Why Did Sex Evolve?

 

 

Some reproduction is sexual and some is asexual. There is no biological necessity about sexual reproduction, despite its prevalence. How could there be any such necessity, given that the basic principle of evolutionary biology is just that organisms are designed to maximize the presence of their genes in later generations? This says nothing about mixing genes or about a division between the sexes. Why not reproduce purely by cloning? Why isn’t all genesis parthenogenesis? This seems perfectly possible, much simpler, and evidently how reproduction began on planet earth. So why did sex evolve from non-sex?

            The problem is not just that no obvious adaptive rationale for sex seems to suggest itself; there are positive reasons why the existence of sex seems to violate basic principles of evolutionary biology. The most obvious point is what might be called “gene dilution”: instead of passing down a hundred percent of one’s genes, one passes down only fifty percent. In parthenogenesis a hundred percent are inherited, so surely an organism would prefer that figure to a mere fifty per cent. Genes that build bodies that pass on only a fraction of themselves will not be as frequent in later populations as genes that pass on a hundred per cent of themselves. Sexual reproduction appears to thwart the prime directive governing genes: maximization. Second, in sexual reproduction it is necessary to find a suitable sexual partner, whereas in cloning you can go it alone. That requires expenditure of energy and risk of failure: why take such a hard road when parthenogenesis enables one to stay home alone and get on with the job without going out in search of unreliable mates? Third, from the female’s point of view sexual reproduction looks a lot like altruism: she is providing a service to the male by passing on his genes, using her own energy resources, for which she does not seem adequately recompensed. She seems to be doing the male a favor, but organisms built by selfish genes don’t do each other favors. The role of female looks unacceptably altruistic. We need to show what is in it for her genetic prospects. Why tolerate males at all? Why aren’t all organisms female?

            Sex thus appears biologically paradoxical—inconsistent with even the most basic principles of evolution. We must find a way to explain its origin and persistence that comports with basic biology. Many theories have been proposed, which I won’t discuss here. I intend to propose, as economically as possible, another theory, which respects the game-theoretic selfish gene perspective now prevalent in the field. I call this the “genetic parasite theory”.

            Imagine a population of single-celled eukaryotic organisms (ones with a sheathed nucleus containing DNA) and suppose their mode of reproduction to be asexual. They are all, in effect, female, and reproduce by cell division, transmitting one hundred percent of their genes into each offspring. Now, life being what it is, opportunities for parasitism will arise: some of these cells may adapt to exploit the resources of other cells in the population, without killing them. Let us suppose that they attach themselves to the surface of host cells and siphon off nutrition found in the host. The host will resist such nutritional theft, but it may persist nevertheless, possibly following an arms race between parasite and host. Being a parasite is always a highly attractive option for any evolved creature, having all the benefits of theft over honest toil, and is not easily foiled (it is really just a kind of non-fatal predation). But suppose that some cells are more ambitious: they seek not just food but also reproductive assistance—they want to use other cells to pass on their genes, sparing themselves the expense and trouble. They therefore evolve a pointy organ that can penetrate the surface membrane of other cells and transfer their own DNA into the nucleus of the host cell, where it can enjoy the resources of the host cell in getting itself reproduced. These cells are not nutritional parasites but genetic parasites. They might even be able to replace entirely the DNA of the host cell, by inserting all their own DNA into the nucleus. That would mean that none of the host’s genes are transmitted and all of theirs are. By the laws of gene selection such a host would soon go extinct; its offspring would be copies of the parasitic cell. We would thus expect that counter-measures to the genetic infiltration would evolve, and an arms race would develop. The host cell might develop ways of poisoning the parasite or dissolving its genetic residue once inside or blunting its pointy organ. Let us suppose that an equilibrium point is reached in which fifty percent of the parasite’s DNA is permitted inside the host’s nucleus and fifty percent of the host’s DNA remains. Perhaps if the host accepts this amount less damage is done to it by the invasive cell, which will limit its aggressive incursions if the host cooperates to some extent (otherwise it will fight to the death). Still, this is a highly unsatisfactory outcome for the host, because of gene dilution. How might it adapt to this state of affairs? It needs to find a way to get something out of the new arrangement—some sort of genetic payoff.

            Some of the genetic parasites will contain better genes than others. If poor quality genes are mixed with the host’s genes, then the result will be less advantageous than if good quality genes are mixed. Given that the host is losing fifty percent of her genes in the new arrangement, it would clearly be better if she were to have good quality alien genes than poor quality ones, since the whole package will then do better, which is good for her genes. So she begins to favor parasitic genes that are better than others—she exercises quality control with respect to her genetic parasites. She becomes selective in her resistance. She is still not as well off genetically as she was before all this happened, when she reproduced by solitary cloning, since she is still suffering from gene dilution. But there is little she can do about it given the aggressive parasites she has to contend with. It is always better to have no parasites than some, but it can be better to have some parasites rather than others. You want the ones that can do you a favor in return, if that is at all feasible. Thus our host will want to select the best genes she can from her would-be parasites, because these will aid her own genes better than other parasitic genes will. The situation is still unstable, however, because there will be selective pressure to revert to the pre-parasite state of things, where all of her genes get perpetuated. She will want to resist the genetic parasites as much as possible, consistently with the arms race and the costs of resistance. How can things be made more palatable to her?

            Suppose that among her “suitors” a select few have genes with the following property: if they are combined with hers they will actually increase the chances of her own genes surviving into the future, relative to their chances without such combination. Given genetic variation in the population, some cells will be more viable than others—and these are the best ones to “mate” with. In other words, the optimal strategy for an invaded host cell is to select a parasite that will improve her genetic prospects—not just relative to other potential parasites but also relative to her chances without such parasites. If she mates with such a fine specimen, then her genes will actually be better off than if she reproduced all on her own. True, there will be fewer of her genes in the next generation, but by combining with genes superior to her own she will ensure that more of her genes will eventually survive and reproduce. The result of this kind of upgrade combination is a “leg up” in terms of genetic survival, compared to the way things used to be. This, then, is how sexual reproduction evolved as a stable mode of reproduction: genetic parasitism combined with genetic selection that provides a “leg up”. What started as straight parasitism, with the usual arms race and compromise, turned into a kind of symbiosis, when the female improved her genes’ chances by selecting high quality “male” genes. Now there was something in it for her, beyond simply minimizing the bad effects of determined parasites. If she could have won the arms race against the parasites, reverting to her untroubled asexual mode of reproduction, that would have been quite satisfactory; but it is even better to find a way to exploit the parasite by selecting only parasites that serve her own genetic interests better than the old regime. And if she could not win the arms race anyway, it is better to turn a fait accompli into an unexpected triumph: the female cells that are better at selecting the male genetic parasites with the best genes will do better than those that are not so good at this. Thus we get competition among males to be selected and competition among females for the best males. 

            Here are a couple of analogies to bring out the logic of the situation. Suppose there was a parasitic worm that could actually affect the DNA of its host: it secretes a chemical into the DNA and changes its composition, producing new genes. Suppose some of these worms produced worse DNA and some produced better DNA. Clearly it is to the advantage of the host organism that it selects the worms that improve its DNA, since these will then have a better chance of being passed on. It might be better to have no such worm, but given that this is unavoidable, natural selection will favor the “good” worms over the “bad”. And maybe there are some worms so good that it is better to have them than to have no worms at all—since they can build organisms greatly superior to any built by the host’s original genetic composition. These super-worms produce simply outstanding children for the host. Similarly, alien DNA (deriving from a “male”) might so improve the female’s gene complex that the necessary genetic dilution is acceptable, according to the genetic calculations. Fifty per cent of my genes surviving for a thousand generations is a lot better than one hundred percept surviving for only ten generations. It is like five of my ten children living to be a hundred with the other five dying in childbirth, compared to all of them living only to the age of three. A worm that re-tooled your genes to make them substantially better at surviving would pay its way in the unforgiving genetic arithmetic. Genes for tolerating such a worm would be more likely to be passed on.           

            The second analogy concerns coalitions. If someone comes to you to form a coalition in order to secure some future benefit, you must ask yourself a simple question: am I better of with her or without her? If I can secure the benefit without the coalition, I do well to decline her offer, since I would then have to share the benefit. But if I judge that I cannot achieve the end without her help, then I should join with her in a coalition, since I will get nothing otherwise. Sexual reproduction has the same logic: if my genes go it alone they have a certain probability of surviving to reproductive age (maybe zero), but if I combine them with someone else’s genes (losing fifty per cent of them, say), then there is a different probability of their survival. If the latter exceeds the former, then I am rational to choose the latter over the former. A potential mate is like someone offering you a coalition: if you mate with me I assure you the chances of genetic happiness are high, compared to the chances if you mate with someone else or just decide to go it alone. Suppose you happen to have both means of reproduction available to you, sexual and asexual. You have to choose which to employ. You compute the payoffs by multiplying the number of your genes that will get passed on by the probability of their survival (over, say, the next million years). If a hundred per cent get passed on by the asexual method, but there is a low probability of their long term survival, you might opt for the sexual method where fewer get passed on but the probability of survival is much higher—but only if you believe the “donor” genes have this kind of survival power. In the same way, your coalition mate has to be good enough to warrant dividing the spoils with her later, or else you will choose to go it alone and keep all the spoils for yourself. Sex arises from genetic coalitions, possibly preceded by genetic parasitism. This is better for both parties, because there is something in it for the host and the parasite benefits because its incursions are no longer resisted. Thus we move from resistance to consent: the male benefits but so does the female. This solves the problem we started out with, which was to explain how sexual reproduction could make sense given that asexual reproduction seems so much more sensible biologically. The answer is that it results from a strategy for dealing with genetic parasitism.

            Let me restate the point in less abstract terms. Why should a female mammal allow her womb to be colonized by a male mammal with a different set of DNA? Why should her energy resources be diverted into generating his child? He should take care of it himself! He is just freeloading off her womb and energy resources. The suggested answer is that she is gambling that the influx of his genes will improve the prospects of her genes. Given that the male would just parasitize her womb anyway, it is better to be selective about mates and try to improve her own chances in the genetic lottery. In the payoff matrix that describes all the options, with their various costs and benefits, sexual reproduction seems the best choice—the best compromise, we might say. Asexual reproduction makes perfect biological sense—it is how a well-meaning Creator might have arranged things—but given the rough and tumble of evolution, with the ever-present threat of unscrupulous parasites, sex has emerged as a kind of game-theoretic solution to an inevitable problem: namely, what to do about those pesky genetic parasites. The parasites are with us always, given the attraction of that line of work; the question is what can be done about them. And the answer in one word is: compromise. Sex is a kind of accommodation to the harsh reality of biological existence—ultimately, access to energy.

            If this explanation is on the right lines, what might we expect to characterize animals and their sexual behavior? One point has already been mentioned: we would expect male competition for females, selectivity from females, and competition within females for outstanding males. Of course, these are all abundant features of animal behavior. Correspondingly, we would expect female sexual anatomy to conform to the general theoretical picture: it should not be too easy to impregnate the female, which would impair her ability to be selective. Her consent to copulation should be required for copulation to be feasible for the male. Rape should be, at least, difficult and potentially hazardous. At the same time, copulation should not be so difficult that a suitable male is just not up to the task: hence difficult but not too difficult. We might also expect sex to be somewhat predatory, given that the male is always essentially exploiting the female, in order to spare himself the effort of gestating offspring; and the female will always be wary and choosy, wondering if this suitor is really “the one”. She is giving up a lot to incubate his progeny, in terms of energy and commitment; so she has to be sure there is something in it for her (i.e. her genes). The genes of the female must move her in such a way that their interests are respected, even though only fifty per cent of them will end up in the next generation. The genes of the male have no such concerns, given that he is not called upon to act as incubator; and he can spread those genes around ad libitum. The underlying logic of sex predicts these kinds of phenotypic facts, and they are evident enough in animal behavior. Fundamentally, the male is still the aggressive parasite and the female the reluctant host trying to make the best of a bad job. Of course, once the sexual machinery is in place and the female has no other reproductive option, she will act with enthusiasm and commitment; but the genesis of sexual reproduction is still written into the underlying structure of the sexual relationship.

            A less obvious consequence concerns sexual selection. The female exercises quality control: she evaluates her potential mates by formulating hypotheses about their genetic fitness, based on what she can observe. She cannot peer directly into the suitor’s genes but must go by outward appearance. Thus she espies the peacock’s lavish tail and infers genetic superiority within. This causes males to improve their appearance so that females will evaluate them highly: but to improve their appearance they have to improve their reality. They have to be bigger and stronger, less infested with parasites, and more able to sustain pointless bits of flamboyance. So there is selective pressure on males to improve. Thus sex leads to sexual selection, which leads to improvement. That is, sex is what powers evolution to produce ever more complex and accomplished animals, via sexual selection. But asexual reproduction has no such consequence: the organism just reproduces itself according to its original design. There is no sexual selection when reproduction is asexual, and hence no motor to drive biological progress. The result is likely to be stasis, uniformity, and dullness. You don’t get complex beautiful animals when the method of reproduction is asexual. It is not, of course, that anyone is aiming for such complex beauty; it is just that the mechanism for producing it does not exist in a world without sexual reproduction. We owe it to sex to kick start evolution into a higher gear; before sex the pressures for change were minimal. It was when females started to be choosy, as a way of making the best out of living in a world of genetic parasites, that sexual selection triggered the kind of evolutionary changes that we see. Without sex Earth might never have got beyond boring bacteria floating in nondescript oceans. We owe it to the parasites among them to have initiated a process that led to the impressive variety of animal life that now exists.

            Here is one final point–a kind of theorem: a genetically perfect female has no rationale for engaging in sex in a world in which she is subject to genetic parasitism. If she cannot improve her genetic fitness by merging her genes with those of a male, then she has no motive to permit her body to be used as incubator. For her, all genetic mixing is genetic degradation. She therefore has every reason to fight off all male incursions. But the same is not true of a genetically perfect male: he still has every reason to reproduce sexually, since he can thereby produce more copies of his genes than by solitary cloning. He just has to deposit them in as many willing (or unwilling) female bodies as possible. There is a huge logical asymmetry between being the one with the incubating body and being the one who uses someone else’s body as incubator. That asymmetry is the real basis of sexual reproduction (and indeed ultimately defines the difference between the sexes). Genetic perfection in the female leads naturally to frigidity, but genetic perfection in the male entails no diminution of sexual appetite. In other words, the genes see no point in sexual reproduction for the genetically perfect female, but they see a lot of point in it for the genetically perfect male.  Of course, there is no such thing as genetic perfection in the real biological world–but I am making a purely logical point.

 

Colin McGinn

 

                                                The Language of Emotion

 

 

Proponents of the language of thought typically don’t have much to say about emotion. We are said to deploy an internal language when we think, but it is not suggested that we do so when we feel. Internal speech is characteristic of thought but not of emotion—we don’t “feel in words”. And the same might be said of desire: the idea of a “language of desire” has not met with enthusiastic acceptance (or even formulation). Language has to do with the cognitive part of the mind not the affective. Perhaps theorists think that the affective part of the mind is what we have in common with non-linguistic animals and so is not an appropriate object for linguistic explanation; only thought calls for linguistic representation. Emotion and desire are like bodily sensations: no one thinks that pain and pleasure should be analyzed linguistically—to be in pain is not to say to oneself “That hurts!” and the taste of pineapple is not an inward utterance of “Lo, pineapple”. Emotion just doesn’t have this kind of intellectual sophistication: it has no grammar or logic, no internal discursive structure. Emotions, like sensations, don’t entail each other or have subject-predicate structure. So it may be supposed.

            But is that true? Take fear: we can fear that p as well as fearing x. For example, yesterday I feared that I would collide with a car that pulled out in front of me. Fear has propositional content: at the moment I slammed on the brakes I was afraid that I was about to have an accident. This is the same proposition that I believed to be true—in fact, I feared its truth because I believed it to be true. I thought that a collision was imminent and so I feared that a collision was imminent. We can recognize this connection between mental states without committing ourselves to a cognitive theory of emotion: it is simply a fact about our psychological economy. Of course, if emotions arethoughts (or essentially incorporate thoughts), then we can derive a language of emotion directly from a language of thought, but even without that assumption it is evident that emotions are (or can be) propositional. If emotions of fear have propositional content, then they have logical form, in virtue of the propositional object of the emotion. And so they have logical entailments—the content of my fear entailed, for example, that someone was about to have an accident. But then the case for a language of emotion is exactly as strong as the case for a language of thought, insofar as the latter case rests on the propositional content of thoughts. One of the main arguments for LOT is the productivity of thought, but emotions are also productive in this sense, since they invoke conceptually structured propositions—so we have the same argument for LOE. I can fear that I will not be selected for clemency just as I can believe that I will not be selected for clemency, and I can fear that I will be captured by the enemy and then tortured just as I can believe that conjunctive proposition. I can fear the same propositions that I can believe, including those built by logical operations like negation and conjunction. Thus emotions are logically structured, combinatorial, finitely based, and potentially infinite—just like beliefs and thoughts. If there is a LOT, then there must be a LOE.

            It might be wondered whether emotion verbs accept every complement clause that cognitive verbs accept. Can we fear everything we can think? Can we feel sad about every state of affairs that we can believe to obtain? Can we be disgusted by everything to which we can assent? For example, I can believe that necessarily 2 + 2 = 4, but can I fear that necessarily 2 + 2 = 4? Can I feel sad that gravity obeys an inverse square law? Can I be disgusted that Hesperus is Phosphorous or that modus ponens is a valid rule of inference? With sufficient ingenuity we could probably contrive situations in which each of these peculiar emotions could be felt, though they are certainly not part of the normal run of things. But we don’t need to establish full correspondence between thought and emotion in order to recognize that emotions have an extraordinary variety of complex propositional objects, and that they therefore qualify for linguistic analysis given that thoughts do. Just as we think in a language, so we feel in a language—the content of our emotions has a linguistic underpinning. Other animals may not, just as other animals may think without deploying an internal language (possibly in images). But human emotions, like human thoughts, have a degree of conceptual sophistication that invites the idea of a LOE. Indeed, if we call the human LOT “Mentalese”, we can say that the LOE is also Mentalese: we feel in the same language in which we think. Why would we (or our genes) deploy two distinct languages for these two tasks? And if the propositional character of emotions derives from their cognitive component, we would expect that Mentalese would simply carry over to LOE. Thought and emotion would then share a common underlying symbolic system, with the same grammar and lexicon.  [1]

            The picture that results regards Mentalese as an internal language suitable for deployment in both thought and emotion (as well as desire, since we have complex logically related desires too). We might take it to be neutralbetween cognitive and affective uses, not privileging thought over emotion. It is not that we first have a language specifically of thought and then co-opt it to serve our emotions; rather, we have a neutral language that can be deployed for both thought and emotion. The Mentalese language faculty is a psychological module ready to be exploited by different parts of the mind—a general machine that can be used for different purposes. It doesn’t have thought built into it any more than it has emotion built into it; it’s more abstract than that. It is a language of mindgenerally (LOM). Thus LOM can be employed as an LOT or as an LOE. Some theorists might wish to go even further in divorcing LOM from thought specifically by suggesting that emotion and desire are primary in the mind. These theorists might maintain that desire and emotion precede thought in evolution, and that they require a symbolic medium in order to achieve their purposes optimally. Thus there was an LOE before there was an LOT: LOT is a later adaptation grounded in LOE. Maybe LOE evolved in fish long before anything deserving the name of thought arrived; then thought came along and recruited LOE for its purposes. There is no need to privilege the cognitive just because one adopts an internal language theory of mental operations. To put it differently, a computational model of mind is not committed to taking thought to be primary in the mind. Conceptually structured emotions (or desires) might be more basic than conceptually structured thoughts. Emotions are clearly important biologically, as well as being ancient, and having a sophisticated structure clearly aids their effectiveness. The affective is discursive. 

            When it was believed that thoughts consist of mental images the idea of a language of thought held little appeal; similarly for the theory that thoughts are behavioral dispositions. It took appreciation of the propositional nature of thoughts for LOT to gain traction—theorists had to accept that a thought is always a thought that p. Likewise, if we think of emotions as bodily sensations (as with many traditional theories), or as dispositions to behavior, then we will not appreciate their propositional nature. But once we accept that fear and sadness are fear and sadness that p, we are prepared to accept that emotions are underwritten by an internal symbolic system. The important move in both cases is accepting the correct logical analysis of ascriptions of thought and emotion.  [2]Once philosophers had grasped how reports of thought worked they were ready to take the plunge into LOT, but they don’t seem to have appreciated that emotion reports are much the same, so that a dip into LOE might be indicated too.

 

  [1] There are also such attitudes as hope and trust: these are clearly propositional and close to belief and thought. If thought comes with an internal language, surely hope and trust do. But these attitudes have an emotional dimension, so we are already close to a language of emotion. In fact, the whole distinction between thought and emotion is quite artificial, so we should expect a general theory that subsumes both. 

  [2] I mean such things as referential opacity, the de re/de dicto distinction, the connection between entailment and logical form, the notions of sense and reference, semantic externalism, and so on. These are the things that encouraged philosophers to postulate a language underlying thought (Fodor needed Frege and Quine), but the same points apply to emotion and desire. The mind is thoroughly propositional, a subject of that-clauses.

                                               

 

 

Science and Philosophy

 

 

What does the value of science consist in? There are two possible answers: its usefulness and its interest. Nothing needs to be said about the first, but the second raises the question of what kind of interest science has. Let me distinguish specialist interest and general interest—the interests of professional scientists themselves and the interests of what we may as well call the general public. Funding and the like depend on the general interest of science (putting usefulness aside as too obvious to harp on). So what does the general interest of science consist in? When the average intelligent person takes an interest in science, what explains his or her interest? 

            We can best answer this question by considering the specific kinds of science that people tend to find most interesting. The answer is: astronomy, physics, biology, and psychology. Thus people have been very interested in astronomical findings about our place in the physical universe (the heliocentric theory, the big bang, the distribution of galaxies, etc); physical discoveries about the fine structure of matter (the atomic theory), the general nature of motion (Newton, Einstein), space and time, etc; biological discoveries about the origin of species (Darwin), the nature of inheritance (DNA), our kinship with other animals, etc; and discoveries about the roots of our mental life, the existence of an unconscious (Freud), how our minds relate to our brains, etc. That is, people are interested in findings about the physical nature of the universe (micro and macro), the origins of life (especially human life), and the underlying nature of the mind (especially the human mind). They are not generally interested in the fine details; what intrigue them are the large-scale conclusions.

            We can imagine a species without such interests. Apart from us, all terrestrial species lack any interest in science, mainly for reasons of intellectual limitation; and even if they could be made to understand the questions, there is no guarantee they would find much interest in the answers (though they might). On the other hand, extraterrestrials might naturally and innately possess scientific knowledge and hence take it for granted, finding it nothing to write home about. I think the reason we humans find such things so interesting is that they impinge on our natural conception of ourselves and of the world around us. We experience reality in certain ways, and these ways are limited and partial, also sometimes distorted. We see the stars in a certain way; we sense matter with our various senses; we observe similarities and differences between ourselves and other animals; we are aware of our own mind and its peculiarities. Scientific knowledge expands and sometimes questions our ordinary conception of things. Science is interesting to us because it bears on the big questions raised by our ordinary consciousness of the world: we want to know whether that ordinary consciousness is accurate, complete, and objectively correct.

            But doesn’t that sound a lot like philosophy? Isn’t that what philosophy is about? Philosophy is about the big questions: the universe, life, mind, and everything—especially the status of our ordinary conceptions of things. It is because we have such general philosophical interests that we find the contributions of science so interesting. We find that science helps us with our philosophical concerns, as these concerns spontaneously arise in us. If we had no such concerns, science would be of interest only to specialists and those devoted to its usefulness. We are interested in science in the way we are because we are philosophers—because we ask big questions about reality and dwell on our own natural awareness of the world. Are we the center of the universe? It feels as if we are—but astronomy teaches us otherwise. Is matter as solid and continuous as it looks? Atomic physics teaches us otherwise. Was life created by a superior form of intelligence? That seems likely on the surface, but it turns out that life arose by a succession of mindless accidents. Is the mind limited to what we are conscious of? Psychology teaches us otherwise, since an unconscious needs to be postulated. These are broad philosophical questions, and science is interesting precisely because it helps us answer them. It is the implications of science for these very general questions that seizes the attention of the general public—not so much the nuts and bolts of the scientific theories. We are moved by the significance of science for the big philosophical questions.

In particular, we perceive how science bears on our ordinary consciousness of the world—our perception and our common sense. We are thinking of this ordinary consciousness whenever we are gripped by a piece of science: we are comparing the way we naturally experience things and the way science tells us that they are. So we are reflecting on our own perspective on reality and assessing it in the light of scientific findings. We are thinking such thoughts as, “The world is actually very different from the way it strikes me”. That is a philosophical thought—self-reflective and self-critical. The general human interest in science depends on the availability of this kind of thought. Science is interesting to people because philosophy is (science used to be called “natural philosophy”). Thus science and philosophy are intertwined when it comes to human interest, even if individual scientists and philosophers have little to do with each other.

            The interest of philosophy, then, does not depend on its being an approximation to science; we are not interested in philosophy because it is on the way to becoming science. Rather, the interest of science depends on the existence of a prior philosophical interest. Humankind has been asking philosophical questions for a long time, and answering them in different ways, notably by appeal to religion, tradition, and revelation; but it has turned out that science is the best way to answer these questions. The questions themselves pre-date science, or even any conception of science. We would have them even if science had never been invented. Science would not have the same interest for us if it were detached from these ancient questions—they are what give science the human interest that it has. If science were valuable only because of its practical uses that would be a very different state of affairs: but actually it engages with our deepest questions about the world and our place in it. The value of science thus partly derives from its aspiration to meet our philosophical needs. Bluntly, science is interesting (to non-specialists) only because philosophy is.

            None of this is to say that science can answer our deepest philosophical questions; it is only to say that people find science interesting because of the hope that it may. When people are fascinated by the big bang theory because it appears to explain where the universe came from, it may be that they have other origin questions in mind—such as how anything at all came to exist. The big bang theory does not in fact answer those questions (what existed before the big bang?). My point is that the intellectual value of science (as opposed to its practical value) for most people depends on the belief that the big philosophical questions can be answered by science. Some of these big questions can be answered by science (whether we are at the center of the universe, how animal life evolved), but some cannot (whether we have free will, whether we can really know anything). In either case the general public interest in science reflects a thirst for such answers.  [1]

 

  [1] If people were to stop asking the big questions, abandoning philosophy altogether, perhaps at the urging of scientists, the result would be that science would lose its general interest, becoming merely a subject for specialists and practical application. Scientists need philosophers in order to maintain their appeal. (This would all be clearer if we didn’t make such a sharp distinction these days between science and philosophy.)

                                   

 

Principles of Radical Interpretation

 

 

How should we set about interpreting an alien language and the people who speak it? Specifically, how should we ascribe beliefs to others? One idea is that we should use a principle of charity: ascribe to others the beliefs that we have, so that interpreter and interpreted converge in their belief systems. This principle will apply both to logical beliefs and beliefs about ordinary matters of fact. Much has been written about the principle, and I won’t repeat any of that here. Instead, I will give a simple but instructive counterexample. Suppose I encounter an alien tribe in the deepest jungle and present members of the tribe with a cell phone, and suppose they have never seen a cell phone or any other electronic device. They will clearly not form the belief that the object in front of them is a cell phone—they have no such concept. They have no beliefs about cell phones or any similar technology. It would be absurd to appeal to the principle of charity in ascribing such a belief to our natives (perhaps what they believe is that the thing they are holding is a piece of a star fallen from the sky). Sometimes it is suggested that the principle of charity should be amended to a principle of humanity, which prescribes that we should ascribe the beliefs we would form if we were in the epistemological position of the native. Thus if the native is presented with a visual illusion, not known by them to be such, we should ascribe the false belief appropriate to that illusion, not the true belief that we have in knowing about the illusion. But this won’t help with the cell phone case, because presenting the native with a fake cell phone will not warrant assigning to them the belief that the object is a cell phone (as opposed to a fake cell phone); for again, they have no such concept.

            What if they are presented with a familiar object, say a rabbit—should we say they believe it is a rabbit, thus sharing our belief? Not necessarily, since they may have beliefs about the animal in front of them that excludes them from having the zoological concept rabbit: they may believe of rabbits that they are gods not animals. They do not share our beliefs about rabbits. The problem is that they believe that this thing is a god, not an animal, and hence they don’t apply the concept rabbit to the thing in question. Maybe they have the concept rabbit and apply it to certain kinds of rabbit only; when it comes to white rabbits, say, they withhold the concept, since these creatures they take to be gods, not animals, and hence withhold the rabbit concept. So we can’t ascribe a belief to them based on what we believe. We can’t use ourselves as the yardstick of their beliefs, since they differ radically from us about what the world contains. What if they are convinced skeptics who never believe that anything they experience is real? They don’t even share our belief that a square object is in front of them, let alone our general beliefs about nature, the weather, world history, the good, and the beautiful. Charity will get us nowhere with these independent thinkers, just as it will get them nowhere with us.

            So how can we interpret them? The difficulty applies even to logical beliefs: what if they subscribe to a deviant logic? We obviously can’t interpret them as holding to our logic—they may be convinced intuitionists or even adherents of para-consistent logic. We surely don’t want to say that no one can believe in a deviant logic, or that a deviant logician cannot be interpreted as holding the logical beliefs they in fact hold. We need a way to ascribe divergent logical beliefs, as we do divergent factual beliefs. No theory of interpretation that requires belief convergence between the interpreter and the interpreted can be correct. We need another principle entirely. I propose what I shall call “the principle of culturality”, for want of a better label. The general idea is that we need to take account of the material and cognitive culture of the people we are trying to interpret. Thus there are no cell phones in the material culture of our earlier tribe and their religious culture decrees rabbits to be gods. In order to interpret a people we need to look at their technology, life-style, interpersonal relations, and so on: do they have agriculture, maps, idols, money, advanced tools, animal sacrifice, and so on? This is all observable and accessible before we have made any belief attributions. We must also take note of their ecological niche, the acuity of their sense organs, possibly their genetic make-up, as well as their general level of sanity (interpreting a schizophrenic will require special methods). We will then ascribe to them the beliefs that all these factors suggest—and these beliefs may diverge dramatically from ours. They may be constantly hallucinating on drugs, possessed of only the most rudimentary tools, incurably superstitious, logical nihilists, and completely un-self-critical. In other words, we need to do serious empirical anthropology. Merely recording the stimuli that trigger their assent behavior isn’t going to cut it.

            Someone might object that the principle of culturality is not a rule like the principle of charity. That is quite true: it just tells us to take everything observable into account, particular the totality of the people’s culture. The principle of charity, by contrast, can be applied without any knowledge of the particularities of the natives’ culture—we simply ascribe what we ourselves believe, knowing already exactly what that is. This will work for any subject of interpretation, no matter their culture. But that is totally unrealistic, since people can differ enormously in their beliefs: beliefs are inherently protean in nature. Instead, we should adopt a far more context-sensitive and multi-dimensional approach, recognizing the extreme flexibility of belief: people can believe just about anything if they put their mind to it. We cannot sidestep the complexity of interpretation by adopting a simple rule like the principle of charity; and we may have to accept considerable uncertainty as to what the other believes. There may be para-consistent idealist creationists out there who don’t even believe in rabbits and square objects. They are no doubt mistaken, but they are not conceptually impossible.

            There are also children, animals, and Neanderthals—all of whom need interpretation. The principle of charity will not be of much help with them, since they will not necessarily agree with normal human adults in the beliefs they form. What about the denizens of Plato’s cave or intelligent underground worms? The case should be compared with ascertaining the chemical composition of a distant planet. It’s no use assuming that a distant planet will necessarily resemble the earth in its chemical composition, on the principle that we have no alternative than to use our local environment as a model of any environment (as if all planets must converge geologically with earth). Instead we must observe the environment local to the planet being investigated, by spectral analysis and whatever other data we can glean—we look at the peculiarities of the planet itself. If we followed a principle of “charity” in astronomy, assuming similarity between every celestial body and our own planet, we would end up with a hopelessly uniform account of astronomical reality. Not every object out there is the size and mass of the earth, with the same quantities of basic elements and geological structure. Not all planets have the same “planetary scheme”.

            And the same point applies to radical interpretation directed inwards. We also seek to discover what goes on in our unconscious—we need a way to figure out what beliefs and desires exist there. For the sake of concreteness, let’s accept a Freudian account of the unconscious: how shall we find out what we unconsciously think and feel? One view would be that we should use a principle of charity: we unconsciously think and feel what we consciously think and feel. But what is striking about Freud’s unconscious is how much it is supposed to differ from our conscious life; so charity would get things quite wrong. Instead, we need to adopt a more circumspect and holistic approach, appealing to free association, dreams, neuroses, jokes, slips of the tongue, and the early family dynamic. We need to look at how the unconscious manifests itself in our lives—as we need to look at the way other people’s minds manifest themselves in their lives (particularly in culture). Using a principle of charity will not do justice to the variety of minds. The basic assumption of that principle is that there is uniformity of the mental across all peoples and all types of mind: we all believe and desire pretty much the same things. So we could generalize the principle of charity into a “principle of uniformity”: all minds are pretty much the same—the same as ours, that is. And this is not an empirical discovery (as with linguistic universals) but a methodological requirement: we can’t interpret unless we assume uniformity.  [1]

This is like a principle of uniformity for planets: all planets resemble the earth. Granted, there may be some similarities between the various minds and the various planets, but they won’t be as great as the principle of uniformity supposes. We can’t sidestep empirical anthropology and astronomy by announcing an a priori principle that guarantees that everything resembles the local conditions. Just as there can be different “astronomical schemes”, so there can be different conceptual schemes. Surely no one would advocate a principle of uniformity in biology, according to which every species must have the same basic anatomy and physiology as humans—there is clearly great variety in animal bodies. We don’t do zoology by consulting our own bodies and then assuming every body is built like ours; we have a look at other bodies and find out their individual structure. Radical interpretation is no more conducted from the first-person standpoint than radical zoology is. And it is perfectly conceivable that a group of believers disputes every opinion we hold, from what is in their immediate environment to the general nature of the universe. Things differ from place to place and any method for discovering how things are needs to respect this variety. Projecting our own mind into the mind of the alien other is not the way to further human understanding.

 

  [1] It would be different if it were a natural law that everyone shares the same beliefs, but that is not the reasoning behind the principle of charity (and is very implausible); the idea, rather, is that charity is the only viable method of belief attribution.