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Darwin and Philosophy

One must add the rashness of the prophet to the stubbornness of the partisan to venture a systematic exposition of the influence upon philosophy of the Darwinian method.¹
John Dewey

It is two hundred years since Charles Darwin's birth and one hundred and fifty years since the publication of his most famous book: On The Origin of Species by Means of Natural Selection. This is therefore a propitious year to acknowledge his achievement and to assess the extent of his impact on contemporary thought.

Darwin's influence upon the biological sciences has been enormous and is widely recognised as such. There are very few people today, certainly very few scientifically educated people, who would begrudge Darwin his status as one of the greats of the biological sciences, just as Isaac Newton is recognized as one of the greats of the physical sciences.²

Darwin's influence upon other areas of intellectual life - religious belief, for example - is rather more controversial; likewise his influence upon philosophy. Writing one hundred years ago John Dewey presented Darwin's work as a transformative moment not just for science but also for philosophy:

The conceptions that had reigned in the philosophy of nature and knowledge for two thousand years, the conceptions that had become familiar furniture of the mind, rested on the assumption of the superiority of the fixed and final ... the "Origin of Species" introduced a mode of thinking that in the end was bound to transform the logic of knowledge, and hence the treatment of morals, politics, and religion.³

By contrast, in the Tractatus, published in 1921, Ludwig Wittgenstein forcefully expressed the opposite view:

4.1122 Darwin's theory has no more to do with philosophy than any other hypothesis in natural science.

Wittgenstein, at this stage of his career, was not interested in the influence that scientific discoveries might have upon philosophy; on the contrary, he wanted to establish a clear separation between the work of the scientist and the work of the philosopher. The next paragraph of the Tractatus reads:

4.113 Philosophy sets limits to the much disputed sphere of natural science.⁴

According to Dewey, Darwin's work changes everything in philosophy, whereas according to Wittgenstein it changes nothing. Which of them was right? Or, were they both wrong?

I

Darwin's theory of natural selection, set out in The Origin of Species, was the result of three decades of reading, reflection and experimentation. While the theory made good sense of what he knew and had observed it was only much later, after his death, that the mechanism that lies at the heart of the theory became known. Darwin did not know how natural selection worked in practice. The term "gene", which describes the basic unit of heredity through which specific features are passed from one generation to the next, was not used until 1909, fifty years after The Origin of Species was published.⁵

Despite the lack of detail in his theory, Darwin provided an argument that explained both the diversity of living organisms and the connections between these organisms. Why do many plants and animals appear to resemble one another in certain respects without being exactly the same? What reason is there for variation between organisms, rather that close identity? Darwin offered an argument that explained the variety among living organisms, within an overall framework that emphasised the shared heritage of all living things.

Darwin's argument involved four steps.⁶  First he noted the wide variation between many types of living organism: between species of plant, fish, bird and mammal; and also between different family groups within the same species; and also between different exemplars within the same family. Wherever we look - and during his five year voyage on The Beagle in his early twenties, there were few places on earth where Darwin had not looked - we see differences between organisms: different sizes, different colours, different features, different behaviours and, of course, different survival rates. The theory of natural selection takes variation of species and within species as its starting point.

Second, Darwin noticed that within species the closest resemblances were between members of the same family. Which is another way of saying that in a world of great variety, variation is least in evidence when dealing with close biological relations. The rapid spread of photography⁷ in the mid nineteenth century allowed observant viewers to note the widespread existence of family resemblances between children, parents and grandchildren, and the lesser resemblances between cousins. Darwin's conversations with animal breeders - for farm livestock, but also for racing pigeons - established that family resemblance was not simply a human phenomenon.

Although he did not know how features were passed from one generation to the next, Darwin could see that they were; that we inherit more from our parents than their furniture.⁸  However much we are like our parents we are not identical to them. First, we have two parents, who are different, and we cannot be just like both of them. Second, even though there might be strong similarities between a father and a son, or a mother and a daughter, there might also be dissimilarities. Some children are more like their parents than others. Inheritance reduces the degree of variation within the species but it does not abolish it.

If the first puzzle for Darwin concerned variety and similarity, the second concerned survival and fitness. Darwin observed that throughout nature there is competition for the scarce resources necessary for survival: competition between species and competition between members of the same species.⁹   Most plants and animals produce a large number of offspring, not all of which survive long enough themselves to reproduce. If too few offspring survive, then the species faces the danger of extinction; if too many offspring survive they face significantly increased competition for food and shelter and those that are unable to secure resources are forced to migrate or face starvation.

There is a constant battle for each family within each species to find sufficient space and food to survive and reproduce in any given location. Darwin also observed than many plants and animals appear to be extremely well adapted to their habitats. They not only survive, they flourish. They do so because they are perfectly suited to the environment in which they live: they do well because they fit-in well. So while there is a struggle for survival throughout nature, there is also evidence that the winners of this struggle are those that are well adapted.¹⁰

Bringing together these four ideas - variation, inheritance, struggle and adaptation - Darwin proposed the theory of natural selection: that individual organisms have a range of features many of which are passed on directly to their offspring; that in the struggle for existence not all offspring survive long enough to reproduce; that the organisms that are best adapted to their habitats are the most likely to survive long enough to reproduce; that these survivors - the successfully adapted organisms - pass on to their offspring the set of features that enabled them to survive; and that over time these features become characteristic of this group of organisms.

As habitats change, so different features become important for survival and the organisms that possess these features have an increased chance of survival and reproduction. The previously dominant set of characteristics in a group of organisms is replaced by a new set, better suited to the new conditions. Adaptation is sustained by successful reproduction over generations, while variation is sustained by survival in different environments.

The theory of natural selection allowed Darwin to explain the wide variety of living organisms in the world and their successful adaptation to their different habitats. It suggested that as habitats changed - temperature and rainfall levels, the arrival of new predators, the decline of food sources etc. - so too species would change. Those features that promoted successful adaptation would be passed on by those organisms that survived and reproduced. However, the theory also allowed Darwin to look backwards, to use evidence from contemporary organisms to infer conclusions about their ancestors.

It was at this point that Darwin set out the claims that made his work so controversial.¹¹   If species change over time then it is possible that species that are similar to one another in some respects might also be related to each other. Although they are now separate species, they might not always have been so. It is not just that one species might change into another species; it is also that two species might share a common ancestor.¹²   If this is true, and if we go back far enough, we might find that all species share the same common ancestors.

Using the analogy of a tree of life, Darwin's theory suggests not just that humans are descended from apes but also that apes are merely our most recent ancestors. It suggests that humans, like all other primates, like all other mammals, like all other animals, are descended from the same primal organisms. The living world, according to Darwin, is one very large, very diverse and very old family in which all the members are related one to another, however distantly. The numerous species we see around us today are all distant descendants of the original species: humans are not the starting point in a great chain of being but simply one of its endpoints.

II

John Dewey claimed that Darwin's work had overturned two thousand years of received opinion in philosophy. Strange then, one hundred years later, that philosophy departments around the world still teach the ideas of Plato and Aristotle and not simply as part of a pedagogical exercise to demonstrate how easy it is to fall into error. Classical Greek philosophy appears to be better adapted to survival in the university habitat than Dewey imagined.

The classical Greek philosophers can be divided into those who saw change and flux as the central fact of the natural world and those, by contrast who saw permanence and stasis as the central fact. Heraclitus is associated with the first of these views and Parmenides with the second. For Heraclitus the universe is fundamentally in flux, and stability and permanence are deceptive appearances.¹³   For Parmenides the universe is constant and stable, and change is a deceptive appearance.¹⁴

Plato and Aristotle drew ideas from both of these traditions, but it turns out that they picked the wrong mix of elements. In Plato's cosmology¹⁵ the natural world was fashioned into order by a divine craftsman, from a previous, chaotic state. The different sorts of living being (gods, birds, animals and fish) were all created with the features and characteristics that are familiar to us now. Unlike the realm of ideas, which is eternal and unchanging, the natural world is subject to change. However, the form of the world and the species that inhabit it were set fast at the moment of creation.

In Aristotle's writings on biology - in which he classified more than 500 species of living organism - and in his writings on ethics and politics, he emphasized the important of the nature of each species. Each organism has a goal or purpose - a telos - that unfolds as the organism grows and develops. A good life is one in which the goal of the organism is achieved; "For what each thing is when fully developed, we call its nature, whether we are speaking of a man, a horse or a family."¹⁶   Success, for Aristotle, can be measured by comparing the achievement of a completed individual life against the goal that all examples of that type of organism should be able to achieve.

Thus Plato and Aristotle accommodated the ideas of change and permanence. For Plato the natural world experienced change but the world of ideas was permanent. The nature and number of species and organisms were fixed at the start of the creation of our natural world by design. Individuals might come and go, but species were permanent. For Aristotle, the changes experienced during an organism's life revealed the unfolding of its goal, but the nature of an organism determined what that goal would be and this did not change. Our natures were fixed because our membership of a species was fixed.

By contrast Darwin's theory of natural selection implies that the nature and number of species was not fixed at the inception of the natural world, but has changed significantly over time. One species has become many; the world we see today is radically different from how the world was in the distant past. In addition, the nature of any given species has changed and will continue to change, in response to changes to habitats. There is no fixed goal that defines what it is to be a member of a species; some changes are beneficial because they help us to adapt to our environment and some are not beneficial because they do not.

In Darwin's theory the natural world is in a permanent state of change. These changes - to the habitat, to individual organisms, and to species - are not always immediately perceptible to us because they might take place over many generations. Nevertheless, nature for Darwin is quite unlike nature as described by Plato and Aristotle: there are no fixed number of species and no fixed nature for any given species. The only permanent item in Darwin's theory is the process of adaptive change.

The importance of Darwin's view of nature can be made clearer by a consideration of Aristotle's account of what we do when we offer a scientific explanation. To explain a natural phenomenon Aristotle thought that we needed to describe four different causes of that phenomenon: the material cause, the efficient cause, the formal cause and the final cause. ¹⁷

In the case of a house, for example, the material cause would be the bricks from which it is built; the efficient cause would be the builder's labour in constructing the house; the formal cause would be the architect's plans which are used in the design; and the final cause would be the owner's desire for a place to live in comfort and safety, which led to the house being built. Together these four causes explain all we need to know about the house.

Now take the example of an animal species over time. For Aristotle the material cause would be the flesh, blood and bone from which the animal was made. Likewise for Darwin: there is no disagreement about the materiality of nature.¹⁸   With regard to the efficient cause, for Aristotle this would have something to do with the natural order of the world, in which each species occupies its allotted place and role within the overall pattern.¹⁹   By contrast, for Darwin this would have to do with the competition for scarce resources, between species and between organisms of the same species. Aristotle's image of natural harmony is replaced by Darwin's picture of the struggle for existence.

With regard to the formal cause - the plan or pattern by which a species develops - Aristotle proposed the telos that each organism has by nature. The unfolding of an organism's goal, its attempt to become a good exemplar of its nature, is the formal cause of its development over time. Darwin, by contrast, describes the way in which species change over time as variations prove to be more or less successful adaptations, and are passed on to succeeding generations through inheritance. He did not yet know the mechanism but he understood that species change by a process of adaptation to their habitat and not by some pre-ordained expression of an unchanging goal.

The most important difference between Darwin's theory and Aristotle's is found in their account of the final cause, that is the meaning or purpose behind natural processes. One hundred years or more before Plato and Aristotle came to prominence in Athens, a Greek philosopher from Sicily called Empedocles proposed an evolutionary theory to account for the origins of human life.²⁰   His theory was speculative and lacked much evidence, but was interesting nonetheless because he emphasized the role of chance and suggested that only the fittest or most successful organisms would survive and flourish.

Aristotle was dismissive of this theory: in the Physics he summarises Empedocles' idea that something might come to be spontaneously, without design or purpose, and then dismisses it. Instead Aristotle says that, "Nature belongs to the class of causes which act for the sake of something" and that "... action for an end is present in things which come to be and are by nature".²¹   In nature there are always final causes because there are always purposes; for Aristotle there can be no change without a goal.

In later editions of The Origin of Species, Darwin published "An Historical Sketch of the Progress of Opinion on The Origin of Species", which includes a footnote that cites the first part of this passage from Aristotle (i.e. his summary of Empedocles' theory). Darwin comments, "We see here the principle of natural selection shadowed forth".²²   It is not clear whether Darwin realised that Empedocles rather than Aristotle had foreshadowed his theory. Aristotle did not believe that nature could be governed by chance events, whereas Darwin (like Empedocles before him) did. In Darwin's theory the struggle for existence leading to successful adaptation provides all the explanation that is required: for Darwin there are no final causes in nature.

It is worth noting that Darwin's work does not replace or supersede the whole of the classical Greek tradition. Rather, Darwin's work revives Greek ideas that pre-date the theories of Plato and Aristotle, notably the work of Empedocles. In this respect, we see the repeat of a process that occurred in the seventeenth century, when progress in the physical sciences led to a revival of interest in classical Greek atomism.²³

The ideas of Democritus and Epicurus, had long been overshadowed by the writings of Plato and Aristotle. Yet from its inception, modern science drew increasingly upon the philosophical traditions of materialism and atomism and abandoned the Aristotelian approach to the study of the physical world. Two centuries later, Darwin's revolution in thinking about the organic world completed the earlier scientific revolution in thinking about the non-organic world.

III

John Dewey's claim about the significance of Darwin's work is at least in part true. Ideas that were central to the work of Plato and Aristotle turn out to be false. The concepts of the "fixed" (with regard to species and natures) and the "final" (with regard to causes and purposes) have been replaced by the Darwinian concept of adaptive change driven by chance.

What is less clear is how important these changes are for philosophy as a whole. Just because Plato and Aristotle were wrong about something does not make them wrong about everything; and the way in which they went about doing philosophy continues to be held in high regard even if some of their substantive conclusions are no longer accepted. Moreover, it is not clear that changes to our beliefs about the structure of the natural world and causality within the natural world will automatically lead to changes in our beliefs about morals, politics and religion.

Yet, ever since Darwin's work was published, thinkers from disciplines outside of the biological sciences have tried to apply Darwinian-type explanations to other fields of study: sociology, politics, ethics, jurisprudence, aesthetics and economics to name the most obvious.²⁴   In many cases, philosophers have argued by analogy: that is, they have used the model that Darwin described for the process of natural selection - variation, inheritance, survival, adaptation - to describe processes of selection that are non-biological. While metaphors often work well in poetry²⁵ in philosophical argument the use of analogies can be as much a source of obfuscation as of enlightenment.

Any explanation of a social phenomenon that depends upon an analogy from the theory of natural selection faces three sorts of difficulty, each of which need to be addressed. First, what is the mechanism by which a given feature is passed from one member of the species to another, thereby improving the survival chances of the recipient? Darwin did not know what this mechanism was for natural selection, although he knew it was something to do with the way parents passed on their features to their children through sexual reproduction.

We now understand the mechanism by which natural selection works: the passing of inherited features to our offspring through our genes; and the introduction of new features through the process of genetic mutations, some of which prove to be adaptive and are therefore selected for over successive reproduction cycles. However, we are still not entirely sure which features are controlled by our genes and which are not. Hair and eye colour are, for sure, transmitted down the generations genetically. But we do not know if the same is true for intelligence, or madness, or character; in some cases it might be, in others it might not.

Once we move away from individual characteristics to wider social phenomenon - religious beliefs, moral codes, economic systems and artistic traditions - it becomes even more difficult to identify the mechanism by which features are passed from one individual to another. This is in part because these features do not seem very similar to the physical characteristics that are controlled by our genes; and in part because the process of inheritance is far more complex than that between parents and children.

To take one example, most human societies have made use of slaves at some point in their history. For some this was essential to their economic system, for others it was simply a by-product of victory in battle, and for others it was connected to their religious system. Nowadays no human societies officially recognize slavery, although it persists in some parts of the world because it proves profitable for criminal gangs. So the question is, why was lawful slavery abolished? Was this a successful adaptation by human societies? Did all societies give up the use of slaves for the same reasons? And what was the mechanism by which the preference for abolition of slavery over the preference for its retention was passed from one individual or one society to another?

A second difficulty with arguments based upon analogies from natural selection is that we do not know which of the current features of society are successful adaptations and which are not. When we compare the natural world and the social world, it is much easier to explain what counts as success in the former than in the latter.²⁶   For example, success for an individual in the natural world involves sufficient food, secure shelter, avoidance of illness and accident, the ability to reproduce successfully and, as a consequence of all of these, a long and fruitful life. But when we consider the economic life of a society, it is not at all clear what counts as success. The absolute amount of wealth created? Or, the level of surplus wealth after taking account of the costs of production? Or, the way in which the wealth is distributed? Or, the amount of happiness that the wealth produces?

If we are not able to give a clear sense of what a successful economy would look like, how can we argue that one economy is more successfully adapted than another? What looks successful to us might tell us more about our own prejudices than it does about the phenomenon we are considering. In the absence of clear set of criteria that establish what success is, it is simply not possible to judge which of two examples is the most successful.

Not only do we not know the mechanism by which adaptive selection might apply to social phenomenon, and not only do we not agree on what adaptive success might look like, we also, thirdly, do not know the ways in which the human habitat might change in the future. Darwin's theory of natural selection does not suggest a unilineal model of progress. He does not argue that species just keep getting better and better; rather that they become better adapted to their current environment. When the environment changes, especially when it changes radically, then new species with different adaptations become more successful.

Our judgements about the success or otherwise of social phenomenon tend to presuppose that the human habitat will remain constant. While a society might appear to be well adapted to its current environment, it might be very poorly adapted to a changed environment. Yet our concept of success - whether in economics, art, religion or some other social phenomena - tends to presume progress within a stable environment. To put this point another way, successful adaptation is not the same as social progress: successful adaptation means doing well in the current circumstances, whereas social progress means doing better in similar circumstances.

If we want to offer meaningful explanations for social phenomena using analogies from natural selection we will need to proceed with caution. It is worth noting that Darwin's model of causal explanation dealt with the organic not the non-organic world. Since social phenomena are part of the organic world, Darwinian analogies might seem to be the most appropriate. But many thinkers have also used analogies from the non-organic world to try to explain social phenomena. The idea of the physical universe in a state of equilibrium, with each force balanced by an equal an opposite force, has been influential in much thinking about politics and economics, for example.

For those who are disposed to be sympathetic to Parmenides' claim that the universe is a stable, unchanging system, and that all movement and motion, all change and progress are illusory, analogies drawn from modern physics are likely to be appealing. By contrast, those who prefer Heraclitus' vision of a universe in constant flux, where nothing remains the same and everything is subject to rearrangement, analogies drawn from modern biology are likely to be preferred. In either case, the application of these systems of explanation to social phenomena is problematic: these analogies might explain much less than we hoped for. ²⁷

IV

To illustrate the possibilities and problems of applying Darwin's theory to social phenomena, consider two cases: Joseph Schumpeter on economics and Friedrich Nietzsche on ethics. Schumpeter used a Darwinian analogy to explain the dynamic process of economic development.²⁸   Writing in 1947, he distinguished between two types of response to "changes in conditions": one is merely a passive response the other an active response. The former he calls "adaptive" and the latter "creative". Although the word "adaptive" might suggest a Darwinian-type explanation, in fact Schumpeter uses this term to describe a reflex response that would be analogous to a reaction in a physical system that was in equilibrium. It is the "creative" response that is the true analogy with Darwin.

Schumpeter illustrates this distinction in the following way:

Whenever an economy or a sector of an economy adapts itself to a change in its data in the way that traditional theory describes, whenever, that is, an economy reacts to an increase in population by simply adding the new brains and hands to the working force in the existing employments, or an industry reacts to a protective duty by expansion within its existing practice, we may speak of the development as an adaptive response. And whenever the economy or an industry or some firms in an industry do something else, something that is outside the range of existing practice, we may speak of creative response ²⁹

Schumpeter defines a successful human response as one that adapts to changed economic circumstances, in ways that are creative and inventive. Schumpeter associated this response with his ideas of innovation and entrepreneurship, which he argued were the driving force for progress in a capitalist economy. ³⁰

Although the creative response is learned not inherited, it is described in Darwinian terms: it is an adaptation to new circumstances that allows the individual or firm to be more successful in their struggle for existence. How is the creative response passed from one individual to another? Not, for sure, by genetic inheritance. The success of capitalism depends on the ability of the owners of wealth to hire talented outsiders to manage their businesses for them. Successful adaptation is achieved by hiring individuals with the features that support creative response, not by the transmission of these features from parent to child.

While Schumpeter made use of a Darwinian-type explanation to explain the role of innovation in economic progress, he was sceptical about the uncritical application of Darwinian ideas. Discussing the ideas of Hebert Spencer, he wrote:

What is worth our while to note is the argument that any policy aiming at social betterment stands condemned on the ground that it interferes with natural selection and therefore with the progress of humanity. The reader should observe, however, that the almost pathetic nonsense could have been avoided and that the sound element in his argument could have been partly salvaged by adding, "unless methods more humane and more scientific than natural selection can be found in order to achieve what survival of the fittest is supposed to achieve".³¹

In other words, while Schumpeter was willing to explain certain economic phenomena by use of a Darwinian analogy, he did not support the idea of basing political decisions on supposed Darwinian principles. Explaining social phenomena and justifying social phenomena are different activities; what is appropriate for one might not be appropriate for the other.

Friedrich Nietzsche was very critical of the importation of Darwinian ideas into ethics, although he too made use of Darwinian language in his own theories. He suggested that within each individual there was a struggle between different parts, some of which prevail over others. One part of our nature conquers another part, which then withers away. According to Nietzsche, this struggle has nothing to do with our external environment and everything to do with inner drives:

Darwin absurdly overestimates the influence of 'external circumstances'; the essential thing about the life process is precisely the tremendous force which shapes, creates from within, which utilises and exploits 'external circumstances'.³²

Nietzsche, like Darwin, sees humans as the product of "struggle", although his focus in on the internal, not the external causes.

According to Nietzsche, human societies do not represent the successful adaptation of higher values and qualities: quite the contrary. Human societies are dominated by the weak, by the average and below-average, and the by values of the herd:

If one wants to formulate reality as morality, then this morality runs as follows: the average are worth more than the exceptions, the products of decadence more than the average, the will to nothingness has the upper hand over the will to life.³³

In other words, if we simply treat established ethical values as if they were evolutionarily successful values, then ethics becomes nothing more than a stamp of approval for the status quo.

This idea is central to Nietzsche's work On the Genealogy of Morality, in which he argues, that:

the origin of the emergence of a thing and its ultimate usefulness, its practical application and incorporation into a system of ends, are toto caelo separate.³⁴

If we are interested in the usefulness of some human activity - Nietzsche's example in this section of the book is the idea of punishment - we cannot simply assume that it emerged to fulfil the function that it now performs. Genealogy and utility are quite different.

Central to Nietzsche's critique of ethical Darwinism is his insistence that the idea of "adaptation" is insufficient properly to explain the nature of human motivation and morality. He rejects the idea, which he attributes to Herbert Spencer, that human life is merely an "increasingly efficient inner adaptation to external circumstances". This, he says,

... is to misunderstand the essence of life, its will to power, we overlook the prime importance that the spontaneous, aggressive, expansive, re-interpreting, re-directing and formative forces have, which "adaptation" follows only when they have had their effect ...³⁵

For Nietzsche, adaptation is a secondary factor in explaining human activity; much more important is human creativity.

It is possible to accept the force of Nietzsche's criticism of ethical Darwinism, while subscribing neither to his particular version of heroic virtue-ethics, nor his views about the herd morality of his contemporaries. Regardless of what he would put in their place, his attack on the simplistic translation of biological explanation into ethical explanation contains real force. We just do not know whether the dominant moral beliefs of our society are successfully adaptive or, to the contrary, whether they are evidence of intellectual weaknesses that hold us back from success.³⁶

V

To return to our starting point: who was right, Dewey or Wittgenstein? Or were they both wrong? It seems clear that Wittgenstein is wrong; to claim that Darwin's theory has no relevance for philosophy is to insist on a narrow and insular conception of philosophy, one which almost all philosophers past and present would not recognize. Whereas Dewey appears to be right in part: if Aristotle's approach to science was undermined by the emergence of modern science in the seventeenth century, it was wholly destroyed by the emergence of Darwin's theory in the nineteenth century. Scientific explanations of nature - whether organic or non-organic - no longer make use of final cause: Aristotle's theory is overturned and a revolution in philosophy has been achieved.

However, it is not yet clear that Dewey's second claim - that this would lead to the transformation of our thinking about morals, politics and religion - is true. Despite the widespread influence of Darwin upon other areas of thought, attempts to explain and justify particular forms of economic organization, or ethical practice, have proved much harder than Dewey anticipated. In the absence of evidence for the precise mechanism by which adaptive selections are passed on within a species, from one organism to another, analogies based on Darwin's theory of natural selection appear to be suggestive rather than conclusive.

This is not to say that Dewey will not turn out to be right in the long run. In 2109, when the three hundredth anniversary of Darwin's birth will be celebrated, and a full two hundred years after Dewey's prediction, there may be sufficient evidence to decide the case. By then we might have discovered how ethical values and beliefs are passed on within the community and why some promote the survival and flourishing of the community more than others. We might also understand better how modern economies work and how innovation and entrepreneurship act to promote successful adaptation, leading to improvements in the quantity and quality of the wealth of the community.

Until then, perhaps we should limit ourselves to the following judgement: that Darwin's theory continues to be hugely influential in our thinking about human life, in all of its biological and social aspects, but that our enthusiasm for the explanatory power of the theory of natural selection should not blind us to the importance of understanding properly the mechanisms by which it works. Darwin himself was famous for his caution, his propensity for understatement, and his determination to account for all of the evidence even when it appeared not to support his theory.³⁷   These are admirable qualities and we would do well to adopt them.

Endnotes

¹ John Dewey, "The Influence of Darwinism on Philosophy", lecture at Columbia University, 1909. Reprinted in John Dewey, The Influence of Darwin on Philosophy and other essays, Prometheus Books, New York, 1997. The quotation is taken from page 9.

² Although not everyone believes that it is appropriate to speak of "greats" in scientific research. For example R C Lewontin, a leading evolutionary biologist, writes: "... a remarkable amount of the history of science has been written through the medium of biographies of "great" scientists to whose brilliant discoveries we owe our understanding of the material world, and this historical methodology has reinforced the common notion that history is made by outstanding individuals. No respectable historian would claim that if Newton had never been born we would still be ignorant about gravitation. Yet we still refer to the regularities of the behaviour of physical bodies as "Newton's Laws," the general regularities of simple inheritance as "Mendelism," and the science of biological evolution as "Darwinism." Even the famous history of science written by the Marxist J.D. Bernal is a recounting of the discoveries and inventions of individuals." From "Why Darwin?" in The New York Review of Books, 56:9, 29 May 2009.

³ John Dewey, "The Influence of Darwinism on Philosophy". The quotation is taken from pages 1-2.

⁴ Ludwig Wittgenstein, Tractatus Logico Philosophicus, trans. D F Pears & B F McGuinness, Routledge Kegan Paul, London, 1961. First published as Logisch-Philosophische Abhandlung in the German periodical Annalen der Natur-philosophie in 1921.

⁵ By Wilhelm Johannsen, the Danish botanist.

⁶ My account follows what I take to be the logical structure of Darwin's argument, rather than the sequence of chapters in The Origin of Species, which provides its rhetorical structure.

⁷ The daguerreotype method of photography was developed in 1839 and there is a least one extant example from that year from America. Sir John Herschel coined the term "photography" (from the Greek, meaning to draw with light) also in 1839. Darwin had visited Herschel in June 1836 at Cape Town, near the end of his five-year voyage on The Beagle. He later wrote of Herschel, "He never talked much, but every word he uttered was worth listening to". From page 62, Charles Darwin, Autobiographies, M Neve & S Messenger {eds.}, Penguin Classics, London, 2002.

⁸ Robert Lowell, "My children, my blood, accept graciously the loot of your inheritance. We are all dealers in used furniture." From "91 Revere Street", in Life Studies, Faber & Faber, London, 1959.

⁹ Darwin acknowledged his debt to Thomas Malthus in the development of this idea: "In October 1838, that is, fifteen months after I had begun my systematic enquiry, I happened to read for amusement 'Malthus on Population' and being well prepared to appreciate the struggle for existence which everywhere goes on from long-continued observation of the habits of animals and plants, it at once struck me that under these circumstances favourable variations would tend to be preserved and unfavourable ones to be destroyed. The result of this would be the formation of new species." From page 72, Charles Darwin, Autobiographies, M Neve & S Messenger {eds.}, Penguin Classics, London, 2002.

¹⁰ In the 1869 edition of The Origin of Species Darwin adopted the phrase "survival of the fittest" from Herbert Spencer's Principles of Biology (1865). Darwin wrote: "I have called this principle, by which each slight variation, if useful, is preserved, by the term Natural Selection, in order to mark its relation to man's power of selection. But the expression often used by Mr Herbert Spencer of the Survival of the Fittest is more accurate, and is sometimes equally convenient", The Origin of Species, Chapter III "The Struggle for Existence". It is worth noting that the word "fittest" means well adapted to the conditions or circumstances, rather than the contemporary colloquial use of the word to mean to be in good physical condition. Survival of the fittest does not mean the survival of the fastest of the strongest; it means the survival of those best adapted to their environment.

¹¹ Darwin described his twin aims in writing The Origin of Species thus: "I had two disticnt objects in view: firstly, to show that species had not been separately created, and secondly, that natural selection had been the chief agent of change, though largely aided by the inherited effects of habit, and slightly by the direct action of the surrounding conditions.... Some of those who admit the principle of evolution, but reject natural selection, seem to forget, when criticizing my book, that I had the above two objects in view; hence if I have erred in giving to natural selection great power, which I am very far from admitting, or in having exaggerated its power, which is in itself probable, I have at least, as I hope, done good service in aiding to overthrow the dogma of separate creations." Quotation taken from page 61 of the second edition (1874) of Darwin's The Descent of Man, reprinted by Gibson Square Books, London, 2003.

¹² C Kenneth Waters writes, "The claim of common descent distinguishes Darwin's theory of evolution from those of his precursors. Although Darwin didn't insist that all species are related through a single common ancestor, he held that all animals descended from at most four or five ancestral species and all plants from at most four. This idea is logically distinct from transmutation, because individual species might dramatically change over time without ever splitting. Each species might have its own, first ancestor from which it evolved. This is what Lamarck believed." From page 123, "The Arguments in The Origin of Species" in J Hodge and G Radick {eds.}, The Cambridge Companion to Darwin, Cambridge, 2009.

¹³ Heraclitus: "Upon those that step into the same rivers different and different waters flow... They scatter and... gather... come together and flow away... approach and depart." Plato paraphrases this aphorism in the Cratylus: "Heraclitus somewhere says that all things are in process and nothing stays still, and likening existing things to the stream of a river he says that you would not step into the same river twice". Aristotle's comment in Physics: "And some say not that some existing things are moving, and not others, but that all things are in motion all the time, but that this escapes our perception". From page 195, GS Kirk, JE Raven and M Schofield {eds.}, The Presocratic Philosophers, Cambridge University Press, 1983.

¹⁴ Parmenides on reality: "Nor is it divided, since it all exists alike; nor is it more here and less there; which would prevent it from holding together, but it is all full of being. So it is all continuous: for what is draws near to what is." And again: "But changeless within the limits of great bonds it exists without beginning or ceasing, since coming to be and perishing have wandered very far away, and true conviction has thrust them off. Remaining the same and in the same place it lies on its own and thus fixed it will remain. For strong Necessity holds it within the bonds of a limit, and keeps it on every side." From page 250-251, GS Kirk, JE Raven and M Schofield {eds.}, The Presocratic Philosophers, Cambridge University Press, 1983.

¹⁵ This is set out most clearly in his dialogue Timaeus.

¹⁶ Aristotle, Politics, Book 1, Chapter 2, 1252b.

¹⁷ Aristotle, Metaphysics, Book A, Chapter 3, 983a.

¹⁸ Plato would have said that any given animal or species of animal was merely a physical exemplar of the ideal form of that animal. The ideal form is perfect, immaterial and accessible not to the senses but to reason. Neither Aristotle nor Darwin would have accepted this proposal.

¹⁹ Aristotle: "[Nature] makes each thing for a single use, and every instrument is best made when intended for one and not many uses". From Politics, Book 1, Chapter 2, 1252b.

²⁰ Excepts from Empedocles' account of evolution are given on pages 302-305 of GS Kirk, JE Raven and M Schofield {eds.}, The Presocratic Philosophers, Cambridge University Press, 1983.

²¹ Aristotle, Physics, Book II, Chapter 8, 198b and 199a.

²² Charles Darwin, "An Historical Sketch." From page 53 of The Origin of Species, J Burrow {ed.}, Penguin Classics, London, 1985.

²³ The influence of Epicurean philosophy on seventeenth century scientists and philosophers is described at length in, Catherine Wilson, Epicureanism and the Origins of Modernity, Oxford University Press, 2008. According to Wilson: "The success of Epicureanism can be measured by the extent to which the universities abandoned, as they did to a remarkable extent, their role as centres for the study of incorporeal entities and eschatological and miraculous states of affairs. They became instead institutions devoted to the close and careful examination and remodelling of the material and social worlds and devoted as well to the cultivation of intellectual and sensory pleasures and the remediation of pain and deprivation", page 38.

²⁴ Early advocates of the application of evolutionary ideas from the biological to the social sciences included Herbert Spencer (Darwin's contemporary) and Francis Galton (Darwin's cousin). Karl Marx wrote that "Darwin's book is very important and serves me as a basis in natural science for the class struggle in history", a view he later modified because of his dislike of the influence of Malthus on Darwin's work. Quotation from a letter from Karl Marx to Ferdinand Lassalle, dated 16 January 1861.

²⁵ Not all literary uses of metaphor are successful. Susan Sontag argues that they can be, literally, unhealthy: "My subject is not physical illness itself but the uses of illness as a figure or metaphor. My point is that illness is not a metaphor, and that the most truthful way of regarding illness - and the healthiest way of being ill - is one most purified of, most resistant to, metaphoric thinking." The quotation is from page 7 of Illness as Metaphor Penguin Books, London 1983.

²⁶ However, it is important to note that even in the natural world simply identifying features that allow an individual to live a successful life is not the same as explaining how or why these features might have come to be selected for in the past. As Stephen Jay Gould writes, "... current utility permits no necessary conclusion about historical origin. Structures now indispensable for survival may have arisen for other reasons and been "coopted" by functional shift for their new role." He continues: "No one doubts, for example, that the human brain became large for a set of complex reasons related to selection. But, having reached its unprecedented bulk, it could, as a computer of some sophistication, perform in an unimagined range of ways bearing no relation to the selective reasons for initial enlargement.... Selection may be the ultimate source of evolutionary change, but most actual events may owe more of their shape to its nonadaptive sequelae." S J Gould, "Darwinism and the Expansion of Evolutionary Theory", Science, 216, April 1982. The quotations are taken from pages 383 and 384.

²⁷ Not least because the explanatory model from biological science, on which the analogies are based, is far more complex that is often supposed. To quote Stephen Jay Gould once more: "If many features that operate as adaptations under present regimes of natural selection were exapted from ancestral features with nonadaptive origins - and were not built as direct adaptations for their current use (or exapted from ancestral features with adaptive origins for different functions) - then we cannot explain all pathways of evolutionary change under functionalist mechanics of the theory of natural selection. Instead, we must allow that many important (and currently adaptive) traits originated for nonadaptive reasons that cannot be attributed to the direct action of natural selection at all and, moreover, cannot be inferred from the exaptive utility of the trait in living species." Quotation taken from pages 1247-1248 of S J Gould, The Structure of Evolutionary Theory Harvard University Press, 2002. Gould illustrates this point with his famous discussion of the spandrels of San Marco, on pages 1249-1270.

²⁸ Schumpeter was not the first economist to employ the language of evolutionary biology in the description of economic processes and activities. According to Thorstein Veblen, economics underwent a transformation from a discipline principally concerned with taxonomy to one principally concerned with causal explanation, that is, economics was transformed into an evolutionary science, as recently as the start of the twentieth century. Thorstein Veblen, "Why is Economics not an Evolutionary Science?", The Quarterly Journal of Economics XII, 1898.

²⁹ Joseph Schumpeter, "The Creative Response in Economic History" reprinted in Joseph Schumpeter, Essays on Entrepreneurs, Innovations, Business Cycles and the Evolution of Capitalism, R V Clemence {ed.}, Transaction Publishers, New Brunswick, New Jersey, 1989. The quotation is from page 222.

³⁰ For a recent and wide ranging survey of evolutionary economics, see Eric Beinhocker, The Origin of Wealth: Evolution, Complexity and the Radical Remaking of Economics, Harvard Business School Press, 2006: "... evolution is a general-purpose and highly powerful recipe for finding innovative solutions to complex problems. It is a learning algorithm that adapts to changing environments and accumulates knowledge over time. It is a formula responsible for all the order, complexity and diversity of the natural world. And ... it is the same formula that lies behind all the order, complexity, diversity and ultimately, wealth in the economic world." The quotation is from page 187.

³¹ Joseph Schumpeter, History of Economic Analysis, Routledge, London, 1997. The quotation is taken from footnote 5 on pages 773-4.

³² Friedrich Nietzsche, Writings from the Late Notebooks, R Bittner {ed.}, Cambridge University Press, 2003. The quotation is taken from section 7[25] on page 135.

³³ Friedrich Nietzsche, Writings from the Late Notebooks, R Bittner {ed.}, Cambridge University Press, 2003. The quotation is taken from section 14[123] on page 259.

³⁴ Friedrich Nietzsche, On the Genealogy of Morality, K Ansell-Pearson {ed.}, Cambridge University Press, 2007. The quotation is from chapter 12 of the second essay, on page 51.

³⁵ Friedrich Nietzsche, On the Genealogy of Morality, K Ansell-Pearson {ed.}, Cambridge University Press, 2007. The quotation is from page 52.

³⁶ John Dewey made this point in his essay "Intelligence and Morals", first delivered as a lecture at Columbia University in March 1908: "Aristotle ... yielded to the besetting sin of all philosophers, the idealization of the existent: he declared that the class distinctions of superiority and inferiority as between man and woman, master and slave, liberal-minded and base mechanic, exist in and are justified by nature - a nature which aims at embodied reason." And again, speaking of Europe between the fifth and fifteenth centuries: "But when intelligence fixed fluctuating circumstances into final ideals, petrifaction is likely to occur; and philosophy gratuitously took upon itself the responsibility for justifying the worst defects of barbarian Europe by showing their necessary connection with divine reason." Quotations from pages 50 and 52 of John Dewey, The Influence of Darwin on Philosophy and other essays, Prometheus Books, New York, 1997.

³⁷ Describing the public reception of The Origin of Species, Darwin wrote: "I had, also, during many years, followed a golden rule, namely, that whenever a published fact, a new observation or thought came across me, which was opposed to my general results, to make a memorandum of it without fail and at once; for I had found by experience that such facts and thoughts were far more apt to escape from the memory than favourable ones. Owing to this habit, very few objections were raised against my views which I had not at least noticed and attempted to answer." From page 75, Charles Darwin, Autobiographies, M Neve & S Messenger {eds.}, Penguin Classics, London, 2002.

© Mark Hannam © 2009