Post modern philosophy of science and science

"Is Science 'Forever Tentative' and 'Socially Constructed'? No Way!"

by

David H. Bailey and Jonathan M. Borwein

June 7th, 2012

The Huffington Post

Introduction

In "postmodern science studies" or "postmodern philosophy of science," scholars critique science and mathematics from a high-level meta-perspective. Two of these writers, Karl Popper and Thomas Kuhn, in the view of many scientists, have significant merit and are worth taking seriously, although both published their most influential books 50 years ago.

Karl Popper

Popper (1902-1994) declared in The Logic of Scientific Discovery [Popper 1959, pg. 40-41], "It must be possible for an empirical scientific system to be refuted by experience." Popper's ideas on falsifiability remain highly influential in scientific research to the present day. For example, various prominent scientists have recently questioned whether it is prudent to continue pursuing string theory, given practitioners have not been able to derive testable consequences after 25 years of effort [Smolin 2006, pg. 352].

Popper's ideas have limitations, some pointed out by Popper himself. In modern-day science, major theories are seldom falsified by a single experiment. There are always questions regarding experimental design, measurement procedures, data analysis and error statistics. Multiple follow-on studies are necessary to conclusively decide the hypothesis one way or the other. The recent "faster than light" neutrino measurements at CERN provides an illuminating case study.

Moreover in most cases, modern "falsified" theories continue to be extremely accurate within appropriate domains. Even today, over 100 years after Newton's mechanics and Maxwell's electromagnetic equations were "falsified" and supplanted by new physics, they remain the basis of almost all practical engineering and scientific computations, giving results practically indistinguishable from modern theories.

Thomas Kuhn

Another hugely influential postmodernist author is Thomas Kuhn (1922-1996). His seminal 1962 The Structure of Scientific Revolutions analyzed numerous historical cases of scientific advancements, and argued compellingly that periods of normal science were interrupted by key paradigm shifts in which old ideas were abandoned [Kuhn 1970]. He likened shifts to "religious experiences" which do not come easily.

Kuhn was a trained scientist with a 1949 Harvard physics Ph.D., and was able to bring significant technical insight to his analyses of historical scientific revolutions. Sadly, the term "paradigm shift" is vastly over-used, and Kuhn's writings, much as Popper's, have been badly misused by a host of eager amateurs thinking they can smash the reigning orthodoxies of modern science.

In a newly published posthumous fiftieth-anniversary interview of Kuhn by Scientific American writer John Horgan, Kuhn was deeply upset he had become a patron saint to such would-be scientific revolutionaries: "I get a lot of letters saying, 'I've just read your book, and it's transformed my life. I'm trying to start a revolution. Please help me,' and accompanied by a book-length manuscript." [Horgan 2012].

More recent postmodern writings

More recent post-modern science studies have over-zealously extended the scope of their critiques, declaring that much of modern science, like literary and historical analysis, is "socially constructed," dependent on the social and political environment of the researchers, with no claim to fundamental truth [Koertge 1998, pg. 258].

Scientists counter that these scholars have distorted a few historical controversies, and have parlayed these to a global condemnation of the scientific enterprise [Gross 1998]. What's more the postmodern science literature abounds with: (a) serious confusion on technical issues; (b) politically charged rhetoric; (c) lengthy discussions of mathematical or scientific principles of which the author has only hazy familiarity; (d) applications of highly sophisticated concepts from mathematics or physics where they don't apply; (e) text peppered with sophisticated technical terms or mathematical formulas and vacuous technical passages [Sokal 1998, pg 4-5; SkepticalTeacher].

The Sokal hoax

Tension between scientific and postmodernist communities came to a head in 1996, when Alan Sokal, a physicist at New York University, wrote a parody postmodern science article, "Transgressing the Boundaries: Toward a Transformative Hermeneutics of Quantum Gravity," and submitted it to Social Text, a prominent postmodern studies field journal [Sokal 1996a].

The article was filled with pages of erudite-sounding nonsense, political rhetoric, irrelevant references to arcane science, and approving quotations from leading postmodern science scholars. In spite of its clear flaws, the article was not only accepted, but appeared in a special issue devoted to defending the legitimacy of postmodern science studies against its detractors.

Sokal had resorted to the hoax to highlight his concern that postmodern science has rejected the Enlightenment which identified with science and rationalism and rejected such obscurantism.

"Theorizing about 'the social construction of reality' won't help us find an effective treatment for AIDS or devise strategies for preventing global warming. Nor can we combat false ideas in history, sociology, economics, and politics if we reject the notions of truth and falsity." [Lingua 2000, pg. 52].

In the same issue as Sokal, a prominent postmodernist (seriously) wrote:

Once it is acknowledged that the West does not have a monopoly on all the good scientific ideas in the world, ... then can we begin to talk about different ways of doing science, ways that downgrade methodology, experiment, and manufacturing in favor of local environments, cultural values, and principles of social justice. [ Ross 1996, pg. 3-4].

Imagine if this extreme cultural relativism were widely adopted in modern science and society. A few years ago the Mexican government encouraged potters, for their safety, to use lead-free glazes, but the local potters were convinced that this was a foreign conspiracy. Unfortunately, as Michael Sullivan has noted, "lead does not care who believes what." [Sullivan 1996]. South Africa's experience with AIDS also shows how destructive of human life ill-educated views of "imperialist scientific plots" can be.

So where are we 50 years on?

The consensus of scientists is that post Kuhn and Popper, "postmodern science studies" have not advanced scientific research (or much else), and even their own writings have often been misappropriated. As biologist Paul Gross wrote [Gross 1996, pg. 50]:

    "The dictum that everything that people do is 'cultural' ... licenses the idea that every cultural critic can meaningfully analyze even the most intricate accomplishments of art and science. ... It is distinctly weird to listen to pronouncements on the nature of mathematics from the lips of someone who cannot tell you what a complex number is!"

Similarly, Canadian-American physicist Lawrence Krauss wrote that "philosophical speculations about physics and the nature of science are not particularly useful, and have had little or no impact upon progress in my field" [Krauss2012 ].

One broad criticism is that post-modernist scholars work almost entirely from outside the realm of real scientific research. Unlike predecessors such as Kuhn and Popper, most do not have substantial scientific training and/or credentials; do not address state-of-the-art scientific theories or methods in significant technical depth; and do not participate with scientific research teams in performing peer-reviewed scientific research.

Their approach is best exemplified by a comment made by a leading postmodern writer in the introduction to one of his works: "This book is dedicated to all of the science teachers I never had. It could only have been written without them." [Ross 1991].

However, such writers cannot possibly hope to have tangible impact in the scientific enterprise, since real scientific work is all about the details -- experimental design, careful execution, analysis of results. And when leading figures in this community openly express their contempt for day-to-day scientific work, they are not building bridges that will lead to productive collaborations with real scientists in the future.

Maybe one day the tide will turn, opening the way for a more respectful dialogue between science and philosophy. As physicist Carlos Rovelli recently wrote, "I believe [we] can teach one another enormously." Philosopher Tim Maudlin expressed similar views in his 2007 book The Metaphysics within Physics. In any event, the modern scientific method taking its full form after the Enlightenment has been astonishingly successful, as anyone who has ever been treated for a major once incurable disease can attest. While no knowledge may be certain, modern science comes remarkably close.

Astronomy: Classic debates

Being the year of astronomy it would be worthwhile to review some of the great debates of the past: The 1921 debate between Harlow Shapley and Herber Curtis in 1921 and the cosmological debates of the 1930s and 1940s. Of the latter from the Stanford Encyclopedia of Philosophy...

Sometimes, philosophy drives science. Cosmology between 1932-48 provides an excellent example how explicitly philosophical considerations directed the evolution of a modern science during a crucial period of its development. The following article exhibits these philosophical aspects of cosmological thinking in detail, beginning with a brief sketch of the historical development of general relativity cosmology until 1932. Following this, the historical participants in the philosophical debate are introduced, along with the basic ideas of their competing positions. Then the critical stages of the debate -- 1935-37 -- are closely explored by focussing directly upon the arguments of the participating scientists and philosophers. Finally, the concluding stage of the philosophical debate, namely, the emergence of the steady-state theory of the Universe, is presented in the context of its development from Popper's philosophy of science.


Read more...


"The Great Debate" [1921]--Shapley & Curtis

The astronomy/cosmology debates of the 1930's & 1940's

An over zealous Sir Arthur Stanley Eddington?

Bacon's bum rap?

Francis Bacon

Remember Friedrich Nietzsche's "Übermensch" meaning "overman"? And that Adolph Hitler took that word and construed it as "superman" and applied it to his Aryan race doctrine. Bum rap for Nietzsche. And Fancis Bacon? Similar situation? Lambast Bacon if you like for modern delimas of the environment and the relationship between science and technology but read: "...Works are of greater value as pledges of truth than as contributing to the comforts or life...." This is not unusual for people to remove statements from context and historical perspective and use them to champion some political cause or agenda.

"Is Bacon to blame for the evils of our polluted age?"

by

Nieves H. De Madariaga Mathews

When considering at what point we took a wrong turning, destructive to the earth and all that dwell upon it, those who are working for a new concept of science often invoke, as the villain of our disastrous piece, Francis Bacon, the 'father of experimental science', whose prophetic New Atlantis was published soon after his death in 1626. Bacon is reproached (along with Descartes) for spearheading a scientific revolution which promoted a mechanistic view of nature, and abdicated all responsibility for the results of its discoveries. Some have seen in a 'Messianic' Bacon the very model of the biotechnology at work today in the global markets - a 'cult camouflaged as science', 'a mindset that views science as a way of bringing man closer to God', and claims to improve our lives while actually degrading them.

In the film Mindwalk, based on the ideas of Fritjof Capra in The Turning Point (1982), Liv Ullman, as 'the physicist', indignantly decries our modern science, of which Francis Bacon is made the epitome. According to Bacon, the physicist declares, 'nature had to be hounded and made a slave to the new mechanicized devices; science had to torture nature's secrets out of her'.

And 'hasn't modern science', she concludes, 'done exactly what Francis Bacon preached - hasn't it tortured our planet?'

Did Bacon really preach these things? Many have believed he did, since, half-way through our century, two illustrious thinkers at the opposite extremes of the political scale concurred in laying at his door not only our polluted air, sea and soil, but the polluted lives of our alienated consumer society. In 1942 Herbert Marcuse, the patron saint of a generation of leftist extremists, described Bacon as the 'evil animus' of modern science, while Martin Heidegger, who was still celebrating in 1953 what he called 'the inner truth and greatness of Nazism', denounced in Bacon the symbol of a nefarious identification of science with technology. During those same decades Bacon's reputation as a scientist was also at its lowest ebb. At the hands of Karl Popper and others, the 'Great Secretary of Nature' had been demoted to sham thinker - a mere fact-collecting inductionist - and altogether excluded from the present scientific scene. Struck by the paradox, an eminent Baconian scholar, Paolo Rossi, pointed out that those who exalted science allowed Bacon no part in it, while those who looked on it as thoroughly evil, saw him as 'its very essence'.

When we turn to what Bacon actually said, however, these various dismissals prove groundless. Absorbed in their respective ideologies, their authors had failed to read Bacon in the original - and to read him in context - thus making a gross travesty of his model of science, and reducing his philosophy to a handful of slogans. This was the conclusion of various Baconian scholars who, in the 1980s, closely studied the meaning of his texts, reconstructing the situation in which he worked. Bacon's induction, based on the generation of laws from observation and experiment, by means of an intuitive 'analogical leap' from the observed to the unobservable, was shown to be a highly original contribution to philosophical thought, and he was rehabilitated as a founder of the new science, alongside Galileo and Descartes. His apparently one-sided exaltation of technology was similarly shown to have sprung from a misinterpretation - where not an actual misreading - of his words, in particular from the neglect of his basic tenet, that 'works are of greater value as pledges of truth than as contributing to the comforts or life'. We owe these misunderstandings in part to the tendency of some commentators to project the experience of a later time onto past ages (thus making Bacon, among others, a nineteenth century utilitarian, a positivist and even a Marxist). But we have also to understand why Bacon alone among English Renaissance thinkers, has been singled out in our time for consistent vilification. This anomaly has a good deal to do with the distorted image or his life which most of us have been brought up on, ever since, in 1837, the historian Macaulay published his brilliant but thoroughly untrustworthy essay, depicting a contemptible Bacon, soon to be loaded by subsequent biographers with every conceivable vice. This negative image of the man, which could not but influence that of the thinker, is still present in many people's minds, and it has made them only too ready to see him as a scapegoat for the harmful effects of the science he had heralded with so much acclaim. Bearing these points in mind we can now look at the principal complaints made of Bacon by the friends of Gaia.

Bacon's scientific revolution launched a mechanistic view of nature, in which living organisms are seen - and treated - as machines. The partition of the universe into live human mind and passive, mechanical nature was Descartes's gift to modern science, not that of Bacon, who stopped well short of 'the pitfall of classical mechanization', as it has been called.

Already in the eighteenth century the Italian philosopher, Vico, had congratulated his predecessor on having wisely avoided 'the rocks of mechanistic thought', while a contemporary recalled that, as a youth, he was given the works of Bacon to read so that he could be on his guard against 'the aberrations of Descartes'. For Coleridge 'the impulse towards a true natural philosophy, based on legitimate experience', had been betrayed by Descartes's science of mechanics. Like Shelley, Coleridge regarded Bacon as the man 'by whom Science was married to Poetry', while early in our century Alfred North Whitehead appreciated Bacon above all as a Renaissance vitalist.

And so we will find him. In his own Theory of Heaven he categorically denied the void he had earlier envisaged, and conjured up instead a starry heaven of 'fluctuating waves and reciprocations', an earth on which 'all objects emit rays'. He conceived the dynamic processes of nature - organic and inorganic - as a constant flow and ebb of 'vital spirits', struggling against the 'spirits' of inanimate matter to preserve youth and beauty, and to develop higher organic forms. It was by the synthesis of this universe in perpetual fluctuation with the quantitative aspects of his new science - a unique feat, as has been noted - that he sought to interpret all natural phenomena, 'from planet to planet, from spirit to star'. Indeed, with hisvital spirits, 'impressed by God upon the primary particles of matter', it looks as if Bacon had by-passed Newton's clockwork universe to rejoin the quantum scientist, Heisenberg, just as he had by-passed Aristotle to rejoin the pre-Socratic Heraclitus - that 'tracker-down of truth', as Bacon called him - whose complementary opposites he liked to recall, and with whose fire, 'both matter and moving force', Heisenberg identified his own 'particles of energy'. Anyone inclined to attribute a cold, mechanistic view of nature to Bacon should read his notes for a History of Generations and Pretergenerations, with its cascades or 'perturbations', 'vivifications' and 'gestations', its limitless 'potentialities', all leading to an order based on the 'generative and vivifying power in things' - a power which bears within it, 'like a second chaos', that air 'in which the seeds of so many things act, wander, endeavour and experiment'.

Bacon advocated 'the torture or nature'. 'The art of enquiry into nature itself, and or putting it on the rack', was never Bacon's, and these words, so often quoted against him, will not be found in any of his works. As recalled by Peter Pesic (from whose thorough studies of this subject, in Isis 1999 and elsewhere, I have taken most of the material for this section), they were written in 1696, by his great admirer, Leibniz, in praise or 'the art of experimentation which Lord Bacon began so ably'. Influenced, perhaps, by the fact that torture was still used in his day as a touchstone of certainty, Leibniz failed to distinguish, as Bacon emphatically did, between the concept or racking, or torture - terms which Bacon invariably connected with a brutal abuse - and that of 'the trials and vexation of art', indicating the agitation or provocation of nature in the course of an experiment aimed at verifying the evidence of the senses. Bacon depicted this 'vexing' or 'crossing' of nature with vivid images related to discovery or pursuit - never to torture. Many of them - such as 'espials', examination, trial, interrogation, deciphering - are taken from legal practice. Others are grouped around his concept of 'the Hunt or Pan, or Learned Experience' - a hunt 'in the woods or experience' for nature's laws - all of nature being 'nothing else than a hunt', while man himself 'hunts after his works'. If you 'follow and as it were, hound nature in her wanderings, you can drive her afterwards to the same place again': this is Bacon's description of controlled experiments aimed at making results replicable.

Turning to mythology, he described experimentation as a wrestling-match with that indestructible 'thrice-great prophet, Proteus, or Matter' - a matter permeated with spirit - who has to be gently but firmly held in place with the 'handcuffs' of mechanical aids, as he wriggles from one shape to another - or disappears for a time, as a gas; until, having rung all his changes, he finally discloses some of nature's secrets, thus assisting her to 'achieve her ends'. The experimenter is also tested in this process (being much in need of purification, since the mind of man is ever prone 'to distort the nature of things by mingling his own nature with it'). In the end, however, his part is a small one, for, Bacon insisted, 'all that man can do is to put together and put asunder natural bodies. The rest is done by nature within.' On the role played by man in vexing nature, within these limits, Bacon is quite clear. He gives examples from the age-old crafts - baking, brewing, pruning - by which nature is 'forced out of her natural state, and squeezed and moulded', and he cites experiments such as confining the spirits of wine in a sealed vessel, or making a rainbow in a spray of water.

We are far from the 'racking of nature' imagined by Leibniz. None the less, a few others were to follow him in confusing Bacon's charged images, and more recently various feminist writers - including Carolyn Merchant (1980), from whom, alas, Capra took his notion of Bacon's views - have contributed their own brand of confusion. Bacon is now denounced for launching 'a science infused with sexual and misogynistic metaphors' - in particular with images of rape and torture - aimed at encouraging middle-class male entrepreneurs 'to exploit nature, as a female to be tortured through mechanical inventions'. As Alan Soble has demonstrated (Oxford, 1998), none of the passages adduced by these writers remotely supports their claims. By omitting key words and sentences, and introducing metaphors of rape and of 'the torture chamber' where there are none, they completely transform his meaning. Thus Bacon's remark that 'a useful light' might be gained by the scientist from an inquiry into the arts of witchcraft, to Merchant 'strongly suggests the interrogations of the witch trials and the rnechanical devices used to torture witches' - and in Mindwalk he will be made out presiding over the witch trials of King James, though these were held in Scotland, many years before Bacon became Attorney General. Merchant saw caverns like that of the Sybil as 'sexual holes', and, she complained, Bacon 'frequently described matter in female imagery, as a "a common harlot"'. In fact he referred (twice) to an 'untenable opinion' of Plato's 'that matter is like a common harlot, always seeking after new forms'.

Nature cannot literally be tortured, but some of her creatures can, and often are today, in our service. At a time when vagabonds were regularly flogged, thieves hanged alive in chains, and felons gradually crushed to death under rocks, people were not much preoccupied with the suffering of animals. Descartes defended vivisection, and compared animals to creaking machines. Even Spinoza, half a century later, declamed in his Ethica that we could treat them 'in any way which best suits us'. Bacon was in two minds.

He believed that vivisection had rightly been condemned, but, in exceptional cases 'of great usefulness', it could have been a mistake to 'relinquish it altogether'. We may doubt that he ever came across such a case, for this 'tender-hearted' judge, as he was known to his contemporaries, who looked on offenders 'with the eye of compassion' - and who searched for ways of mitigating pain - repudiated torture, not only for its cruelty, but because he believed it was more liable to evoke 'strange fallacies' than to discover the truth. When 'vexing' even inorganic matter (which to him was alive) Bacon compared the care to be taken in regulating and varying the heat used in experiments to the gentle action of the womb. As for living tissue, eggs might be studied, but cutting out the foetus from the womb (as advocated by his contemporary William Harvey, who discovered the circulation of the blood) 'would be too inhuman'.

The womb is very present in Bacon's writings. He saw his own thought 'rooted in the lap and womb' of a nature more subtle 'many times over' than the mind of man, while the Scholastics 'touched nature only with the tips of their fingers, without mingling themselves into her being'. Had they 'remained attached to the womb of nature and continued to draw nourishment from her', he said, there would be no need for a new science. Far from preaching the rape of nature, the closer union Bacon sought with her was as the bride in 'a chaste and lawful marriage', from which 'many helps to man' might spring. (And should anyone object to the patriarchal view or her as a 'fruitful spouse', let us recall that nature appears as the dominant partner in another patriarchal image, with the arts subject to her 'as the wife is subject to the husband'). Bacon obviously preferred a 'happy match' to a grappling, however gentle. It is only men 'too intent upon their ends', he said, who 'rather struggle with Nature than woo her embraces with due observance and attention'.

Bacon offered mankind the boundless expansion of human power which has given science its daemonic and Faustian character. The power Bacon offered was never boundless. 'All knowledge is to be limited by religion', he said, 'and referred to use and action'. And keen as he was for man to 'open and dilate the powers of his understanding' and reach out to the spacious new worlds of discovery that lay beyond the pillars of Hercules, he never once lost sight of those essential restraints. The arrogant claim of unlimited power for man is precisely what he most strongly deprecated in the magicians of his day -those self-seeking and vainglorious 'braggarts', as he called them, who looked on themselves as gods, and in their 'blind greed' attempted 'to domineer over nature', merely to boost their own personal influence. It was not long since Marlowe's Dr Faustus, 'lord and commander or the elements', had boasted on the stage that his dominion 'stretched as far as doth the mind of man'. Bacon too, in The Advancement or Learning (1623), sought 'to extend the bounds of human empire' - but read on: 'as far as God Almighty in his goodness may permit.' (This limiting condition does not appear in the New Atlantis, where the sentence ends 'to the effecting of all things possible'. But the words are spoken there in the same religious context, 'for the love of God and man'.

What exactly do these religious limits to knowledge imply? While in sympathy with 'the heathen' (the fathers of whose church, he said, were the poets), Bacon lived his spirituality within the newly reformed Church of his time, as a practising Christian - witness his inspired religious writings, and his evident interest in 'the true temper of a man who has religion deeply seated in his heart'. He conceived his New Instauration as the fulfilment of a Biblical prophecy and a rediscovery of 'the seal of God on things'. Which did not mean that he could ever see in the practice of a technology 'a first step to becoming one with God' - as proclaimed of child-cloning by one of its famous promoters. On the contrary, Bacon repeatedly warned his readers against the 'unwholesome' mixture of things human and divine, and admonished them never to 'presume by the contemplation of nature to attain to the mysteries of God'. The meaning of that crucial condition, 'as far as the Almighty may permit', is simple. Bacon solemnly disavowed both 'power and knowledge such as is not dedicated to goodness or love'. The words are used with precision. 'Goodness' means the search of truth for its own sake - since 'the very beholding of light is itself a more excellent thing than all the uses of it'. 'Love', or 'goodness applied', means doing everything possible to relieve 'the immeasurable helplessness of the human race'.

This aim was the leitmotiv of Bacon's life, and his whole new concept of science was geared to it. He had seen the effects of hunger at first hand as a young legal counsel, when examining a band of rebel yeomen. Shocked by what he found, he had set out to study their condition, and had defended, in Parliament after Parliament - with a heat that surprised fellow Members - a Statute for the Relief of the Poor that was to last for centuries, and his two bills against the enclosure of common lands - which, he rightly insisted, 'destroyed the bread of the poor'. Bacon believed that poverty could best be eliminated by achieving abundance for all, and it was to remedy 'the pinched and narrow state of human fortunes' that he wanted to multiply the discoveries of science, made so far by accident, like that of silk, glass or the magnet. This claim, now used by some multinationals to justify their depredations, was a new one at that time, although he had inherited his strong sense of the service owed to mankind from an ancient Platonic and Christian tradition known as the vita activa, of which his friend, Sir Philip Sidney, was the living example. Bacon was however the first scientific thinker to have appropriated the vita activa to science, and made 'the weal of man' his goal.

It is in this light, and recalling his precept that 'the true ends of knowledge' are neither profit, fame nor power, that we should interpret his concept of dominion over nature - a dominion evoking the benevolent authority of the first King of Atlantis, with his 'large heart, inscrutable for good'. For Bacon, power meant 'the power to do good'. There is no place in the New Atlantis for a world dominion, which he described as 'the evil dream of a prosperous brigand'. In the heyday of colonization he stressed that 'people are not to be planted' so as to displace others, and he lamented the miserable fate of 'the poor Indies, brought from freedom to be slaves'. Neither did he look on nature as man's slave. The only case in which he appears to couple slavery with nature - when offering an imaginary pupil 'to bind nature to your service and make her your slave' - has been found to be a mistranslation of the Latin original for 'slave', 'mancipaturus', which actually means 'to be assigned to an office'. It implies a bond - in Bacon's case a mutual one - but without the indignity of slavery. Himself, as he believed, 'born for the service of mankind', Bacon took every opportunity to emphasize that man is but the servant of that nature which he was now joyfully placing at the service of his 'dear, dear son'; that beyond following and observing her order, he 'knows nothing and can do nothing'; and above all that 'the least part of knowledge' is passed to him 'by a Charter from God', and 'must be subject to that use for which God hath granted it'. Failing which 'all manner of knowledge becometh malign and serpentine.'

In the New Atlantis Bacon set up a model for the manipulation of nature which, carried to extremes, has led to the widespread genetic modification of plants by our multinational corporations. Bacon extended his inexhaustible capacity for wonder to 'the border regions of knowledge', as he put it. There was nothing he did not propose to study, from the transmutation of metals, and 'those minute particles that do so great effect ', to a drink he had heard of 'called coffa, as black as soot and of a sharp scent, which comforteth the brain and heart'. He wished an inquiry to be carried out 'with all sobriety and severity', into 'the transmission of spirits at a distance', precognition, hypnosis and telepathic dreams. And he was interested in every aspect of plant life, from their 'enlarging and dwarfing', and 'transplanting one species into another', to the effects of 'the force of imagination' on 'their sudden fading or lively coming up', their closing and opening, their 'bending one way or another'.

But, whatever our opinion of his programme, we cannot reproach Bacon for holding the man-centred - and in his case still earth-centred - view of the universe, which has been an essential part of our Western tradition since Genesis. Or for advocating a manipulation of nature that has been with us ever since Cain ploughed the first field and a Persian gardener bred the first rose. That our species should thrive at the expense of the rest of creation, appears to us now increasingly 'malign and serpentine'. Many of us are more in sympathy - at least as a counsel of perfection - with Eastern attitudes that deprecate stepping on an insect, or those of native Americans, when they ask a plant's permission to harvest it. But where exactly does each of us stand? Do we accept the human kidney transplant but not the heart of a pig? Can we take as a gift from Bacon's prescience hearing aids and spectacles, microscopes and air-conditioners - submarines even, but not those dangerously polluting aeroplanes? Do we accept 'the multiplication of light at a distance', and Bacon's binary scale, on which our computers are based, but not the medical panaceas - or at least not the cosmetics - we owe to the suffering of mice and dogs? Some of us now think we should not destroy life 'without sufficient reason'. But how much is sufficient? Ought we to eat miserable factory-farmed animals, when a less sentient vegetable could feed us? Bacon's position was clear. He would 'try all things and hold that which is good.' We are trying all things, but we no longer know what is good. And we stop at nothing. In each case it is possible to identifiy the point at which we disregarded the limits Bacon laid down, and, failing to obey nature, brought - and are still bringing - upon ourselves every kind of disaster. ('Force maketh Nature more violent in the return.')

We will find Bacon in radical disagreement with the promoters of present day biotechnology on at least four fundamental counts. The first relates to their respective priorities. For Bacon, profit was excluded. Research was a matter of public funds - a task, he said, 'for Kings and Popes', and he stringently admonished scientists who 'turn aside after profit or commodity' : they do so, he warned, 'to the infinite loss of mankind'. There can be no comparison between a philosopher whose 'only earthly wish', from youth to old age, was to promote inventions that could relieve the poverty of man, and a corporation professing to 'do the right thing (namely, to feed mankind) while doing business', and publicizing this worthy aim out of the huge profits they had made with ventures such as Agent Orange and the defoliation of Vietnam; or planning the sinister Terminator Seed 'to protect their investments'. The second difference is one of scale. The ever moderate, middle-of-the-way Bacon, who noted that 'the personal fruition of man cannot attain to feel great riches', knew that more is not better. ('It is the empty things that are vast, things solid are most contracted, and lie in little room.') Bacon could not have conceived the escalating size, the global greed of corporations coolly planning to take over a large portion of the earth's water resources or feverishly decoding some three billion DNA sequences, in a bid to patent the entire human genome. The third radical difference between corporation practice and the thinker who would not reap the green corn, and who reminded us that it is not the tempest but 'the soaking rain that relieves the ground', is one of timeliness. Bacon would have deplored, as the worst 'levity and rashness in new experiments', the immoderate haste with which giant multinationals are now combing the virgin forests for plants that have yielded their healing properties over the millennia, in a headlong rush to extract, code, genetically modify and patent substances which would require generations of testing before they can be fed to adults - rnuch less to babies. The fourth, and perhaps most striking difference, is the contrast between the corporations' stealthy moves to impose their untested wares on us, as a part of their silent progress towards world supremacy - with Bacon's declared goals of open communication and exchange of knowledge, placed at the service of mankind.

Bacon promoted a science in which the experimenter abdicates all responsibility for the results of his discoveries. In fact Bacon was the only thinker of his day to unite scientific knowledge with ethical ideals, as he was the first to evolve a concept of fraternity in 'learning and illumination' among scientists of all countries, 'joining forces for the common good'. Bacon presents his new scientist - neither 'Schoolman' nor magus, but a 'pioner' (or digger) in the mine of truth - with 'tears of tenderness' for his fellow beings in his eyes. And it is because he envisaged a succession of such scientists, handing down the torch of a continuous tradition, at his symbolic 'Promethean Games', that Loren Eiseley described Bacon as 'the first great statesman of science'. But as a statesman Bacon was also aware of the dangers of scientific knowledge, and, on setting forth his plan of work for the Great Instauration, he confessedto 'inward hesitations and scruples'. The new learning, he feared, 'might open a fountain', and who could tell where its waters would fall? Alone among the forerunners of modern science Bacon foresaw the possibility of that 'Rape of Minerva (wise nature), by Vulcan (the mechanical arts)', which we have since perpetrated. His myth of 'Daedalus, or the Mechanic' - famous for his 'pernicious genius', 'unlawful inventions' and 'depraved applications' - sounds a dire warning against the 'imperfect births and lame works' which 'chemical productions and mechanical subtleties' could lead to, if mechanical art should attempt 'to force Nature to its will. And well we know how far in cruelty and destructiveness they exceed the Minotaur himself.'

Bacon hoped, as many have after him, that the mechanical arts might 'serve as well for the cure as for the hurt'. And since people are not to be trusted with dangerous discoveries, the brotherhood of Salomon took an oath of secrecy for 'the concealing of all inventions they thought fit to keep secret', even, if necessary, from the state - a solution not open to our democracies, although some scientists have resorted to it, and one great poet has appealed for it to be practised in our time. (In any case the salutary independence of scientists from Bacon's Utopian state compares favourably with the tacit understanding between powerful corporations and some of our governments.) The only reliable safeguard, however, in Bacon's view, was the age-old remedy of prayer, and in New Atlantis daily services were held 'of laud and thanks to God for his marvellous works', and of prayers (similar to those Bacon affixed to his own works) 'imploring God's aid and blessing for the illuminatiori of our labours, and the turning of them to good and holy uses'. For Bacon the efficacy of prayer was not in doubt. He saw the orations of the monastic orders as 'true works that cast their beams upon society for the benefit of man'. In our less believing age we may look on the prayers offered daily at Salomon's House as a declaration of intent, and a decision to maintain that intent by concentrating the mind upon it.

It is for the firmness of his own purpose and the stress he laid on turning our labours to good uses that I think ecologists can look on Bacon as an ally in the struggle ahead. The needs of humanity are changing, but never has it been more imperative for us to 'join forces for the common good' - that of our whole planet, this time. Bacon's was a cyclical view of history, in which 'the sciences have their ebbs and flows'. Four centuries ago he proclaimed a science that was to go on 'fructifying and begetting', as long as there was room for its wastes. But now that the tide has begun to turn, might not the forward-looking Bacon, had he lived today, be urging us to redirect our inborn thirst for knowledge away from the dead-ends of uncontrolled genetic engineering and the nuclear nightmare? Towards - new variants of earth-healing culture, perhaps? Undiscovered forms of renewable energy, a 'revivifying' concept of growth, or some other form of resurgence we haven't yet thought of?

Be that as it may, he appears to be in unison with the ecological vision in one respect. There is a remarkable affinity between Bacon's dynamic concept of the origins of life, and the cosmologies now emerging in centres like Schumacher College at Dartington, and the Santa Fe Institute of New Mexico - an affinity perceptible even in the vocabulary of these seekers. The 'fluctuating patterns' now found 'running deep in nature' (as cited by Brian Goodwin, in How the Leopard Changed his Spots, 1994), bring to mind those 'fluctuating reciprocations' noticed above in Bacon, the 'resemblances and conjugations' which, he believed, 'reveal the unity of nature' and 'the fabric of the universe'. And when we read today of 'the dynamic fluidity' with which elements 'move from chaos to order and back again', interacting rather than competing, in 'a creative play of forms', or 'a sacred dance', we are very close to that world which, in Bacon, 'enjoys itself and in itself all things that are', while 'the souls of the living leap about and dance with infinite variety'; a world in which 'Pan, or Nature' is ever inclined to 'fall back into ancient chaos' - but that Cupid foils him in the contest; in which God himself 'delights in hiding his works', so as to give man the pleasure of finding them.

We must not forget that if Bacon took the dominion of Adam over his fellow-creatures for granted, he himself extended his 'feeling of communion with men also to beasts', had thoughts of 'nourishing and comforting the trees', and dearly loved birds. He believed that nature was 'corrupted by too much cultivation' - after all the first scientists were 'the brute beasts, quadrupeds, fishes and serpents'. And when it rained, we are told, he would go out in his open coach 'to receive the Nitre in the air and the Universal Spirit of the World'. Let us hear him in his History of the Winds, a late work, urging us to 'make a stay with nature' and 'meditate upon her':

'Wherefore if there be any humility towards the Creator; if there be any praise and reverence towards his works; if there be any charity towards men and zeal to lessen human want and sufferings; if there be any love of truth in natural things ... men are to be entreated again and again ... that they should humbly and with reverence draw near to the book of Creation, and becoming again as little children, deign to take its alphabet into their hands.'

****

For further information and references for most of the above, see chapter 33 of Francis Bacon, The History of a Character Assassination, by Nieves Mathews (Yale U.P. 1996), and for Bacon's attitude towards judicial torture, chapter 24.

On the 'torture of nature' see Carolyn Merchant, The Death of Nature (1980); Alan Soble in A House Built on Sand, ed. Noretta Koertge (Oxford, OUP, 1998); Peter Pesic, "Nature on the Rack, Leibniz's Attitude towards Judicial Torture and the 'Torture' of Nature", Studia Leibnitiana, Band XXXIX/2, (1997), and "Wrestling with Proteus, Francis Bacon and the 'Torture' of Nature", Isis (1999).

On the rehabilitation of Bacon's science after the criticism of Karl Popper, Alexandre Koyré, Peter Medawar and others, see Thomas Kuhn (1977) Peter Urbach (1987), Antonio Perez Ramos (1988), Brian Vickers, "Bacon's so-called 'Utilitarianism'", and Paolo Rossi "Ants, Spiders and Epistemologists", both in Francis Bacon, Seminario Internazionale, ed. Marta Fattori, Rome, 1984.

Also Rossi, "Bacon's Idea of Science", in The Cambridge Companion to Bacon, ed. Markku Peltonen (CUP 1996); On Bacon's cosmology, Graham Rees, (1984).


Fancis Bacon's Works

The astronomy/cosmology debates of the 1930's & 1940's

Some Of The Players of This Philosophical/Scientific Drama

William De Sitter

Georges Le Maitre

Sir Herman Bondi


I well remember him working with Fred Hoyle and promotion of the "steady state universe" hypothesis. The Universe at Large, Relativity and Common Sense, The Steady State Theory of the Expanding Universe [with Professor Thomas Gold], and Assumption and Myth in Physical Theory [with Dame Kathleen Ollerenshaw] are some representative texts.

"Sir Hermann Bondi: 1919 - 2005"

"ESA pays tribute to Professor Sir Hermann Bondi"

Sir Arthur Eddington

Karl Popper

"Cosmology: Methodological Debates in the 1930s and 1940s"

by

George Gale

University of Missouri at Kansas City

[First published May 18th, 2002 with substantive revision June 20th, 2007]

Sometimes, philosophy drives science. Cosmology between 1932-48 provides an excellent example how explicitly philosophical considerations directed the evolution of a modern science during a crucial period of its development. The following article exhibits these philosophical aspects of cosmological thinking in detail, beginning with a brief sketch of the historical development of general relativity cosmology until 1932. Following this, the historical participants in the philosophical debate are introduced, along with the basic ideas of their competing positions. Then the critical stages of the debate -- 1935-37 -- are closely explored by focussing directly upon the arguments of the participating scientists and philosophers. Finally, the concluding stage of the philosophical debate, namely, the emergence of the steady-state theory of the Universe, is presented in the context of its development from Popper's philosophy of science.
Introduction:

One of the most vigorous philosophical debates of the century broke out among cosmologists during the 1930s and 1940s. At the peak of the debate, 1936-37, many of the most prominent scientists in Britain, as well as several leading philosophers of science, had gotten themselves publically involved. Their arguments, attacks and rebuttals were chronicled in many of the leading scientific journals, including a special edition of the foremost general scientific journal, Nature, devoted entirely to philosophical arguments and counter-arguments.

Methodology was the central issue of the debate, although metaphysical questions also arose, particularly those concerning the actual reality of certain structures and forces imputed to the Universe by the new cosmological theories and observations. But in the end, methodology was the real goad spurring on most of the participants.

At bottom, there were just two opposing positions in the debate, each of which comprised a two-point stance. On one side were those scientists who had their roots mostly in the experimental side of natural science. To them, there was one and only one legitimate method for science. Theory construction, they believed, involved two closely-linked steps. First, one began from the empirical observations, that is, from measurements, manipulations, experiments, whose results were evident to the human senses; this is classic empiricist epistemology. Observational results would then suggest possible hypotheses to examine via further empirical testing. When enough data concerning the hypothesis had been gathered, logical generalization could be carried out, thereby producing a theory; this is classic inductivist logic.

Opposing these inductive-empiricist scientists were those whose roots were mostly in the theoretical side of natural science, most especially mathematical physics. To them, there was another, more logically sound, method to construct theories. First, hypotheses could be generated in any fashion, although most believed that imagining hypotheses which were based upon very general, very reasonable concepts—that the Universe's physical processes had simple mathematical descriptions, for example—was the best place to begin; this is classic rationalist epistemology. Once the hypothesis had been generated, strict analytical reasoning could be used to make predictions about observations; this is classic deductivist logic. Scientists who held this view came to be called hypothetico-deductivists; their views about both hypothesis generation and deductive predictions were each strongly opposed by the inductive-empiricists.

Part of the controversy may be laid to the fact that cosmology was a new science, and disputes about methodology in new sciences are not rare in the history of the sciences. What is rare about this case, however, is the vigor, sometimes even bitterness, with which the philosophical controversy was waged. Another reason for the controversy lies in the fact that cosmology is a data-poor science: observations are hard-won and rare, and they frequently must be run through elaborate theoretical manipulations and corrections in order to make sense at all. With a paucity of data results, scientists must rely upon philosophical argument to undergird their views about how the scientific work should be done.

One final feature of the debate must be noted. The participants are almost universally scientists, and not philosophers. Yet this does not much affect the level of philosophical thinking going on; these scientists knew their philosophy well, and they wielded philosophy's weapons and defenses with great skill. In the end, their debate shaped cosmology into the science we know today.

It will be useful to look briefly at the history of cosmology leading up to the debate.

The Lead-up to the Debate:

Since about 1700 theories about the nature and structure of the Universe were derived from Newtonian theory, most especially his theory of gravitation, which was used to account for the behavior of heavenly bodies and their systems. Newton's theory hypothesized a force—gravitation—acting upon material bodies, free to move over time within the passive, inert ‘container’ of three-dimensional space. Bodies, paths, and space itself exemplified the classical geometry of Euclid. All these features changed with the publication of Einstein's General Theory of Relativity, 1915-17.

Einstein's General Theory of Relativity:

Einstein's intended his theory to replace Newton's theory of gravitation completely. In Einstein's view, gravity was not a force existing independently of the spatial ‘container’; rather, gravitation arises as a curvature of the space (and time, which is necessarily connected to space in the new theory), which means that geometry and gravity and astronomical behavior are all intimately connected. For example, near the sun the geometrical structure, the curvature, of spacetime changes radically, which expresses itself as an increasing velocity of incoming orbiting bodies such as comets or satellites. One immediate, and to some, puzzling, consequence of Einstein's theory is that the geometry of the Universe is no longer taken to be Euclidean. Although there are several different candidates for the actual geometry of space, it was not known which is correct.

It was not recognized at first that the General Theory of Relativity could be applied to the Universe as a single, whole, individual object, thereby producing a new cosmological theory, one completely different from its predecessors. Although the mathematics involved are extremely difficult, two solutions, one by Einstein himself, the other by the Dutch astronomer Willem de Sitter, were produced in just a short time in 1917. Unfortunately, the universes predicted by the two solutions were extreme: Einstein's universe would be densely packed with matter, whereas de Sitter's would be essentially empty.

Obviously, the universe as observed by astronomers did not conform at all to the description provided by either solution, a fact many found troubling. Moreover, no additional solutions were forthcoming (even though both Friedmann and LeMaître had developed alternatives, they remained unknown and unnoticed). For nearly twelve years, the new cosmology appeared to be going nowhere. Then Hubble at California's Mt. Palomar made public his astonishing observations of a cosmic Doppler shift, a shift toward the red in the color of light coming from the most distant star systems.

Hubble's Expanding Universe:

Most cosmologists—with the interesting exception of Hubble himself—came to the immediate conclusion that the red shift could only mean that the universe was expanding. Immediately the relativity theorists were able to interpret the expansion as a continuous change in the geometry of spacetime, which was thoroughly accounted for by the General Theory of Relativity. After over a decade of stagnation in face of the meager choice between just two models of the cosmos, Hubble's observations spurred theorists on to the construction of a melange of new models, each vying in competition with the other.

In the end, it was the Belgian astronomer Georges LeMaître's theory of an expanding universe that came to be accepted. LeMaître's model was publically proclaimed as appropriate and generally correct during a special session of the British Association for the Advancement of Science, 31 Oct 1931. Modern scientific cosmology had been officially born; because of its birth within the context of Einstein's theory of relativity, the new cosmology became quickly and broadly known as Relativistic Cosmology. The model of this cosmology is most famously that of the blowing up of a balloon painted with dots to represent galaxies. Over time, the radius of the model's spherical space (the balloon) increases, thereby decreasing the curvature of the space (the balloon's skin), and increasing the distance between the dots.

Although cosmologists came from Europe and America as well as Britain, most of the work in theoretical cosmology took place in London, Cambridge and Oxford. Americans Hubble, Tolman and Robertson did their work at CalTech in Pasadena, but were frequently in England; and most of the European and British workers cycled through Pasadena at one time or another. De Sitter, from Holland, and LeMaître, from Belgium, spent important periods in England, as did various of the German workers. Thus, even though cosmology was done throughout the Western world, its major concentrating point was England; our focus in what follows will be the same.

Cosmology and its philosophy:

Because it represented such a radical departure from previous scientific thinking about the Universe, relativistic cosmology needed to work out its philosophical underpinnings, most especially in regard to its methodology. 'How is this new science to be conducted?' was thus a compelling question. But method, of course, is always linked to metaphysics and epistemology. A full-blown philosophical discussion was evidently required. It came soon enough: within a span of less than a year, a vigorous debate between two philosophically opposed camps developed. The debate required nearly two decades to reach its full resolution. But, with the resolution, cosmology had philosophically certified its methodology within the context of a concensus metaphysics and epistemology. Before going into the details of the debate, however, several general points should be noted. Let us turn to the details of the origin of the debate.

Relativistic Cosmology: the majority philosophy:

To begin with, the cosmological thinking of the majority of scientists—including Eddington, de Sitter, Robertson, Tolman, and their colleagues—had betrayed a relatively unexamined, and apparently uncontroversial cluster of philosophical perspectives: on the metaphysical side they held a modest sort of explanatory realism—if an accepted theory referred to entity x, then x was acceptable as a genuinely, physically real object; to this metaphysical stance was coupled a methodology exhibiting a classic sort of inductive empiricism—scientific knowledge consisted of generalizations built up from individual empirical observations. But this cluster of views did not go long unchallenged. In early July 1932, just nine months after relativistic cosmology became the concensus during the British Association meeting, Oxford astrophysicist E. A. Milne published a short article in Nature which directly attacked the current philosophical tenets, proposing their replacement by a new cluster of views, one as radical as the new science it purported to undergird.

Milne's Philosophical Challenge:

Milne's metaphysical views were based in positivism, most especially in operationalism: only those objects whose properties could be directly revealed by some observational procedure, or operation, were to be counted among the real. Thus, for Milne, reality did not contain the usual relativistic cosmology referents "curved space", "expanding space" or even "four-dimensional spacetime", simply because none of these entities were operationalizable. Milne held that ‘what you saw was what you got’; since "curved space" of various geometries couldn't be observed, space was just as it looked—Euclidean. In the same way, the expanding of the Universe was a genuine expanding—each galaxy was retreating from each other—not just a change in the geometry of the curvature, as it was for the relativists. Moreover, in place of relativistic cosmology's inductive empiricism, Milne opted for a hypothetico-deductive rationalism. Cosmologists, Milne believed, were bound to dream up any and all possible models of a universe, and then deduce what, if any, observable consequences followed from their hypotheses. Hypothesizing could be based upon just about anything, although Milne believed that certain very general rational principles derived from aesthetic beliefs about universal order and regularity would be the most fruitful. His ‘cosmological principle’, namely, that every cosmologist in the universe should look out upon the same cosmos, was the prime example of such thinking. Later, Bondi would found Steady-state Cosmology on an even more general version of Milne's principle, which he called the ‘perfect cosmological principle.’
Kinematic Relativity—an alternative cosmology:

Milne's philosophy of cosmology came with a closely associated cosmological model, kinematic relativity, so-called because of its tight links to the kinematics of Einstein's Special Theory of Relativity. Kinematics, in Einstein's Special Theory, is especially concerned with observers trying to make measurements of the behavior of objects moving in systems relative to themselves. According to Milne's understanding, these measurements could only be made by the observers signalling among themselves using light or other electromagnetic radiation, using clocks to time the signals. In the end, all measurement—even space and velocity—reduced to timing the signals as they went from one observer to another. This idea of measurement represented a revolutionary simplification of previous ideas, and held philosophical interest for that reason alone. There were practical consequences as well. As Bondi later remarked, "Milne's idea led straightaway to the radar speed gun!"

Milne's kinematic relativity and its underlying philosophy both immediately brought careful scrutiny, not to mention controversy.

The Great Cosmological Debate Begins: 1933-1934:

Eddington was the first to attack Milne's views. In a series of lectures given at Harvard during late '32 and published early in the new year as The Expanding Universe, Eddington denied the efficacy of both operationalism and hypothetico-deductivism, and not only defended explanatory realism, but strengthened his ontological position heroically: the theoretical entities of relativistic cosmology were not just plausible, they were so necessary to understanding the universe, that cosmological knowledge was essentially impossible without them. (Eddington 1932, p. 19)

Dingle's First Attacks:

Few others would ever go so far as Eddington's ontological heroism; yet epistemological and methodological heroism in the fight against Milne was not rare. Chief hero in this aspect of the attack on Milne was Herbert Dingle, a highly respected astrophysicist, and then-secretary of the Royal Astronomical Society. Dingle's initial foray appeared as a response to Milne's first detailed presentation of kinematic relativity. (Milne 1933) After claiming that while kinematic relativity did not differ appreciably from relativistic cosmology in its mathematical formalism or observable consequences, Dingle asserted that, on the other hand, it invited special criticism because it renounced "the fundamental principles of scientific method," namely, "Newton's principle of induction from phenomena."(Dingle 1933 p178) Dingle was never to relent in his attacks upon Milne's hypothetico-deductivism, at all times rejecting the methodology as even a possible candidate for acceptance by genuine science.

Dingle's article appeared back-to-back with an appraisal of kinematic relativity by the important American cosmologist H. P. Robertson. (Robertson 1933a) Robertson focussed upon Milne's hypothetico-deducivism as well, noting that the cosmological principle in kinematic relativity functions as an a priori rule, rather than as an empirical generalization, its status in relativistic cosmology. Robertson otherwise is not especially taken with Milne's theory, limiting himself to remarks suggesting that, where they can be compared, kinematic relativity and relativistic cosmology apparently are similar in physical content. As we shall shortly see, Robertson's later work strongly belied this earlier apparent indifference to Milne's theory.

Two Ways to Disagree with Milne:

Right from the start, cosmologists differed in their opinions about both the physical content of Milne's theory, and its underlying philosophy. Dingle disliked Milne's methods, but found the theory itself of not much interest. Robertson initially agreed with Dingle, but within a short time had significant changes of heart. Eddington disliked both the theory and its philosophy, finding them far too deviant from what was typical, i.e., relativistic cosmology and its mainstream philosophy. Younger cosmologists such as McVittie and McCrea, students, respectively, of Eddington and Whittaker, soon joined the fray. McVittie initially found the physics of kinematic relativity quite interesting, and quite different from the physics of relativistic cosmology. (McVittie 1933b) But Milne's philosophy was something else; the strict empiricism McVittie had earlier revealed (McVittie 1933a) made him equally unhappy with both Milne's rationalism and his hypothetico-deductivism.

McCrea's remarks were among the most perceptive and favorable. (Kermack and McCrea 1933) While he thought that Milne's operationalist criticisms of curved and expanding space were of little import, McCrea was the first to notice the parsimony and elegance of Milne's strictly kinematic solution to the problem of the origin of the universe's expansion. Since a search for such a solution had vexed relativistic cosmology for several years (McVittie 1931), McCrea suggested that Milne's mechanism should be immdiately shown to be part of relativistic cosmology. (Kermack and McCrea 1933 p. 529)

Clearly, the so-recently won consensus about relativistic cosmology and its philosophy had dissolved into confusion and controversy over Milne and his methods.

Milne Makes Philosophical Improvements:

Over the next year or so, Milne made strenuous efforts to elucidate both kinematic relativity's physics and its philosophy, beginning, as would be his wont, with the philosophy. In October, Milne addressed the Philosophical Association, giving an explicit and detailed analysis not only of his philosophical views, but also of their history, which, he claimed, extended back to Locke and Hume (Milne 1934a) His description of the two opposed methods—inductive empiricism vs. hypothetico-deductivism—is quite clear and useful:

Strictly speaking, physics has no philosophy. It has method…Now the methods of theoretical physics seem to be reducible to two species, the method of starting with concepts and the method of starting with things observed. …When a subject is developed from concepts the concepts play the part of the terms occurring in the axioms of geometry…. The concepts are undefined save as being governed by propositions of which they are subjects.

Milne's commitment to axiomatization is notable here. It was based in his earlier admiration for the work of Whitehead and Russell (Crowther 1970); commitment to axiomatization in cosmology, once having been initiated by Milne, would be an enduring hallmark of the work of many, including both Robertson and Walker.

Three weeks after this address, Milne spoke on related topics at the monthly meeting of the Royal Astronomical Society. His main point was that theories differed only insofar as their concepts could be cashed out in observations deduced from them. Eddington took strong exception to Milne's arguments, claiming in response that kinematic relativity and relativistic cosmology differed more importantly in their ontology than in their consequences. Eddington was especially concerned with differences in the spacetime-geometry each theory ascribed to the world. For Eddington and his colleagues, the equivalence of gravitation and spacetime geometry was a genuine reality, a feature of the physical world, just as real as suns and moons and stars.

A Major Philosophical Issue: What makes a scientific theory ‘good’?:

Milne was having none of it. In the next month's Observatory—the informal monthly publication of the Royal Astronomical Society—he took Eddington and his theoretical-realist colleagues to task, concluding that "theories differ simply and solely when their predictions as to phenomena differ"; most importantly, "this method of comparison avoids all reference to distance-assignments, world-geometry, schemes of projection or the like." (Milne 1934b) In other words, metaphysics was to be avoided in cosmology; space, spacetime, geometry and the like were to be rejected as scientific realities, replaced by reference simply and solely to observations. The only realities, according to Milne, were what could be reported among observers about light signals and clocks.

During 1934 Milne worked together with his new student A.G. Walker. Walker never evinced much interest in the philosophical aspects of kinematic relativity, choosing instead to focus tightly upon working out the physical details of the theory itself. He had immediate success. (Walker 1934) One of his important conclusions was that other authors, specifically McVittie and Robertson, were wrong to conclude that the physics of Milne's theory ultimately corresponded to relativistic cosmology: "Milne's system is fundamentally different from that of general relativity." (Walker 1934 p. 489; emphasis in original)

How to Choose Among Theories and Philosophies?:

In an important review of the entire confused situation between kinematic relativity and relativistic cosmology, McVittie confessed that "experimentally it seems hopeless to discriminate between them…at present the choice is almost entirely a matter of personal taste." (McVittie 1934 p. 29) At almost the same time, de Sitter took on Milne in serious fashion. (deSitter 1934) Responding to Milne's methodological challenge, he showed that, indeed, it is possible to formulate relativistic cosmology in axiomatic fashion, just as Milne had formulated kinematic relativity "from concepts." But de Sitter explicitly rejected Milne's philosophical use of the cosmological principle, "which asserts that statistically the world pictures of two different observers must be the same." His objection is founded on the matter-of-fact that "we have, however, no means of communicating with other observers, situated on faraway stars, or moving with excessive velocities." (deSitter 1934 p. 598) So much for rational principles as hypotheses!

The year in cosmology ended almost as confused as it had begun, with one exception: Milne had gotten much clearer about his philosophical views, and was applying them to an exhaustive presentation of his cosmology, theory and philosophy. His book Relativity, Gravitation and World Structure (Milne 1935) would be published in just a few months.

The Triumph of Milne's Methods 1935-36:

The new year marked a sudden change. In short order, McCrea, Walker and Robertson succumbed to Milne's methodological recommendations: first, to carry out an operationalist paring of non-observational concepts, then, secondly, to embed the resulting minimalist concept set in an axiomatic hypothetical-deductive structure. Thus was the famous Robertson-Walker spacetime metric born.

McCrea, Walker and Robertson Adopt Milne's Methods:

McCrea's effort operationalized the concept of “distance”, principally and originally by comparison of certain elements of Newtonian cosmology and de Sitter's axiomatized version of relativistic cosmology. (McCrea 1935) Walker's paper specifically eschewed use of "any indefinable concepts", in particular, he did not assume that the "associated metric [of relativistic cosmology] has any a priori physical significance." (Walker 1935) Robertson's article, the first of three, is the most important, both in its content, and in the signal it sends, namely, that one of the original mainstream relativistic cosmology proponents has adopted a major element of Milne's new philosophy for cosmology. (Robertson 1935) Robertson's conclusion exhibits this point clearly and explicitly:

We have examined, from the operational standpoint, the problem of determining the most general kinematical background suitable for an idealized universe in which the cosmological principle holds. Allowing the fundamental observers the use only of clocks and theodolites, and granting them the possibility of sending and receiving we have shown that for each given mode of motion x(t) there necessarily exists a quadratic line element which is invariant, in form as well as in fact, under transformation fqrom one fundamental observer to another. (Robertson 1935 p. 300)

Unlike de Sitter, Robertson accepts the cosmological principle, replete with its observers on far-separated particles. Moreover, as this statement shows, Robertson is intimately familiar with Milne's latest operationalist reduction: space is to be reduced to time measurements given by clock readings on signals exchanged between observers. Robertson gets this idea from Milne's book, which he had earlier reviewed (but which was only subsequently published) for Astrophysical Journal. (Robertson 1936)

But Eddington Scoffd:

Eddington disparages these same methods. In his scathing Nature review of Milne's book, he rejects Milne's hypothetico-deductivism, his cosmological principle, and, above all, his operationalism: "When I visit the Cavendish Laboratory, I do not find its occupants engaged in flashing light-signals at each other, but I find practically everyone employing rigid scales or their equivalent." (Eddington 1935, p. 636) Whittaker's review was not so negative as Eddington's. (Whittaker 1935) While the senior physicist rejects Milne's operationalism and attacks upon the geometrical commitments of relativistic proponents, he is considerably more forgiving about Milne's hypothetico-deductivism, and even goes so far as to remark Milne's "brilliant record in astrophysical discovery." Nonetheless, Milne's break with a tradition including at least "Einstein, de Sitter, Friedmann, LeMaître, Weyl, Eddington, H.P. Robertson and others" is to be regretted. (Whittaker 1935 p. 179) Perhaps, along with Eddington, Whittaker hopes that soon "Professor Milne will return to orthodoxy." (Eddington 1935, p. 636)

But Whittaker's view on Milne must be put into the perspective he held on the whole ongoing debate. As he saw it

…a lively debate is in progress at the present moment between Sir Arthur Eddington and Dr Harold Jeffreys of Cambridge, Professor Milne of Oxford, Sir James Jeans, and Professor Dingle of the Imperial College, the subject being the respective shares of reason and observation in the discovery of the laws of nature. (Whittaker 1941, p. 160)

But lively debate is far too gentlemanly a description for what now occurred. After holding his ire somewhat in check for—as he saw it—already far too long, Dingle finally erupted.

Dingle's Denoument:

Controversy over Milne and his philosophy reached a crescendo in mid-1937. Dingle, his stew having finally boiled over, wrote privately to the editor of Nature, first castigating the rampant cosmological ‘mysticism’ passing itself off for science, and then offering to produce an article taking the sword to the mystics themselves. His offer was immediately accepted. The result was Dingle's notorious "Modern Aristotelianism", a polemical diatribe chiefly against Milne, but aimed as well at Eddington and Dirac on account of their "betrayal" of the scientific method of Newton and his fellow members of the Royal Society. (Dingle 1937)

Modern Aristotles?:

The article is remarkable both for its style and for its content. Dingle's style in the article is vituperative. Thus, emotionally-loaded terms such as "paralysis of reason," "intoxication of the fancy," "'Universe' mania", and the like frequently appear, these to be topped only by references to "delusions," "traitors," and, of course, "treachery," each associated with one or more of the guilty parties. (Dingle 1937, p. 786)

Above and beyond his extreme language, Dingle makes certain substantive claims bearing directly upon central philosophical questions. The issue, as he sees it, is nothing more than the question "Whether the foundation of science shall be observation or invention" (Dingle 1937, p. 786). As always, talk about 'foundations' is philosophical talk. The two opposing positions Dingle here calls "foundational" involve views on both method and epistemology, suitably tangled together. Dingle delineates the opposed alternatives as follows. The way of true science, he claims, shows that "the first step in the study of Nature should be sense observation, no general principles being admitted which are not derived by induction therefrom." (Dingle 1937, p. 784) Stated more explicitly, Dingle here argues that authentic science is empiricist in epistemology (scientific knowledge is founded in sensory observation), and inductivist in method (general principles are reached via inductive logic). Opposed to this view, he argues, is "the doctrine that Nature is the visible working-out of general principles known to the human mind apart from sense perception." (Dingle 1937, p.787) As representative of this latter view Dingle cites Milne, and refers in particular to Milne's claim that "it is, in fact, possible to derive the laws of dynamics rationally…without recourse to experience." (Milne 1937, p. 329) Obviously, Dingle is here arguing against the view, Milne's view, that authentic science may be rationalist in epistemology (scientific knowledge is founded in pure theoretical reasoning apart from sense perception), and hypothetico-deductive in method (general principles are justified by their deductively implying correct observations).

Along with Milne, Dingle indicts Eddington, and, by implication, Dirac, all three of whom, Dingle believes, are guilty of inventing scientific hypotheses by free mental imaginings rather than by strict immersion in observations and observational data.

Dingle as 'True Believer':

What is going on here? Put bluntly, Dingle is an old-fashioned empiricist and inductivist. He believes that the only way to do true science is to first collect data, then, and only then, to hypothesize on the basis of that data. Observation, then hypothesis. As he sees it, Eddington, Milne and Dirac have got it exactly backwards. They first (as he terms it) assume an hypothesis, then, and only then, go about collecting data. Except, according to his lights, the data isn't ever collected: "to [the Aristotelians'] modern representatives it seems as though a fancy is no sooner in the head than it is on paper and sent for publication." (Dingle 1937, p. 785) Obviously Dingle is simply wrong; it never occurred to his opponents that hypotheses would not be followed immediately by attempts at deductive prediction of observational consequences. But it was enough, in Dingle's mind, that they didn't use induction, for them to come under blame.

Wrong from the Very Start:

But there is something else at work here as well. Dingle doesn't object solely to his opponents' lack of inductive logic. Of equal importance is the fact that they find the source of their hypotheses in fairly general principles, wide-ranging rational proposals about the structure of the universe at large. These principles Dingle takes to be a priori, in the most pejorative sense of that term. They are phantasms, "chimeras" he calls them, which seduce the imaginations of his opponents, and lead them and their dumb-struck admirers away from the genuine, authentic method of science. This is what really sticks in Dingle's craw. In turn, Eddington, Milne and Dirac are chastised, each for something slightly different, but at bottom the same, namely, they one and all "appear as a victim of the great 'Universe' mania." (Dingle 1937, p. 786) In the end, Dingle believes, the danger of this new 'methodology' is real, and serious. As he notes in conclusion:

Nor are we dealing with a mere skin disease which time itself will heal. Such ailments are familiar enough; every age has its delusions and every cause its traitors. But the danger here is radical. Our leaders themselves are bemused, so that treachery can pass unnoticed and even think itself fidelity. It is the noblest minds that are o'erthrown…the very council of the elect can violate its charter and think it is doing science service. (Dingle 1937, p. 786)

Here Dingle obviously goes over the top. Yet overblown as it is, there is no doubting his sincerity: Milne and the other cosmologists have betrayed the true science bequeathed them by their ancestors in the Royal Society.

How could Dingle be answered?

The Debate Goes Very Public:

The response arrived three months later, on 12 June. On this particular Saturday in June, Nature published a fifteen-page special supplement as No. 3528. Contained within were contributions from sixteen "representative investigators", as the editor referred to them, each responding to "Modern Aristotelianism" Nature's Editor, R.A. Gregory, introduces the occasion by noting that "in Nature of May 8, we published an article by Dr. Herbert Dingle entitled ‘Modern Aristotelianism'". Because the article, as Gregory goes on to say, "created considerable interest", Nature "decided to invite further contributions on the subject from a number of representative investigators."

"Created considerable interest" is, to understate the issue, an understatement. Some of the contributors were quite obviously livid with rage and other volatile emotions. Others, such as Milne himself, who had come in for particularly scathing criticism in Dingle's article, were patient and careful in rebuttal. Each of the sixteen contributors to the special article chose a side in the controversy, either pro Dingle's inductive empiricism, and con Milne et al.'s rationalist hypothetico-deductivism, or vice versa. Remarks made by the participants exhibit the full diversity of philosophy of science in their contemporary community. Dingle's views, in particular, were not without favor.

Harold Jeffreys, F.R.S., noted geologist and astronomer, and author of a well-regarded philosophy of science book Scientific Inference (1957), led off with a nice ad hominem: "Without using induction, Milne and Eddington could not order their lives for a day, and what they are really asserting is that they are entitled to use special axioms in physics, for which no need has been shown." Jeffreys' criticism here of course ignores the role of deductive observations in justifying the “special” axioms. The problem, as Jeffreys sees it, originates in the perpetrators' "belief that there is some special virtue in mathematics." L.N.G. Filon, F.R.S., vice-chancellor of the University of London agrees on this point, noting that "some men of science appear to think that they can solve the whole problem of Nature by some all-inclusive mathematical intuition." R.A. Sampson, the Astronomer Royal, focusses upon the rationalistic aspects of the ‘modern Aristotelians’, to wit, for their "framing a theory independent of experience, such as is denounced in Dr. Dingle's article", which produces work not unlike that "of a poet or other humanist, who gives us at most a number of illustrative cases."

The Counterattack:

But Milne, Eddington, and Dirac had their supporters as well. N.R. Campbell, whose theory of science was already well-known, makes an uncontroversial interpretation of the affair. "Science" he begins, "(or at least physics) has long consisted of two distinct but complementary activities", one of which is experimental and empirical; "its procedure is induction." The other activity attempts to provide explanations of scientific laws, which explanations have the "pecularity" that "they often (not always) predict new laws in addition to explaining old ones." Campbell cannot resist ending on an ad hominem of his own: "If he [Dingle] does not deem it important to observe the distinction between what is and what is not demonstrable experiment, surely he should welcome a movement to amalgamate the Royal with the Aristotelian Society." Indeed.

G.J. Whitrow, then a young lecturer at Christ Church, Oxford, returns to the mathematical theme. Dingle, he argues, "not only attacks the particular methods adopted by contemporary mathematical investigators in relativistic cosmology, but even refuses to admit that this subject is worthy of scientific investigation as it is based not only on experience but also on reason." Hypotheses, by this light, may originate rationalistically as well as any other way, certainly there is no problem with this.

The Coolest Voice:

The clearest, most temperate discription of the issues at hand is given by young cosmologist William McCrea, then professor of mathematics at Queen's, Belfast, and editor of the R.A.S.'s Observatory. Not to be outdone by Jeffreys, McCrea begins with an ad hominem of his own: "Dr. H. Dingle's objection to ‘modern Aristotelianism’ seems to be itself what he would call Aristotelian rather than Galilean." In other words, Dingle raises a non-empirical objection about Milne et al.'s non-empiricism! But McCrea soon gets to the heart of the matter, the role of hypothetico-deductivism in mathematical physics:

What Dr. Dingle has done is to reopen the question of the relation of mathematical physics to experimental physics, since he claims to detect a new and perverted point of view in the former. Now a system of mathematical physics, apart from the alleged perversion, is the working out of the mathematical consequences of certain hypotheses. The worth of the theory is judged…by the closeness of the agreement of its predictions with the results of observation, and also the number of phenomena which it can so predict from the one set of hypotheses. The scientific attitude is, not to cavil at the attempt, but to see if it is successful.

This is an absolutely standard interpretation of how the H-D method works. Throughout his own writings, beginning right from his inaugural lecture in Oxford (Milne 1929), Milne had subscribed to precisely the same interpretation of the Hypothetico-Deductive (H-D) method. Whatever the controversy is about, the issue is not how to interpret hypothetico-deductivism. That much is evident.

Moreover, it is quite clear that Dingle et al. are not mounting opposition to something we, today, would consider philosophically radical; rather, they are objecting to what, today, would be considered completely unobjectionable. Given today's acceptance of the H-D method, yet its rejection by otherwise well-regarded scientists at that time, it seems to follow that it was, at least in part, this debate and its followup which settled the issue. In any case, Dingle and his supporters generally went silent, restricting their activities for the most part to books, or relatively positive statements of their own positions. (A.D.R. 1938, Dingle 1938) Things settled down, just in time for the War.

The Calm Between the Storms:

During the next several years, it became evident that Milne's methods, and kinematic relativity as well, had reached respectability. One important sign of this progress was exhibited at an early 1939 joint meeting between the Royal Astronomical Society and the Physical Society of London, The meeting had as its goal a thorough review of the situation in cosmology. McVittie was chosen to present the observational situation; his report was soon published. (McVittie, 1939) Reviewing the theoretical situation was George Temple, one of the most highly respected mathematicians of the time. Temple's report saw print almost immediately. (Temple 1939) Within a short time, Temple's paper took on the role of

Two Equal Competitors:

Both McVittie and Temple presented kinematic relativity and relativistic cosmology as equal competitors in accounting for the cosmological observations. Unfortunately, as McVittie noted, observations could not, at that time, discriminate between the two theories. Temple's analysis of Milne's work praises its simplicity and elegance, and refers in particular to its operationalism and axiomatization, which "start from a completely novel discussion of the correlation of measurements made by different observers in terms of light signals only." (Temple 1939, p. 468) Throughout the rest of his discussion of the two theories, Temple utilizes Milne's light-signal correlation method, explicitly rejecting rigid-rod transport for distance measurement. Milne's methods have triumphed.

Later that year McCrea publishes an important paper in Philosophy of Science. (McCrea 1939) Put most simply, the paper starts out to defend Milne's methods, but ends up by presenting a full-blown and interesting, although quite unhistorical, account of the evolution and structure of physical theories.

The Origin and Evolution of Theories:

McCrea's overall view is that theories are set up to be hypothetico-deductive in structure. His account is based on his view of the evolution of theories of space-time and mechanics, beginning with Newton, through the General Theory of Relativity and ending in kinematic relativity. His argument reduces to the claim that, insofar as Milne and e.g., Newton, can be shown to follow the same procedure, any attack upon Milne is also an attack upon Newton. First, he states his goals in the paper.

The first goal is to emphasise how each theory leaves us in a position in which the succeeding one appears as a perfectly natural next step in the development of ideas. (McCrea 1939, p. 137) McCrea embeds this argument in an account of how analogue models (à la Campbell) are used to set up new theories—this is essentially an account of how discovery might proceed in linking an older theory with its successor.The second goal is to show how, in spite of superficial differences in character, the theories in question all necessarily possess the same general structure constituted by the presence of hypotheses, from which certain general mathematical relations are deduced, which in their turn are used to predict relations between observable quantities. As McCrea notes, "this study may claim an interest of its own, but it is presented also for a further reason" namely, that

it has been contended [by Dingle, most especially] that theories like Milne's represent a fundamentally new outlook on the part of some theorists, in that such theories are purely mental constructs divorced from experince of the physical world. We shall see that on the contrary Milne's theory is easily brought into line with the others in such a way that this criticism is neither more nor less true of it than of the rest. (McCrea 1939, p. 138)

In McCrea's discussion of the theories he asserts that "the consituents [of the theories themselves] which are of physical significance are sets of mathematical relations, coupled with sets of rules of interpretation" which yield, "after observational test, descriptions rather than explanations of physical phenomena." According to McCrea, one real advantage of his view is that it "leads to simple criteria for comparing the merits of different theories." Finally, on the metaphysics of the original hypotheses, McCrea claims that "the initial hypotheses from which the mathematical relations are deduced do not ultimately have any direct physical significance."

McCrea's paper, published in the leading philosophy of science journal of the time, is the final imprimateur on Milne's views.

Milne's Ultimate Success:

Three years later, Milne was awarded the James Scott prize, the most prestigious award for ‘natural philosophy’ in the Anglophone world. Milne's lecture title is telling: "Fundamental Concepts of Natural Philosophy." (Milne 1943) Although Milne does concede to Dingle that he no longer believes that it is possible to deduce physics completely in the absence of reference to phenomena, for the most part his award lecture is a long reiteration of his previous twelve years' work in cosmology.

One year later, Milne received his ultimate accolade, election as president of the Royal Astronomical Society. In his inaugural lecture, Milne again reviews his work, but adds two remarks of interest. First, he modifies his earlier view that theories are acceptable solely on the basis of their successful predictive power; to this, he now adds that a theory cannot be accepted as satisfactory unless it is philosophically satisfying. (Milne 1943, p. 120) Secondly, on a personal note, he admits that he is still amazed at the outcry that his theory and its philosophy caused. Milne here is being a bit disingenuous. In many places in his letters he not only recognizes the outcry, he delights in it, and seeks to provoke it even more. (Milne 1932-37, 12 May 35; 28 Jul 36)

From this point onward, cosmology's philosophy is no longer directly influenced by Milne himself. Moreover, kinematic relativity began to stagnate as a research programme; except for Whitrow, Milne had no new students, and failed to attract any new converts to the theory. His work was done. But his philosophical influence didn't end, in fact it wasn't to crest until the end of the 40s in the work of another man, Hermann Bondi. Again, however, a storm was generated by Milne's methods, even though they were now in the hands of another.

Steady-state Cosmology:

In 1948, a young mathematician, Herman Bondi, in concert with two close friends Thomas Gold and Fred Hoyle, proposed a radical new cosmological theory, the Steady State theory. This theory differs from the basic picture shared by both kinematic relativity and relativistic cosmology, namely, that of a universe with a definite origin in a small, dense knot, followed by evolution into the universe we have today. According to Bondi's theory, the universe as far back into the past as we might look would always look the same; there was no evolution, there could be no “fossils”, as Bondi called putative evidence of a universe different in the past from our present one. What we observe today is the same state of a universe that has been and always will be steady. Bondi came to his notion of the steady state primarily from his commitment to the philosophical components of Milne's work, most especially the methodology of rationalism plus hypothetico-deductivism; additionally, Bondi coupled to these Milnean notions some ideas taken directly from the philosophy of Karl Popper.

Bondi's Philosophical Origins:

Bondi reveals his philosophical commitments in several ways. First, he argues against induction and extrapolation from small-scale experiment, that is, against the inductive empiricism of Dingle et al. Secondly, he argues in favor of hypothesis and deduction, that is, in favor of Milne et al. Finally, he specifically remarks the excellence of Milne's Methods, and the theory—kinematic relativity—created therefrom, and remarks the significance of these elements in the creation of his version of the new steady-state cosmology.

From the very beginning Bondi admits the validity of both positions in the methodological debate:

In particular, there are two important approaches to the subject [cosmology] so different from each other that it is hardly surprising that they lead to different answers...The contrast between the ‘extrapolating’ and the ‘deductive’ attitudes to cosmology is very great indeed. (Bondi 1960), p. 3-5)

The extrapolating approach, which Bondi sometimes calls the empirical school, is represented by Dingle, McVittie, and their colleagues. Opposed to the extrapolative approach is the deductive approach, which "is reached from investigations in the borderland between physics and philosophy." Milne is obviously the major proponent of this view. Although Bondi finds good points in both approaches, he also finds problems in both approaches. In the end, cosmology is the worse for excesses from either end of the spectrum:

Just as some adherents of the ‘empirical’ school tend to regard cosmology as a testing ground for their extrapolations and as a legitimate playground for the geometers, so some adherents of the deductive approach appear to regard cosmology as a purely logical subject. (Bondi 1960, p. 7)

In this latter case, the deductive extremists, in their mathematical zeal, seem to forget that cosmology, after all, should have some relation to observation: "To them all that is of interest in a theory is its logical character, not its relevance to the interpretation of observational data." Obviously, this danger must be avoided: according to Bondi, deductivism can be a scientific approach in cosmology only if its postulates (or axioms) are candidates for disproof.

Enter Popper:

Clearly, with this reference to the connection between science and disproof, Bondi has added a distinctly Poppererian element to the deductivist methodology, one which had not previously appeared in the works of any of the earlier members of the hypothetico-deductive school. According to Popper's philosophy of science, a theory can legitimately be called “scientific” only if that theory makes a prediction that, in principle, can be shown to be false, or falsified, to use Popper's own term. Thus astrology, for example, fails to be a scientific theory because it cannot be falsified: although astrology seems to make predictions, these statements about the future are so vague, so general and abstract, that they cannot be tied down to definite claims about observations to be made at a definite time and place. Hence there is no explicit observation to be made in falsification. Astronomy, in comparison, makes explicit, specific predictions about what will occur in the sky on such-and-such a date, in such-and-such a place. If the prediction fails, then we know that the element of astronomical theory which made the prediction is deficient, maybe even false.

Cosmology is a borderline case: since observations of cosmological significance are so rare and hard-won—Hubble's observation of the red shift was one of the first solid ones—it is very difficult, not to mention brave, to tie one's cosmological theory to Popper's falsificationist principle as a guarantee of scientific acceptability. But this is exactly what Bondi did.

Much later Bondi was to make explicit his debt to Popper:

I think the person from whom we had most help on the philosophical side was Popper. His analysis of science encouraged one to be imaginative, and encouraged one to go for something that was very rigid and therefore empirically disprovable. (Bondi 1990, p. 194)

But It's Milne In the End:

Yet Bondi's major philosophical debt was to Milne. According to Bondi, Milne's theory was through and through deductive, which was reason enough for some of his colleagues to condemn it:

The aim of this discipline [= kinematic relativity] is to deduce as much as possible merely from the cosmological principle and the basic properties of space, time and the propagation of light. The beauty of this, as indeed of any deductive theory, rests on the rigour of the arguments and the small number of the axioms required...When the theory was first developed it met with great hostility and was criticized very severely, often unjustly, and sometimes frivolously. (Bondi 1960), p. 123)

In addition to his admiration of Milne's H-D methodology, Bondi has high praise as well for Milne's operationalism, particularly its use in defining distance:

Imperfect as Milne's definition of distance may be, it is very much better than the ‘rigid ruler’ one used in most other theories…Milne's definition of distance, by no means perfect as it is, is probably the best yet devised. (Bondi 1960, p. 126-9)

In the end, Bondi sums up Milne's contributions with no uncertain praise:

The foregoing brief description will have indicated the remarkable success of kinematic relativity in attempting to use the cosmological principle not only for the construction of the substratum but as chief guide in formulating ordinary physics. In this respect it differs greatly from all other cosmologies which either rely on a conventionally obtained body of physics or have not yet succeeded in drawing conclusions of local interest from the cosmological principle. (Bondi 1960, p. 136)

Return of the Cosmological Principle:

Here Bondi speaks of Milne's cosmological principle. According to Milne's principle, every observer in the universe should get the same world picture, that is, should make precisely the same observations of the universe at the same moment as any other observer. (Milne 1934b) Uniformity over spatial slices is guaranted by Milne's invoking of the principle. Yet Milne's universe evolves, it changes its form over time. Hence it has no temporal uniformity. Bondi felt that this raised the possibility that physics itself might change over time. Because of this risk, Bondi generalized Milne's cosmological principle into what he called the perfect cosmological principle [=PCP]. According to this principle, all observers at all places and at all times will look out upon the same unchanging, unevolving, universe. Such a universe is a universe in a steady-state—hence the name.

Clearly, PCP is a daring, indeed heroic, interpretation of a methodological necessity. Forty years after the fact, Bondi described the "philosophical attitude" which underlay his "implausible" PCP:

But the essential point of the philosophy was and is that if the universe was evolving and changing, then there is no reason to trust what we call the laws of physics, established by experiments performed here and now, to have permanent validity. (Bondi 1990, p. 192)

Hence, or so Bondi's argument goes, since there is reason not to trust the laws of physics if the universe is evolving, let us presume that the universe is not evolving and changing; that is, let us presume PCP. Although the principle (and the theory which results from it—steady state cosmology) is, as McVittie remarked, “much more restrictive than general relativity”; (McVittie 1990, p. 45) it is this very restrictiveness which satisfies Bondi's Popperian wishes:

For the correct argument has always been that the steady state model was the one that could be disproved most easily by observation, Therefore, it should take precedence over other less disprovable ones until it has been disproved. (Bondi and Kilmister 1959, p. 55-6)

In another place, Bondi makes a similar point: "Comparison with observation becomes then possible and renders the PCP liable to observational disproof. This possibility of a clear-cut disproof establishes the scientific status of PCP." (Bondi 1957, p. 198) Comments such as this make clear Bondi's committment to a Popperian addition to the basic deductive methodology he inherited from Milne.

A Popperian Conclusion:

In the end, the philosophical purity of Bondi's steady state theory served him, and cosmology, well. Of course, the usual suspect, Dingle, and others of his ilk, such as McVittie in particular, were outraged, and loudly, at Bondi's extension of Milne's methods. A passage from Dingle's R.A.S. Presidential Address suffices to show the tenor of the debate's declining days:

Even idle speculation may not be quite valueless if it is recognized for what it is. If the new cosmologists would observe this proviso, calling a spade a spade and not a perfect agricultural principle, one's only cause for regret would be that such great talents were spent for so little profit. (Dingle 1953, p. 404)

But PCP and the theory which it engendered were exactly as described: eminently falsifiable. No matter the extent of Dingle et al's disdain, Steady State theory stayed right out in front, ready for whatever empirical observations might be slung at it. As Bondi said "Show me some fossils from an evolving universe, and I'll give it up." In 1965, the fossils arrived, courtesy of the observations of the 3° K remnant microwave radiation.

And Bondi, true to his philosophy, gave it up.

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