Endeavour

Full text provided by www.sciencedirect.com

Vol. 38 No. 3–4

ScienceDirect

Was there a Darwinian Revolution? Yes, no, and maybe! Michael Ruse Program in the History and Philosophy of Science, Florida State University, Tallahassee, FL 32306, USA

Was there a Darwinian Revolution and was it but part of the Scientific Revolution? Before Thomas Kuhn’s Structure of Scientific Revolutions in 1962, most people thought that there was a Darwinian Revolution, that it was in some sense connected to the Scientific Revolution, but that neither question nor answer was terribly interesting. Then revolutions in science became a matter of intense debate, not so much about their very existence but about their nature. Was there a switch in world-views? Did the facts change? What was the importance of social groups? And so forth. Recently however some students of the history of science have started to argue that the very questions are misconceived and that there cannot have been a Darwinian Revolution and its relationship to the Scientific Revolution is imaginary because there are no such revolutions in science! This paper takes a sympathetic look at these issues, concluding that there is still life in the revolution-in-science issue, that Kuhn’s book was seminal and still has things of importance to say, but that matters are more complex and more interesting than we thought back then. Rather more than thirty years ago, I wrote a book with the title ‘The Darwinian Revolution’.1 Some of the reviews were friendly. Some rather less so. Several objected that my sub-title – ‘Science Red in Tooth and Claw’ – was rather flip.2 But no one objected to the main title, saying something like – ‘Well, was there a revolution in the first place? I am not so sure’. Today, however, one hears precisely this kind of complaint, voiced for instance by Jonathan Hodge,3 and since he is a leading historian of the Darwinian period he surely should know. The objection in part is over the flexibility – some might say flabbiness – of the very notion of ‘revolution’. Perhaps there are similarities between the American Revolution and the French Revolution. But does this extend to the Industrial Revolution? And what about the technological revolution brought on by personal Corresponding author: Ruse, M. ([email protected]). Michael Ruse, The Darwinian Revolution: Science Red in Tooth and Claw (Chicago, 1979). 2 The sub-title was suggested by my friend David Hull, although I was not supposed to know, because he did so while acting as the supposedly anonymous referee of the manuscript. 3 See Jonathan Hodge, ‘Against ‘‘Revolution’’ and ‘‘Evolution’’’, Journal of the History of Biology 38 (2005), 101–124. Available online 1 November 2014 1

www.sciencedirect.com

computers and the internet and so forth? The objection in part is that we are caught in a strait-jacket thanks to Thomas Kuhn’s attractive little book, The Structure of Scientific Revolutions4 [Figure 1]. We have been taught to think that science – good science that is – is all about revolutions, even though for the rest of his life Kuhn kept qualifying his position, until one could almost say that it had died a death of a thousand qualifications. For what it is worth, Ernest Nagel’s superb, detailed, philosophical account of the nature of science, The Structure of Science, published in 1961 the year before Kuhn, does not have the word ‘revolution’ in the index.5 What is a ‘revolution’ in science? I suppose the best place to start the discussion is with the so-called ‘Scientific Revolution’, that huge event that started in the sixteenth century with Copernicus’s new theory about the heavens and came if not to an end to its culmination in the seventeenth century with Isaac Newton’s explanation of the motions of things, including most prominently his central cause of gravitational attraction.6 We can say, speaking conceptually not temporarily, a lot of new facts were uncovered (think of Galileo’s discoveries with his telescope) and better measurements made (think of Brahe’s mapping of the skies). These led to new phenomenal laws (Kepler’s laws of the planets and Galileo’s laws of terrestrial motion), and thus to new theories in explanation (Copernicus’s heliocentric theory, the beginnings of gas theory). 4

Thomas Kuhn, The Structure of Scientific Revolutions (Chicago, 1962). See Ernest Nagel, The Structure of Science (New York, 1961). It may be thought that my comments suggest that the focus on revolutions is mistaken. If I do suggest that, then I negate fifty happy years of thinking about that very topic! The truth is that mid-century philosophy of science, represented by Nagel, was essentially ahistorical, in that it was not that interested in theory change or indeed in historical processes generally. The context of discovery, for instance, was simply ruled out of philosophical discourse. I am sure that the change was not due only to Kuhn, but more generally to the fact that the history of science was now being professionalized and exciting work incorporating the temporal dimension was being produced. Kuhn, the author a year or two before Structure of the definitive history of the Copernican Revolution (1957), of which my Darwin book was a conscious imitator, was not alone in feeing the currents of change. See Thomas S. Kuhn, The Copernican Revolution (Cambridge, Mass., 1957). Stephen Toulmin, ‘The evolutionary development of science’, American Scientist 57 (1967), 456–471, and Norwood Russell Hanson, Patterns of Discovery (Cambridge, 1958) were others. Not everyone appreciated the shift. See Israel Scheffler, Science and Subjectivity (Indianapolis, Ind., 1967) and Dudley Shapere, ‘The structure of scientific revolutions’, Philosophical Review 73 (1964), 383–394. If anyone has any doubts about current interest in the topic of revolutions in science, or of the continued relevance of Thomas Kuhn, I can only suggest that they check Wikipedia for ‘‘Scientific Revolution’’, ‘‘Paradigm Shift’’, and related topics. 6 E.J. Dijksterhuis, The Mechanization of the World Picture (Oxford, 1961). 5

0160-9327/ß 2014 Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.endeavour.2014.10.002

160

Endeavour Vol. 38 No. 3–4

Figure 1. Thomas Kuhn (1922–1996).

Along with the facts and theory went a change of methodology. Some, like William Whewell7 in the nineteenth century, thought it was all about observation and insisting on using the senses rather than relying on authority, in the case of the Scientific Revolution the authority of the Greek authors like Aristotle. But although there is truth in this, it is an exaggeration. Aristotle had studied marine fauna carefully at the time of his life when he was more a scientist than a philosopher. It was more a change of root metaphors, from seeing the world through the lens of organisms to seeing the world through the lens of machines, of clocks.8 One of the definitive histories of the Scientific Revolution ends its introduction thus: Christianity furnished the scientist with God as the first cause of things. But if this first cause had, so to speak, set the universe to run its course and endowed man with free-will to make his own destiny, the phenomena of nature could only be the result of determined processes, manifestations of a mechanistic design, like an infinitely complex automaton or clock. A clock is not explained by saying that the hands have a natural desire to turn, or that the bell has a natural appetite for striking the hours, but by tracing its movements to the interconnections of its parts, and so to the driving force, the weight. If God was the driving force in the universe, were not its motions and other properties also to be ascribed to the interconnections of its parts? The question, slowly compelling attention over three hundred years, received a positive answer in the seventeenth century. The only sort of explanation science could give must be in terms of descriptions and processes, mechanisms, interconnections of parts. Greek animism was dead. Appetites, natural tendencies, sympathies, attractions, were moribund concepts in science, too. The universe of classical physics, in which the only reality is a matter and motion, could begin to take shape.9 7

William Whewell, The Philosophy of the Inductive Sciences (London, 1840). 8 Michael Ruse, Science and Spirituality: Making Room for Faith in the Age of Science (Cambridge, 2010). 9 A. Rupert Hall, The Scientific Revolution 1500–1800: The Formation of the Modern Scientific Attitude (London, 1954), xvii. www.sciencedirect.com

A Kuhnian revolution – that is, the characterization of change given by Kuhn in his book – shares only some features of this kind of revolution. There certainly is change, but it is as much sociological and psychological as epistemological. A lot of it is a question of groups forming around theories, or what Kuhn dubs ‘paradigms’, sharing ideas and techniques and indoctrinating students with the ideology of the group. It is a matter not just of achievements but of future prospects. Is there work for me to do? Can I justify taking on students? Can I expect to win a prize or two if I follow this path? Not that epistemology is irrelevant. In fact, the most daring thing about a Kuhnian revolution is the extreme claims made in its name. We see things in a different way – the Wittgensteinian duck/rabbit comes into play here. Now you see it one way. Now you see it another way. Underlying the perspectives is a fairly hardline idealism. In some genuine way, the world changes through a revolution. Before and after are not contradicting each other. They really are different. Claims about them are ‘incommensurable’. That is why changing sides in a Kuhnian revolution has something of the political or religious experience about it. It is not something driven exclusively by reason, but more an act of faith. You make an emotional commitment to your new paradigm. I don’t think anyone would deny that both of these ways of looking at revolutions are deeply insightful. I don’t think anyone would affirm that either of these ways of looking at revolutions is fully entire and adequate. But it is worth the effort. Most people would say that ‘revolution’ talk is toooften overdone, not the least by scientists wanting to make a name for themselves – Stephen Jay Gould and punctuated equilibrium comes to mind.10 Yet, it is far from silly or unprofitable to think of science in terms of revolutions and to go searching for them, and to try to explain them. Take for instance geology.11 Just after the middle of the last century something happened in that science. Something very important that changed the science dramatically and all now would say very much for the better. Until then, with some few exceptions, people thought that the continents stayed put. I can still remember, as an undergrad in 1962, the very nice geologist with whom I roomed laughed at me when I pointed out that Africa and South America seem to ready to snuggle together rather nicely. Then geologists changed their minds and the continents moved. I suspect my former roommate has spent fifty years explaining to people that Africa and South America fit together and so. . .. There was surely a revolution. Did it involve new facts? Yes it did. Deep sea rifts for a start and magnetic changes for a second. Did it involve new theory? Yes it did, at least in the sense of accepting a theory from earlier in the century that had generally been denied. As German geologist Alfred Wegener claimed, continents move. Did it involve new theory? Yes, plate tectonics. People rightly refused to accept moving continents when they thought they were supposed to plow through rock, but when they 10 Niles Eldredge and Stephen Jay Gould, ‘Punctuated equilibria: an alternative to phyletic gradualism’, in T.J.M. Schopf (eds.), Models in Paleobiology (San Francisco, 1972), 82–115. 11 Anthony Hallam, A Revolution in the Earth Sciences (Oxford, 1973); Michael Ruse, ‘What kind of revolution occurred in geology?’ PSA 1978 (East Lansing, Mich., 1981), 2: 240–273.

Endeavour

Vol. 38 No. 3–4

161

were seen to ride on the backs of large plates emerging and then again vanishing, moving continents made good sense. Was the world changed in some dramatic epistemological sense? Not really. The coasts of Africa and South America were there before and after. Did the theory point to new directions? Did it ever! Biogeography is transformed as people put together the anomalous fossils we find in the record. Was there a conversion experience? Undoubtedly. Accounts from the time tell of people suddenly cutting out paper shapes and spreading them excitedly on the parlor floor and piecing them together into new patterns. What I find truly amazing is how my roommate and his fellow geology students, in what was generally considered a topnotch department, simply had no idea of what was about to hit them. It was like the collapse of the Soviet Empire. Was there a ‘Darwinian’ Revolution? Turn now to the Darwinian Revolution, so called. I think we can all agree that something significant happened in biology around the middle of the nineteenth century, give or take a decade or two. I am speaking now of the historical side to biology, the side that deals with origins. I leave physiology and related subjects out of the picture, although all would agree that exciting things were happening there too. In historical biology there was a move from seeing organisms as in some sense miraculously created, to seeing organisms as in some sense the end result of a long, slow, natural process of development.12 One can take as one’s touchstone the early science examinations at the University of Cambridge.13 In 1851 (the first round of exams), students were asked to discuss why evolution (people generally did not yet use that term) was false; in 1865, students were told to assume the truth of evolution and to discuss causes. If this was not a significant change and if this does not merit calling a ‘revolution’ I don’t know what does. It is now that the fun begins. First, was it Darwinian? Historians of evolutionary theory have shown in very great detail that Charles Darwin was far from the first evolutionist, meaning believing that all organisms including humans are the end results of a long natural process of development.14 We can go back a hundred and fifty years to the French man of letters Denis Diderot, who combined a happy career of writing pornographic novels about lesbian nuns with floating speculations about natural origins.15 More staid, but as committed to such ideas, was Charles 12 None of the serious scientists in the decades before Darwin were Creationists in the modern American sense of thinking that Genesis is literally true, without qualification. But they did think that God was involved in the origins of organisms, in a way that He was perhaps not involved in the origins of mountains. In his presidential address to the Geological Society of 1831, Sedgwick is unambiguous on this point. See Adam Sedgwick, ‘Address to the Geological Society’, Proceedings of the Geological Society of London 1 (1831), 281–316. And if we cross to the continent and go back in time say to Immanuel Kant, we find in the Third Critique that he is twisting himself into knots trying to keep God out of science but admitting that organisms do very much seem to need a designer. See Immanuel Kant, [1790] 1928. The Critique of Teleological Judgement. Translator J.C. Meredith (Oxford, 1790 [1928]): and also Michael Ruse, ‘Kant and evolution’, in J. Smith (ed.), Theories of Generation (Cambridge, 2006), 402– 415. Of course, the evolutionists like Erasmus Darwin and Lamarck were not into miracles as such, but they too thought the god of deism was behind everything. 13 Ruse, The Darwinian Revolution, xi–xii. 14 Peter Bowler, Evolution: The History of an Idea (Berkeley, 1984). 15 I don’t think these activities were independent. Diderot saw the need to attack the old paradigm, Christianity and its story of origins, as much as to promote the new paradigm, evolution and its story of origins. See Michael Ruse, The Evolution-Creation Dispute (Cambridge, Mass., 2005).

www.sciencedirect.com

Figure 2. Erasmus Darwin (1731–1802).

Darwin’s grandfather, who hymned evolution in prose and verse [Figure 2]. Imperious man, who rules the bestial crowd, Of language, reason, and reflection proud, With brow erect who scorns this earthy sod, And styles himself the image of his God; Arose from rudiments of form and sense, An embryon point, or microscopic ens!16

This kind of thinking kept going all of the way through the first part of the nineteenth century up to 1859 when Darwin published the Origin. Included here are Jean-Baptiste Lamarck,17 Etienne Geoffroy Saint-Hilaire,18 the aged Johann Wolfgang von Goethe,19 Robert Grant,20 and Robert Chambers.21 Then in the 1850s came Herbert Spencer,22 arguing for an evolutionary perspective on everything. So there was a lot of evolutionism before Darwin, especially before Darwin published. How widely was it accepted? It is still hard to say. Undoubtedly, at the professional level there was huge opposition. In Britain, Adam Sedgwick,23 William 16

Erasmus Darwin, The Temple of Nature (London, 1803), 1, 11, 295–314. Jean-Baptiste Lamarck, Philosophie zoologique (Paris, 1809). 18 Etienne Geoffroy Saint Hilaire, Philosophie anatomique (Paris, 1809). 19 Robert J. Richards, The Romantic Conception of Life: Science and Philosophy in the Age of Goethe (Chicago, 2003). 20 Robert Grant, ‘Lectures on comparative anatomy and animal physiology’, Lancet 1 through 2, 60 lectures, (1833–1934). 21 Robert Chambers, Vestiges of the Natural History of Creation (London, 1844). 22 Herbert Spencer, ‘The development hypothesis’, in Essays: Scientific, Political and Speculative (London, 1852 [1867]), 377–383. 23 Adam Sedgwick, ‘Vestiges’, Edinburgh Review 82 (1845), 1–85. 17

162

Endeavour Vol. 38 No. 3–4

Whewell,24 and David Brewster25 led the pack. In the 1850s, Thomas Henry Huxley26 was a sarcastic voice against the idea. However, there were professional scientists, especially on the continent, who were sympathetic to the idea, and the general public often lapped it up.27 Alfred Tennyson28 for example used Chambers’ ideas in his beloved poem In Memoriam. Depressed at the thought (taken from Charles Lyell) that the history of life is meaningless, he found inspiration in Chambers. The poem, a tribute to a dead friend, finds meaning in the thought that friend was a higher form of being, born too soon. A soul shall strike from out the vast And strike his being into bounds, And moved thro’ life of lower phase, Result in man, be born and think, And act and love, a closer link Betwixt us and the crowning race ............................................................ Whereof the man, that with me trod This planet, was a noble type Appearing ere the times were ripe, That friend of mine who lives in God. The dear Queen (Victoria) found this a great comfort when Prince Albert died. I note also that one of the marks of a revolution – Kuhn is good on this – is the way that the old paradigm starts to come apart at the seams. More and more it ceases to have the ring of authenticity or truth. In the early 1850s, Whewell – one of the stalwarts of the fixity-of-species position – started to worry about the old problem of the plurality of worlds.29 His revealed theology, about Jesus and his purpose here on Earth given to us by faith, seemed to be clashing with his natural theology, the nature of the universe as attesting to God as shown by the faculty of reason. Why does the rest of this truly vast universe exist? If it is to house other living intelligent beings, does this not downgrade our importance in the eyes of our creator? Does Jesus spend the whole of eternity hopping from one planet to the next, suffering the same fate as on ours? Surely not! But then isn’t everything else just a waste? And this seems to attack the argument from design, an essential part of the non-evolutionary thinking – organisms seem as if designed because they are designed, by God. What was the Creator thinking when he made so much useless material? Whewell’s solution was to appeal to a kind of elegance – God is into repetition almost as an esthetic enterprise and hence He created the rest of the universe. In support of his position, Whewell appealed to something pushed by continental biologists influenced by the Romantic 24

William Whewell, Indications of the Creator (London, 1845). David Brewster, ‘Vestiges’, North British Review 3 (1844), 470–515. 26 Thomas Henry Huxley, ‘Vestiges, etc.’, British and Foreign Medico-Chirurgical Review 13 (1854), 425–439. 27 James Secord, Victorian Sensation: The Extraordinary Publication, Reception, and Secret Authorship of Vestiges of the Natural History of Creation (Chicago, 2000). 28 Alfred Tennyson, ‘In Memoriam’, in R.H. Ross (ed.), In Memoriam: An Authoritative Text Backgrounds and Sources Criticism (New York, [1850] 1974), 3–90. 29 William Whewell, Of the Plurality of Worlds. A Facsimile of the First Edition of 1853: Plus Previously Unpublished Material Excised by the Author Just Before the Book Went to Press; and Whewell’s Dialogue Rebutting His Critics, Reprinted from the Second Edition. Edited with an introduction by Michael Ruse. (Chicago, [1853] 2001). 25

www.sciencedirect.com

movement – the Naturphilosophen – who made much of the isomorphisms (what the biologist Richard Owen had just christened ‘homologies’) between the parts of organisms and across between different organisms – the forearm of the human, the wing of the bat, the leg of the horse, and that sort of thing.30 God is into copying so the vastness of the universe is explicable. There is no need to suppose that it has an immediate function, like being homes for many human-like species. Which of course is all fair enough, but now you are rather attacking the (‘utilitarian’) version of the argument from design – given definitive treatment in the textbook of Archdeacon William Paley31 – that focusses on the worth and value of organic features and stressing that much of the living world has no direct purpose. And in doing this, you are chipping away at one of the more important underpinnings of the anti-evolution position – pushed particularly by the early-nineteenth-century French comparative anatomist, Georges Cuvier – that organisms are so tightly designed that intermediates between species – an essential part of the evolutionary story – would simply be non-functional.32 More than this, of course, you are now focusing on the very things that – as the Naturphilosophen were quick to note and stress – most naturally suppose that organic origins involve evolution. Why should the forearm of the human and the wing of the bat be so similar except they had common origins? The point is not that Whewell was becoming an evolutionist – he was not – but that his paradigm was starting to creak badly and let in water. There was a reason why – to continue the metaphor – in the next decade people were to jump from Whewell’s ship and get aboard the ship of the evolutionists. If the idea of evolution was around, and if the old static way of thinking was coming apart, what then was Darwin’s contribution? With respect to evolution as such – what could be called ‘evolution as fact’ as opposed to ‘evolution as theory’ – the big forward move in the Origin was the collecting of all of the evidence and the presentation of it in a systematic fashion. This latter point is crucial. Darwin did not just collect evidence for evolution in a haphazard fashion. The Origin is carefully structured according to the best methodological prescriptions of the day about how one produces good science.33 Central here is the notion of a vera causa, a true cause, something that Newton claimed to have with his force of gravitational attraction. Thanks to Newton’s somewhat cryptic characterization of the notion, there was division over exactly what constitutes a vera causa, with the more empiricist John F. W. Herschel34 preferring to think in analogical terms – if you have sensed 30 The definitive study of the Naturphilosophen and evolution is Richards, The Romantic Conception of Life. Richard Owen, although later to become the violent opponent of the Darwinians, was much influenced by German biology, even to the point of probably having yearnings of idealistic evolution of his own well before the Origin was published. At the end of the 1940s, Owen was being very vocal about the significance of homology, and obviously Whewell picked up on this. See Richard Owen, On the Nature of Limbs (London, 1849). 31 William Paley, Natural Theology. Collected Works, IV. (London, 1802 [1819]). 32 William Coleman, Georges Cuvier Zoologist. A Study in the History of Evolution Theory (Cambridge, Mass., 1964). 33 Michael Ruse, ‘Darwin’s debt to philosophy: an examination of the influence of the philosophical ideas of John F.W. Herschel and William Whewell on the development of Charles Darwin’s theory of evolution’, Studies in History and Philosophy of Science 6 (1975), 159–181. 34 John F.W. Herschel, Preliminary Discourse on the Study of Natural Philosophy (London, 1830).

Endeavour

Vol. 38 No. 3–4

a cause directly (like the force needed to hold a stone going in a circle at the end of a piece of string) then this is good evidence for a similar unsensed cause (the force that keeps the moon from flying off away from the Earth) – and the more rationalist William Whewell35 preferring to think in terms of what he called a ‘consilience of inductions’ – all of the evidence is collected together under one unifying hypothesis. Darwin covered his tracks by providing support for both kinds of vera causa, starting with the analogy from artificial selection and then going on to show how evolution through selection throws light on social behavior, paleontology, biogeography, anatomy and morphology, systematics, and embryology. I think it fair to say that people appreciated what he had done, and virtually overnight, with some exceptions, the world – the scientific world and the everyday world, including the religious world – moved over to acceptance of the fact of evolution. Darwin made it acceptable to believe in evolution. In fact, the onus was now on those who did not accept evolution to explain their stance. The Swiss-transplant ichthyologist Louis Agassiz at Harvard put a lot of effort into his continued denial.36 So in this sense we can say there was a Darwinian Revolution. Progress and teleology We can go a bit further down the line here.37 Note the underlying theme of Erasmus Darwin. It is biological progress! We go from the blob to the human, or as they used to say, from the monad to the man. This was the shared leitmotif of everyone up to Charles Darwin. Listen to Robert Chambers. A progression resembling development may be traced in human nature, both in the individual and in large groups of men. . . Now all of this is in conformity with what we have seen of the progress of organic creation. It seems but the minute hand of a watch, of which the hour hand is the transition from species to species. Knowing what we do of that latter transition, the possibility of a decided and general retrogression of the highest species towards a meaner type is scarce admissible, but a forward movement seems anything but unlikely.38 This is what attracted Tennyson. There is progress and his dead friend was a higher form of being, who came too soon. This view of biological progress reflected people’s commitment to some kind of social progress. Erasmus Darwin was explicit. The idea of organic progressive evolution ‘is analogous to the improving excellence observable in every part of the creation;. . . such as the progressive increase of the wisdom and happiness of its inhabitants’.39 Fifty years later Herbert Spencer was singing the same song. Now we propose in the first place to show, that this law of organic progress is the law of all progress. Whether 35

William Whewell, Philosophy of the Inductive Sciences (London, 1840). E. Lurie, Louis Agassiz: A Life in Science (Chicago, 1960). Michael Ruse, Monad to Man: The Concept of Progress in Evolutionary Biology (Cambridge, Mass., 1996). 38 Robert Chambers, Vestiges, 400–402. This from the third edition of 1846. 39 Erasmus Darwin, Zoonomia; or, The Laws of Organic Life (London, 1794–1796), 509.

163

it be in the development of the Earth, in the development of Life upon its surface, in the development of Society, of Government, of Manufactures, of Commerce, of Language, Literature, Science, Art, this same evolution of the simple into the complex, through successive differentiations, hold throughout. From the earliest traceable cosmical changes down to the latest results of civilization, we shall find that the transformation of the homogeneous into the heterogeneous is that in which Progress essentially consists.40

Of course there was some empirical evidence for evolution. Chambers was pretty good on the fossil record. Facts of embryology were starting to look very suggestive. But generally the evidence before Charles Darwin was simply not there or not connected to show its full relevance. Instead, people accepted evolution because they interpreted it in terms of biological progress and they saw biological progress as the reflection of cultural and social progress. Often, believing in the latter they pushed the former as confirmation. I might add, almost parenthetically, and certainly paradoxically and rather amusingly, Christian notions about Providence – history shows a movement from Genesis to Revelation, and God is guiding things and at the end (some) humans will emerge triumphant – might also have been playing a role here. Note that the clock metaphor is static, in the sense that the hands come back to the same place at the top every twelve hours. No progress, even though Chambers in the above passage makes reference to the clock. (I don’t think Chambers was that sophisticated to think through issues fully here.) For someone like Paley, who made famous use of the clock, the static picture was quite acceptable. He laid Providence on the top of things. As it happens, through the eighteenth century the clock was increasingly replaced by the Newcomen Engine – the pump to remove water from mines – but it too is static and simply goes in a cycle back to the starting point. For someone like Charles Lyell, who following William Hutton, had a view of the Earth as being a continuous Newcomen Engine, this was just fine.41 His ‘uniformitarianism’, stressing the workings of unbroken law functioning at intensities we find today, incorporated this steady state – everything going nowhere – and indeed he used it in an attack on Lamarckian evolution. There isn’t the direction that evolution seems to demand. I think the social notion of progress was enough to generate direction and evolution, as Paley’s notion of Providence was enough to generate his needed direction, but I would not entirely deny the possibility of a young person, schooled in Providential theology, taking this as a reason to think in terms of upwards rise, quite unintended by his teachers. This is particularly true since these teachers – Adam Sedgwick particularly42 – were pushing what William Whewell43 called a ‘catastrophic’ view of world history, with systematic upheavals directing the Earth to a cooler state ready for humankind.

36 37

www.sciencedirect.com

40 Herbert Spencer, ‘Progress: Its law and cause’, Westminster Review LXVII (1857), 244–267, 245. 41 Michael Ruse, The Gaia Hypothesis: Science on a Pagan Planet (Chicago, 2013). 42 Sedgwick, ‘Address to the Geological Society’. 43 William Whewell, History of the Inductive Sciences (London, 1837).

164

Endeavour Vol. 38 No. 3–4

Such a young person might take the message of uniformitarianism, and especially the guide to working with and only with unbroken law at today’s intensities, and use it to push an Earth history redolent of the directional history of the religious catastrophists. Darwin and progress Charles Darwin certainly believed in social progress. As the grandson of one of Britain’s most successful industrialists, Josiah Wedgwood, he was not about to deny that family creed.44 He also believed in biological progress. Consider the famous final worlds of the Origin. It is interesting to contemplate an entangled bank, clothed with many plants of many kinds, with birds singing on the bushes, with various insects flitting about, and with worms crawling through the damp earth, and to reflect that these elaborately constructed forms, so different from each other, and dependent upon each other, in so complex a manner, have all been produced by laws acting around us. These laws, taken in the largest sense, being Growth with Reproduction;. . . a Rate of Increase so high as to lead to a Struggle for Life, and as a consequence Natural Selection entailing, a Divergence of Character and the extinction of less-improved forms. Thus, from the war of nature, from famine and death, the most exalted object we are capable of conceiving, namely, the production of the higher animals, directly follows. There is grandeur in this view of life, with its several powers, having been originally breathed into a few forms or into one; and that, whilst this planet has gone cycling on according to the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been and are being, evolved.45 However, there is a major difference. Darwin was not relying on his belief in social progress to push a belief in biological progress and hence evolution. In fact, he rather realized that his theory poses difficulties for progress – selection itself is relativistic and new variations are nondirected – and so two years later Darwin turned to fresh arguments to make progress seem plausible. (Like many of today’s evolutionists he employed a kind of arms race notion, with lines competing and getting ever better.46) And in any case, Darwin realized that science is supposed to tell it like it is, not as we would like it to be. In other 44 Also picking up the point made in the last paragraph, Darwin had been schooled in British Providential theology. Whewell particularly knew the score here – and also about the possibility of combining regular unbroken laws with Earth direction – and I much suspect his young prote´ge´ was likewise sensitive to the point, although drawing very non-Whewellian conclusions. 45 Charles Darwin, On the Origin of Species (London, 1859), 489–490. 46 In the third edition of the Origin, of 1861, Darwin wrote:If we look at the differentiation and specialisation of the several organs of each being when adult (and this will include the advancement of the brain for intellectual purposes) as the best standard of highness of organisation, natural selection clearly leads towards highness; for all physiologists admit that the specialisation of organs, inasmuch as they perform in this state their functions better, is an advantage to each being; and hence the accumulation of variations tending towards specialisation is within the scope of natural selection. (134)Recently, people like Richard Dawkins have been following Julian Huxley, The Individual in the Animal World (London, 1912) in putting things in military terms. Lines of organism compete, their weapons of attack or their armor gets ever better, and finally electronics get involved. Humans are simply the organisms with the best on-board computers.

www.sciencedirect.com

Figure 3. Ernst Haeckel’s progressive tree of life, from The Evolution of Man (New York, 1896), showing how persistent was the notion of progress.

words, science is supposed to be value free and a theory that proves that humans are best is hardly value free, even if one in fact believes (as did Darwin) that humans are best. My point is that (even if he was not always completely successful) the Origin represents a shift to getting values out of science, and in this respect is also revolutionary.47 The language I like to use is that before Darwin essentially evolution was a pseudo-science, something pushed because of its ideological content and without proper empirical backing. After Darwin, evolution was at least a popular science, meaning it was something that people could 47 Let us say making it possible to get values out of science, because obviously most people did not when it came to evolution. Most were happy to go on promoting progress, although my suspicion is that a reason why many religious people were able to accept evolution was that the evolution-progress link was broken, and one could for instance hold to a view of God’s Providential working in the world and be an evolutionist. See James Moore, The Post-Darwinian Controversies: A Study of the Protestant Struggle to come to terms with Darwin in Great Britain and America, 1870– 1900 (Cambridge, 1979), and Jon H. Roberts, Darwinism and the Divine in America: Protestant Intellectuals and Organic Evolution, 1859–1900 (Madison, Wisconsin, 1988).

Endeavour

Vol. 38 No. 3–4

accept, without being tarred by commitments to ideologies that not all shared48 [Figure 3]. There is one more way that we might think of what happened as Darwinian. Before Darwin, either you ignored adaptations and any problems they raise – this was the stance of Robert Chambers – or you grasped the nettle and agreed that things like the hand and the eye call for (in the old language) a ‘final cause’ explanation or (in the new language) ‘teleological’ understanding. And this latter meant that either (like Plato) you put it all down to God’s creative intelligence or (like Aristotle) to some kind of vital force.49 After Darwin you could explain the hand and the eye naturalistically.50 Those that did well in the struggle tended on average to be different from those that did not, and the differences taken over time added up to adaptations. Can it. . . be thought improbable, seeing that variations useful to man have undoubtedly occurred, that other variations useful in some way to each being in the great and complex battle of life, should sometimes occur in the course of thousands of generations? If such do occur, can we doubt (remembering that many more individuals are born than can possibly survive) that individuals having any advantage, however slight, over others, would have the best chance of surviving and of procreating their kind? On the other hand we may feel sure that any variation in the least degree injurious would be rigidly destroyed. This preservation of favourable variations and the rejection of injurious variations, I call Natural Selection.51

Of course in a broader sense you might want to say that this is not so much a Darwinian revolutionary move as a subsection of what went on in the Scientific Revolution. That was essentially all about the expulsion of final causes, and so what Darwin was doing was part of this agenda. We can accept this, although it is surely not a case of ‘either, or, but not both’. The Darwinian Revolution was part of the general process set in motion by the Scientific Revolution – perhaps cognitive science is also part of this general process – but this does not diminish its importance nor does it diminish the contribution of Charles Darwin. Deliberately, with the exception of Alfred Russel Wallace, I ignore those 48 The Descent of Man published in 1871, twelve years after the Origin, is in respects a lot more value-laden than the Origin. Darwin makes very clear his personal views on such things as capitalism. This is a major reason why I speak of post-Origin evolution as being popular. Values still played a major role in thinking about evolution, even if they were no longer essential. Of course, there were professional evolutionists. Ernst Haeckel was certainly one, as is shown by Robert J. Richards, The Tragic Sense of Life: Ernst Haeckel and the Struggle over Evolutionary Thought (Chicago 2008). But generally evolution was metaphysical, a kind of Christianity alternative, and people regarded it that way. Hence, Darwin felt free to express his value-commitments, even though I think his original intent had been to provide something a lot more professional, within paradigm science in the sense used by Kuhn. 49 I think particularly because of the vitalists, Hans Driesch, The Science and the Philosophy of the Organism (London, 1908) and Henri Bergson, L’e´volution cre´atrice (Paris, 1907), there is the thought that an Aristotelian vital force is a bit like a regular force, only ethereal. Such a characterization may not be entirely unfair of Driesch and Bergson, but Aristotle is far more subtle. For a start, any such forces are not frontloaded, pushing things along, but rather bound up with ends, and somehow influencing the present by serving as goals. 50 Michael Ruse, Darwin and Design: Does Nature have a Purpose? (Cambridge, Mass., 2003). 51 Darwin, Origin, 80–81.

www.sciencedirect.com

165

who also discovered natural selection independently. They did not see its importance. Wallace certainly did, and if you want to call it the Darwin-Wallace Revolution, I would not object. However, he certainly did not do all that Darwin did, most particularly collecting all of the evidence into a vera causa. I do object to calling it the Wallace-Darwin Revolution. Was there a Darwinian ‘Revolution’? Move on now to focus more on the Revolution side to the Darwinian Revolution. Does Kuhn help us here? How did people react to the Origin?52 Famously, on hearing of natural selection, Huxley showed a very Kuhnian reaction. ‘‘The ‘Origin’ provided us with the working hypothesis we sought. Moreover, it did the immense service of freeing us for ever from the dilemma – Refuse to accept the creation hypothesis, and what have you to propose that can be accepted by any cautious reasoner? In 1857 I had no answer ready, and I do not think that anyone else had. A year later we reproached ourselves with dullness for being perplexed with such an inquiry. My reflection, when I first made myself master of the central idea of the ‘Origin’ was, ‘How extremely stupid not to have thought of that!’ I suppose that Columbus’ companions said much the same when he made the egg stand on end.’’ 53

Some on the other side of the matter seem also to have reacted in an analogously emotional way. Darwin’s old teacher Adam Sedgwick was one [Figure 4]. I have read your book with more pain than pleasure. Parts of it I admired greatly; parts I laughed at till my sides were almost sore; other parts I read with absolute sorrow; because I think them utterly false & grievously mischievous—You have deserted—after a start in that tram-road of all solid physical truth— the true method of induction—& started up a machinery as wild I think as Bishop Wilkin’s locomotive that was to sail with us to the Moon. Many of your wide conclusions are based upon assumptions which can neither be proved nor disproved. Why then express them in the language & arrangements of philosophical induction?.—54

This said, not everyone reacted in so emotive a manner. Indeed, one of the most striking things about postOrigin writings by scientists is that you often cannot tell surely if they have committed to evolution or not. This is particularly true of some of the students of Louis Agassiz across the Atlantic at Harvard.55 As noted, Agassiz never 52 Of the voluminous literature on Darwin and Kuhn, to which (in my first-ever paper) I contributed in a very unsophisticated fashion – Michael Ruse, ‘The revolution in biology’, Theoria XXXVI (1970), 1–22 – John Greene, ‘The Kuhnian paradigm and the Darwinian Revolution in natural history’, in Science, Ideology and World View. Essays in the History of Evolutionary Ideas (Berkeley, 1981), 30–59, has always struck me as characteristically balanced and thoughtful. 53 T.H. Huxley, ‘On the reception of the Origin of Species’, in Francis Darwin (ed.), The Life and Letters of Charles Darwin (London, 1887), 2: 197. 54 Adam Sedgwick to Charles Darwin, 24 Nov 1859; Darwin Correspondence, Letter 2548. 55 Michael Ruse, Monad to Man.

166

Endeavour Vol. 38 No. 3–4

the same. The embryos of dog and human were similar before Darwin and they were the same similar embryos after Darwin. The finches of the Galapagos had an odd distribution before Darwin and they had that same distribution after Darwin. Workers at the nest were infertile before Darwin and they were infertile after Darwin. The way I like to put things is that Darwin was a great revolutionary but he was no rebel.57 He drew non-stop on what was offered to him, be it religious like the importance of seeing adaptations from an end-directed perspective, be it philosophical like the significance of a consilience of inductions, be it economic like the division of labor or the Malthusian calculations, be it practical like the success of the breeders, be it empirical like the homologies shared by humans and dogs and horses and bats and birds and porpoises and much more. His genius was to take all of these elements and to rearrange them into a striking new pattern. As happens with a kaleidoscope. Darwin was not kicking against the pricks.58 But he was steering us in a very new direction. This point is confirmed if we return to the final-cause issue. Darwin got rid of the need to think either in Platonic (external designer) terms or Aristotelian (vital forces) terms. Note that what Darwin was doing was getting these out of science. He wasn’t denying them as such. In fact, at the time of writing the Origin Darwin still believed in God as the force behind final causes. He made this clear in a letter to Gray. I agree with you that my views are not at all necessarily atheistical. The lightning kills a man, whether a good one or bad one, owing to the excessively complex action of natural laws,—a child (who may turn out an idiot) is born by action of even more complex laws,—and I can see no reason, why a man, or other animal, may not have been aboriginally produced by other laws; & that all these laws may have been expressly designed by an omniscient Creator, who foresaw every future event & consequence.59

Figure 4. Adam Sedgwick (1785–1873), Professor of Geology at the University of Cambridge, Anglican clergyman, mentor of Charles Darwin, and strong opponent of evolution.

accepted evolution, but we know from letters and other evidence that Agassiz’s students (including his own son) pretty much all accepted evolution. However, from just reading their papers it is often hard to tell, if not impossible. They just keep going right on doing the science as they were taught. This shows that at least in a sense we had more of a metaphysical switch than a purely scientific switch. People were interpreting things naturalistically rather than spiritually, and of course this was important, but in the physical sciences they had been doing this for centuries. It wasn’t that they didn’t until Darwin want to do this in the biological sciences; it was rather that they didn’t know how. So when the switch came, in a way it was no big deal, because it was just an extension of what was alreadyaccepted practice. This ties in with what has just been said about the Darwinian Revolution being in a sense part of the Scientific Revolution. We are going from a spirit-filled world to a world of dead matter, explicable naturalistically but without ultimate meaning. (Of course not everyone went quite that far. Asa Gray56 for one wanted directed variations, and even today Christians usually insist on nonnatural causes for souls and such things.) This lack of emotion points to another thing pertinent to the Kuhnian understanding of revolution – that the facts change. I don’t think anyone would deny that after Darwin things were seen in a different manner. Perhaps even the duck/rabbit analogy is pertinent here. But the facts were 56

Asa Gray, Darwiniana (New York, 1876).

www.sciencedirect.com

As importantly, Darwin did not get rid of final-cause type thinking as a mode of understanding. We still can and should ask: What is the point of the eye? What purpose do the hands serve? Although the overall root metaphor has changed from that of an organism to that of a machine – organisms are now in Richard Dawkins’s felicitous phrase ‘survival machines’60 – we still can and should continue to use the organic metaphor to make sense of adaptations. We treat organisms ‘as if’ designed, because that is the effect that natural selection produces. Kant61 argued that we must do this and while it is true that he never made the transition to the machine view of organisms – he denied that there will ever be a Newton of the blade of grass – he 57

Robert J. Richards and Michael Ruse, Debating Darwin (Chicago, 2015). ‘‘And when we were all fallen to the earth, I heard a voice speaking unto me, and saying in the Hebrew tongue, Saul, Saul, why persecutest thou me? it is hard for thee to kick against the pricks’’. Acts, 26, 14. 59 Charles Darwin to Asa Gray, May 22, 1860, Darwin Correspondence, Letter 2814. 60 See Richard Dawkins, The Selfish Gene (Oxford, 1976). In a series of recent publications, I have explored in some detail the mechanical model in evolutionary biology. See Michael Ruse, Science and Spirituality; The Gaia Hypothesis; and Richards and Ruse, Debating Darwin. 61 Immanuel Kant, The Teleological Critique of Judgement. 58

Endeavour

Vol. 38 No. 3–4

167

did have a point. So this is another reason why there is continuity over the Darwinian Revolution – change (a revolutionary) but continuity (no rebel). Was there a new paradigm? There are at least two further aspects of Kuhnian thinking that are very insightful when applied to the Darwinian episode. First, Kuhn makes much of the fact that paradigms have a strong sociological component. Like a religion or a political party, once you are in you identify with the group and against others, and there is a certain solidarity with your fellow members. Particularly, you are into the business of finding new followers and inculcating them within the membership. ‘Invisible colleges’, to use a term one sometimes sees.62 We see this very much in the Darwinian case and Darwin himself had much to do with it (and coincidentally Wallace had nothing to do with it). Darwin was a very professional scientist who from his Cambridge days had mixed with the elite and who was encouraged and helped by them, and whose respect he much desired.63 This was almost certainly the major reason why he did not publish as soon as he had become an evolutionist. It is also a major reason why as soon as he became an evolutionist he started recruiting supporters. Joseph Hooker almost from the first and then as the years went by and his own status as a scientist rose and the old guard started to drop off, Darwin looked to recruit people like Huxley and Lyell and, in America, Gray. This paid off because as soon as the Origin was published there was a Darwinian party eager to get out there and fight for the cause – Huxley against the Bishop of Oxford in England and Gray against Louis Agassiz in Boston [Figure 5]. Actually, subscribing to everything claimed in the Origin came second – Huxley was never that keen on selection, Gray was never that keen on non-directed variations – but the group and the cause were paramount. Students and followers were brought into the circle and cherished. When Henry Walter Bates came up with brilliant work on mimicry, Darwin praised the work and then more practically got Bates’ book published and on top of that, through his publisher (John Murray), Darwin got Bates a good job (which lasted a lifetime) as secretary to the Royal Geological Society.64 Conversely when people did not toe the line, they were ostracized and pushed out and away. This happened to Huxley’s student St George Mivart when the latter decided that as a good Catholic he could no longer go along with the Darwinian naturalistic program. He was not just rejected; he was accused of not being a gentleman.65 The same for Samuel Butler, the novelist and sometime enthusiast for and then (later) critic of Darwinism.66 62 See Diana Crane, Invisible colleges. Diffusion of knowledge in scientific communities (Chicago, 1972). The term goes back at least to the seventeenth century and was used of the informal group of scientists who later went on to found the Royal Society of London. 63 Michael Ruse, Charles Darwin (Oxford, 2008). 64 Michael Ruse (ed.), The Cambridge Encyclopedia of Darwin and Evolutionary Thought (Cambridge, 2013). 65 J.W. Gruber, A Conscience in Conflict: The Life of St. George Jackson Mivart (Philadelphia, 1960). 66 Michael Ruse, ‘The paradox of Samuel Butler: Insider or outsider?’, in O. Harman and M. Dietrich (eds.), Outsider Scientists: Routes to Innovation in Biology (Chicago, 2013), 75–89.

www.sciencedirect.com

Figure 5. Thomas Henry Huxley (1825–1895), biologist, controversialist, and strong supporter of Charles Darwin.

The second major thing claimed by Kuhn about paradigms is that they are the basis for new and ongoing work. A scientific ‘problem’ for Kuhn has no given answer. Like the mind-body problem, it may never be solved. At least, not unless you get a new paradigm in which case it may not be solved but also may now be judged unimportant. Within a paradigm, however, you have a whole new range of what Kuhn calls ‘puzzles’, meaning challenges that tax you but that you know can be solved. Science within a paradigm is like doing a crossword puzzle. If you cannot find the answer, you know that it is your weakness because an answer is there. Frankly, for many years the Origin flunked this test. It wasn’t much of a puzzle generator. With some notable exceptions, Bates on mimicry has been mentioned, no one found Darwin’s vera causa – natural selection – very useful as a tool of discovery. People like Huxley were morphologists and paleontologists and – in line with what has been said – the Darwinian Revolution was metaphysical but not that scientific. Indeed adaptation was often a nuisance, particularly if you were trying to work out relationships based on homologies. Darwin’s theory back then was not much of a puzzle generator so few thanks to Darwin were puzzle solvers. They are today. Evolutionists almost entirely use natural selection as their tool of inquiry, even those for whom

168

Endeavour Vol. 38 No. 3–4

development or like areas are primary.67 You want to study guppies, for example? You go to Trinidad with David Reznick and spend time in the streams catching and counting and marking and measuring. Or you stay home in his laboratory at UC Riverside and work on the specimens in his literally hundreds of tanks.68 You want to look at finches? Go to the Galapagos with Peter and Rosemary Grant, spend the summer in the field, and then return to Princeton and spend the winter doing molecular analyses.69 You want to know if radically new features can occur in the course of evolution? Explore the findings of Richard Lenski through his long-term experimental evolution study of E. coli. It is natural selection that is the guide to all of this work.70 Why do some guppies mature quickly and others less so? Because selection has worked on life histories to maximize success in the face of different kinds of predators. Why do some finches have large strong beaks and other fine delicate beaks? Because some finches live on hard seeds and plants and need cutting and breaking tools and other finches are insectivorous and need dainty instruments to catch their foodstuffs. Why do some lines of bacteria go one way and others go other ways? Because of the forces of selection. Historians are unanimous that the big shift came in the 1930s.71 It was then that Mendelian genetics, basically unknown before 1900, was generalized to populations by mathematically gifted thinkers – Ronald Fisher and J. B. S. Haldane in Britain and Sewall Wright in America – and melded with Darwinian selection into what was to be called (in America) the synthetic theory of evolution and (in Britain) neo-Darwinism. Rapidly, after the theoreticians had done their work, the empiricists moved in and as it were put flesh on the mathematical skeletons. Russian-born Theodosius Dobzhansky was the key figure in the USA and Oxford based E. B. ‘Henry’ Ford was the key figure in Britain.72 Now, but really not much before then, one had a functioning paradigm in a Kuhnian sense. I have spoken of Darwin making the move from pseudo-science to popular science. Finally,

Answers So, was there a Darwinian Revolution? Of course there was! People changed from thinking that organisms came probably miraculously and instantaneously to thinking that organisms are the end results of a long, slow, natural process of development from, as Darwin said, a few forms or one. Darwin forced people to accept this by his mastering of the evidence and his presenting it in a convincing form. Final causes in the old senses were kicked out of biology. Natural selection was on the scene and this is the mechanism that today is seen as the chief reason for organic change. Was there a Darwinian Revolution? I am afraid not. Darwin was not the first evolutionist. Little of the evidence he presented was new to him. What he did was part of the overall Scientific Revolution.73 He may have got rid of final-cause thinking in the sense of a designer, although this is problematic, and he may have got rid of final-cause thinking in terms of vital forces, but the method of thinking in final-cause terms remained and is with us today, a matter that not all approve of entirely.74 And natural selection as a tool of understanding was a flop. Was there a Darwinian Revolution? Well, maybe! It really depends on how you are looking at things, what kinds of questions you are asking, what kinds of answers you are seeking and prepared to accept. It simply wasn’t an all or nothing phenomenon. It was clearly tremendously important – given its huge implications for humankind, it is hard to think of anything more important – but ferreting out and understanding the various levels and dimensions is no easy matter. But I hope if nothing else this somewhat introductory and exploratory paper has shown that the task may be hard but it is worth taking on.

67 Michael Ruse, Darwinism and its Discontents (Cambridge, 2006); Michael Ruse and Joseph Travis (eds.), Evolution: The First Four Billion Years (Cambridge, Mass., 2009). 68 See D.N. Reznick, M.V. Butler IV, and H. Rodd, ‘Differential mortality as a mechanism for natural selection in the guppy (Poecilia reticulata)’, Evolution, 50 (1996), 1651–1660. 69 See Peter R. Grant, Ecology and Evolution of Darwin’s Finches (Princeton, N.J., 1986) and Peter R. Grant and Rosemary Grant. How and Why Species Multiply: The Radiation of Darwin’s Finches (Princeton, N.J., 2007). 70 See Z.D. Blount, C.Z. Borland, and R.E. Lenski, ‘Historical contingency and the evolution of a key innovation in an experimental population of Escherichia coli’, Proceedings of the National Academy of Sciences 105 (2008), 7899–7906. 71 William Provine, The Origins of Theoretical Population Genetics (Chicago, 1971). 72 Ruse, Cambridge Encyclopedia of Darwin and Evolutionary Thought.

73 Note what I am saying so I am not taken out of context. If you insist that it ought to be called ‘‘Scientific Revolution (Darwinian contribution)’’ I cannot entirely oppose you. But I would oppose any move to make this the reason to downplay what Darwin did and the great importance of what he did. 74 See Stephen Jay Gould, Richard C. Lewontin, ‘The spandrels of San Marco and the Panglossian paradigm: a critique of the adaptationist programme’, Proceedings of the Royal Society of London, Series B: Biological Sciences 205 (1979), 581–598.

www.sciencedirect.com

what I think had been Darwin’s hope all along, we had the move from popular science to professional science. A revolution had really taken place, although it was only a Darwinian Revolution in part and the Darwinian part only came into its own a half century after Darwin had died.