James Lovelock, Gaia Theory, and the Rejection of Fact/Value Dualism

Transcription

1 James Lovelock, Gaia Theory, and the Rejection of Fact/Value Dualism Department of Philosophy, University of Pisa, V. Pasquale Paoli, 15, Pisa, Italy; In this paper the relationship between Gaia theory and fact/value dualism must be understood from two angles: I shall use Gaia as a case study to show the philosophical limits of dualism, and I shall also use the discussion of fact/value dualism to clarify the contents of Gaia theory. My basic thesis is that Lovelock is right when rejecting the suggestion that he should clear his theory of evaluative considerations. He is right because in his theory facts and moral values are strictly interwoven and therefore cannot be conceptually separated. I shall show this point by arguing that if we dropped the evaluative components from Gaia theory we would not have the same theory cleared of those evaluative components. Instead we would have a theory with a different empirical meaning and different explanatory characteristics. 1. Introduction Commonsense tells us that facts and values are sharply distinct. 1 This view traces back at least to David Hume, who explicitly endorsed it. For Hume factual statements are true or false, while moral judgments can be neither true nor false, since they concern our feelings, sentiments, or commitments to action. Of course, since Hume many things have changed in philosophy. In environmental ethics many have already questioned the fact/value distinction derived from Hume. 2 Yet I shall argue that Gaia theory 1. This paper was written during my pleasant stay in Pittsburgh at the Centre of the Philosophy of Science. I wish to thank the Director of the Centre, John Norton, and all the participants in the reading group seminar for their helpful comments: H. Douglas, K. Khalifa, H. Kochiras, B. Leuridan, P.D. Magnus, R. Samuels, S. Schindler, P. Vickers, I. Votsis. I also wish to thank Peter Machamer and Marcello Pera, who have read and commented on previous versions of the paper. Finally, an anonymous referee and Ted Toadvine helped me improve the final version of the paper. 2. Cf. Næss 1989 (67): In an analysis that begins with the concrete contents, the is-ought and fact value dichotomies don t look quite as they did from where Hume started.... Expressions of the kind object x has value y immediately lead to the question: Given an object x, how do I assess its value? If we start with designations of concrete contents, for instance delicious, red tomato to be Environmental Philosophy <vol #> (<iss #>), <ARTICLE PAGE RANGE #-#.>. Copyright 2011 by Environmental Philosophy. Printed in the United States of America. All rights reserved.

2 2 teaches us a novel way of attacking dualism, a way which is more directly related to the received view among scientists and epistemologists. Indeed, I have little doubt that present scientific mentality is still largely indebted to Hume. Science, it is often said, is morally neutral, since it concerns only the way facts are, not the way they ought to be according to our preferences. The Gaia theory proposed by James Lovelock is at odds with this tradition. As a consequence, Lovelock has often been accused of concocting facts and values in a way incompatible with the correct procedures of scientific investigation. Lovelock s idea of a living Earth has encouraged a respect for nature, but it is argued that this value-laden view has hindered an unbiased scientific investigation. For instance, James Kirchner, whose criticisms I shall focus on soon, is rather trenchant on this point: Gaia s vision of Earth as a harmonious whole... is emotionally very appealing to me. [However] in the human enterprise of science, our most daunting task is to see things as they are, rather than as we wish they were.... We should get on with it, as free as possible from our preconceptions of the way the world ought to be (2002, 406). No doubt the vast majority of scientists would agree with Kirchner that moral values are foreign to science. Of course some scientists are ready to admit that Lovelock has helped science develop in the right direction. It is also thanks to Lovelock that it is now widely accepted that the evolution of life and the evolution of the environment are intertwined, each affecting the other. 3 In the eighties a new discipline was born out of this basic insight, namely Earth System Science, which is now illustrated even in some university textbooks. However, even the most sympathetic scientists disagree with Lovelock s unorthodox epistemology. What the scientific community at large suggests is apparently reasonable: as scientists, let us focus on Earth System Science and on the factual content of Gaia theory. Obviously, there is nothing wrong in defending the moral values usually associated with Gaia, but eaten at once or repugnant, rotten tomato the evaluative terms are there from the very beginning of our analysis. And there is no separable tomato to value! Just to give another well-known example, Holmes Rolston III writes: Some worry that we here commit the naturalistic fallacy.... But does it not rather seem that the facts here are value facts, when we are describing what benefits the tree? Such value is pretty much fact of the matter (1994, 19). 3. Kirchner 1991 and Kirchner 2002 deny any real novelty, but other scientists are fairer towards Lovelock. Cf. Kaplan and Bartley 2000 (295): Whether or not Lovelock s theory is accurate in its description of the effects of life on Earth, it has almost certainly caused scientists to think about the planet in terms of complex, interactive cycles, rather than separate, distinct entities

3 Gaia Theory and the Rejection of Fact/Value Dualism 3 these values lie beyond the scope of science. It is in this context that the above-mentioned Humean tradition comes to the fore. In this paper I shall question the dualism between facts and values in light of Gaia theory. I shall argue that Lovelock is right when rejecting the suggestion to reduce Gaia theory to Earth System Science so as to make his theory clear of moral considerations. He is right because in his theory facts and moral values are strictly interwoven and therefore cannot be conceptually separated. Note that in this paper the relationship between Gaia theory and fact/value dualism is bidirectional: I shall use Gaia as a case-study to show the philosophical limits of dualism, and I shall also use the discussion of fact/value dualism to clarify the content of Gaia theory. In the following section I shall state what I call the Gaian principle, along with a more analytic statement of the basic thesis of this paper. In Section 3 I shall focus on the empirical meaning the above-mentioned Gaian Principle. In Section 4 I shall show the moral content of Gaia Theory, which is intrinsically linked to the nature of the Gaian principle. In the last Section I shall finally vindicate and clarify (the otherwise somewhat confusing) claim made by Lovelock that his theory is both moral and scientific, and I shall show why Gaia theory is a good counterexample to the philosophy of David Hume and the received epistemological wisdom. 2. The Gaian Principle The reasons why Lovelock claims that Gaia, our Earth, is alive are rather complex. When defending this idea he does not hesitate to cross even the boundaries between science and religion. 4 Nonetheless, there is little doubt that he has also tried to qualify his view in such a way to make it palatable to a scientific mind. He makes it clear that Gaia is not a goddess or some sentient being (2005, 57). Obviously Gaia cannot reproduce, she cannot create baby-earths; neither has she a sense of purpose or a free will. Yet Lovelock emphasizes that life is a highly theoretical concept 5, and consequently he finds it legitimate to offer a different definition from those offered by neo-darwinists, physicists, and biochemists. For Lovelock, Gaia is alive in that it is a self-regulating system which is able to keep its internal conditions constant, despite changing external conditions (ibid., 29). 6 For instance, Gaia is able 4. Cf. Lovelock 1995 (194): Gaia is a religious as well a scientific concept, and in both spheres it is manageable. 5. As Lovelock writes: since no one has yet succeeded in defining life, why should anything as significant as life be the sole property of a single discipline of science? (1995, 16 and 27). 6. It is worth emphasising that Lovelock s definition of life does not lead us to counter-intuitively consider mechanical devices such as refrigerators and

4 4 to maintain both thermostasis and chemostasis. Furthermore, Gaia demonstrates a metabolism of her own (she takes in free energy from the environment and produces waste and low-grade energy), she is able to evolve, and even proves to be capable of self-healing processes. Compared with mammals, Gaia only lacks the capacity of reproduction. Additionally, she is endowed with thermostasis, which is absent in acknowledged living organisms such as bacteria and trees (ibid., 30). Thus, for Lovelock the basic point is that Gaia, our Earth, is a biogeochemical system with a highly integrated hierarchical structure, capable of selfregulation and preservation. In what follows I shall call this idea The Gaian Principle, which is at the core of Lovelock s theory. To understand correctly the nature of this principle we should carefully keep in mind that human beings, along with the whole biota, are a fundamental component of the system. We shall come back to the issue soon. The notion of selfregulation and preservation is more problematic. In the beginning, Lovelock thought of Gaia as a control system capable of keeping the Earth in homeostasis. 7 Later on, the upholders of Gaia have moved to broader concepts such as those of homeorhesis (which refers to dynamic systems returning not to a state, but to a given trajectory) or punctuated equilibria. 8 This change of view appears to be opportune, since the Earth s history shows several transitions between states of relative stability, as the critics of Gaia were quick to emphasize. 9 Fortunately, for my purposes I do not need to be more specific, and consequently we can understand the concept of self-regulation and preservation at an intuitive level. 10 ovens as alive. Mechanical devices can stay in a homeostatic equilibrium, but they are heterodirected. For instance, the particular temperatures of refrigerators and ovens are set by the users. On the contrary, Gaia is self-regulating. This distinction is equivalent to that between first order cybernetics and second order cybernetics. As Bruce Clarke writes: First order cybernetics is about control, second order cybernetics is about autonomy (2009, 295). 7. This is clear even in the title of the seminal paper by Lovelock and Margulis published in 1974: Atmospheric Homeostasis by and for the Biosphere: The Gaia Hypothesis. See also Lovelock 1979 (52ff.). 8. Cf. Lenton, quoted in Steffen and Sanderson 2005 (70): The notion of homeostasis was restricted to specific cases and time intervals and self-regulation adopted as a more general term.... Both homeorhesis (regulation around a moving point) and punctuated equilibria (a series of different stable regimes) were early suggested as a more accurate description of Earth history. 9. See Kirchner 1991 (41 2) and Kirchner 2002 (sec. 2). It is worth noting that Lovelock himself describes some of the dramatic changes the Earth went through. See Lovelock For a reply to Kirchner on the so-called Homeostatic Gaia, see Lenton and Wilkinson 2003, especially p Another problem concerns whether such properties can arise from a mechanism of natural selection. As is well known, Lovelock s theory has been

5 Gaia Theory and the Rejection of Fact/Value Dualism 5 It is important to note that not all the upholders of Gaia claim that the Earth is alive. Lynn Margulis prefers to consider Gaia a single giant eco-system, the properties of which emerge from the interactions between the biota and the environment. For Margulis, Gaia shows similarities with physiological systems, but only in a certain limited way. 11 On the contrary, Lovelock is happy with his unorthodox idea of life, even though sometimes he seems to admit that the idea of a living Earth is not that fundamental to his theory. 12 Indeed as I shall argue, within Gaia theory it is a minor point whether we consider the Earth alive or not. Those who are willing to defend the moral import of the theory should not be worried about this issue. One of my theses is that we do not need the concept of a living Earth to derive moral insights from the theory, such as the respect for nature. It is the Gaian principle that is truly fundamental, and it is worth noting that when stating the principle I have made no reference to a living Earth. This should also help us pour cold water on the issue, which has sometimes led to redhot discussions. Lovelock s ideas have attracted the attention of many people whose cultural background is sometimes clearly foreign to a scientific mentality: not only environmentalists, but also theologians, science fiction writers, mystics, and new age movements. 13 It is not surprising then that the vast majority of scientists have distanced themselves from Lovelock. I have no problem agreeing that Gaia theory has sometimes attracted embarrassing friends. Yet I disagree with scientists when claiming that Lovelock, as a scientist, should get rid of the moral content of Gaia charged with being incompatible with the neo-darwinism mainstream in evolutionary biology. For this charge see Doolittle 1981 and Dawkins 1982 (234 7). For an answer see, for instance, Lenton I shall not deal with this issue here. 11. Margulis 1996 (54): I reject Jim s statement The earth is alive ; this metaphor, stated this way alienates precisely those scientists who should be working in a Gaian context.... Gaia is an extremely complex system, a set of interacting ecosystems, with identifiable regulatory properties which are very specific to the lower atmosphere. Cf. Margulis 1998 (119 and 123): Gaia is not an organism. Any organism must either eat or, by photosynthesis or chemosynthesis, produce its own food.... The surface of the planet, Gaia theory posits, behaves as a physiological system in certain limited ways. The aspects that are physiologically controlled include surface temperature, atmospheric composition of reactive gases, including oxygen, and ph or acidity-alkalinity. 12. Cf. Lovelock 2005 (13): I recognize that to view the Earth as if it were alive is just a convenient, but different, way of organizing the facts of the Earth. 13. Some of these extravagant responses to Gaia are lively described in Turney 2003 (72ff.). As for the religious import of Gaia, of course not all religious meditations on Gaia are worthless. An eminent theologian, such as Moltmann, devoted much attention to Gaia. See Moltmann 1991.

6 6 theory. In fact, I shall argue that Lovelock is right in emphasizing that the evaluative content of Gaia is an essential component of his theory. In fact, values and facts are strictly intermingled in his theory, and in no way can we disentangle the moral component from the factual component. More specifically I set out to defend the following anti- Humean thesis: If we dropped the evaluative components from Gaia theory we would not have the same theory cleared of those evaluative components. We would rather have a different empirical theory. Of course, this is the same as saying that facts and values are strictly interwoven in the theory, and consequently cannot be conceptually separated The Empirical Meaning of Gaia Theory. In this section I shall state two claims. The first claim is that the Gaian principle is empirically meaningful. My second claim, which is strictly connected with the first, is that if we drop the Gaian principle we will end up with a different theory, namely a theory with a different empirical meaning and different explanatory characteristics. Many scientists have argued that Gaia is only a metaphor with no empirical meaning. Here I shall mainly focus on the works of James Kirchner, since he has shown interest in Gaia for many years. Kirchner notices that Lovelock has proposed different versions of the theory. Some of them, such as Co-evolutionary Gaia, simply state that the evolution of life and the evolution of the environment are intertwined. They are acceptable, but for Kirchner they are rather trivial. Others, such as Homeostatic Gaia, are more interesting but unfortunately have been falsified. 15 Yet Kirchner mainly focuses on what he calls Geophysiological Gaia, namely, the idea that the biosphere could be usefully modeled as a single giant physiological system that is capable of self-regulation and preservation. 16 This is precisely the basic characteristic of the Gaian principle as I have stated above. For Kirchner this form of Gaia does not belong to science, since it is only a vague metaphor that makes Lovelock s theory unfalsifiable. He explicitly refers to Karl Popper to substantiate his criticism Needless to say, if we accept the Gaian principle we are not forced to accept the extravagant metaphysical ideas often associated with the theory. On the contrary, it would be worth exploring the appropriate metaphysical presuppositions of Gaia, even though this is not the task of my paper. On this issue see the work of David Abram, Abram 1991 and Abram See Kirchner 1991 and Kirchner I have already referred to these versions of Gaia in footnotes 2 and See, for instance, Kirchner See Kirchner See also Kirchner To be precise, Kirchner s criticisms are ambiguous from a Popperian point of view. On some occasions, Kirchner seems to claim that the theory is unfalsifiable because of moral

7 Gaia Theory and the Rejection of Fact/Value Dualism 7 I am ready to admit that Geophysiological Gaia is not falsifiable. 18 However it is worth noting that unfalsifiability and lack of empirical meaning are two different concepts. Popper (and presumably Kirchner) makes a mistake when conflating them. As Popper writes: In so far as a scientific statement speaks about reality, it must be falsifiable; and in so far as it is not falsifiable, it does not speak about reality (1959, 316). Popper s statement cannot be accepted, unless we take for granted a questionable form of operationalism. As Coffa noted, in order for a theory to have empirical meaning it is sufficient to claim that it is possibly true, in the sense that we can conceive of a state of affairs that would make the theory true or false. 19 In this sense, the empirical meaning of a theory is independent of the existence of empirical procedures and methodological rules that allow one to test its truth or falsity. This is the case even when a sentence is unfalsifiable for strictly syntactic reasons. Let us consider a purely existential statement. As we know, there is no empirical procedure that allows its falsification, since the class of potential falsifiers (to use Popper s terminology) is empty. However, the statement does have empirical meaning, since we can conceive of a state of affairs that makes it true or false. We may claim that it speaks about reality since it is possibly true (think of a statement such as There exists an animal that can run faster than one hundred miles per hour ). Once more, the empirical procedures of testing and empirical meaningfulness of a statement are two different concepts. considerations, which unduly intrude into the realm of science. These considerations would make the upholders of the theory blind to negative results: when the data contradict... conjectures, it is essential to see them for the refutation they are (Kirchner 2003, 42). If this is the case, then Gaia theory is like Marx s theory, which was in the beginning testable but has survived empirical refutations only thanks to ad hoc moves. On other occasions, he suggests that Gaia theory is unfalsifiable because it is just a metaphor: Treating a metaphor as a scientific proposition that is factually true or false is simply a waste of time (Kirchner 1991, 40). This would make Gaia theory similar to psychoanalysis, which for Popper is an untestable piece of (bad) metaphysics. Yet these remarks are not exceedingly important for my analysis, and consequently I shall not dwell upon them. 18. As a (currently cautious) upholder of Gaia also claims: According to Popper, science proceeds by logically unjustified and unjustifiable conjectures, theories or hypotheses. These generate predictions which are open to refutation or testing. One problem with the Gaia hypothesis is that, in common with other conjectures in the field of Earth history, its subject matter is remarkably difficult to test by direct experiment (Watson 1996, 72). However, as we shall see soon, Watson does not make the methodological mistake made by Kirchner and Popper himself. 19. See Coffa 1973.

8 8 The relevance of this analysis for Gaia theory should be clear. Kirchner complains that Geophysiological Gaia is unfalsifiable. Yet, a theory that is unfalsifiable is not the same thing as a theory that, to quote Popper again, does not speak about reality. In fact, we can easily conceive of a well-defined state of affairs that makes the theory true. To illustrate this point I can refer to a paper by Andrew Watson. 20 I have drastically simplified his line of reasoning, but this will help us make his basic idea clear. The Gaian principle claims that when life takes hold it generates a highly integrated system that is capable of selfregulation and preservation. Now let us imagine that in the universe there are a fairly large number of planets showing signs of life. The majority of these are young planets. That would mean that life may appear quite often, but it is not resistant or resilient to exogenous shocks. Even worse, it could mean that life generates positive feedback loops or, in other words, that life tends to destroy itself. Elaborating on some insights of Kirchner, the paleontologist Peter Ward has recently put forward precisely such a hypothesis, the so-called Medea hypothesis (Ward 2009). On the other hand, if the vast majority of planets where life is present are old, that would mean either that life takes a long time to arise, or more plausibly, that once life takes hold it is bound to evolve in ways that lead to a self-regulating system that is able to preserve itself over time. In the former case we should not trust the Gaian principle, since there is evidence showing that we have been lucky so far. The latter case on the contrary supports the reliability of the Gaian principle. 21 I have used the word evidence, but what has been said has little to do with empirical testing. It is a thought experiment that appears to be remote from real science. This is so at least partially because of the simplifications I have introduced into Watson s line of reasoning. Yet, it clearly shows my point. Even though, as Watson is ready to admit, his claims are untestable speculations, given our state of near-complete ignorance about the distribution and properties of life on other planets (Watson 2004, 207), the Gaian principle is empirically meaningful in that we can easily conceive of states of affairs that make the principle true (or false). Thus, to reiterate, as soon as we break the link between testability and empirical meaning, as Coffa suggests, we can no longer claim that the principle has no empirical meaning. Now we are in a position to establish easily the second claim of this section: if we drop the Gaian principle we will end up with a different 20. See Watson See also Turney 2003 (148ff.). 21. The comparison between a Lucky Gaia, where life persists by mere luck, and an Innate Gaia, where life tends towards a self-regulating system, can be explored in more empirically oriented ways, without referring to the fantastic idea of a sample of planet where life is present. See Lenton 2002.

9 Gaia Theory and the Rejection of Fact/Value Dualism 9 theory. Many scientists have invited Lovelock to replace Gaia with the notion of an Earth System Science. As I have said, this new discipline was born in the 1980s and studies precisely the interactions between biota and the physical environment. Admittedly, it too was born thanks to Lovelock and his efforts to think globally. However, Gaia is not the same thing as Earth System Science. Earth System Science includes thousands of different lines of inquiry. It studies for instance the different biogeochemical cycles, such as the oxygen cycle, the carbon dioxide cycle, the sulphur cycle, and so on. 22 Though Earth System Science studies the interaction between life and the physical environment, it avoids assuming the existence of global mechanisms connecting life with the environment across the several features of the biosphere. The Gaian principle claims that biogeochemical feedbacks lead to a selfregulating and preserving system, and this claim, as Kirchner argues, is far from being accepted by mainstream science. 23 The differences between Gaia and Earth System Science are clear-cut. Yet, it is worth examining the issue also from the point of view of the models of explanations based on functional analysis. In fact, explanatory models based on functional analysis mark another difference between Gaia theory and Earth System Science. It is well-known that functional analysis is typically used by Lovelock. This is far from surprising, since the Gaian principle states 22. The studies of these cycles are at the core of Earth System Science, but of course this new discipline is not limited to them. Cf. Schulze et al (xviii): The discipline of biogeochemistry confronts a wide array of scientific and methodological challenges.... These are not limited to the cycles of carbon and nitrogen, but include the role of phosphorus, iron, calcium, aluminum, and acidity, to name just a few. 23. Basically, scientists are willing to accept that the biota and environment together form a system (what Kirchner calls Co-evolutionary Gaia ), but do not accept the idea that the whole system is in some sense self-regulatory. This is clear also in a textbook more sympathetic with Lovelock: Although there is little doubt that the word regulate is too strong, it is clear that the total biosphere plays a vital role in maintaining environmental systems (Fyfe 2000, 508). The difference between Earth System Science and Gaia theory has been made clear also by Volk (2002, 427 8): [I was asked] whether in my view Gaia theory is not equivalent to figuring out the global biogeochemical cycles. In some sense, yes.... In another sense, however, I also had to answer no.... What initially made Lovelock s ideas do exciting, in the early books, was the potential of a common explanatory principle behind many aspects of biosphere chemistry. Volk now rejects the idea of a self-regulating Earth, but he continues to believe that the quest for general principles should not be given up in favor of the present state of the Earth System Science: I do suggest that we also keep the essence of Lovelock s search. This essence is the possibility for general principles that apply across many specific instances of the biosphere.

10 10 that the Earth can be modeled as a self-regulating system emerging from the interaction between biota and the environment or, in its boldest version, as a real living organism. For instance he claims that: Within the context of Gaia, it is appropriate to ask what is the function of a gas such as methane. It is no more illogical than asking what is the function of glucose or of insulin in the blood.... What then, is the purpose of methane and how does it relate to oxygen? One obvious function is to maintain the integrity of the anaerobic zones of its origin. (2000a, 67) Admittedly, the concept of purpose might be misleading in this context. In fact, purposes are intentional phenomena, while organs have no intention: they arise by natural selection, and natural selection is a blind mechanical process. 24 Yet, Lovelock has repeatedly denied that the components of the whole system constituting Gaia act purposefully. Self-regulation of the system is simply an emerging property. 25 Thus, what Lovelock really means is that the science of Gaia should explain what the components of the system are for. His explanations are teleological in the weak sense that the theory aims to explain the functions of the components within the system, as it is altogether clear in the above quoted passages. Now explanations based on Earth System Science are not functional in character. They are not so because it is precisely the Gaian principle that makes functional explanations meaningful. By stating that Gaia, our Earth, is a self-regulating and preserving system, Gaian scientists look for specific underlying mechanisms that contribute to the functioning of the whole system. 26 In this way they are legitimate in claiming that components of the system (microbes, methane, carbon dioxide, and so forth) must perform a given function in order to allow the system to work properly. Without the Gaian principle they could only claim that those components happen to have given features and consequences, not that those components must work in a certain way 24. Again, here I have indirectly touched upon the problem whether Gaia theory is compatible with natural selection. Neo-Darwinists claim that it is incompatible, whereas its upholders rebut such a charge. I shall not deal with this issue. See footnote 9 for references. 25. As is well known, Lovelock has distanced himself from the strong teleological concepts implicit in his first works. In [my] first book I made mistakes. Some were serious, such as the idea that the Earth was kept comfortable by and for its inhabitants, the living organisms. I failed to make clear that it was not the biosphere alone that did the regulating but the whole thing, life, the air, the oceans, and the rocks (2000a, ix). 26. This is the rationale of the top-down or holistic approach often emphasized by Lovelock. For instance, see Lovelock 1995 (200ff).

11 Gaia Theory and the Rejection of Fact/Value Dualism 11 in order to allow the whole system to continue to work. Thus to have functional explanations we do not simply need highly interactive systems. We need systems where the features of the components and their interactions give rise to higher-level systemic features, the proper functioning of which depends on the functioning of the components. For instance, we are entitled to claim that the heart must beat regularly, because a decrease in the heart s capacity to pump blood regularly would affect the capacity of the circulatory system to deliver nutrients, and this in turn would eventually hinder the higher-level capacities of the organism, such as physical strength and the capacity of reasoning lucidly. 27 It is in this sense that Lovelock makes his bold claim of a living Earth, a claim that actually is not necessary in order to derive moral conclusions from the theory. As I suggested earlier and will explain shortly, we only need to assume the Gaian Principle, which is altogether neutral on this topic. The differences between Earth System Science and Gaia theory are apparent independently of functional analysis. Yet functional analysis adds further evidence to my point. Not only should we say that Gaia theory has a different meaning from Earth Science System, we should also say that Earth System Science and Gaia theory use different models of explanation, since the latter provides us with functional explanations that are not available in the former. As I have argued, the main difference is provided by the Gaian Principle. Therefore, I can finally draw my first conclusion, which I stated at the beginning of this Section: if we drop the Gaian principle we will end up with a theory with a different empirical meaning and different explanatory characteristics. 4. The Moral Content of Gaia Theory It is easy to misunderstand Lovelock when he speaks about ethical issues. His point of view is the point of view of Gaia, not that of human beings. 28 Admittedly, sometimes when we read the word we, Lovelock means we human beings, but most of the time he refers to the highly interconnected components of the whole system. 29 But what are the 27. Though I am not committed to any specific model of functional explanation, I wholeheartedly agree with Sheldon Davies on this point. See Davies 2001, especially ch Cf. Lovelock 1995 (xx): Gaia theory forces a planetary perspective. It is the health of the planet that matters, not that of some individual species of organisms. This is where Gaia and the environmental movements, which represent people not the planet, part company. Cf. Margulis 1996 (58 9): Gaia hardly requires man.... We are just another one of these mammalian weeds ; species that come and go every million of years. 29. This point has been well stated by Joseph (1990, 208): unlike most modern ideologies and doctrines, human beings, taken in groups or individually, are

12 12 moral implications of this peculiar viewpoint? We can find an answer through the works of ethical naturalists. The work of Philippa Foot in particular clarifies considerably the rationale behind Lovelock s moral conviction. In the works of both of them evaluative judgments are based on facts belonging to the natural world. The initial step of their approach is provided by the concept of organism. In fact, as soon as an entity is identified as an organism, we are authorized to introduce norms and evaluations that are based on facts of nature. For Foot and Lovelock this point is of fundamental importance, because in their view moral judgments show the very same logical structure as these norms and evaluations. When claiming that something is an organism, we mean that it is functionally organized. That is to say, we claim that the organism performs some vital processes in order to guarantee its self-maintenance. 30 When, for instance, we say that The heart beats regularly in order to pump blood, we precisely refer to a vital process of this kind. Note that the identification of an entity as an organism is conceptually antecedent to the ascertainment of what function a component of the organism performs. The specific function of components can only be established though empirical analysis. The very same could be said about the features characterizing the life-cycles of species. Without empirical evidence we cannot even know if a certain feature really performs any functions in the life-cycle of a given species. As an example, Philippa Foot compares the following two sentences: The blue tit has a round blue patch on its head, and The male peacock has a brightly colored tail (Foot 2001, 30ff.). 31 These two sentences appear to be similar, since both of them refer to the color of animal species. But to a less superficial analysis, they are very different. Peacocks colored tails perform a function in the life-cycle of that species. We know that male peacocks have brightly colored tails in order to attract female peacocks and allow them to reproduce. As a consequence, the knowledge of their function provides the answer to the question: Why do peacocks have such a characteristic? Instead, the round blue patch on a blue tit s head does not play any role of that kind. The color could be different without putting its survival and reproduction in danger. That is, it does not perform any function in the life-cycle of blue tits. Thus, the recognition of organisms and species not at the center of Gaian belief. We, in the Gaian worldview, start with the most primitive microbes and end up with the great planetary organism and do manage to include human beings along the way. 30. Cf. Foot 2001 (33): The way an individual should be is determined by what is needed for development, self-maintenance, and reproduction: in most species involving defense, and in some the rearing of the young. 31. On this issue see also Hacker-Wright 2009.

13 Gaia Theory and the Rejection of Fact/Value Dualism 13 requires the conceptual assumption that these entities are functionally organized, but only scientific research can inform us about their vital processes and characteristics. At the same time, using the same line of argument, such recognition allows us to make normative or evaluative judgments. Let us take our previous functional explanations, The heart beats regularly in order to pump blood or The male peacock has a brightly colored tail in order to attract female peacocks. If a heart does not beat regularly or a male peacock has no bright color, then we are in a position to say that these are cases of malfunctioning. They show specific defects or weaknesses, and this provides us with evaluative guidelines. We are, for instance, allowed to claim that that particular male peacock should exhibit different features, since the bright color of his tail performs an essential function in his life-cycle. The basic point is that contrasting the male peacock to the properties and functions allowing the self-maintenance and reproduction of the species to which he belongs is looking at him also from a normative point of view. 32 This analysis provides the groundwork for the moral evaluation of human behavior. For Philippa Foot, moral judgments are to be based on the nature of human beings, on their form of life as a species. A man who breaks a promise and acts as a free rider is as defective as a root that is too shallow to support the trunk of a plant, or as a wolf that refuses to collaborate with the rest of the pack in hunting a deer. 33 In a similar vein, Lovelock introduces the point of view of Gaia to evaluate the behavior of humankind. Human beings are morally defective if they hinder the proper functioning of Gaia. In both Foot and Lovelock, moral defects have the same logical form as the evaluation of plants, animals, and their constitutive parts. 32. For Fitzpatrick (2000), Foot ignores that in evolutionary biology functions are not related to the welfare of individuals, but to gene replication. Yet Foot explicitly denies that her concept of function is based on evolutionary biology. See Foot 2001 (31ff.). For a defence of Foot s ethical naturalism against the criticisms proposed by Fitzpatrick, see Hacker-Wright Mutatis mutandis, in a similar vein Lenton and Wilkinson 2003 claim that the functions allowing the Earth s self-maintenance and regulation are an emergent property of many systems that should be studied independently from Darwinian selection and evolutionary biology. Once more see also fn Cf. Foot 2001: oaks need to have deep sturdy roots: there is something wrong with them if they do not, and this is how the normative proposition can be derived (46); Similarly, cooperation is something on which good hangs in the life of the wolf, and the free-riding wolf is not behaving as it should. Such facts will be relevant when we come to consider analogies and disanalogies between life forms of animal and human beings (35); Thus the structure of the derivation is the same whether we derive an evaluation of the roots of a particular tree or the action of a particular human being (47).

14 14 It could rightly be argued that Foot and Lovelock focus on different entities. Foot focuses on what she calls the form of life characterizing humankind. 34 Lovelock dwells on the Gaian principle, according to which human beings are components of a highly integrated and selfpreserving system. No doubt, if too hastily interpreted the Gaian principle may lead to an extremely strong form of collectivism, where individuals have little value, while Foot s ethical naturalism has no implications of this kind. 35 However, to emphasize once more, the logical structure of moral judgments appears to be the same, even though only Foot attempts to provide a detailed philosophical analysis, while in Lovelock ethical naturalism is largely implicit. Admittedly, ethical naturalism is at odds with contemporary mentality, which is broadly indebted to the philosophy of Hume. For instance, one could reasonably object: Why should Gaia, or the form of life to which I belong, determine what I ought to do? Why is that so important for me? As human beings we are free to choose whatever we like, according to our desires. As a consequence, I need motives that convince me to do what I am asked to do. 36 However, this objection misconstrues the logic of Gaia theory. We distort its argument by adopting a contemporary perspective, which is incompatible with ethical naturalism and its structure of moral judgments. In the context of ethical naturalism, the real issue is not whether we should aim at what we desire, but rather why we should do what we have already established we must morally do. In fact, since human beings are an important component of Gaia, there is a sense in which we misbehave if we do not allow the preservation of Gaia. Exactly like the root of an oak tree that is defective when too short to support the tree, we are morally defective if we hinder a well-functioning 34. Cf. Foot 2001 (40): The question is.... whether characteristics of humans can be evaluated in relation to the part they play in human life, according to the schema of natural normativity. 35. This danger has been clearly explained by Weston. See Weston However, it is a matter of interpretation. What I am arguing is that Gaian ethical naturalism is important because it shows how from facts of nature we may derive at least one moral norm. However, I agree that in specific circumstances this moral norm could rightly be overridden by other moral norms, which give more importance to individuals. In other words, in my view Gaia theory only provides a prima facie moral duty. 36. Cf. Foot 2001 (37): There will surely be objection to the idea that a natural form of life characteristic of humankind could determine what you or I ought to do. What does it matter to me what species I belong to? Should we not protest on behalf of individuality and creativity against bringing in the human species when asking what I myself this particular person should do?

15 Gaia Theory and the Rejection of Fact/Value Dualism 15 Gaia. Such defects are objective since, as Philippa Foot writes, a moral judgment says[**author: PLEASE CONFIRM THIS QUOTE; WE ADDED AN S TO SAY **]... something about the reason that there is for him to do it or not do it, whether or not he recognizes that, and whether or not, if he does recognize it, he also acts on it as he should (2001, 18). In other words the contemporary view, coherent with Humean tradition, starts with human desires and tries to build a moral theory from this psychic material; on the contrary, ethical naturalism establishes morality independently of desires, the importance of which in moral theory comes to the fore only subsequently. 37 Of course, ethical naturalism is a controversial moral view. One could utterly reject the kind of ethical naturalism that is inherent in the Gaian principle. I am personally sympathetic with ethical naturalism, but I do not need to defend it in this context. In fact, by attacking the kind of ethical naturalism inherent in the Gaian principle one has already conceded the point I set out to argue for, namely, the moral import of the Gaian principle. To attack the conclusion I set out to establish, one should rather break the conceptual link between ethical naturalism and the Gaian principle. This is not an easy task. In fact, we would need to get rid of ethical naturalism and at the same time keep the idea that the Earth is an integrated and self-preserving system of which we human beings represent a fundamental component. And I remind you, the Gaian principle is precisely the premise from which this form of ethical naturalism starts. The link appears to me sufficiently well established, and consequently the burden of the proof is on those who want to challenge it. Once we have established where the burden of proof lies, I am allowed to conclude that the Gaian principle provides Gaia theory with moral content. Now we are finally in a position to draw the most general conclusion of this paper. Final Remarks In Section 3, I defended the empirical meaningfulness of the Gaian principle. In that section, I established the following claim: If we dropped the Gaian principle we would end up with a theory with a different empirical meaning and different explanatory characteristics. In the previous section, I established a second preliminary claim, namely, The Gaian principle provides Gaia theory with moral content. From these two claims follows the general anti-humean thesis of this paper, which was stated in the Introduction: If we dropped the moral content in Gaia theory we would not end up with the same theory 37. For instance, in the theory of happiness. See Foot 2001 (ch. 6), where she discusses the several meanings of the word happiness.

16 16 cleared of evaluative considerations. We would rather have a different theory, namely, a theory with a different empirical meaning and different explanatory characteristics. There is no need to emphasize the anti-humean nature of this claim. It is no easy task to reconcile the conclusion we have come to with the philosophy of David Hume. Here we find interesting analogies with the concept of thick terms discussed in moral philosophy. It has been noted that terms such as courage or cruelty are descriptive as well as evaluative. They are both action-guiding, which is a basic characteristic of morality, and worldguided, since they describe actions or characters, and these descriptions can be true or false. 38 The same is the case for the Gaian principle. The statement that human beings belong to a highly integrated system that is capable of self-regulation and preservation, is action-guiding (we can derive evaluative insights), and is world-guided (since it is empirically meaningful and, together with the rest of the theory, allows us to derive explanatory models and possibly predictions). Yet there are differences, too. Moral philosophers have focused on single terms. We have focused on a proposition and its function in a theory. Moral philosophers have argued that, if we try to disentangle the evaluative component of a thick term from its descriptive component, we will likely change the extension of that term. 39 Here we have argued that, if we dropped the evaluative component of Gaia theory, we would have a theory with a different empirical meaning. However important these differences might be 38. The label thick term has been used in Williams Yet Philippa Foot was one of the first philosophers to understand the philosophical importance of the concept, in an essay published in See Foot Their argument appears to be the following, as summarized by McDowell 1981 (144): Consider, for instance, a specific conception of some moral virtue: the conception current in a reasonably cohesive moral community [i.e., a thick concept]. If the disentangling maneuver is always possible, that implies that the extension of the associated term, as it would be used by someone who belonged to the community, could be mastered independently of the special concerns....[**author: THIS WAS AN INCOMPLETE SENTENCE; WE DELETED CONTENT; PLEASE CONFIRM REVISED QUOTATION**] That is: one could know which actions the term would be applied to, so that one would be able to predict applications and withholdings of it in new cases not merely without oneself sharing the community s admiration (there need be no difficulty about that), but without even embarking on an attempt to make sense of their admiration. That would be an attempt to comprehend their perspective; whereas, according to the [non-cognitivist] position I am considering, the genuine feature to which the term is applied should be graspable without benefit of understanding the special perspective, since sensitivity to it is singled out as an independent ingredient in a purported explanation of why occupants of the perspective see things as they do. But is it at all plausible that this singling out can always be brought off?

17 Gaia Theory and the Rejection of Fact/Value Dualism 17 from an analytical viewpoint, they point to the very same philosophical issue: the limits of fact/value dualism. Lovelock is right when arguing that his theory is conceptually both moral and scientific, and in no way should we disentangle the scientific component from its moral counterpart. Admittedly, he sometimes uses an emotivist language that is at odds with the conceptual structure of his own theory. 40 On some occasions, he even ventures to claim that his theory is morally neutral, contradicting in this way that which he has all the time claimed. 41 However, these positivist statements are no more than slips of the pen. Lovelock is an unorthodox scientist, and, not surprisingly, Gaia theory leads us to unorthodox philosophical attitudes. References Abram, David The Mechanical and the Organic: On the Impact of Metaphor in Science. In Schneider and Boston (1991), In the Depths of a Breathing Planet: Gaia and the Transformation of Experience. In Crist and Rinker (2010), Bunyard, Peter, ed Gaia in Action: Science of the Living Earth. Edinburgh: Floris Book. Clarke, Bruce Neocybernetics of Gaia: The Emergence of Second-Order Gaia Theory. In Crist and Rinker (2010), Coffa, J. A Foundations of Inductive Explanations. Ph.D. dissertation, University of Pittsburgh. Crist, Eileen and H. Bruce Rinker, eds Gaia in Turmoil: Climate Change, Biodepletion and Earth Ethics in an Age of Crisis. Cambridge, MA: MIT Press. Davies, Paul Sheldon Norms and Nature: Naturalism and the Nature of Functions. Cambridge, MA: MIT Press. Dawkins, Richard The Extended Phenotype. The Long Reach of the Gene. Oxford: Oxford University Press. Doolittle, W. Ford Is Nature Really Motherly? CoEvolution Quarterly 29: 40. Cf. Lovelock 2000b (275): The extraordinary range of its power to inspire confirms the importance of this larger influence Gaia has provided for artists, writers, poets, painters, sculptors and musicians. This is why Lovelock turned down his own suggestion that perhaps we should talk about Geophysiology rather than Gaia to make it more acceptable to mainstream scientists. Of course, there is nothing wrong with the emotions that Gaia can inspire, but emotivism is certainly an unsatisfactory philosophical tenet, especially from the point of view of the upholders of Gaia. 41. Cf. Lovelock 1987 (96): Scientific hypotheses are all too often used as metaphors in arguments about the human condition. This misuse of Gaia is as inappropriate as was the use of Darwin s theory to justify the morality of laissez faire capitalism. Gaia is a hypothesis within science and therefore ethically neutral.