Darwin, Evolution, and Philosophy

Ted Everett

(presented March 4, 2008)

 

            I am very glad to be speaking at this 150th year celebration of Charles Darwin's The Origin of Species.  I am sorry that Darwin couldn't be here himself tonight, having long since gone to meet his maker – which is to say, if Darwin is to be believed, nobody.   As you probably know, the main elements of Darwin's theory were first drafted not 150 years ago but back in 1842, some 17 years before The Origin of Species came out, but Darwin kept the theory in his bottom drawer until he was forced by looming competition to produce a final draft for publication.  He had delayed this project – the central project of his life – for so long, in part because he was a very anxious sort of person and he wanted get things right as a biologist, but also because he could foresee much of the turmoil that was going to result from his theory’s publication in the larger world, the world beyond biology.  I would like to talk about some of the ongoing intellectual repercussions of Darwin's theory upon academic philosophy, and also with respect to intellectual trends more generally.  These have not always been very pleasant, and I want to point out what I think are some dangers ahead.

 

Philosophy of science.

            Darwin's influence on professional philosophy has been profound, and, especially within the past twenty or thirty years, extensive.  Evolutionary theory has of course had much effect on the philosophy of science, philosophy of religion, and social philosophy, and it has recently been gaining influence also within the core areas of epistemology and the philosophy of mind.  In the philosophy of science, evolutionary theory has had three main consequences.  The first is a move away from physics and chemistry as the central paradigms of scientific theory.  Evolutionary biology is really very different in structure, in its use of trial-and-error forms of explanation, and in its historicity.  Much has been written, for example, about the evident irreducibility of biological notions – life, organism, species, fitness, and so on – to lower-level chemical or physical properties.  Instead of scientific theories ultimately stacking together semantically, so that biological facts could be expressed as statements within chemistry or physics, which is what people used to think, most philosophers now take it that distinctly biological phenomena at best emerge from or supervene over phenomena at the molecular and lower levels.  Not that we have any settled idea what these terms actually mean – but there is plenty of new literature that explores these vague ideas.

            Secondly, consideration of the often imprecise and speculative nature of evolutionary biology has affected philosophers' ideas about the difference between science and non-science.  This is the so-called demarcation problem: how do you tell of any given methodology or theory whether or not it is a scientific one?   Though evolutionary biology is obviously powerful, successful science, this is not primarily because it makes predictions that are experimentally confirmable (or, alternatively, falsifiable) in the precise ways that many philosophers used to expect.  It is rather that the theory as a whole seems to explain and tie together disparate phenomena in a systematic and somehow intellectually satisfying way.  This supports a general trend, especially since Thomas Kuhn's The Structure of Scientific Revolutions, toward both holism and eclecticism in the philosophy of science, leaving the demarcation issue more and more problematic.

            The third big effect is that there is now a flourishing sub-field in professional philosophy called the philosophy of biology.  Much discussion in this area is about the controversy over creationism and intelligent design, but there is a lot else besides, including work on the analysis of problematic concepts like fitness and species, arguments about adaptationism, and philosophical debate about altruism and the units of selection.  Elliot Sober, for example, one of the most prominent people in this sub-field, has done a lot of work on the logic of group-selectionism as a factor in the evolution of altruistic behavior, along with the biologist David Sloan Wilson.  (For a good general look at the philosophy of biology, see Sober's text The Philosophy of Biology.)  I should note that philosophers of biology do not, in general, try to do biology, except to the extent that biologists are already doing philosophy.  There is a lot of conceptual confusion within any field, and philosophers sometimes jump in to help straighten out problems that are ultimately not empirical but logical ones.  The biologist Richard Dawkins, for example, has this concept of the "selfish gene", and one or two philosophers have launched embarrassing, point-missing attacks on what they take to be the implications of this concept.  But it is actually very hard to make exact sense of Dawkins's theory, even if one is quite sympathetic to his intuitions.  So, when he talks about genes for altruism that survive the deaths of their "vehicles" by making copies of themselves, it is clear enough what sort of picture of events he is trying to paint.  It is a good-enough statement that he makes to get his main idea across.  But what, precisely, can it mean to say that something survives when only copies of it stay alive?  For it is not the gene in the sense of a physical chunk of DNA that survives in natural selection, but rather the type of gene, or the information that the gene encodes, or something like that.  And if we are going to talk about types of genes as units of selection, why not just talk about types of organisms in the first place?  This sort of thing is confusing to philosophers not, I think, because they are naïve about biology, but because the concepts themselves need clarification.

 

Philosophy of religion.

            In the philosophy of religion, Darwinism has of course been massively important.  In specific, evolutionary theory has been taken very widely, and for a long time, to have conclusively refuted an important argument for the existence of God, the so-called design or teleological argument.  This argument is best known from William Paley's Natural Theology, in terms of his "watchmaker analogy", something that Darwin himself found convincing in his youth.  [By the way, Paley was borrowing here from the Roman philosopher Cicero, who had contrived the "sundial-maker analogy"].  I like to put the argument this way: you are walking along the beach of what you think is a deserted island, and you find a stone there that is perfectly smooth and elliptical, as though someone had fashioned it this way for its beauty, or perhaps to use as a weapon.  Looking out at the breaking waves, though, you can readily imagine how the rubbing of wet sand against any stone in such turbulent waters, over years and years, would tend to create this kind of perfect form without any telos or end or intention.  It is just a kind of accidental functionality that sometimes occurs in nature.  But next, a few yards further down the beach, you find this other thing, made out of metal, with an ornate cover and a glass shield over two little arrows that steadily revolve around a disk  marked out in even increments of twelve and sixty, just as if its purpose was to tell time.  Well, that is because it is a watch, and its purpose is to tell time, and somebody pretty intelligent made this thing deliberately for that purpose.  There isn't any other explanation for this object that makes sense.  Then you walk a few steps further down the beach and find a crab, with legs and claws and mouth and shell, and for a while you watch it move about and eat and so on.  Now, which is this crab more like, the smooth stone or the watch?  Obviously, it is more like the watch.  We are never going to make a crab by smacking rocks together in the water, or through any other purely natural process, be it rain or snow or lightening or volcanoes, any more than such blind processes are going to produce a pocket watch.  It should be obvious to anybody, on consideration, that such elaborately functional, self-moving, even self-replicating mechanisms as a crab must be the products of an intelligent, potent, and purposeful creator.

            This is one of the most powerful arguments in Western history (and completely independent from the Bible, by the way).  For at least two thousand years, the philosophical case for theism rested on this argument more than any other.  Darwin refuted it by providing the first plausible sketch of how crabs and plants and other complex organisms, including human beings, could have been produced without intelligent design, over enough time, through the processes of natural and sexual selection.  And, as you know, over the last 150 years this sketch has been considerably filled out by further analysis, plus the incorporation of modern genetics, biochemistry, and statistical population theory.  For a lot of philosophers, this refutation of the design argument has effectively destroyed all of theistic religion intellectually, and established finally and firmly the superior prestige of science.  (It is actually David Hume who is credited among philosophers with first framing an evolutionary objection to the design argument, in his Dialogues Concerning Natural Religion of 1779.  The difference is that Darwin produced a serious scientific theory, and Hume was only speculating hypothetically.)

            It is important to note that refuting the design argument does not in itself disprove the existence of God – a lot of people, including some philosophers and some biologists and, officially, the Catholic Church, have been content to say that God's existence is at least consistent with modern evolutionary biology.  After all, why shouldn't God use natural selection as a mechanism to produce the sorts of beings that he wishes to create, humans in particular?  But what's important to philosophy here is not whether God can exist consistently with modern science, but whether we still have reason to believe that he exists.  To the extent that theists have depended on the argument from design to rationally justify their faith in God, that justification is now largely gone, and they are left with faith alone.

            I should also make note of the newer, more sophisticated arguments from intelligent design, including arguments from so-called irreducible complexity, that have been showing up in colleges and courts and web pages over the past few years.  For example, Michael Behe has recently argued that the rotary "engines" of bacterial flagella could not have evolved in a piece by piece way – only the whole assembly makes sense as a functional system – and similar things have been said about the complexity of eyes, and birds's lungs, and other organs.  Biologists seem to have been doing a successful job so far of accounting for the evolvability of such little systems, and pressure remains on the intelligent-design theorists to keep looking for cases that cannot be brushed aside in this way.  But I do not know of any professional philosophers who take this remaining disputation very seriously, except as a political matter.  Within the field, the teleological argument is now mostly taken for dead, or at best pushed back into an argument about the Big Bang, and why there is any universe at all.

            The involvement of philosophers in court cases and political disputes about creationism has been, I think, a bad thing for the field, and the philosophy of science in particular.  Judges and politicians and school boards would like to have a nice, clear demarcation line between what counts as science and what doesn’t – hence, between what can be required or permitted in science curriculums and what can legally or fairly be excluded.  Philosophers like Michael Ruse have been all too happy to involve themselves as expert witnesses, eager as they are politically to keep religion out of schools.  This would be fine if there were really such a thing as expertise within the field, but there is not.  That is, to be an expert in philosophy of science is not to know what science is – this has not been figured out yet, and there is nothing like a clear consensus coming into view.  All that an expert knows is what the current range of theories says, and what kinds of arguments are being made.  But nothing has been concluded by philosophers in general, and it bothers me a lot to see Ruse’s own thoughtful but controversial opinions about unsettled issues being written into law (initially by federal judge Frank White, in the 1981 Arkansas creationism case).  [Denny Showers, who I think approves of these things, will discuss such cases in the next talk in this series.]

 

Epistemology and the philosophy of mind

            The Darwinian defeat of theism has provided fuel to a broad movement in philosophy called naturalism, or scientific naturalism, which has ancient roots but is held to have started in its current version with the work of Willard Quine in the 1950s.  This movement continues to gain strength against traditional philosophical methods, and against the linguistic sort of analysis that formed the basis of Anglo-American philosophy during the early and mid-20th century.  Naturalism is the view that philosophy should see itself as part of, or at least continuous with, empirical science.  No longer should philosophy be viewed as fundamentally an a priori discipline, based on the analysis of concepts through mere introspection and debate.  Instead, philosophers should typically defer to the work of the relevant scientists for explanations of what things like consciousness and knowledge really are, in the way that it was scientists, not philosophers, who figured out what water really is, namely H2O.  So it is incumbent on philosophy to join hands with neuroscience and psychology and linguistics and computer science so that problems like the nature of consciousness and rationality and knowledge can be worked out as a part of a general cognitive science – in the same general way that I have said philosophers of biology seek to assist real biologists with logical and conceptual issues as they arise.  This includes explicitly evolutionary theories of knowledge and mind, which attempt to analyze these concepts in terms of something like adaptive value, rather than searching for definitions and counterexamples in the traditional, dialectical way.  According to these naturalists, it was a terrible mistake for the philosopher Descartes to assume a subjective, rather than an objective and empirical, point of view in asking himself how he could really know that he was sitting by the fire rather than dreaming in bed.

            I am not sure whether this approach to philosophy is going to be very fruitful.  On the one hand, I do think that science, including cognitive science, is great stuff, and I am certainly interested in our finding out as much objective truth about things as we can.  But the traditional, and still the most central, questions in philosophy are not, I think, susceptible to such objective, so-called externalist approaches.  I want to know what knowledge is, for example, but I don't think that I can ever be fully satisfied with an entirely naturalistic approach, because the method of objective science simply presupposes much of what is deeply in question among philosophers.  It is like this: I want to know whether my experiences are generally veridical, whether they tell me what the world is really like.  This is a problem in principle, not just in practice, because I can easily conceive of situations where I would be systematically deceived about the world, not just occasionally wrong.  Suppose I was, to use the standard philosophical example, just a "brain in a vat", being fed my experiences through electrodes, something like what happened in the recent film The Matrix.  My subjective perceptions could then be just the same as they are now, without being connected in any reliable way to reality.  So, how can I know now that I am not in some such situation?  The traditional, internalist approach takes problems like this seriously.  But the externalist, objective, scientific naturalist approach can only respond in something like the following way.  If you want to find out whether you are a brain in a vat, just go to where they keep the vats, and see if any of the brains is yours (perhaps they're labeled with one’s name or social security number).  This is not an intellectually satisfactory sort of answer.

            My other main concern about naturalism is less narrowly focused.  It seems to me that there is emerging a kind of scientific triumphalism within intellectual life lately, and I don't like it very much, though again, I want to stress that I do like science very much.  But I don't believe that scientific reasoning automatically trumps everything else, and I particularly do not think that human scientists, and their admirers among naturalistic philosophers, are especially to be trusted about anything outside of their (usually narrow) specialties.  I have already complained about Michael Ruse talking judges into his particular "expert" opinions about science and religion.  But this kind of thing seems to be everywhere these days.  There is even a movement among naturalists to rename themselves (have you heard about this?) "brights", along the lines of homosexuals having named themselves "gays".  The idea is that scientific atheists are a discriminated-against minority group, and it is time for them to come out of the closet and campaign for some kind of enhanced public respect.  This whole thing strikes me as childish, obnoxious, and misconceived.  Yet it includes important thinkers like Dawkins, Steven Pinker and the top naturalistic philosopher Daniel Dennett – people I really admire for their actual professional work.  Their use of the word "brights" as a name for themselves gets me especially.  I think it reeks of arrogance, and of contempt for the capacities of ordinary people, especially religious ones.  But this is one of the unfortunate effects of the entrenched success of evolutionary theory, that is has become for some people almost a religion in itself.  Now that we know what we know, we can set out to rid the world of ignorance and superstition.  This attitude is plain to see in recent anti-religious best-sellers by Dawkins (The God Delusion) and Dennett (Breaking the Spell) – Dawkins is particularly fanatical, referring to religion as a “virus of the brain”.  I caution against anybody ever trying to justify an essentially social or political attitude on the basis of science.  (And something similar seems to be happening with global warming and environmental politics.)  We have had trouble with this sort of thing before.

 

Social philosophy and ethics.

            We know, for example, what nasty effects Darwin's biology had on the social philosophy of his own day, in providing motivation for the eugenics movement in Europe and America, and inspiring generally what is called, not flatteringly, Social Darwinism.  If natural life is a ruthless competition for survival and reproductive opportunity, and if this is what produces greater fitness over time, including intelligence and other evident forms of strength among humans, then it would seem best to let nature take its course in continuing to kill off those people who are not biologically fit to survive on their own, or to raise families of healthy children.  Indeed, far from providing welfare or other institutional support for weak, sick, simple, or otherwise defective people, it would seem to be in the community's interest to extinguish lines of the unfit through careful pruning, for example by humane sterilization of the retarded, and to promote the reproduction of the strong.  It is hard to exaggerate the extent to which this sort of attitude counted as common sense a hundred years ago, especially among scientific-minded, educated people like ourselves, essentially because of the prestige of evolutionary theory.   

            We also know what happened, for the most part, to this attitude, which is that it was practically extinguished after World War II, as German and Japanese racial supremacy lay smoldering at the hands of mutts like the Russians and ourselves, and as the horrors of the Holocaust were brought to light.  After the war, no civilized person wanted to get on the slippery slope of judging people biologically again.  But the serious questions about human nature, human progress, and human equality raised by Darwinism had not themselves been obliterated, and after a decent interval of fifty years or so are lately coming back into relatively frank discussion.  How equal are we?  How equal should we be?  To what extent should we require ourselves to share our goods with other people, outside of those bonds of family and friendship that tend to make helping others also in our own self-interest?  Is there any reason to expect some kind of universal justice among creatures who evolved in an intensely and persistently competitive environment? 

            In current terms, as in the much more vivid terms of the last century, Darwinism seems to favor the political right over the left.  If we allow as natural, and therefore unavoidable, a preference for friends and family over strangers in our moral calculations, it is not easy to see how any stable, full-fledged socialism could arise.  Really, what would have to be established is that it is in each family's interest to accept an equal share of social goods – or else, new conditions would somehow have to be created under which it would become in every family’s interest to accept that level of equality.  It much easier to imagine everyone accepting equal rights under a more limited form of government, one that would guarantee something like fair and peaceful competition, rather than equal results.  (See Larry Arnhart, Darwinian Natural Right; also his blog, Darwinian Conservatism).  It seems to me that even the notion of equal opportunity, beloved of the right as well as the left in current politics, does not fit well with the limited cooperativity that is implied by evolutionary theory.  Do I really want all children to have equal educational opportunities, for example?  Or do I want my own children to have something better than average?  The best people I know all do extra stuff for their own children, even though they're nice to other children – especially when it comes to education, which is the main form of unequal opportunity in our society.  

            In any case, it appears that the most popular general moral theory among philosophers, namely utilitarianism, is radically incongruent with human nature as explained by evolution.  Utilitarianism accepts each individual's interests as equal to all others, and commands us each to act for the ultimate benefit of all mankind.  But why should we sacrifice the lives of our own two parents, say, in order to save the lives of three strangers in a distant country?  This is precisely the kind of decision that utilitarianism seems to require, on the simple grounds that three lives are more valuable than two.  And this may even make an abstract kind of sense – but it isn’t very human, and a thoughtful Darwinism backs this intuition up.  A truly Darwinian morality would seem to tend instead toward some kind of mainly local deontology – ethics as a set of principles regarding being a good parent, child, or sibling, contracting honestly with others, respecting other people's rights and property, and so on.  Confucianism and the Ten Commandments make more sense in this regard than universalist theories like utilitarianism.

            Not everyone is happy to accept such right-wing implications for morality of Darwin's theory.  There is an interesting recent book by the renowned utilitarian extremist Peter Singer, called A Darwinian Left (also the most expensive book per word that I have ever purchased: $10 for 61 tiny pages of text).  Singer acknowledges that Marxist and similarly hard-core leftist theories that propose to remake human nature in a strictly egalitarian mold fly in the face of evolutionary theory, that perfect equality and selflessness will never become the human norm, and can only be simulated on a large scale temporarily, by means of  violence.  But he believes that much of the left agenda can be saved.  For even if we have by nature "selfish" preferences for family and friends, this does not mean that that we cannot develop over time greater and greater fellow-feeling for more and more distant relations, encompassing finally all of humanity (and, Singer famously argues, sentient animals as well).  Clearly humanity has made lots of moral progress of this sort already, and there is no telling how far we can go in systematically resisting selfishness in honor of the greater good, short of eliminating selfishness altogether.  Singer’s point is a reasonable one.  And it is useful to note that evolutionary theory lends support to the movement for animal rights, just as it makes human rights more problematic, by tending to erase the barriers, religious and philosophical, that have kept humans separate from other animals throughout our  history. 

            But Singer concedes a lot when it comes to more specific left positions.  Not much can be said, for example, from a Darwinian perspective, in favor of the feminist theory that men and women are exactly alike psychologically, other than whatever our societies "construct" as "gender".  Evolutionary psychology pretty much begins with sexual differentiation, on the grounds of the different, and to some extent competing, interests and capacities that men and women have in reproduction (eggs are precious, sperm is not).  This does not entail that evolutionists ought to be anti-feminists, or that women ought to be kept out of any particular professions as a rule.  But the feminist expectation that fair treatment will put exactly equal proportions of women in men in all social positions and jobs seems unrealistic from a Darwinian perspective.  This sours the outlook for, and, I think, greatly complicates the politics of, quota- or goal-based forms of affirmative action.  If you want 50% male nursery school teachers and 50% female engineers, the logic of evolution suggests that you're not going to get it.

            Evolutionary psychology is also getting brought into the politics of sexual preference.  The basic problem of homosexuality within biology is pretty simple: how is it that such a trait, however it initially appears, is not extinguished very quickly through natural selection, given that homosexual preference strongly implies a lesser likelihood of reproduction?  There are a number of suggestions available to those who wish to argue that homosexuality is biologically normal (rather than some kind of a perverted choice, or the result of an unusually stressed environment), including kin selection (i.e. the helpful aunts and uncles hypothesis) and heterozygote superiority (the idea that having one but not two recessive “genes for homosexuality” enhances one’s fertility as a heterosexual).  I have no sense of what truth is, here, myself.  I am only pointing out that this is another area in which evolutionary theory may have explosive consequences outside of biology.

            Potentially the nastiest such thing, I think, would be a re-emergence of something like race as a serious concept in science.  Progressive people like to say that race is an illusion, and to treat all ethnic groups as though they shared identical percentages of every interesting trait.  And maybe this is true, too, but again, the logic of evolution suggests otherwise: to whatever extent populations are historically isolated, or distributed in different environments, to that extent we rationally should expect to find some differentiation.  It may turn out, for example, as it certainly seems to have, that Kenyans (or Eastern Africans in general) are better at long-distance running, on the average, than any other ethnic group.  It may even turn out, as one recent study suggests, that Ashkenazi Jews are smarter, on the average, than most other people – given their centuries of being restricted in Europe to intellectually intensive forms of labor (that's the argument).  I don't know, myself, and I don't care much about any of these issues in particular.  But I do wonder if we are ready, philosophically and politically, to handle in a reasonable, decent way whatever minor forms of biologically-based social inequality may be proven in the future to exist.  Perhaps the best thing to do, regarding all of these potential issues, would be for us to move back to the liberal, anti-discriminatory individualism of the early 1960s, and break away from the progressive notions of group-wise equality that dominate the left today, especially on campus.