition from these supposedly evident precepts to a natural acceptance of facts in the context of rational and undogmatic thinking.
     First, then, I have called gravity a "force of the wholeness" Then I have demonstrated that our -known universe might be a part-universe. This raises the question of which wholeness manifests the "-force of the wholeness". Is gravity the force of a part-universe or the force of an even bigger wholeness? I think the entangled particles can give tis an important clue here, since their entanglement is the consequence of their common emission. lf the Big-Bang singularity is the common emission of all parts of the part-universe, then it also defines the wholeness; that is "a same", as Parmenides would say. In this view of entangled forces of a big-bang, in which everything is involved, gravity and the big-bang are closely related to each other, for gravity is a prerequisite for a big-bang to occur. Being entangled through a common origin, instantaneous effects would be a general property of matter, a view which warrants further examination.

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[1] The Fragments of Parmenides A. H. Coxon, van Gorcum, Assem/Maastricht (NL and USA) 1986, fragment 8, verses 55-60.
[2] ibid. fragment 8, v.22-25.
[3] Principia Mathematica I. Newton, transl. by Florian Cajori, University of California Press, Berkeley, California (USA) 1947, Def. VII, p.5.
[4] Teaching physicists try to explain gravity more intuitively, with "dips" or "dents" in space-time, which allow test-objects to roll "down" inclined planes. This is, however, a deceptive analogy, since without presence of an Newtonian centripetal force, defining the "downward direction", there is no "up", "down" or "inclined", so that a ball has no reason to roll into a dent. The "curved spacetime" appears here as an "as-if" description of the consequences of gravity, like the cycles of Ptolemeus or Aristotle's "strive for the natural place". These are phenomena caused by gravity and so are without value in explaining gravity. Newton's formula applies rigorously for pointlike masses only losing its validity for extended masses at short distances. It suffices, however, for distant objects, like planets. For near test-objects various formulae which describe the distribution of gravity sources in space, do the better practical job, but do not, on their own, provide a better understanding of gravity.
[5] op. cit., fragment 8, v. 5.
[6] ibid., fragment 6.
[7] Zeit und Wissen C.F. v. Weizsäcker, dtv Munich, 1995, p. 785.