Apes and the Idea of Kindred
In PAOLA CAVALIERI & PETER SINGER (eds.), The Great Ape Project
New York: St. Martin's Griffin, 1993, pp. 113-125
How Were the Apes Demoted?
There was serious debate in the seventeenth and eighteenth centuries as to the precise limits of humankind. Monboddo, in particular, concluded that such apes as the orang-utan and chimpanzee (counted together as the Ouran Outang) were of our kind, a notion satirised by Thomas Love Peacock in Melincourt, in the person of Sir Oran Haut-ton, a parliamentary candidate for the rotten borough of Onevote.
They are exactly of the human form, walking erect, not upon all-four. . . . They use sticks for weapons; they live in society; they make huts of branches of trees, and they carry off negro girls, whom they make slaves of and use both for work and pleasure. . . . But though from the particulars mentioned it appears certain that they are of our species, and though they have made some progress in the arts of life, they have not come to the lengths of language.
Monboddo was gravely misinformed in some respects, and engagingly open in his judgement that our species-nature was shown chiefly in war, rape and domination rather than, as tradition said, in the use of language. He guessed right, though perhaps for not entirely happy reasons, that 'if ever men were in that state which [he] call[ed] natural, it must have been in such a country and climate as Africa'. Maybe he guessed wrong about our species-nature. His inclusion of apes within 'our kind' is matched by those of his contemporaries who excluded Hottentots (like Voltaire). Those who insisted, with J.G. Herder, that 'neither the Pongo [probably the chimpanzee] nor the Longtmanus [the gibbon] is your brother; but truly the American [that is, the Amerindian!] and the Negro are', now occupy the scientific and the ethical high ground. Any attempt to re-open the question is bound to seem offensive, especially if it is conjoined with the somewhat salacious details enjoyed by earlier anthropologists and explorers. I share with liberal critics a suspicion that supposedly 'objective' examinations of, say, the brains of 'Australids' (that is, native Australians), orang-utans and 'Europids' are profoundly racist in their motivation and execution. But there really are important questions here. The story of the exclusion of such apes from 'our' kind requires an examination of the relations between folk taxonomy (which is strongly evaluative) and scientific taxonomy ( by which biological taxa are defined genealogically). What follows is a beginning.
Either we are simply natural products of evolutionary processes or we are not. In this part of the chapter, I explore the former hypothesis. My conclusions are very much like those of Richard Dawkins in Chapter 7: if we are products of evolutionary processes, then any objective judge would be likely to count us together with the other apes (just as we think ants or dolphins or finches are of single kinds even though there may be many (strict) species of ant, finch or dolphin). This is not to say that all such kinds display a single nature. Chimpanzees and pygmy chimpanzees and gorillas and orang-utans and humans are different in many ways. But it does not follow that they are not of the same biological kind. To explain this in more detail than Dawkins attempts, and to show why it is that moralists have neglected this, requires careful attention. Nothing that I say in this section is really original, but it is sufficiently unfamiliar and unwelcome to sound both strange and difficult. Really, it is neither.
One of the points on which philosophers have yet to agree with biologists is that there are no natural biological kinds in the sense once intended. 'Natural kinds', so-called, are sets of creatures with a shared, distinctive nature, but biological taxa, including species, are not so defined. Even if all members of such a taxon happen to have shared, distinctive properties that is not why they are its members. Cows are not mammals because they feed their young on milk; bovine mothers feed their young on milk because they are mammals. Being a mammal is being genealogically linked with a complex individual, the order Mammalia, such that its members are more closely related to each other than to members of any other order. This is not to say that they more closely resemble each other. The order's members, or those now judged to have been its members long ago, were not always more closely related to present-day mammals than to their non-mammalian contemporaries. Even now, there may be mammals that look more like non-mammals than they look like any other existing mammals. There might even be mammals whose parturient females do not secrete milk, just as there might be birds without wings or feathers. They are not therefore 'imperfect mammals', though such phrases are not wholly unhelpful. When Aristotle identified seals, for example, as 'deformed quadrupeds', he was partly right - though any implication that seals are therefore not what they should be must be resisted (Aristotle also suggested that women were deformed men!). Whereas philosophers still tend to believe that there are 'typical' members of a taxon, and to be as eager as Aristotle was to identify defect or anomaly, modern biologists think that cheetahs are as obviously cats, Down's Syndrome children as obviously human, as any 'type-specimen'. Either might have been the type-specimen of the relevant taxon, because the biological type of a taxon is simply the specimen (however unusual it eventually turns out to be) that serves as the referential tie for that particular taxon.
Biological taxa are individuals. That may seem thoroughly mistaken: surely taxa are sets of individuals who more or less 'resemble' each other? Quine stated that a biological kind is the set of all things 'to which [the paradigm] a is more similar than a is to [the foil] b'. There may be such sets, but they are not the same as taxa. Drosophila pseudoobscura and Drosophila persimilis are sibling species, indistinguishible to naive observers, but certainly distinct (because their members do not successfully breed together). If one such species vanished from the world, but there later appeared creatures indistinguishable even to an expert eye (but having a different ancestry) the older taxon would not have reappeared. The dodo, once extinct, is gone forever, because 'dodos' are not just those creatures that look more or less like the pictures, nor even those creatures whose DNA looks more or less like that of the old birds (if we could discover this). There is no need for members of a given taxon to resemble each other more than any of them do members of another taxon. There is no need for them even to share any particular genes which are not shared with creatures of another kind. So being a member of that taxon is not a matter of instantiating any non-historical property, whether obvious or hidden away. The taxon is an individual, and ordinary individuals are parts of it, segments of a lineage. 'Academic classification extends to classes, which it divides according to resemblances while natural classification divides according to relationships, by taking reproduction into account.'
Where two or more species emerge within a previously existing taxon that till then had only been one species, it is customary to give both of them new names, even if one such species is indistinguishable to us and to its members from the older species. If the earlier species merely develops, as a single population of interbreeding individuals, taxonomic practice varies: some will judge that the differences are such that if the species had been contemporaneous they would not form a single breeding population; others that there is no clear break between the old and new, which may as well be counted as one species. Homo erectus, Homo habilis and Homo sapiens can be one species or three. Traced back through time, of course, the difference between species will often seem quite arbitrary, even when there are two or more daughter species to consider. Why, after all, should x be a different species from y merely because there is another species, distinct from x but equally descended from y? If that other species had not been discovered, or had been extinguished before it was truly established, x would be uncontroversially the same species as y. Even at one time there are populations which reveal the transience of species: the different varieties of herring gull described by Richard Dawkins in Chapter 7 are one species in the sense that genes from one variety can spread, by degrees, to any other, but they are two or more species if particular varieties are paired. This phenomenon is, in Kant's terminology, a Realgattung, a historical collection of interbreeding populations, and in more modern terms a Formenkreis, or ring species. It is probable that humankind, historically, is such a Realgattung; it may even be that it still is, that there are particular varieties within the species that would be judged different species if the intervening varieties were lost. As Dawkins points out, humans and chimpanzees are judged to be of different species precisely because the intervening varieties are indeed extinct.
Once synchronic species barriers are established, the flow of genes will be restricted: that is what species barriers are, and that is why lions and tigers are of different species. But their ancestors were not, and genes flowed equally from the urcat to lion and tiger populations. It is because there are, by hypothesis, no diachronic species barriers, that some have reckoned that palaeospecies (like Homo habilis) are only metaphorically species at all. Nor can we always claim that the barriers against interbreeding were established by some other general change in the character and conduct of ur-lions and ur-tigers. More likely the barriers were established, by distance or mountain or river, for reasons having nothing to do with any original characters, and the other general differences accumulated since. We cannot even be sure that what had seemed like barriers against interbreeding are always more than accidents of preferences or opportunity: maybe lions and tigers would interbreed successfully often enough to identify them as a ring species if enough of them had the chance. There is good reason, after all, to think that domestic dogs, wolves and coyotes are really all one, variegated species such that not all its varieties will willingly interbreed. Lose all the other dogs, and wolfhounds and chihuahuas would be unlikely con-specifics — far more so than Voltaire reckoned 'Hottentots, Negroes and Portuguese'.
But surely human beings are all one species in a more important sense than this? Maybe other grades of taxon, family or order or phylum, are merely genealogically united. Maybe there are taxa that look like species but are really not. Species, real species, are, precisely, special. Don't members of a single species share a nature? Don't human beings? Isn't that the axiom on which humanism and the United Nations charter depend? If modern biological theory suggests that there need be no shared natures, no perfect types, and even that the purity of species must be questioned, so much the worse for biological theory. The Negro and the American must be our brothers and sisters, and therefore must be like us. It is insufferable to suggest that there are real varieties of humankind that might not willingly interbreed. Still less sufferable to imply that Pan, Pongo, Gorilla and Homo might perhaps have been, or still may be, a ring species. What varieties of Homo might breed, or once have bred, with Pan? Isn't there a submerged, and prurient, racism at work here? 'Ape' is an easy, racist insult. Those whites who use it should perhaps be reminded that most commentators, worldwide, will suspect the smelly, hairy Europids (which is, 'the whites') of being 'closest' to the ape. Do we need to abandon biological science to avoid being racists?
Racism, on the contrary, is the natural expression of misplaced essentialism, the belief that groups embody different natures. Or else it is an early version of the barriers against interbreeding that establish distinct species. New species is but old race writ large. There need be no antagonism between such newborn species: the consequence may actually be a lessening of competition, because the species eventually graze in different places and on different things. There may also be a reduction in adaptive variation, since one newly distinct lineage has lost the input from the other. There may be many good reasons for us not to allow the emergence of barriers between human varieties, and maybe the other breeds of hominoid are now sufficiently distant (as once they were not) from 'ours' as to make all present interbreeding doubtful. But we do not know this to be true. I do not recommend the experiment -but mostly because the fate of any such cross-breed as that imagined by Dawkins would probably be to serve as laboratory material. As long as misplaced essendalism rules, we will suppose that cross-breeds do not really share our nature, that they are throwbacks to a pre-human kind not 'of our kind'. The truth is otherwise.
A further difficulty for moralists is the rejection of norms in nature. If there is no one way of life and character which best suits all or most members of a particular kind, such that we may detect deformity, disease or deviance by comparison with that ideal type, can there be 'a good human life'? Can we truthfully suggest that battery chickens are deprived by being denied 'the' life that chickens would live 'in nature'? If species are only genealogical groups, such that members need not especially resemble each other, we have no right to suppose that there is one way only (however vaguely defined) for any particular species. The limits of variation will be empirically discoverable: what a kind can adapt to will be shown by what as a matter of fact it does, and there will be nothing normative about its 'natural' life. Lineages evolve to make and fit their environments, or else are extinguished. I am a member of the Clark family: but not because I resemble other Clarks, nor yet because there is a way that Clarks will naturally live that is unlike the way that others live. Even if Clarks were more inbred than they are (and so approximated the condition of a species) they need not always resemble each other. There might be atavisms, sports, changelings or disabled Clarks, but they would all be Clarks, and such variations would not be failures: on the contrary, they would contain the Clarks' hope of posterity. Variation is not a dysfunction of sexual reproduction (even if animal breeders are annoyed if the line they are concerned about does not 'breed true'): it is what sex is for.
This may seem old news. After all, moral philosophers have insisted for most of this century that no natural facts are norms, that 'natural' is not necessarily a term of praise. They have even insisted that human beings are special because they have no single species-nature. The claim is flawed: partly because nothing has such a nature, and partly because the claim exactly identifies a nature shared, at least in potency, by every human being. As Aristotle said, we are creatures whose life is one of acting out decisions. Aristotle was less essentialist than his heirs, because he never identified that 'we' straightforwardly with a species.
Not all those born into our species will be capable of their own actions. In some the capacity for choice, or even for understanding, is missing from the start. The good life for us is the life well-lived by those who ask such questions. The very same moralists who have emphasised our freedom from natural constraint actually think but poorly of those who do not, or even cannot, make their 'own' decisions, and constantly deplore attempts to make divisions within the species, which we ought (by their account) to be entirely free to make. So once again the primary danger is not from the biologically grounded notion of kinds, but from our habitual confusion of species and natural kind. We can find out a lot about what individual creatures need and like, what sort of lives they can arrange to live together. We do not need to think that there are goals that only and all conspecifics share.
A fully Aristotelian ethic can accommodate the remarks on species-natures that modern biologists endorse. 'We' means only those engaged, or potentially engaged, in this sort of conversation. 'We' are probably all human, as being members of the Realgattung of humankind. But not all our conspecifics need be self-motivating or rational in any way. 'Maybe all triangles must have three angles, but not all reptiles must have a three-chambered heart, though in point of fact they might'. By the same token, Monboddo was right to think that not all human beings must be able to speak. And creatures who are not now of our species, though their ancestors once were, may share as much with us as any disabled human. The thought is a dangerous one, no doubt. We are not long removed from moralists who deployed Aristotle's ethics to suggest that Amerindians were natural slaves, owed no respect as real images of God. Any suggestion that not all our conspecifics share our nature is heard as licence to oppress and kill. But there is no such licence, nor any proper argument from neo-Aristotelian premises to ignore the ties of kindred.
Who Is My Sister?
A fully modernised neo-Aristotelianism is probably inadequate, for reasons that I shall address below. But it may serve us for a moment. UNESCO's declaration that 'all men [sic] belong to the same species' was clearly intended as a moral commitment to the thesis that all human beings have very similar needs, and that those needs should be met by the global community, acting through the various national authorities that are the best we can yet manage (however obviously imperfect they are). It was certainly a necessary commitment, in the face of those who had sought to divide the species against itself, and create a new, predatory species on the ruins of the old. As a moral programme, some will say, there was no need to give reasons, or to found our commitment in any agreed facts. That we are all one species was never really a biological claim, as might be a similar assertion about dogs, wolves, dingoes and coyotes (but not marsupial wolves). Nor would its authors, we must suppose, have been really alarmed to find that humankind was rather a Realgattung that might easily become two or more species. They might not even have been moved by the discovery (if such there could be ) that not all our conspecifics possessed rational souls, or were capable of reasoned action. Moral commitments need not and cannot, so we have often been told, rest on any non-moral dictum.
This is not the time to explore that particular error, except to say that it is an error. If non-moral dicta are ones that can coherently be joined both to one moral dictum and its opposite, then it is, of course, impossible to demonstrate either one of those moral dicta from a dictum that, by definition, does not have moral implications. P cannot strictly imply Q if (P &c Q) and (P &c -Q) both make sense. It does not follow either that there are such 'non-moral dicta', or that strict demonstration is the only rational form of argument, or that there are no ordinarily factual dicta with moral implications. At the very least, ordinary moral argument is possible, and most of us expect to give some reasons, even if not demonstrative reasons, for the causes we endorse. UNESCO's declaration was not intended as an arbitrary judgement, a dictat of the world's new rulers: its authors obviously thought that those who disputed it were wrong.
They thought, that is, that our conspecificity should make a difference to the extent and nature of our obligations. Whereas what is now called 'racism' claims the right to treat human beings of other races less favourably than the racist's own, UNESCO's demand was that no differences of race, sex, age, intellect, capacity or creed should license what would otherwise be obvious injustice. It may be that one historical explanation of the slogan's popularity in the West, in addition to the shocked discovery of what racist jibes about 'backward races' had led to in the West, was the converse discovery that, for example, the Japanese so heartily despised the smelly, hairy Europids they captured. We all began to realise how vulnerable we were.
The natural conclusion has been that species differences do license such injustice, perhaps because such differences are real and predictable, and relevant to the nature of the putative injustice. Those reasons are not wholly wrong, but of course they hardly touch the real point: some of our conspecifics would not be injured by acts that injure us, just as some creatures not of our species would be injured by those acts. If what matters is only the quality of the putative injury, then there will be many occasions when, if we ought not to injure those capable of being injured, we ought not to injure those outside our species, and may do to
Apes and the Idea of Kindred our conspecifics what, in their case, will be no injury. That we are conspecifics plays no central role in the argument. Nor are any of the merely rationalist arguments very successful: respect for humankind's unity is not well represented by respect for rational autonomy, since not all human beings are thus rational. If UNESCO wished to oppose the Nazi project (as of course it did) it could hardly do so by endorsing the Nazi preoccupation with such forms of human living as they deemed rational. The object of the declaration was to oppose the extermination of the 'mentally unfit' or 'the backward races', and not merely to dispute the Nazis' identifications, as though their error was only a case of mistaken identity.
So it seems likely that conspecificity was really offered as a moral fact, a fact that ought to influence our actions and omissions. 'We be of one blood, you and I' was the slogan taught to Mowgli for his safety's sake. In that fictional case the slogan is a sort of magic, which compels courtesy even if it is literally false; or else it is a promise to live by the same law as is invoked, the rule of mercy. But part of its force, and the reason for the metaphor, is that we do care for our kindred. Because we share our ancestors and may yet share descendants, because we live under the same sky, are nourished by the same foods, share the same diseases even, we are part, and know ourselves a part, of one individual lineage. What we do to others of our kind we do to ourselves, because we are all one, variegated kind. It is not that we are all or most of us alike. Our pleasure in each other is that we are different, and yet the same.
The moral truth that lies behind the error that others have called 'speciesism' (and justly rebuked) is that we both do and should treat those 'of our kind' better. But now recall the remarks I have already made about the actual nature of a species. We retain the word as physicists retain the word 'atomic'. But modern atoms are not atomic (which is indivisible), and modern species are not specific (any more than Aristotle's were). Species kinship rests on relationship, and not resemblance, although there will be various similarities to reckon with within and without the kind. UNESCO's sloganeers did not recognise that Pan, Pongo and Gorilla were our sisters, any more than the writers of the American Declaration of Independence fully realised what they had committed themselves to by saying that all men were equal. They and their successors could have insisted that no mention was made here of women, or that the obvious intention at the time was not to include Negroes (since the passages denouncing Britain's involvement in the slave trade were, of set purpose, omitted from the final document). Instead, the real implications were allowed to emerge. All those of one kind with us begin as equals: we are, each one of us, a part of one long, variegated lineage, sharing enough of our habits, gestures and abilities to reveal our common source.
The real danger to a decent humanism (that is, to the rule of law, the rejection of oppression and genocide) is not from those who emphasise our kinship with the other apes, but from those who rest the demands of humanism only on resemblance. Resemblances are easily denied or altered; historical relationships are not. Not all our kindred are adept at language of the familiar, human kind; not even all our ordinary conspecifics are. It is enough that we are apes together, and know from the inside what it is usually like to be a versatile, manipulative primate with a sense of family and friendship. The American and Negro are indeed my sisters and my brothers; so also are the other apes who form, with us, the great individual, Hominoidea (which is the greater humankind).
What then is the good life for Hominoidea? Hominoids live well when they can gather in friendship, in groups small enough that their individual status can be recognised and large enough that they can find congenial companions. They live well when they are fairly secure from arbitrary arrest and murder, with some opportunity to innovate and to explore. Who can secure this for them? Plainly, at present, only those with power and foresight enough to face and solve the problem. There is a risk that any such creative minority will conceive itself to be an intellectual and political elite, and run things only for its immediate interest. It is certainly a good thing that recent elites have been constrained at least to pay lip service to the slogan that all human beings are 'equal' and all owed a like respect which they cannot enforce. Demanding a similar respect for hominoids (including, please remember, us) may place too great a strain on intellectuals still in the grip of fantasy. With care, however, we may risk the attempt.
The Spiritual Form of Humanity
I said before that either we are simply natural products of evolutionary processes or we are not. If we are, then it seems clear that there are no rigid boundaries between species groups, that species, and other taxa, are quite real, but only as Realgattungen. There is a real difficulty, however, in believing this, despite the efforts made by other contributors to this very volume to expound a fully naturalised epistemology. The argument, which is a powerful one even if it has not convinced all theorists, runs as follows. If we are the products of evolutionary processes, then we have no good ground for thinking that our thoughts are anything but none-too-harmful fantasies. As Nietzsche saw, we must presume that we have evolved as the descendants of creatures who could ignore a lot, who could live out their fantasies. There is nothing in evolutionary epistemology to give us reason to expect that we would care about the abstract truth, or ever be able to obtain it. If the theory is correct, we have no reason to think that we could find out any correct theories, beyond (at best) such truths or falsehoods as we need to obtain the next meal or avoid being one. And so we have no reason to suppose that any theory that we have devised is really true, including the current theory of evolution. Only if the divine reason is somehow present in us can we expect that we could find out truths, or trust our moral instincts. That, after all, was what Enlightenment thinkers thought, borrowing a Platonic doctrine about the powers of reason that does not fit the neo-Aristotelian framework I have so far described.
This alternative picture — that evolutionary theory does not leave room for the kind of being we have to think we are (namely truth-seeking and would-be moral images of a divine reason) - is what has often lain behind attempts to insist upon a radical disjunction between apes and people. But there is a better answer. Plato, after all, denied that it was sensible to contrast human and nonhuman things, creatures of our specific kind and all others. We might as well divide the universe into cranes and noncranes. By his account (or at least the account developed from his writings), there are indeed real natures, but they are not identical with the things that partly remind us of them. Even we ourselves are not wholly identical with the Form of Humanity, though we are called to serve it. The Form of Humanity is the divine reason, and we are indeed more human, in this sense, insofar as we think and do as the divine reason requires. The true image of humanity, for us, is the saint or perfect sage.
How are such forms related to the Realgattungen I have described before? Simply enough: one lineage after another has tuned in (as it were) to the Form of Life-at-Sea, and so produced the lesser kinds of shark, mackerel, plesiosaur, whale, dugong, seal. Life-in-Society has found its images among the ants, termites, bees and mammals. Maybe we can bring the Form more clearly into temporal existence, but we can hardly do so by denying all its influence on beings outside our immediate kin, as if it were our possession. If saints are the ones who best embody Humanity (as the Platonic tradition would suggest), then we will do the best we can by imitating them. From which it follows that we should respect those other 'apes', our kindred.
If there are no natural kinds but only Realgattungen, then it is reasonable to think of ourselves as parts of Hominoidea, 'greater humankind'. If there are such kinds as Platonists imagine, and 'we' here now are partial imitations of the Form of Humanity, let us imitate it better by being humane. Such Forms require no special ancestry, nor can we boast of being children of Adam, as if the Creator could not raise up new children of the spirit from the dead stones. That spirit, if it is so truly universal as to contain the truth of things (which is the condition of our finding truth), must also be present everywhere. If we should respect Humanity in ourselves and others we should, by the same token, respect the other creatures that reflect that Form in however tarnished a mirror. If we are apes, let us be apes together. If we are 'apes' (as aping the Divine), let us acknowledge what our duty is as would-be saints and give the courtesy we owe to those from among whom we sprang. Either we evolved along with them, by the processes described elsewhere, or else we evolved, in part, to imitate a Divine Humanity. Neither theory licenses a radical disjunction between ourselves and other apes. Either may give us reason to esteem and serve the greater humankind.
 T.L. Peacock, Melincourt (1817) especially ch. 6.
 Lord J.B. Monboddo, Of the Origin and Progress of Language (Kincaid & Creech, Edinburgh, 1773-92), cited in J. Baker, Race (Oxford University Press, London, 1974), p. 23.
 Monboddo, Origin, book ii, ch. 5, cited in Peacock, Melincourt, ch. 6.
 See Baker, Race, pp. 19f.
 Cited in Baker, Race, p. 22.
 See Baker, Race, pp. 292ff., after E. Smith (1904).
 S.R.L. Clark, 'Is humanity a natural kind?', in Tim Ingold (ed.), What is an Animal;1 (Unwin Hyman, London, 1988), pp. 17-34.
 See E. Sober, 'Evolution, population thinking and essentialism', Philosophy of Science, vol. 47 (1980) pp. 350-83.
 On which see S.R.L. Clark, Aristotle's Man (Clarendon Press, Oxford, 1975), ch. 2.2; and S.R.L. Clark, 'Aristotle's woman', History of Political Thought, vol. 3 (1982) pp. 177-91.
 D. Hull, 'Are species really individuals?', Systematic Zoology, vol. 25 (1974) pp. 178-91.
 W.V. Quine, 'Natural kinds', in N. Rescher (ed.), Essays in Honour ofC.G. Hempel (D. Reidel, Dordrecht, 1969), p. 9.
 I. Kant, Gesammelte Schrifften, vol. 2, pp. 427-33, cited in Baker, Race, p. 81.
 For further details of modern taxonomic practice see E. Mayr, Principles of Systematic Zoology (McGraw-Hill, New York, 1969); C. Jeffrey, Biological Nomenclature (Edward Arnold, Cambridge, 1973); C.N. Slobodchikoff (ed.), Concepts of Species (Dowden, Hutchinson & Ross, Stroudsberg, PA, 1976).
 Questions sur I'encyclopedie, cited in Baker, Race, p. 20.
 All these are genera, with several species usually included in them (as Pan satyrus paniscus, the pygmy chimpanzee). Linnaeus identified the chimpanzee instead as Homo troglodytes. Nowadays, the level of the taxon is determined by professional judgement having to do with presumed ancestry and relative degree of relatedness.
 See S.R.L. Clark, 'Slaves and citizens', Philosophy, vol. 60 (1985) pp. 27-46; and S.R.L. Clark, 'Animals, ecosystems and the liberal ethic', Monist, vol. 70 (1987) pp. 114-33.
 D. Hull, Philosophy of Biological Science (Prentice-Hall, Englewood Cliffs, NJ, 1974), p. 79.
 R. Kipling, The Two Jungle Books (Macmillan, London, 1910), p. 49.
 Since scientists generally learn their Aristotle solely from Enlightenment anti-scholasticism, their picture of Aristotle is unrecognisable to any competent Aristotelian scholar; see D.M. Balme, 'Aristotle's biology was not essentialist', Archiv fur Geschichte der Philosophie, vol. 62 (1980) pp. 1-12.
 This is technically a superfamily, including Pongidae and Hominidae as families. The pongids include gibbons and siamangs as well as the great apes and now extinct varieties such as Ramapithecus. Hominidae includes Australopithecus, Pithecanthropus and the various, mostly extinct, species and palaeospecies of Homo. These classifications, remember, are still guesses about the likeliest historical relationships. Pithecanthropus is classed by some in Homo.
 See further S.R.L. Clark, God's World and the Great Awakening (Clarendon Press, Oxford, 1991).
 Plato, Politicus, 263d.