Isaac Levi is more interested in inquiry and how it progresses than he is in metaphysics. Questions concerning the role of disposition predicates in inquiry are more central to him than those concerning the nature and reality of dispositions. It has not stopped him from giving me and others very useful metaphysical advice. Currently, where empirical metaphysics is in vogue, there is every reason to see whether the two forms of philosophical interest might interlock substantially. Levi has stimulating ideas indeed (...) on the two forms of philosophical interest, and has recently summarized them in the slogan: “The reality of dispositions is a work in progress”. We can learn much about what kinds of dispositions are acceptable from tracing and comparing the histories of successful and less successful disposition predicates in scientific inquiry. Levi explores one route along which dispositions become real. His idea is that the introduction of dispositions facilitates covering law explanation by increasing the number of laws. The successful disposition predicate eventually becomes integrated in scientific theory, much like an ordinary theoretical term, whereas the unsuccessful does not. My impression is that Levi thinks that this is the only way a disposition can become real. To evaluate this claim, an alternative course suggested by Jon Elster is introduced. I then try to bring out the differences between Levi's and Elster's views on dispositions, partly by suggesting that they resemble two aspects of full explanations discussed by Wesley Salmon. But more about that below. (shrink)

This paper is an attempt to further our understanding of mechanisms conceived of as ontologically separable from laws. What opportunities are there for a mechanistic perspective to be independent of, or even more fundamental than, a law perspective?

According to Jon Elster, mechanisms are frequently occurring and easily recognizable causal patterns that are triggered under generally unknown conditions or with indeterminate consequences. In the absence of laws, moreover, mechanisms provide explanations. In this paper I argue that Elster’s view has difficulties with progressing knowledge. Normally, filling in the causal picture without revising it should not threaten one’s explanation. But this seems to be Elster’s case. The critique is constructive in the sense that it is built up from a (...) discussion of a mechanism that might explain ‘unwarranted’ risk taking in connection with swimming—a mechanism that is mirrored in the proverb: The best swimmers drown. (shrink)

Interdisciplinary research within the field of sustainability studies often faces incompatible ontological assumptions deriving from natural and social sciences. The importance of this fact is often underrated and sometimes leads to the wrong strategies. We distinguish between two broad approaches in interdisciplinarity: unificationism and pluralism. Unificationism seeks unification and perceives disciplinary boundaries as conventional, representing no long-term obstacle to progress, whereas pluralism emphasizes more ephemeral and transient interdisciplinary connections and underscores the autonomy of the disciplines with respect to one another. (...) Both approaches have their merits and pitfalls. Unification runs the risk of scientific imperialism, while pluralism can result in insurmountable barriers between disciplines. We made a comparison of eight distinct interdisciplinary attempts at integration of knowledge across social and natural sciences. The comparison was carried out as four pairwise comparisons: environmental economics versus ecological economics, environmental history versus historical ecology, resilience theory versus political ecology, and socio-biology versus actor-network theory. We conclude by showing that none of these prominent eight interdisciplinary fields in and of itself manages to provide, in a satisfactory way, such an integrated understanding of sustainability. We argue for pluralism and advocate complex ways of articulating divergent ontological assumptions. This is not equivalent to pursuing knowledge unification either through scientific imperialism or by catering to the requirements of narrow practical utility. It means prioritizing interdisciplinary integration by simultaneously acknowledging the role of societal and natural factors in accounting for sustainability issues. (shrink)

This paper is an attempt to further our understanding of mechanisms conceived of as ontologically separable from laws. What opportunities are there for a mechanistic perspective to be independent of, or even more fundamental than, a law perspective? Advocates of the mechanistic view often play with the possibility of internal and external reliability, or with the paralleling possibilities of enforcing, counteracting, redirecting, etc., the mechanisms’ power to produce To further this discussion I adopt a trope ontology. It is independent of (...) the notion of law, and can easily be adapted to account for such characteristics of mechanisms. The idea of tropes as mechanisms is worked out in some detail. According to the resulting picture, there is still an opportunity to link mechanisms and laws. But while the predominant law view conceives of mechanistic approaches as special kinds of law accounts, this study indicates that the converse may be true. Law accounts are special cases of mechanistic accounts, and they work only in those worlds where the mechanisms are of the right kind. (shrink)

This book highlights some of the conceptual problems that still need to be solved and points out a number of fresh philosophical ideas to explore.

BACKGROUND: Representing is about theories and theory formation. Philosophy of science has a long-standing interest in representing. At least since Ian Hacking's modern classic Representing and Intervening analytical philosophers have struggled to combine that interest with a study of the roles of intervention studies. With few exceptions this focus of philosophy of science has been on physics and other natural sciences. In particular, there have been few attempts to analyse the use of the notion of intervention in other disciplines where (...) intervention studies are important, such as in nursing research. One unintended consequence of this is that the relations between representing and intervening tend to be less understood outside the natural sciences. OBJECTIVES AND DESIGN: This article highlights a number of possible topics on which nursing science and analytic philosophy of science can fruitfully interact. The basic idea is simple. Building on a characterisation of interventions in terms of what is intervened on and with respect to what, we suggest that interventions in nursing research typically are a blend of varieties belonging to the three dimensions of agency, epistemology, and ontology. The details of the blend determine the relation of the particular intervention study to traditional representational categories such as inductivism and hypothetico-deductive method, and have a bearing on its explanatory power and other more theory independent features of research as well. The framework we suggest should be relevant for nurse researchers who want to adopt a more general and analytically entrenched perspective on representing and intervening than the methodological boundaries in nursing research typically allow. (shrink)

Jon Elster worries about the explanatory power of the social sciences. His main concern is that they have so few well-established laws. Elster develops an interesting substitute: a special kind of mechanism designed to fill the explanatory gap between laws and mere description. However, his mechanisms suffer from a characteristic problem that I will explore in this article. As our causal knowledge of a specific problem grows we might come to know too much to make use of an Elsterian mechanism (...) but still lack a law. We might then find ourselves in the paradoxical position of knowing more relevant causal truths about the phenomenon we are interested in than we did before, but being able to explain less. If this possibility is realized in social science settings, as I argue it might well be, Elster?s mechanistic account is threatened. Moreover, even if the possibility is rarely realized in that way, it raises, simply as a possibility, a conceptual problem with Elster?s mechanistic framework. (shrink)

Polygenic effects have more than one cause. They testify to the fact that several causal contributors are sometimes simultaneously involved in causation. The importance of polygenic causation was noticed early on by Mill (1893). It has since been shown to be a problem for causal-law approaches to causation and accounts of causation cast in terms of capacities. However, polygenic causation needs to be examined more thoroughly in the emerging literature on causal mechanisms. In this paper I examine whether an influential (...) theory of mechanisms proposed by Peter Machamer, Lindley Darden and Carl Craver can accommodate polygenic effects and other forms of causal interaction. This theory is problematic, I will argue, because it ascribes a central role to activities. In it, activities are needed not only to constitute mechanisms but also to perform the causal role of mechanisms. Any such mechanism-as-activity will be incompatible with causal situations where either no or merely another kind of activity occurs. But, as I will try to illustrate in this paper, both kinds of situation may be frequent. If I am right, the view that Machamer and colleagues suggest leads to an impoverished conception of mechanism. (shrink)

The calls for evidence-based public policy making have increased dramatically in the last decades, and so has the interest in evidence-based sustainability studies. But questions remain about what “evidence” actually means in different contexts and if the concept travels well between different domains of application. Some of the most relevant questions asked by sustainability studies are not, and in some cases cannot be, directly answered by relying on research evidence of the kinds favored by the evidence-based movement. Therefore, sustainability studies (...) must also harness other forms of knowledge, based on forms of practical experience. How to integrate these two sources of knowledge is one of the most fundamental epistemological and practical problems society is facing. Identifying what kind of practical experience and research evidence we need to integrate is another challenging question. We draw on examples from our research in the Global South and suggest an efficient principle, problem-feeding, for harnessing practical experience within an adapted version of evidence-based sustainability studies. (shrink)

Proven experience can be shared. Given this, we cannot assume that the character of proven experience is always manifest as a physical token in each individual sharing it. But the token might still exist somewhere. Perhaps that is a condition of the proven experience’s existence. Something similar could have been accepted as true of scientific knowledge, especially if those who argued that scientific claims were only shorthand for more complicated claims about observations had been right. But it seems that they (...) were not. Hence there might be an ontological difference explaining why there will always be a netto divergence between science and proven experience. (shrink)

Recently the importance of addressing values in discussions of risk perception and adaptation to climate change has become manifest. Values-based approaches to climate change adaptation and the cultural cognition thesis both illustrate this trend. We argue that in the wake of this development it is necessary to take the dynamic relationship between values and beliefs seriously, to acknowledge the possibility of bi-directional relationships between values and beliefs, and to address the variety of values involved. The dynamic relationship between values and (...) beliefs, we claim, highlights the need to bring ethical considerations to bear on climate change communication. In particular, we must ask whether it is acceptable to tailor information about the risks of climate change in an effort to maximize communicative effectiveness given the values of the target group. (shrink)

Background Positivism is sometimes rejected for the wrong reasons. Influential textbooks on nursing research and in other disciplines tend to reinforce the misconceptions underlying these rejections. This is problematic, since it provides students of these disciplines with a poor basis for making epistemological and methodological decisions. It is particularly common for positivist views on reality and causation to be obscured. Objectives and design The first part of this discussion paper identifies and explains the misconceptions about positivism as they appear in (...) two influential textbooks. The second part pinpoints five mistakes these misconceptions easily result in when the researcher adopts an epistemological and methodological standpoint. What is already known about the topic? There are several impeccable descriptions of positivism in nursing research literature; but a relatively large number of inaccurate or confused views of positivism appear in the nursing research literature as well. Mistakes of the kind identified in this paper have been noted before—for instance, in Shadish. What this paper adds: This paper provides a detailed analysis of two particularly common and influential misconceptions about positivism. It traces the historical roots of these misconceptions and characterizes them more carefully than many earlier attempts have done. The paper shows how and why these misconceptions affect epistemological and methodological decisions negatively, regardless of one’s interest in positivism. (shrink)

Facts are once again put to work in philosophical enterprises. The discussion in this paper is conducted under the presumption that we for this reason need to examine the nature of facts anew. To some extent it has been taken for granted that the question of properties and particulars is the primary problem to solve, and that the question of facts is secondary. This approach naturally leads to many of the old problems of facts and complexes. By taking facts as (...) truly basic, we should see how we can construct the particulars and universals we still have need for. In order to further this idea, I suggest that facts may be though of as tropes or once-for-all occurrent properties. However, this characterisation of facts is acceptable only if tropes manage without substances or "thin" particulars for their instantiation. (shrink)

Inference to the best explanation is theoretically interesting in that it promises to throw new light on what an explanation is. IBE challenges the standard view of the relation between inference and explanation. But sometimes it seems that previous explanation is more independent of inference than IBE suggests. Sometimes we have explanation before inference which is not IBE. This chapter examines the possibility that the latter is the rule rather than the exception.

A key question for evidence-based medicine is how best to model the way in which EBM should “[integrate] individual clinical expertise and the best external evidence”. We argue that the formulations and models available in the literature today are modest variations on a common theme and face very similar problems. For example, both the early and updated models of evidence-based clinical decisions presented in Haynes, Devereaux and Guyatt assume that EBM consists of, among other things, evidence from clinical research and (...) clinical expertise. On this A-view, EBM describes all that goes on in a specific justifiable medical decision. There is, however, an alternative interpretation of EBM, the B-view, in which EBM describes just one component of the decision situation and in which, together with other types of evidence, EBM leads to a justifiable clincial decision but does not describe the decision itself. This B-view is inspired by a 100-years older version of EBM, a Swedish standard requiring medical decision-making and practice to be in accordance with ‘science and proven experience’. In the paper we outline how the Swedish concept leads to an improved understanding of the way in which scientific evidence and clinical experience can and cannot be integrated in light of EBM. In addition the paper sketches the as yet unexplored historical background to EBM. (shrink)

We are good at discussing law statements of different epistemic status, and to describe logical relationships between different law statements. But contemporary discussion often suffers from a difficulty to formulate questions concerning laws of different ontological status. This paper presents a framework for distinguishing between properties and fake properties that seems to provide better tools for such inquiries. This paper also examines criteria for properties in connection with laws of nature. It discusses three suggested tests for properties, by Maxwell, Ramsey, (...) and Cartwright. None of these tests is good as it stands. Rather than favouring one particular test, we should opt for methodologically stable decisions, i.e. decisions where several tests come to the same conclusion. (shrink)

I am grateful to Daniel Little for his insightful reply to my recent article in Social Epistemology about what appears to be a flaw in Jon Elster’s conception of mechanisms. I agree with much of what Little says, but want to amplify a different underlying problem with Elster’s conception than Little suggests in his reply. This underlying problem connects nicely with a passage in Little’s reply, which he thinks unconnected with the point on which I focus.

The overall aim of this paper is to examine the claim that explanation is asymmetrical because causation is asymmetrical. The link between causal and explanatory asymmetry is focussed on. It is argued that many theories of causation account for causal asymmetry in a way that stops a causal model from contributing to our understanding of explanatory asymmetry. What appears to be generally advantageous with causal approaches is normally true only of a few specific causal accounts. These remaining alternatives, however, may (...) well have some less attractive features that would never be brought to mind in the familiar explanatory contexts of balloons, flag poles, and the like—and with a standard concept of causation. (shrink)

Accounts of ontic explanation have often been devised so as to provide an understanding of mechanism and of causation. Ontic accounts differ quite radically in their ontologies, and one of the latest additions to this tradition proposed by Peter Machamer, Lindley Darden and Carl Craver reintroduces the concept of activity. In this paper I ask whether this influential and activity-based account of mechanisms is viable as an ontic account. I focus on polygenic scenarios—scenarios in which the causal truths depend on (...) more than one cause. The importance of polygenic causation was noticed early on by Mill (1893). It has since been shown to be a problem for both causal-law approaches to causation (Cartwright 1983) and accounts of causation cast in terms of capacities (Dupré 1993; Glennan 1997, pp. 605-626). However, whereas mechanistic accounts seem to be attractive precisely because they promise to handle complicated causal scenarios, polygenic causation needs to be examined more thoroughly in the emerging literature on activity-based mechanisms. The activity-based account proposed in Machamer et al. (2000, pp. 1-25) is problematic as an ontic account, I will argue. It seems necessary to ask, of any ontic account, how well it performs in causal situations where—at the explanandum level of mechanism—no activity occurs. In addition, it should be asked how well the activity-based account performs in situations where there are too few activities around to match the polygenic causal origin of the explanandum. The first situation presents an explanandum-problem and the second situation presents an explanans-problem—I will argue—both of which threaten activity-based frameworks. (shrink)

Philosophers of science have often favoured reductive approaches to how-possibly explanation. This article identifies three alternative conceptions making how-possibly explanation an interesting phenomenon in its own right. The first variety approaches “how possibly X?” by showing that X is not epistemically impossible. This can sometimes be achieved by removing misunderstandings concerning the implications of one’s current belief system but involves characteristically a modification of this belief system so that acceptance of X does not result in contradiction. The second variety offers (...) a potential how-explanation of X. It is usually followed by a range of further potential how-explanations of the same phenomenon. In recent literature the factual claims implied by the second variety have been downplayed whereas the heuristic role of mapping the space of conceptual possibilities has been emphasized. I will focus especially on this truth-bracketing sense of potentiality when looking closer at the second variety in the paper. The third variety has attracted less interest. It presents a partial how-explanation of X. Typically it aims to establish the existence of a mechanism by which X could be and was generated. The third conception stands out as the natural alternative for the advocate of ontic how-possibly explanations. This article transfers Salmon’s view that explanation-concepts can be broadly divided into epistemic, modal, and ontic to the context of how-possibly explanations. Moreover, it is argued that each of the three above-mentioned varieties of how-possibly explanation occurs in science. To recognize this may be especially relevant for philosophers. We are often misled by the promises of various why-explanation accounts, and seem to have forgotten nearly everything about the diversity of how-possibly explanations. (shrink)

Kimberly Chuang’s detailed and very helpful reply to my article concerns Jon Elster’s struggle to develop a mechanistic account that sheds light on explanation in social science. I argue that a problem exists with Elster’s current conception of mechanistic explanation in social contexts. Chuang defends Elster’s conception against my critique. I still believe I have identified a problem with Elster’s conception. In this reply I want to recapitulate briefly Elster’s idea, as I understand it, and then use some of Chuang’s (...) critical points to advance the position I advocate. (shrink)

Interdisciplinary research in the fields of forestry and sustainability studies often encounters seemingly incompatible ontological assumptions deriving from natural and social sciences. The perceived incompatibilities might emerge from the epistemological and ontological claims of the theories or models directly employed in the interdisciplinary collaboration, or they might be created by other epistemological and ontological assumptions that these interdisciplinary researchers find no reason to question. In this paper we discuss the benefits and risks of two possible approaches, Popperian optimism and Kuhnian (...) pessimism, to interdisciplinary knowledge integration where epistemological and ontological differences between the sciences involved can be expected. (shrink)

The thesis addresses the nature of causation. It is argued that causation exists and is as local as its causes and effects. As a consequence, the position advocated is contrary to the as yet prevailing view that no 'causal tie' between cause and effect exists. Moreover, it is suggested that this tie can be perceived. The essay attempts to elucidate the nature of causes, effects, and causal mechanisms. It is argued that they are facts rather than particulars or universals. Furthermore (...) it is suggested that these facts can be conceived of as tropes. Finally, in the light of this thesis a few traditional issues are discussed: what is the relation between causation and explanation? How should we conceive of causal laws? Does the idea of mechanisms with different degrees of reliability further our understanding of the determinism/indeterminism issue? (shrink)

Semmelweis’s work predates the discovery of the power of randomization in medicine by almost a century. Although Semmelweis would not have consciously used a randomized controlled trial (RCT), some features of his material—the allocation of patients to the first and second clinics—did involve what was in fact a randomization, though this was not realised at the time. This article begins by explaining why Semmelweis’s methodology, nevertheless, did not amount to the use of a RCT. It then shows why it is (...) descriptively and normatively interesting to compare what he did with the modern approach using RCTs. The argumentation centres on causal inferences and the contrast between Semmelweis’s causal concept and that deployed by many advocates of RCTs. It is argued that Semmelweis’s approach has implications for matters of explanation and medical practice. (shrink)

The possibility of apparently negative causation has been discussed in a number of recent works on causation, but the discussion has suffered from beingscattered. In this paper, the problem of apparently negative causation and its attemptedsolutions are examined in more detail. I discuss and discard three attempts that have beensuggested in the literature. My conclusion is negative: Negative causation shows that thetraditional cause & effect view is inadequate. A more unified causal perspective is needed.

The paper is concerned with the existence of objective uncertainties. What would it take for objective uncertainties to exist, and what would be the consequences for our understanding of the world we live in? We approach these questions by considering two common theories on how we are to understand the being of propensities and how it pertains to possible outcomes that remain unmanifested. It is argued that both or these theories should be rejected, and be replaced with a theory we (...) call unrestricted actualism according to which the possible outcomes of propensities are denizens of the actual world. (shrink)

Traditionally, interdisciplinarity has been taken to require conceptual or theoretical integration. However, in the emerging field of sustainability science this kind of integration is often lacking. Indeed sometimes it is regarded as an obstacle to interdisciplinarity. Drawing on examples from sustainability science, we show that problem-feeding, i.e. the transfer of problems, is a common and fruitful-looking way of connecting disparate disciplines and establishing interdisciplinarity. We identify two species of problem-feeding: unilateral and bilateral. Which of these is at issue depends on (...) whether solutions to the problem are fed back to the discipline in which the problem originated. We suggest that there is an interesting difference between the problem-feeding approach to interdisciplinarity and the traditional integrative perspective suggested by among others Erich Jantsch and his colleagues. The interdisciplinarity resulting from problem-feeding between researchers can be local and temporary and does not require collaboration between proximate disciplines. By contrast, to make good sense of traditional integrative interdisciplinarity we must arguably associate it with a longer-term, global form of close, interdisciplinary collaboration. (shrink)

The functional separation of risk assessment and risk management has long been at the heart of risk analysis structures. Equally long it has been criticized for creating technocratic risk management due to valuations being done in the risk assessment to which the stakeholders do not have access. The criticism has mostly been of an ethical nature. Arguably, in separating risk assessment and risk management, one hopes to fulfil two requirements: Social requirement: we want risk management to meet the goals and (...) needs of society. Scientific requirement: we do not want political views to influence the assessment of facts. We ask in this paper whether it is, in principle, possible to separate risk assessment from risk management. The crucial distinction between risk assessment and risk management we take to be between what kinds of values are involved in them and that separation is meant to shield risk assessment from risk management values and vice versa. Risk assessment is judged to be a scientific activity that should only involve scientific values. We go through a paradigmatic example of good science to see what those scientific values are and whether they are the only ones influencing science. We also present an example of a risk assessment in order to compare it to science. We conclude that the values involved in both science and risk assessment are of the same kind and that they both involve extra-scientific values. The paper ends with a short discussion of whether the above requirements can be met even though risk assessment and risk management are interdependent. (shrink)

Sometimes instances of perceived causation turn out to lack causal relata. The reasons may vary. Causation may display itself as prevention, or as omission, and in some cases causation occurs within such complex environments that few of the things we associate with causes and effects are true of them, etc. But even then, there may be causal explanations to be had. This suggests that the explanatory power of causal reports have other sources than the relation between cause and effect. In (...) this paper it is argued that the causal mechanisms we allude to in explanations have relevant determinables other than the traditionally acknowledged ones. The traditional but in this aspect mistaken view of causation is to be blamed. Discernability, complexity of manifestation, originality, and even stability have often been overlooked. We know, that, in fact, heat is a constant attendant of flame; but what is the connexion between them, we have no room so much as to conjecture or imagine. (Hume 1777, VII. 2, 64). (shrink)

We tested two consequences of a currently influential theory based on the notion of seeing adaptations to climate change as local adjustments to deal with changing conditions within the constraints of the broader economic–social–political arrangements. The notion leaves no explicit role for the strength of personal beliefs in climate change and adaptive capacity. The consequences were: adaptive action to climate change taken by an individual who is exposed to and sensitive to climate change is not influenced to a considerable degree (...) by their strength of belief in climate change and adaptive action to climate change taken by an individual who is exposed to and sensitive to climate change is not influenced to a considerable degree by their strength of belief in an adaptive capacity. Data from a 2004 questionnaire of 1950 Swedish private individual forest owners, who were assumed exposed to and sensitive to climate change, were used. Strength of belief in climate change and adaptive capacities were found to be crucial factors for explaining observed differences in adaptation among Swedish forest owners. (shrink)

In Persson & Wallin we show that the common claim that internal validity should be understood as prior to external validity has, at least, three epistemologically problematic aspects: experimental artefacts, the implications of causal relations, and how the mechanism is measured. Each aspect demonstrates how important external validity is for the internal validity of the experimental result. This note is an invited summary of these results.

The objective of our article is to show how “quality of evidence” and “imprecision,” as they are defined in Grading of Recommendations Assessment, Development, and Evaluation articles, may lead to confusion. We focus only on the context of systematic reviews.

In medical research, it is not unusual that risks are ruled out without any specification the exact risk that was ruled out. This makes it difficult to balance expected health benefits and risk of harm when choosing between alternative treatment options. International guidelines for reporting medical research results are sufficiently specific when it comes to establishing health benefits. However, there is a lack of standards for reporting on ruling out risks. We argue that transparency is needed, as in the case (...) of non-inferiority trials. The Consolidated Standards of Reporting Trials and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statements should be revised accordingly. (shrink)

Arguments from explanation, i.e. arguments in which the explanatory value of a hypothesis or premise is appealed to, are common in science, and explanatory considerations are becoming more popular in metaphysics. The paper begins by arguing that explanatory arguments in science—even when these are metaphysical explanations— may fail to be explanatory in metaphysics; there is a distinction to be drawn between metaphysical explanation and explanation in metaphysics. This makes it potentially problematic to deploy arguments from explanation in, for instance, metaphysics (...) of science. Part of this problem has its source in that the explanatory concept differs between contexts. The paper discusses a few explanatory concepts and their corresponding arguments from explanation. Towards the end of the paper, I identify two allegedly explanatory arguments in metaphysical discourse by the concluding decisions they give rise to: the rejection of X as a metaphysical fact if X does not explain anything (the argument from explanatory inability) and the rejection of X as a metaphysical fact if X can be non-metaphysically explained (the argument from the non-metaphysically explained). I ask: What kind of concept of explanation do these arguments rely upon, and is that concept suited to the metaphysical task? Two recent examples of these arguments are used as illustration. The preliminary conclusion is that several of the strengths of arguments from explanation in science seem not to be present in metaphysical contexts. (shrink)

This article is the text of an interview with D. H. Mellor conducted in Cambridge on 30 May 2001 by Anna-Sofia Maurin and Johannes Persson for the philosophical journal Theoria.

Researchers often aim to make correct inferences both about that which is actually studied and about what the results generalize to. The language of internal and external validity is not used by everyone, but many of us would agree that intuitively the distinction makes a lot of sense. Two claims are commonly made with respect to internal and external validity. The first is that internal validity is prior to external validity since there is nothing to generalize if the findings obtained (...) in, for instance, the experimental setting do not hold. The first claim is explicit in many writings. See for instance Francisco Guala’s influential book The methodology of experimental economics. And it is often implicitly relied on. The second claim is that researchers have to make a trade-off between internal and external validity. When one is increased, the other will decrease. The second claim was made already from the start by D.T Campbell in his classic Factors relevant to the validity of experiments in social settings. There is a certain tension between the first and the second claim. It has been argued before that it might be difficult to combine them. We intend to make the stronger point that both claims are misconstrued. Our hypothesis is that the relationship between internal and external validity has to be re-conceptualized, and we will briefly indicate how. (shrink)

In this article I examine whether an influential theory of mechanisms proposed by Peter Machamer, Lindley Darden and Carl Craver can accommodate polygenic effects. This theory is both interesting and problematic, I will argue, because it ascribes a central role to activities. In it, activities are needed not only to constitute mechanisms but also to perform their causal role. These putative functions of activities become problematic in certain situations where several causes or elements of a mechanism contribute simultaneously, i.e. with (...) certain forms of polygenic causation. The problematic form of polygeny, polygeny 2, occurs when the polygenic contribution concerns one and the same property or aspect of the affected object. When the result of such causation is that nothing happens, the theory suggested by Machamer and his colleagues cannot be applied. More generally, it seems that, whenever polygeny 2 is involved, the Machamer approach leads to an impoverished conception of mechanism. (shrink)