Pluralism

the classification – and what is interesting depends on the circumstances.

Therefore we need different species concepts depending on what we want to study.⁶¹³

Thomas Reydon claims that his own view does not belong to pluralism, but that it takes one more step and goes beyond pluralism.⁶¹⁴ He claims that the different species concepts do not just represent different ways of classifying the same thing, but that they in fact deal with four different scientific questions.⁶¹⁵ The term ‘species’ is according to him used both for units of classification, and for units of generalisation. As units of classification, species are used as the units to which we attach our knowledge of the living world. As units of generalisation, species are used as the units of scientific explanations and predictions. He does not believe that the same concept can play both roles.⁶¹⁶

An interesting example of the problems of squeezing all life forms into the same species concept is ciliates. Ciliates are very difficult to classify, and David Nanney, who studies them, asks why we believe that we should be able to use the same taxonomy to organise ciliates as we use for organisms with a much shorter evolutionary history.⁶¹⁷ This looks like a reasonable question. Why would all life forms divide themselves in distinguishable groups along the same principles when they do not evolve along the same lines in other respects?

As a result of these considerations, not only the authors mentioned above, but several others as well advocate pluralism regarding species concepts.⁶¹⁸ It has also become more popular in recent decades.⁶¹⁹ According to pluralism, there is not one universally correct way of classifying organisms into species. Instead, there are many equally legitimate ways of classification – different systems for different purposes.⁶²⁰

Pluralism would help us deal with the problems above by letting us use different species concepts for different purposes or different life forms. It also lets us account for the flexibility and dynamic in nature,⁶²¹ and it would help us adapt theory to practise. When biologists talk about species they are quite pluralistic.⁶²² There also seems to be a difference between ordinary language classification and scientific classification. This is according to Dupré an argument for pluralism. We need different classifications not just for different scientific studies, but also for ordinary life. It is, for instance, rational to distinguish between onion and garlic in gastronomy but not in biology.⁶²³

613 Dupré 1999 pp.5,11

614 Reydon 2005 p.150. It seems to me, however, that since it accepts more than one species concept it can still be classified as pluralistic, at least for the purposes of my investigation.

615 Reydon 2005 pp.136f

616 Reydon 2005 p.138

617 Nanney 1999 p.111

618 As pointed out by Bock 2004 p.178, Dupré 1999 p.3, Horvath 1997 p.225, Hull 1999 p.31, Wilson, Robert A. 1999:1 p.192

619 Reydon 2005 p.150

620 Dupré 1999 pp.4,6

621 Horvath 1997 p.225

622 Rossello-Mora 2003 p.325. This also fits with my own experience from talking to biologists.

623 Dupré 1993 pp.28ff

Not everyone agrees that pluralism is a good idea, however. Christopher Horvath argues that the primary role of the species concept is to identify a unique biological unit. This does not work if we resort to pluralism.⁶²⁴ On the other hand, it is questionable whether finding a unique biological unit is particularly important for biology.

Wilkerson is very critical against pluralism in general and against Dupré in particular. He denies that scientific classifications (contrary to ordinary language-classifications) are a matter of differing human interests.⁶²⁵

I believe, however, that Wilkinson has misunderstood Dupré's point.

Scientific taxonomy reflects the interests of those who make the classification in the sense that depending on what you study you might need to divide the natural world in different ways. Wilkerson divides the world of human interests regarding taxonomy into groups such as zookeepers, cooks, taxidermists, gardeners – and biologists.⁶²⁶ He agrees that the former groups have different interests but he seems to deny that the last group have any interests at all, and in particular that different biologists have different interests. To assume that biologists have no interests seems odd and that they do not have different interests is also difficult to believe.

When it comes to the question of whether biologists have interests at all, Wilkinson suggests “biological classification”, “producing a classification that is usable” and “to gain prizes and honors …” as possible human interests among biologists, and he concludes that none of these answers are worth taking seriously, since the first is circular, the second trivial and the third just cynical.⁶²⁷ The interesting thing is that he has forgotten the most obvious answer: Biologists want to study nature. That is their interest.⁶²⁸ Studying nature can, however, be done in different ways, and most importantly, one can study different parts and different aspects of nature. Two biologists who want to study different aspects of nature obviously have, at least partially, different interests and it might be that these different interests call for different classifications. Biologists too come in different types. There are ecologists, geneticists, evolutionary biologists, etc. Just like zoo-keepers and cooks have reasons to divide the living world in different ways because they are interested in different aspects of the organisms they work with, so do evolutionary biologists and ecologists have reasons to divide the living world in different ways because they too are interested in different aspects of nature.

A more worrying problem with pluralism is that it might be rather confusing to use different species concepts for different purposes. Before Linnaeus, almost every biologist had his own taxonomy and Linnaeus’ big achievement was that he changed that. To resort to pluralism looks like a big step backward in that respect. David L. Hull exclaims: “We are drowning in a sea of

624 Horvath 1997 p.225

625 Wilkerson 1993 pp.10ff

626 Wilkerson 1993 pp.10ff

627 Wilkerson 1993 p.13

628 They might obviously have other interests too, but they do not seem to be relevant here.

species concepts”. For him, the cumbersome excess of species concepts is a good reason to be more monistic.⁶²⁹

Hull has tried to find the best compromise species concept by testing different concepts against three basic criteria: Applicability, significance and universality. It turned out that concepts that were easy to apply had a low significance, and conversely, concepts with a high significance turned out to be difficult to apply. There also seemed to be no covariance between the degree of universality and the other two criteria. Thus, he did not manage to find any concept that managed to cope better than the other concepts with all three criteria.⁶³⁰ This is of course a big problem for the monistic approach. In spite of that, and in spite that he agrees that classification systems are theory dependent,⁶³¹ Hull maintains that even if he cannot find one taxonomy that is equally useful for all purposes, it is at least in principle possible to find one single taxonomy and even if it is not possible to find one system that fits all purposes equally well, it is still better to have one taxonomy than to have several.⁶³² He compares taxonomy with the periodic table.⁶³³ There are many possible ways of ordering the elements, and clearly there are other ways of doing so that would be more useful for certain purposes, but it is still a good idea to have one universally accepted classification.

Even Dupré acknowledges that it would be good if we could have one universal species concept, but he does not believe that nature works that way or that the consequences of not having a universal species concept are as bad as some have suggested. Instead he believes that the advantages outweigh the confusion of having more than one concept.⁶³⁴ On the other hand, in spite of his pluralism, he talks about the desirability of a lingua franca in which specialists from different disciplines can speak with each other.⁶³⁵

The practical difficulties in using more than one species concept might be a good pragmatic argument in favour of monism but it is probably not enough for ecocentrism. In order to be able to claim that species have morally relevant interests in their own right, we need something more solid than a pragmatic need for a common terminology.

What would pluralism in general mean from a preservation perspective – and in particular from an ecocentric perspective? In order to know what is wrong when a species goes extinct, we need to know what we lose. Is the problem that there will be no more flying fury things, or is the problem that there will be no more representatives of a certain branch of the evolutionary tree, or that no one will fulfil the function of eating insects and pollinate plants, or that a group of genes will disappear, or that there will be one less interbreeding population in the

629 Hull 1999 p.44

630 Hull 1999 pp.41f

631 Hull 1999 p.36

632 Hull 1999 p.35

633 Hull 1999 pp.35f

634 Dupré 1993 p.52 Rossello-Mora (Rossello-Mora 2003 p.325) agrees about the unimportance of finding a universal species concept.

635 Dupré 1999 p.18

world? From an anthropocentric perspective, one can imagine different answers to this question that are all relevant. As we have seen in previous chapters, different life forms represent a wide range of different values for human beings.

It therefore seems that pluralism would work very well from an anthropocentric perspective. From that perspective it can be problematic if a certain phenetic species disappear and it can be just as problematic if a certain biological or phylogenetic species disappear, or if the number of biologic, phenetic of phylogenetic species decreases.

From an ecocentric perspective things are different. It is not really the properties we are interested in. The problem is not that a certain function will be lost, as such, or that a certain interbreeding population or evolutionary lineage will be lost as such. What we need to know is what it is that generates morally relevant interests. Is it the interbreeding population, or the gene sequence type, or the property of being furry and able to fly … etc.? The way we answer this question will decide how easy or how difficult it is to establish that species have interests, and it will decide what we have to do to establish that they do. The thing is, however, that the ecocentrists have not attempted to answer this question.

If we accept a pluralistic approach, the ecocentrists will have to explain how groups defined by the common properties of their members, how interbreeding populations, and how gene sequence types, etc. can have interests.

The more pluralistic we are the bigger the task of establishing moral standing for species will be.

Accepting pluralism therefore looks very problematic for the ecocentrists, but it might not have to be devastating. If nature is in fact divided in different ways, ecocentrists will have to accept that but they do not necessarily have to use all species concepts that are found in nature. As we saw above, several of the pluralists argue that we need different species concepts for different purposes.

The ecocentrists could agree with that, accept pluralism, and find one species concept (not necessarily an already existing one) that fits with their purposes.

This presupposes of course that this concept represents a division that actually exists in nature. If it is just a theoretical construct it will be of no use for the ecocentrists. It will also have the drawback that the resulting species might differ substantially from the species that results from other species concepts. The units that gain moral standing might therefore not have much in common with the units that biologists work within their theories or the units people in general see as suitable for protection.

Rolston is, as far as I have found, the only ecocentrist who mentions pluralism regarding species concepts, though he only mentions it briefly. He acknowledges that it is problematic to define what a species is, and that a pluralistic species concept may be called for.⁶³⁶ He does not discuss any possible problems for his theory, but as we saw in the beginning of this section, the only thing he worries about regarding the species category is that species exist

636 Rolston 1988 p.135

independently of us. Does pluralism has any bearing on this particular question?

If it is impossible to find one correct way of classifying nature, maybe there is no correct way of doing it? Scott Atran, for example, suggests that we abandon the species category in the same way as, for instance, ‘ether’ has been abandoned by physics.⁶³⁷

Even if we do not go that far, it might still be quite difficult to maintain that species exist independently of us and that we can have moral duties to them if we take a pluralistic approach. McAlester believes that if species are real there can only be one best species definition.⁶³⁸ Hull, who is a monist himself, is also pessimistic regarding the possibility of being both pluralist and realist regarding species. He associates monism with realism and pluralism with antirealism, and he believes that the opposite combinations – monism/non-realism and pluralism/realism would be quite peculiar.⁶³⁹

Nonetheless, there are writers who claim to be both pluralists and realists.

Dupré and Horvath are both examples of this,⁶⁴⁰ and according to Horvath most monists are in fact realists.⁶⁴¹ This looks plausible as long as one sticks to the idea that nature divides itself along different lines. There is no problem in being both pluralist and realist if one assumes that there are just several ways of classifying nature that all correspond to the real world.⁶⁴²

This is apparently not true for all pluralists, however. Marc Ereshefsky agrees with Hull and claims that pluralism inevitably leads to the conclusion that species have no independent existence at all.⁶⁴³ According to Ereshefsky, the different species concepts do not have a common theoretically important feature, which he sees as a requirement for a category to exist.⁶⁴⁴ According to Reydon, there are two different kinds of pluralism. One that is pluralistic relative to the aim of those who classify, and one that is pluralistic in relation to the organisms that are classified. According to the former, any organism can belong to more than one type of species simultaneously. According to the other, a particular organism can only belong to one type of species but different species concepts are used to classify different organisms.⁶⁴⁵ It seems that the latter but not the former version of pluralism can be realistic.

From an ecocentric perspective it is absolutely vital that species have an independent existence. Otherwise it is impossible to see them as moral objects that have interests independently of our interests. This means that if Hull and Ereshefsky are right, ecocentrism cannot accept pluralism. If pluralism is correct and pluralism entails non-realism, then ecocentrism is doomed. If, on the other hand, pluralism is correct and can be combined with realism as claimed by, for

637 Atran 1999 pp.252f

638 McAlester 1962 p.1377

639 Hull 1999 p.25

640 Dupré 1993 pp.36, 57, Horvath 1997 p.228

641 Horvath 1997 p.228

642 Dupré 1993 p.36

643 Ereshefsky 1999 pp.290, 303 note 3

644 Ereshefsky 1999 p.295

645 Reydon 2004 pp.303, Reydon 2005 pp.151ff

example Dupré and Horvath, ecocentrism still has to deal with the problem of finding moral standing in more than one type of entity. The larger the number of, and the more diverse species concepts we accept, the more difficult it will be. If there really are several types of species out there and only one or a few of these types of species can be a basis for moral status, then ecocentrism will have to leave many existing species with no moral standing.