DARWIN AND PHILOSOPHY

Some scientific thinkers, while not themselves philosophers, make philosophers necessary. Charles Darwin is an obvious case. His conclusions about the history and diversity of life - including the evolutionary origin of humans - have seemed to bear on fundamental questions about being, knowledge, virtue and justice. Are we different in kind from other animals? Do our apparently unique capacities for language, reason and morality point to a divine spark within us, or to ancestral animal legacies still in evidence in our simian relatives? What forms of social life are we naturally disposed towards - competitive and selfish forms, or cooperative and altruistic ones? Once we adopt a Darwinian perspective, moreover, how should we respond to such venerable doctrines of theWestern tradition as Aristotle's essentialism, Descartes' dualism of body and mind and Kant's rejection of the very possibility of a natural science of the mind?

The Cambridge Companion to Darwin aims to facilitate understanding of such issues. It provides an introduction to Darwin’s thinking and to the various and often contentious uses made of his legacies today. To serve these ends, the volume departs somewhat from the precedents of earlier volumes in this series. The chapters come in four clusters, two broadly historical and two broadly philosophical. The first cluster concerns Darwin’s theorising. The second looks at his setting, and the reception and influence Darwin had in his own time. The third examines Darwinian themes in such branches of current philosophy as ethics, social philosophy, philosophy of mind and philosophy of biology.

THE CULTURAL CONDITIONING OF DARWIN’S THEORY

Machines, competition, empire and progress fascinated the Victorians. One of the most famous scientific theories of the era, Charles Darwin's theory of natural selection, tells of machine-like organisms that compete, colonise and improve. To notice resemblances such as these, between the context of Darwin's theory and its content, is nothing new. In 1862, Karl Marx, in a letter to his collaborator Friedrich Engels, wrote: 'It is remarkable how Darwin recognises among beasts and plants his English society with its division of labour, competition, opening up of new markets, “inventions”, and the Malthusian “struggle for existence”. It is Hobbes' “bellum omnium contra omnes” [“the war of all against all”].' In our own day, debates over the cultural conditioning of scientific knowledge have made this old insight newly problematic. This chapter attempts to clarify these new problems. Drawing on recent thinking about culture and science, it looks at how Darwin's social, material and intellectual culture conditioned the form and content of his theory of natural selection.

One view may be dispensed with at the start: that Darwin developed the theory of natural selection because he was a genius, and, since geniuses do not belong to mundane history like most people, it is pointless to ask about the cultural conditioning of his theory. There is general consensus among historians of science that talk of ‘genius’ does not so much explain scientific innovation as redescribe it.

POLAR PERSPECTIVES

Twentieth-century attempts to evaluate the philosophical significance of Darwinism have been dominated by a pair of polar perspectives. At one extreme stand those who insist on the autonomy of philosophy and who conclude, with the early Wittgenstein, that 'Darwin's theory has no more to do with philosophy than any other hypothesis in natural science.' At the other extreme are naturalists who maintain that 'now that we know' this or that other fact about the cosmos, the human brain, or (most pertinently for present purposes) the role of natural selection in hominid evolution, traditional philosophical problems are easily solved. Each opponent lives off the excesses of the other. Both also overlook the possibility that scientific ideas, including Darwin's, might play a useful, but partial, role in a variety of philosophical discussions. It has proved remarkably difficult to give Darwin his due.

Philosophers drawn to the Wittgensteinian pole typically assume that there are concepts and methods whose application to philosophical questions is unaffected by the deliverances of any science, even a science that might transform ideas about life and mind. Their discussions of questions in metaphysics, epistemology and ethics take over the idioms in which traditional philosophy has posed them, often without appreciating the fact that the language they employ was developed in response to a scientific picture that has long been superseded. Consider, for example, the group of philosophers most influenced by the younger Wittgenstein, the Vienna Circle.

SCIENTIFIC METHOD IN THE DEBATES OVER THE ORIGIN

Soon after the publication of the Origin of Species (1859), Darwin sent out over a hundred complimentary copies to a variety of contemporaries, including his former geology teacher, Adam Sedgwick. Darwin was prepared for attacks on the content of his theory. What he had not expected were attacks on his methods. Sedgwick, for example, writing in the Spectator in March 1860, complained that 'Darwin's theory is not inductive, - not based on a series of acknowledged facts pointing to a general conclusion, - not a proposition evolved out of the facts, logically, and of course including them. To use an old figure, I look on the theory as a vast pyramid resting on its apex, and that apex a mathematical point.'

In other words, for Sedgwick, the problem with the theory of natural selection was that Darwin had not supported it in the right way. The right way was to show that the theory was a generalisation from a wide range of particular facts. That was induction. The wrong way was to invent the theory as a hypothesis and then deduce from it particular facts. That was the method of hypothesis. In Sedgwick’s estimation, the theory of natural selection was not an inductive generalisation, but an invented hypothesis, and as such could claim no support from the facts. His image of the pyramid is telling. As he saw it, in induction, a wide base of particular facts supported a single theory up top, just as the base of a pyramid supports the rest of the structure. Darwin had produced an upside-down pyramid of a theory, inverting the relations that ought to obtain between theory and facts. The resulting structure was accordingly doubtful.

DARWINISM AND THE MANIFEST IMAGE OF HUMANKIND

A major task for philosophy is to adjudicate conflicts between our ordinary way of understanding persons and the world - what Wilfrid Sellars called the 'manifest image' - and scientific accounts of persons and the world - the 'scientific image'. Sometimes, of course, it is possible to blend the two images so as to produce a genuinely stereoscopic or synthetic picture. But this is not always possible. In the case of Darwin's theory of natural selection, we seem to have a scientific theory that cannot be comfortably assimilated into the extant manifest image by adding, in Sellars' phrase, a 'needle point of detail' to that image.

As traditionally understood, we humans are made in God’s image and sit beneath God and the angels and above the animals on the ‘Great Chain of Being’. There is a tripartite ontology of Pure Spirit(s) (God and angels), pure matter (rocks, plants and animals), and dualistic beings who, while on earth, partake of both the immaterial realm and the material realm (us). We humans know the material realm through our senses and reason, and the immaterial realm – theological and moral truths in particular – through illumination, grace or other non-empirical and nonrational or arational means. God sets out the moral law, and if we obey it, thereby using our free will properly, we will gain eternal salvation.

Nothing in this metaphysics, epistemology and ethics seems to square with the theory of natural selection. On this theory, no divine, intelligent designer is needed to explain the existence of humans or any other type of organic life. Moreover, as animals, descended from other animals, we humans possess no mysterious epistemic powers to detect what is true or what is good. The idea that morality has a divine origin and justification loses its force. The prospects for personal immortality seem nil. The manifest image of humankind thus takes a major hit at the hands of Darwin2019s theory, and it is not clear how to maintain sensibly the central components of that image.

As such, he was engaged neither in natural history nor in natural philosophy. Natural history, in the tradition of the Swedish botanist Linné (Linnaeus), concerned the systematic ordering of animals and plants and the discovery of new species. Natural philosophy, in the tradition of Descartes and Newton, concerned the search for general physical laws. Darwin was aligning himself with investigators whose work fell outside these traditions. Some were interested in a comparative anatomy based on ideal forms - the so-called 'transcendental' anatomists, such as the French zoologist Etienne Geoffroy Saint-Hilaire and his Scottish disciple Robert Knox. Others, such as the geologist Charles Lyell, were interested in building comprehensive theories about the earth and its inhabitants.

Philosophical naturalists spoke of various ‘laws of life’. They debated the existence of laws, for example, said to relate taxonomic groupings in regular circular arrangements, as in the so-called quinarian system, or to govern organic functions such as the development of the embryo. Another law under discussion was the law of the succession of types. In different areas around the world, it seemed, living species had replaced extinct species of the same kind or type. Living armadillos in South America, for instance, had apparently replaced the armadillo-like creatures fossilised in the rocks of that continent.

THE DARWINIAN CHALLENGE

During his Cambridge years, Darwin was preparing to become a priest in the Anglican Church. Later in life he saw the irony: 'Considering how fiercely I have been attacked by the orthodox it seems ludicrous that I once intended to be a clergyman'. Why he was attacked by the orthodox has never been difficult to explain. Offering a naturalistic account of the emergence of human beings from ape-like ancestors, Darwin offended religious sensibilities as well as common sentiment. His theory of evolution by natural selection reinforced doubts about biblical authority at a particularly sensitive time. It could easily be interpreted as an affront to human dignity and it called for a serious re-thinking - not necessarily a rejection - of traditional Christian doctrines.

Despite friction between competing Christian traditions, and despite political tensions in England between the established Anglican Church and socially disadvantaged dissenters, there were features of a Christian creed that transcended party lines. These were belief in an all-powerful, merciful God on whom the world depended for its creation and continued existence. Humankind had been made in God’s image and had been granted the privilege of free will. The privilege extended to dominion over, and responsibility for, the rest of creation. The Christian God was an active, living God, to whom prayers were directed and whose providence was not confined to an original creative act. Central to most Christian belief was the doctrine that human nature had been tainted through Adam’s disobedience and that in the life of Jesus Christ was a special revelation of the nature of God.

A CLASH OF PERSPECTIVES?o

Human beings are part of nature. We are primates, mammals, animals. Animals, in turn, are nothing but very complex biochemical systems. So humans are biochemical machines, though extraordinarily complex ones. That complexity ensures that it will rarely be practically possible to predict future human behaviour, or explain past human behaviour, through a fine-grained molecular understanding of human bodies. But, in principle, a detailed enough understanding of the physical and chemical processes internal to an agent would suffice to predict and explain all of that agent's behaviour. A full list of the complete physical, natural facts about an agent is all the facts there are. The natural story is the whole story. So, at least, the sciences of physiology, morphology, neuropsychology and the like suppose.

But humans are also conscious agents. We are aware of ourselves and our world. In Thomas Nagel’s famous phrase, there is ‘something that it is like’ to be a person. What is more, we are rational agents. We are not, of course, perfectly rational. We make errors of reason and judgement. Most of the time, however, our beliefs about our immediate environment are sound, and our actions are rational in the light of those beliefs and our goals. My belief that good coffee is available in the student union may be false, perhaps even unreasonable. But given that I have that belief, and that I aim to have an espresso, my taking myself off to the union is rational. My colleagues, knowing these facts about me, can use that knowledge to predict my future actions and to explain my past ones.

AMBIVALENCES AND INFLUENCES

How does Darwin's Darwinism relate to social Darwinism and eugenics? Like many foes of Darwinism, past and present, the American populist and creationist William Jennings Bryan thought a straight line ran from Darwin's theory ('a dogma of darkness and death') to beliefs that it is right for the strong to crowd out the weak, and that the only hope for human improvement lay in selective breeding. Darwin's defenders, on the other hand, have typically viewed social Darwinism and eugenics as perversions of his theory. Daniel Dennett speaks for many biologists and philosophers of science when he characterises social Darwinism as 'an odious misapplication of Darwinian thinking'. Few professional historians believe either that Darwin's theory leads directly to these doctrines or that they are entirely unrelated. But both the nature and significance of the link are disputed.

This chapter examines the views held by Darwin himself and by later Darwinians on the implications of his theory for social life, and it assesses the social impact made by these views. More specifically: section II discusses the debates about human evolution in the wake of Darwin’s Origin of Species (1859).3 Sections III and IV analyse Darwin’s ambiguous contribution to these debates. Sometimes celebrating competitive struggle, he also wished to moderate its effects, but thought restrictions on breeding impractical and immoral. Sections V and VI see how others interpreted both the science and social meaning of Darwinism. Darwin’s followers found in his ambiguities legitimation for whatever they favoured: laissez-faire capitalism, certainly, but also liberal reform, anarchism and socialism; colonial conquest, war and patriarchy, but also anti-imperialism, peace and feminism.

SIGNS OF THE TIMES

Darwinism has long been in the thick of science-religion debates, and never more so than today. Among the latest of a series of American states to legislate in a manner unfriendly to Darwinism is Oklahoma, insisting that science textbooks carry an explicit statement that 'human life was created by one God of the Universe'. Not all religious believers feel so threatened by evolutionary ideas, of course. Pope John Paul II - hardly a man to take doctrine lightly - has sent out a letter endorsing not just evolution per se, but modern theories of organic change. In the same spirit, Keith Ward, Regius Professor of Divinity at Oxford, speaks of natural selection as a 'simple and extremely fruitful theory', and goes on to say that there is 'every reason to think that a scientific evolutionary account and a religious belief in a guiding creative force are not just compatible, but mutually reinforcing'. Nevertheless, even liberal Christians often feel the need to supplement the theory of evolution through natural selection with other special mechanisms.

For their part, many of those on the science side of these debates think that Darwinism sounds the death knell for Christianity and other theistic systems. Writing with the passion of Savonarola, the well-known Darwinian Richard Dawkins (author of The Selfish Gene) regrets that a ‘cowardly flabbiness of the intellect afflicts otherwise rational people confronted with long-established religions’. As a Darwinian, he wants no compromise or mutual embrace. ‘Given a choice between honest to goodness fundamentalism on the one hand, and the obscurantist, disingenuous doublethink of the Roman Catholic Church on the other, I know which I prefer.’

HUMAN EVOLUTION THROUGH HUMBOLDTIAN EYES

From the beginning of his theorising about species, Darwin had human beings in view. In the initial pages of his first transmutation notebook (Notebook B), he observed that 'even mind & instinct become influenced' as the result of adaptation to new circumstances.Considering matters as a Lyellian geologist, he supposed that such adaptations would require many generations of young, pliable minds being exposed to a changing environment. After all, Captain FitzRoy had attempted to 'civilise' the Fuegian Jemmy Button by bringing him to London and instructing him in the Christian religion; but back in South America, Button reverted to his old habits, demonstrating, in Darwin's words, that the 'child of savage not civilized man' - transmutation of mind was not the work of a day. Darwin had nonetheless quickly become convinced that over long periods of time human mind, morals and emotions had progressively developed out of animal origins. As he bluntly expressed it in his first transmutation notebook: 'If all men were dead, monkeys make men. - Men make angels.' Presumably the transmutation of human beings into those higher creatures remained far in the future.

From July 1837, when he jotted these remarks in the first few pages of his Notebook B, to the early 1870s, with the publication of his Descent of Man and Expression of the Emotions in Man and Animals, Darwin gradually worked out theories of the evolution of human mentality that, in the main, we still accept. In the case of moral behaviour, he produced a theory of its evolution that stands as a most plausible empirical account, and displays the range and subtlety of his thought. These theories merit close examination in their own right.

GENTLEMANLY GENERATION

In the summer of 1838, Charles Darwin considered marriage. The disadvantages included losing the 'freedom to go where one liked', while staying single would mean avoiding 'the expense & anxiety of children'. But then, he reflected, 'only picture to yourself a nice soft wife on a sofa with good fire, & books & music perhaps'. Not to mention an 'object to be beloved and played with. better than a dog anyhow'. Wedlock won; within months he was engaged and then married to his cousin, Emma Wedgwood. The pairing brought anxieties, however, especially over whether marriage between such close relatives would issue in unhealthy children.

As a philosophical naturalist, Darwin had long been interested in reproduction or ‘generation’, to use the term of the day. Generational issues would eventually lead him to study subjects as diverse as barnacles, flowers, pigeons and domestic animal and plant breeding. His hypothesis of pangenesis, probably first formulated in 1841 but only published in 1868, was an attempt to give a unified account of all kinds of generation, from the healing of wounds in trees, to propagation by buds and grafting, to sexual pairings and fertilisation. Moreover, in Darwin’s view, since sexual pairings – whether decided by male combat or female choice – were selective, they enabled a selectional evolutionary process separate from, and sometimes in tension with, natural selection. His theory of sexual selection argued that something like a peacock’s tail, while lowering the peacock’s chances of survival, might give him a reproductive advantage as long as peahens choose the males with the finest tails.

Valéry's 'Variation sur Descartes' excellently evokes the vanishing act that has haunted philosophy ever since Darwin overturned the Cartesian tradition. If my body is composed of nothing but a team of a few trillion robotic cells, mindlessly interacting to produce all the large-scale patterns that tradition would attribute to the nonmechanical workings of my mind, there seems to be nothing left over to be me. Lurking in Darwin's shadow there is a bugbear: the incredible Disappearing Self. One of Darwin's earliest critics, Robert MacKenzie, saw what was coming and could scarcely contain his outrage:

This ‘strange inversion of reasoning’ promises – or threatens – to dissolve the Cartesian res cogitans as the wellspring of creativity, and then where will we be? Nowhere, it seems. It seems that if creativity gets ‘reduced’ to ‘mere mechanism’ we will be shown not to exist at all. Or, we will exist, but we won’t be thinkers, we won’t manifest genuine ‘Wisdom in all the achievements of creative skill’. The individual as Author of works and deeds will be demoted: a person, it seems, is a barely salient nexus, a mere slub in the fabric of causation.

FROM THE BEAGLE YEARS TO THE LAWS OF LIFE

In March 1837, five months after returning from the Beagle voyage, Darwin settled in London. He was to live in the capital for five years. They were by far his most productive years intellectually. During them, he formulated almost all the main theories later published in the 1850s, 1860s and 1870s: his theory of the origin of species - natural selection; his theory of generation or reproduction and heredity - pangenesis; his theory of the origin of the moral sense in man from ancestral animal social instincts; and his interpretation of the expression of the emotions in man and animals. Of his prominent intellectual productions only two - the theory of sexual selection and the principle of divergence of varieties and species - came later, and they were conceived as elaborations of the theory of natural selection.

In these five London years, two periods were quite exceptionally consequential: the spring and early summer of 1837, immediately after his move to London, and the summer and early autumn of the following year, 1838. At each of these times Darwin made vast escalating moves in his thinking and his theoretical ambitions. By mid- September 1838, indeed, his ambitions had reached a peak never later to be surpassed. One can therefore read the rest of his life as so many sequels to the brainwork of these months.

The work was mostly done in a series of small leatherbound notebooks. In or about July 1837, Darwin opened two notebooks. One, ‘A’ as he labelled it, was devoted to geology; the other, ‘B’, was headed ‘Zoonomia’ and devoted to the laws of life.