Teleology has a complicated history in the biological sciences. Some have argued that Darwin’s theory has allowed biology to purge itself of teleological explanations. Others have been content to retain teleology and to treat it as metaphorical, or have sought to replace it with less problematic notions like teleonomy. And still others have tried to naturalize it in a way that distances it from the vitalism of the nineteenth century, focusing on the role that function plays in teleological explanation. No (...) consensus has seemed possible in this debate. This paper takes a different approach. It argues that teleology is a perfectly acceptable scientific notion, but that the debate took an unfortunate misstep some 2300 years ago, one that has confused things ever since. The misstep comes in the beginning of Aristotle’s Physics when a distinction is made between two types of teleological explanation. One type pertains to artifacts while the other pertains to entities in nature. For Aristotle, artifacts are guided by something external to themselves, human intentions, while natural entities are guided by an internal nature. We aim to show that there is, in fact, only one type of legitimate teleological explanation, what Aristotle would have considered a variant of an artifact model, where entities are guided by external fields. We begin with an analysis of the differences between the two types of explanation. We then examine some evidence in Aristotle’s biological works suggesting that on account of his natural-artifactual distinction, he encountered difficulties in trying to provide teleological accounts of spontaneous generation. And we show that it is possible to resolve these difficulties with a more robust version of an artifact model of teleology, in other words, with an externalist teleology. This is McShea’s model, in which goal-directed entities are guided by a nested series of upper-level fields. To explain teleological behavior, this account invokes only external physical forces rather than mysterious internal natures. We then consider how field theory differs from other efforts to naturalize teleology in biology. And finally, we show how the account enables us to grapple with certain difficult cases – genes and intentions – where, even in biology today, the temptation to posit internal natures remains strong. (shrink)

There is a certain metaphor that has enjoyed tremendous longevity in the evolution of ageing literature. According to this metaphor, nature has a certain goal or purpose, the perpetuation of the species, or, alternatively, the reproductive success of the individual. In relation to this goal, the individual organism has a function, job, or task, namely, to breed and, in some species, to raise its brood to maturity. On this picture, those who cannot, or can no longer, reproduce are somehow invisible (...) to, or even dispensable to, the evolutionary process. Here, I argue that the metaphor should be discarded, not on the grounds that it is a metaphor, but on the grounds that this particular metaphor distorts our understanding of the evolution of ageing. One reason the metaphor is problematic is that it frames senescence and death as nature’s verdict on the value of older individuals. Instead, we should explore a different metaphor: the lengthy post-reproductive period in humans and some other animals is not an accident of culture, but designed by nature for the purpose of supporting and guiding younger generations. On this alternate picture, different stages of life have their own evolutionary rationales, their distinctive design features, their special mandates. (shrink)

Neo‐Aristotelian ethical naturalism purports to show that moral evaluation of human action and character is an evaluation of natural goodness—a kind of evaluation that applies to living things in virtue of their nature and based on their form of life. The standard neo‐Aristotelian view defines natural goodness by way of generic statements describing the natural history, or the ‘characteristic’ life, of a species. In this paper, I argue that this conception of natural goodness commits the neo‐Aristotelian view to a problematic (...) anti‐individualism that results in the wrong assessment of individuals with uniquely adaptive adjustments. I then offer an alternative account of natural goodness that avoids this problem. Instead of relying on generic statements about a species, my account defines natural goodness based on counterfactual conditionals describing the modal properties of a single individual. I argue that this modal‐explanatory account gives a conception of natural goodness that is more intuitively plausible and better suited to capture the diversity and plasticity distinctive of life. (shrink)

How can we think about things in the outside world? There is still no widely accepted theory of how mental representations get their meaning. In light of pioneering research, Nicholas Shea develops a naturalistic account of the nature of mental representation with a firm focus on the subpersonal representations that pervade the cognitive sciences.

John Searle has argued that functions owe their existence to the value that we put into life and survival. In this paper, I will provide a critique of Searle’s argument concerning the ontology of functions. I rely on a standard analysis of functional predicates as relating not only a biological entity, an activity that constitutes the function of this entity and a type of system but also a goal state. A functional attribution without specification of such a goal state has (...) no truth-value. But if completed with a goal state, functional attributions understood as four-place relations attain a truth-value. The truth conditions of all attributions of function involve a dependence claim of the goal state on the function bearer’s activity. The nature of this dependence may differ; I consider five different possibilities: causality, mechanistic constitution, mereology, supervenience and metaphysical grounding. If these dependency relations are objective, Searle’s central ontological thesis fails. What he ought to have said is that our valuing survival or other goal states may be the reason why biology seeks functional knowledge, but this has nothing to do with ontology. I will show further that Searle also raised an interesting challenge concerning the relationship of functional and causal truths, but it does not threaten the objectivity of functions either. At best, it could show that functional vocabulary is eliminable. However, I will show that functional vocabulary is not so eliminable. (shrink)

This is a short overview of the biological functions debate in philosophy. While it was fairly comprehensive when it was written, my short book ​A Critical Overview of Biological Functions has largely supplanted it as a definitive and up-to-date overview of the debate, both because the book takes into account new developments since then, and because the length of the book allowed me to go into substantially more detail about existing views.

Biological regulation is what allows an organism to handle the effects of a perturbation, modulating its own constitutive dynamics in response to particular changes in internal and external conditions. With the central focus of analysis on the case of minimal living systems, we argue that regulation consists in a specific form of second-order control, exerted over the core regime of production and maintenance of the components that actually put together the organism. The main argument is that regulation requires a distinctive (...) architecture of functional relationships, and specifically the action of a dedicated subsystem whose activity is dynamically decoupled from that of the constitutive regime. We distinguish between two major ways in which control mechanisms contribute to the maintenance of a biological organisation in response to internal and external perturbations: dynamic stability and regulation. Based on this distinction an explicit definition and a set of organisational requirements for regulation are provided, and thoroughly illustrated through the examples of bacterial chemotaxis and the lac-operon. The analysis enables us to mark out the differences between regulation and closely related concepts such as feedback, robustness and homeostasis. (shrink)

In this contribution, I comment on Raffaella Campaner’s defense of explanatory pluralism in psychiatry (in this volume). In her paper, Campaner focuses primarily on explanatory pluralism in contrast to explanatory reductionism. Furthermore, she distinguishes between pluralists who consider pluralism to be a temporary state on the one hand and pluralists who consider it to be a persisting state on the other hand. I suggest that it would be helpful to distinguish more than those two versions of pluralism – different understandings (...) of explanatory pluralism both within philosophy of science and psychiatry – namely moderate/temporary pluralism, anything goes pluralism, isolationist pluralism, integrative pluralism and interactive pluralism. Next, I discuss the pros and cons of these different understandings of explanatory pluralism. Finally, I raise the question of how to implement or operationalize explanatory pluralism in scientific practice; how to structure the “genuine dialogue” or shape “the pluralistic attitude” Campaner is referring to. As tentative answers, I explore a question-based framework for explanatory pluralism as well as social-epistemological procedures for interaction among competing approaches and explanations. (shrink)

Responses are strengthened by consequences having to do with the survival of individuals and species. With respect to the provenance of behavior, we know more about ontogenic than phylogenic contingencies. The contingencies responsible for unlearned behavior acted long ago. This remoteness affects our scientific methods, both experimental and conceptual. Until we have identified he variables responsible for an event, we tend to invent causes. Explanatory entities such as “instincts,” “drives,” and “traits” still survive. Unable to show how organisms can behave (...) effectively under complex circumstances, we endow them with special abilities permitting them to do so.Behavior exhibited by most members of a species is often accepted as inherited if all members were not likely to have been exposed to relevant ontogenic contingencies. When contingencies are not obvious, it is perhaps unwise to call any behavior either inherited or acquired, as the examples of churring in honey guides and following in imprinted ducklings show. Nor can the relative importance of phylogenic and ontogenic contingencies be argued from instances in which unlearned or learned behavior intrudes or dominates. Intrusions occur in both directions.Behavior influenced by its consequences seems directed toward the future, but only past effects are relevant. The mere fact that behavior is adaptive does not indicate whether phylogenic or ontogenic processes have been responsible for it. Examples include the several possible provenances of imitation, aggression, and communication. The generality of such concepts limits their usefulness. A more specific analysis is needed if we are to deal effectively with the two kinds of contingencies and their products. (shrink)

How shall we understand apparently teleological systems? What explains their persistence and their plasticity? Here I argue that all seemingly goal-directed systems—e.g., a food-seeking organism, human-made devices like thermostats and torpedoes, biological development, human goal seeking, and the evolutionary process itself—share a common organization. Specifically, they consist of an entity that moves within a larger containing structure, one that directs its behavior in a general way without precisely determining it. If so, then teleology lies within the domain of the theory (...) of compositional hierarchies. (shrink)

In this paper, I develop and defend a theory of what I call 'implicit goal-directedness', which is a purely causal or dynamical notion, and can be separated from the notion of 'explicit goal-directedness', which implies the representation of a goal-state. I describe the problems that plagued earlier attempts at analyzing goal-directedness in causal/dynamical terms, and then present my own novel solution. I argue that implicit goal-directedness, in the sense presented, plays an important conceptual role in biology and cognitive science, and (...) is distinct, not only from explicit goal-directedness, but also from the other major teleological notion familiar to philosophers of biology: evolutionary function. Indeed, an appreciation of this tripartite distinction is critical for understanding the structure of explanations of behavior in many scientific contexts. (shrink)

Ethologists and others studying animal behavior in a spirit are in need of a descriptive language and method that are neither anachronistically bound by behaviorist scruples nor prematurely committed to particular Just such an interim descriptive method can be found in intentional system theory. The use of intentional system theory is illustrated with the case of the apparently communicative behavior of vervet monkeys. A way of using the theory to generate data - including usable, testable data - is sketched. The (...) underlying assumptions of this approach can be seen to ally it directly with theorizing in evolutionary biology, which has recently come under attack from Stephen Gould and Richard Lewontin, who castigate it as the Their arguments, which are strongly analogous to B. F, Skinner's arguments against point to certain pitfalls that attend the careless exercise of such thinking (and rival varieties of thinking as well), but do not constitute a fundamental objection to either adaptationist theorizing or its cousin, intentional system theory. (shrink)

This book is a critical survey of and guidebook to the literature on biological functions. It ties in with current debates and developments, and at the same time, it looks back on the state of discourse in naturalized teleology prior to the 1970s. It also presents three significant new proposals. First, it describes the generalized selected effects theory, which is one version of the selected effects theory, maintaining that the function of a trait consists in the activity that led to (...) its differential persistence or reproduction in a population, and not merely its differential reproduction. Secondly, it advances “within-discipline pluralism” (as opposed to between-discipline pluralism) a new form of function pluralism, which emphasizes the coexistence of function concepts within diverse biological sub-disciplines. Lastly, it provides a critical assessment of recent alternatives to the selected effects theory of function, namely, the weak etiological theory and the systems-theoretic theory. The book argues that, to the extent that functions purport to offer causal explanations for the existence of a trait, there are no viable alternatives to the selected effects view. -/- The debate about biological functions is still as relevant and important to biology and philosophy as it ever was. Recent controversies surrounding the ENCODE Project Consortium in genetics, the nature of psychiatric classification, and the value of ecological restoration, all point to the continuing relevance to biology of philosophical discussion about the nature of functions. In philosophy, ongoing debates about the nature of biological information, intentionality, health and disease, mechanism, and even biological trait classification, are closely related to debates about biological functions. (shrink)

Functional theories posit that emotions are elicited by particular goal-related situations that represented adaptive problems and that emotions are evolved features of coordinated responses to those situations. Yet little theory or research has addressed the evolutionary aspects of these theories. We apply five criteria that can be used to judge whether features are adaptations. There is evidence that sadness, anger, and anxiety relate to unique changes in physiology, cognition, and behavior, those changes are correlated, situations that give rise to emotions (...) are consistent, and emotions are complex. To date, there is little experimental evidence regarding whether discrete emotions resolve adaptive problems and do so relatively efficiently. Evidence supporting all criteria is required to claim that discrete emotions are evolved features. (shrink)

This paper argues that biological organisation can be legitimately conceived of as an intrinsically teleological causal regime. The core of the argument consists in establishing a connection between organisation and teleology through the concept of self-determination: biological organisation determines itself in the sense that the effects of its activity contribute to determine its own conditions of existence. We suggest that not any kind of circular regime realises self-determination, which should be specifically understood as self-constraint: in biological systems, in particular, self-constraint (...) takes the form of closure, i.e. a network of mutually dependent constitutive constraints. We then explore the occurrence of intrinsic teleology in the biological domain and beyond. On the one hand, the organisational account might possibly concede that supra-organismal biological systems could realise closure, and hence be teleological. On the other hand, the realisation of closure beyond the biological realm appears to be highly unlikely. In turn, the occurrence of simpler forms of self-determination remains a controversial issue, in particular with respect to the case of self-organising dissipative systems. (shrink)

The general process view of learning, which guided research into learning for the first half of this century, has come under attack in recent years from several quarters. One form of criticism has come from proponents of the so-called biological boundaries approach to learning. These theorists have presented a variety of data showing that supposedly general laws of learning may in fact be limited in their applicability to different species and learning tasks, and they argue that the limitations are drawn (...) by the nature of each species' adaptation to the particular requirements of its natural environment. The biological boundaries approach has served an important critical function in the move away from general process learning theory, but it is limited in its ability to provide an alternative to the general process approach. In particular, the biological boundaries approach lacks generality, it is in some respects subservient to the general process tradition, and its ecological content is in too many cases limited toex post factoadaptive explanations of learning skills. A contrasting, ecological approach to learning, which can provide a true alternative to general process theory, is presented. The ecological approach begins by providing an ecological task description for naturally occurring instances of learning; this step answers the question:Whatdoes this animal learn to do? The next step is an analysis of the means by which learning occurs in the course of development, answering the question:Howdoes the animal learn to do this? On the basis of such analyses, local principles of adaptation are formulated to account for the learning abilities of individual species. More global principles are sought by generalization among these local principles and may form the basis for a general ecological theory of learning. (shrink)

A biological function is supposed to be performed adequately, and hence may fail to do so: this is dysfunction. This raises two questions. One is how to make explicit the way in which function can be discriminated from dysfunction without confusing dysfunction with non-function. The second question is how what is “right” and “wrong” can be legitimated by natural regulatory norms. A function can be viewed as a quality to which at least one variable with a definite set of values (...) is associated. Accordingly, function and dysfunction are the same quality of the same trait, but differ in the values associated to this variable. Dysfunction occurs when the associated set of values does not match this normal state. Biological systems have the epistemic singularity that their existence is the consequence of two distinct causal regimes, the so-called “proximate” and “ultimate” causes, whose convergence defines a system’s prescriptive normality. Each cause imposes restrictive rules that limit the possible ways these systems can putatively exist. When a system is insensitive to ultimate cause, it is determined by proximate causation alone, and hence escapes its own prescriptive norms. In conclusion: The normality of a biological system is defined by the convergence of proximate and ultimate causes. A function is a variable-associated quality whose values are defined relative to the norms of the system. Dysfunction occurs when the set of values of the same variable does not match the normality of the system, which can occur when the system is insensitive to ultimate causation. (shrink)

Our understanding of the universe has grown rapidly in recent decades. We’ve discovered evidence of water in nearby planets, discovered planets outside our solar system, mapped the genomes of thousands of organisms, and probed the very origins and limits of life. The scientific perspective of life-as-it-could-be has expanded in part by research in astrobiology, synthetic biology, and artificial life. In the face of such scientific developments, we argue there is an ever-growing need for universal biology, life-as-it-must-be, the multidisciplinary study of (...) non-contingent aspects of life as guided by biological theory and constrained by the universe. We present three distinct but connected ways of universalizing biology—with respect to characterizing aspects of life everywhere, with respect to the explanatory scope of biological theory, and with respect to extending biological insights to the structure of nonbiological entities. For each of these, we sketch the theoretical goals and challenges, as well as give examples of current research that might be labeled universal biology. (shrink)

Holism and reductionism are usually seen as opposite and mutually exclusive approaches to nature. Recently, some have come to see them as complementary rather than mutually exclusive. In this book I have argued that, even stronger, they should be seen as mutually dependent and co-operating research programmes. I have discussed holism and reductionism in biology in general and in ecology in particular. After an introductory chapter I have provided an overview of holistic and reductionistic positions in biology, and of the (...) reduction problems to which they relate. I have argued that it is extremely important to distinguish between ontological, epistemological and methodological aspects of these problems. The overview has shown that there are actually several approaches to reduction problems in biology, which can be characterized as more or less radically or moderately holistic or reductionistic. It has shown also that there are three major ’contradistinctions’ between holism and reductionism in biology, to wit the doctrine of emergence versus the reduction thesis; functional explanations versus causal explanations; and phenomenology versus mechanicism. In later chapters I have shown that these ’contradistinctions’ are not really contradistinctions at all. In the next chapters I have discussed the terms ’reduce’ and ’reduction’ in science. In chapter 3 I have discussed the reduction of laws and theories. I have shown that there are many different types of reduction depending on the auxiliary hypotheses that are being used in addition to the reducing theory: approximation-, aggregation, correlation and/or identification-hypotheses. The distinctions between these types has later, in chapter 5, proved to be of great importance in defining the concept of ’emergence’. The major conclusion of chapter 3 was that reduction is an epistemological issue, pertaining to logical relations between statements or systems of statements. It should not be confused, therefore, with ’ontological reduction’, certainly not in one of its ordinary senses, such as diminishing, devaluating or the like. Scientific reductions are, with the exception of instrumentalistic reductions, kinds of explanation, and, moreover, non-eliminative kinds of explanation. This means that a reduced law or theory is not eliminated by the reducing theory but rather consolidated or even reinforced. The ontology of the reduced law or theory is thereby also being consolidated. In chapter 4 I have argued that the same holds for reductions of concepts. Concept reductions are supposed to be accomplished by means of so-called ontological identity relations, which are in turn supposed to connect terms in the law or theory to be reduced, which do not occur in the reducing theory, with theoretical terms of the reducing theory. Because they are called ontological identity relations, several philosophers have thought that concept reductions imply some form of ontological reduction. And because they often occur in the context of micro-reductions, some have even thought that concept reductions are themselves micro-reductions. As a result, the idea has arisen that ontological identity relations are connections between macro-concepts and micro-concepts. However, concept reductions by means of ontological identity relations cannot be micro-reductions, because micro-reduction is, by definition, reduction with an aggregation step. Moreover, ontological identity relations are relations between different representations of and the same type of thing or attribute. That is, they express different epistemological sides of the same ontological coin. Therefore, concept reductions cannot be considered ontological reductions either, certainly not in the ordinary sense of diminishing, devaluating or the like. Thus, concept reduction is, like law or theory reduction, an epistemological issue: it pertains to relations between, in this case, different concepts or representations of one and the same type of thing or attribute. ’Ontological reduction’, then, may, in the context of scientific reductions, actually be considered a contradiction of terms. In chapter 5 I have linked this conclusion to the emergence thesis and to the alleged contradistinction between this thesis and the reduction thesis. I have shown that the doctrine of emergence actually consists of two separate claims, namely an ontological thesis stating that a whole has emergent properties which the component parts do not possess, neither separately nor in other partial combinations; and an epistemological thesis stating that emergent properties of wholes are ’in principle’ irreducible. I have argued that the first claim may be regarded as a valid, universal thesis about relations between properties of wholes and properties of parts, but that the second claim is untenable. I have discussed many emergent properties of wholes, biological as well as physico-chemical, that have proved to be explainable in terms of micro-theories about the component parts and auxiliary hypotheses. Once again, however, it is important to realize that reduction is an epistemological issue, whereas emergence, in the sense of thesis, is an ontological one. It is not ’wholes’ or ’emergent properties of wholes’ that are being reduced but statements about them. Reduction is a kind of explanation, not of explaining-away. Thus, it leaves the ontology of whatever is reduced fully intact. I have developed a new definition of the term ’emergence’ which expresses emergence in terms of the auxiliary hypotheses that may be used in reductions, in particular aggregation-, correlation- and identification-hypotheses. This has even lead to two very remarkable conclusions. First, emergence may be considered the opposite of ontological identity. And second, if there were no emergence, there wouldn’t be any reductions either. to reduce.) In this respect, therefore, there is absolutely no contradistinction between holism and reductionism. On these grounds I have introduced my thesis that holism and reductionism should rather be seen as mutually dependent, and hence co-operating, research programmes than as conflicting views of nature or of relations between sciences. Holistic programmes play an important role in science as guide programmes for reductionistic programmes by discovering or developing macro-laws or -theories about phenomena at the level of wholes, which they themselves, however, cannot explain. For these explanations they depend on the fruits of reductionistic programmes. If the latter succeed in providing the explanations they act as supply programmes for the holistic guide programmes. Reductionistic programmes depend in turn on holistic programmes for providing the macro-laws or -theories that call for these explanations. In chapter 6 I have discussed an example of this mutual dependency in the form of the reduction of the Bohr-effect in animal physiology. I have shown that this law has been reduced to the theory of allostery, applied to hemoglobin molecules in red blood cells, and that this application of the theory of allostery has been reduced to the theory of chemical bonding. I have also shown that at least six research programmes were involved in these reductions, and that the relations between these programmes can be characterized very well in terms of the model of holistic guide programmes and reductionistic supply programmes. The only, but highly significant, qualification appearing from example was that the terms ’holistic’ and ’reductionistic’ are extremely relative and should always be related to a certain given level of organization. In chapter 7 I have resolved the remaining contradistinction between holism and reductionism in biology, viz. the need for functional explanations and the demand that explanations be causal. I have shown that functional explanations are perfectly legitimate explanations which in a sense can be reconstrued as causal explanations. I have argued that functional explanations are indispensable components of more comprehensive, causal-evolutionary explanations, because the latter appeal to the adaptive value, and hence the function, of the property to be explained. In that sense functions can be regarded as adaptations, and functional explanations can be regarded as a sort of ’short-hand’ for evolutionary explanations. Finally, I have shown that in the context of functional explanations, too, co-operation of holistic and reductionistic research programmes occurs. In part 2 I have applied my thesis to ecology. I have shown that in ecology too, holismreductionism disputes notwithstanding, co-operation of holistic and reductionistic research programmes occurs, or, in so far as this appears to be not the case, that it should be strived after. In chapter 8 I have given an overview of reduction problems in ecology and of the various approaches to these problems. I have noticed that in ecology, too, there are several, radical, moderate and anti-reductionistic research strategies, with respect to the levels of both ecosystems, communities and populations. I have also noticed, however, that concrete solutions to reduction problems in ecology are frustrated by what is called the intellectual immaturity or the anomalous status of ecology. This refers to the almost complete lack of general laws and theories in ecology, at least at the higher levels of communities and ecosystems. Of a number of possible causes I have lifted out two, which lend themselves to philosophical analysis and clarification. The first one is the ambiguity of a major part of the ecological vocabulary. This was the subject of chapters 9 and 10. The second is the inhibitory effect which holism-reductionism disputes have on the growth of knowledge. This was the subject of chapter 13. In chapter 9 I have discussed the concept of an community. It appeared that the term ’community’ is used for several different entities at various levels of organization. This ambiguity alone seems to be sufficient for the lack of ’general’ laws and theories about ’communities’. My purpose in chapter 9 was to try and contribute to a solution of this problem. In doing so I have argued, first, that it seems wise to use the term ’community’ only for groups of species belonging to a single taxonomic or phylogenetic group, and to use the term ’biocoenosis’ for the higher level of organization, defined as the biotic component of an ecosystem. Next I have argued that, although species within communities may of course interact with each other, interaction is itself not a necessary or sufficient condition for community membership. Finally, I have hit upon what is known as the most notorious problem in community ecology, to wit the boundary problem, as well as the problem of heterogeneity. I have found that the cause of these problems lies in the fact that communities are almost invariably being seen as groups of populations occurring together in space and time, whereas the empirical fact is rather that populations of different species mostly do not occur together in the same space, and, moreover, that the species composition of communities changes continuously. This has lead to the suggestion that a community had better be defined as the group of individuals of two or more species occurring in the area of intersection of populations of these species. It is only in such intersection areas that one can really talk of the co-occurrence of species. I have shown the empirical adequacy of this definition by discussing various salt marsh plant communities on the Dutch island of Schiermonnikoog. In chapter 10 I have clarified two other important, yet highly controversial, concepts in ecology, to wit habitat and niche. It appeared that there are at least four different habitat concepts in ecology, and as many niche concepts, the additional complication being that two of these habitat concepts correspond to two of these niche concepts, whence the distinction between habitat and niche is blurred. In addition, different habitat concepts appeared to correspond to different environment concepts and also to different biotope concepts. My purpose in chapter 10 was to disentangle all these concepts from one another and to supply each of them with a suitable term. I have done so by keeping a close eye on commonly accepted notions about habitat differentiation and niche differentiation, two ’principles’ allowing one to explain the coexistence or non-coexistence of species in communities. The results can be found in boxes 5 and 7 in chapter 10. In chapter 11 I was finally able to substantiate my claim that in ecology, too, co-operation of holistic and reductionistic research programmes occurs. I have discussed the reduction of the classical competition model of Lotka and Volterra to modern niche theory. The Lotka/Volterra model is a phenomenological model: it describes the possible effects of competition between two species. Modern niche theory, on the other hand, is a mechanistic theory, in which both the objects of competition and a mechanism are being specified. I have shown that the reduction was established with the help of a relatively simple identification hypothesis and two relatively simple aggregation hypotheses, making it yet another example of heterogeneous microreduction in biology. In the reduction, the Lotka/Volterra model acted as a holistic guide programme and modern niche theory acted as a reductionistic supply programme. In chapter 12 I have discussed another example of co-operation in the form of the approximative reduction of MacArthur and Wilson’s equilibrium theory of island biogeography. I have argued that this can be seen as a holistic model, which has been of great unifying and especially heuristic value, but which in time has been found to be a bit too simple and in some respects had to be corrected. Therefore, it can also be seen as an idealization in the sense of the model of idealization and concretization, which subsequent research programmes have concretized. Because these concretizations have a reductive character, we can see in this structure of idealization and concretization yet another example of the co-operation of holistic and reductionistic research programmes in ecology. A philosophically interesting side-conclusion was that the model of idealization and concretization thus appears to apply also to relations between research programmes, and not only to programme-internal developments. In chapter 13 I have discussed an example of the inhibitory effect that holism-reductionism disputes may have on the growth of knowledge. The example concerns a controversy in island biogeography over the role of interspecific competition in structuring communities. This controversy has lasted for about ten years, appeares to have died out rather than to have been resolved, and has produced nothing new in the field of explanations of community structure. I have shown that the major factors underlying the controversy were differing, in casu holistic and reductionistic, views of communities. Though this presented a problem for my thesis, I have argued that, ultimately, the controversy can be resolved, and in a sense has been resolved, in a way that corroborates my thesis. In the epilogue, finally, I have mentioned some remaining problems concerning the adequacy of the present reduction model in dealing with reduction in ecology. These problems pertain to the question of specificty of ecological laws and theories, the likelihood that reductions in ecology generally occur on the basis of several reducing micro-theories, and the possible relationship between the former two points. (shrink)