What precisely does aristotle mean when he asserts that something is (or comes to be) "for" "the" "sake" "of" something? I suggest that the answer to this question may be found by examining aristotle's position on the problem of reduction in biology, As it arises within his own scientific "and" "philosophical" context. I discuss the role of the concepts of "nature" and "potential" in aristotelian scientific explanation, And reformulate the reduction problem in that light. I answer the main question by (...) establishing that aristotle holds an "irreducibility" thesis in regard to the generation and development of a living organism, And that this thesis is the core of his conception of final causality. I conclude by arguing that aristotle's teleology is fundamentally "empirical" in character, And not an a priori doctrine brought "to" the study of nature. (shrink)

Avicenna's theory of final causality stands out as one of the most profound and original achievements of Islamic philosophy. Writing mainly in Arabic in various cities of Persia from the end of the 4th/10th to the beginning of the 5th/11th centuries AH/AD, Avicenna extended the range of Aristotelian teleology to encompass not only motion but also existence; he did so by dividing the final cause into an extrinsic, kinetic end , and an intrinsic, static perfection . ;My (...) dissertation is organized to test Avicenna's hypothesis that the final cause thus extended was applicable to every subject of every science. I begin by examining how the final cause behaves in the relations between logical entities--terms, premises, definitions, quiddities--and then argue that Avicenna saw the final cause as a bridge between that world of logical entities and the sensible world, whose own relations logic is supposed to systematize. I go on to explain how Avicenna used the twin aspects of Aristotle's notion of nature--one an extrinsic agent keeping the world of natural things in order, the other an intrinsic form serving as the natural thing's source of motion--as a basis for his division of final causes into ends and perfections; I also examine how this division helped Avicenna attempt a reconciliation of chance and natural necessity. I then assess how Avicenna's medical experience--specifically his close observation of the complex teleological processes that cause an organism to exist and function--provided empirical support for his distinction between ends and perfections. Finally I argue that Avicenna viewed the relation between final and efficient causes as one of reciprocal necessitation, based on the premise that each was both cause and effect of the other; here Aristotle's notions of limit and actuality provide some of the metaphysical background to Avicenna's teleology. ;Previous studies of Avicenna's theory of causality have focused almost entirely on the efficient cause; my intention here is to prove that an understanding of Avicenna's teleology should be a prerequisite to any future such study. (shrink)

The present paper has a negative aim and a positive aim, both limited in the present context to a sketch or outline. The negative aim, today less controversial, is to show that Aristotle’s theory of final causality has little or nothing to do with the teleology rejected by modern science and that, therefore, far from having been rendered obsolete, it has yet to be fully understood. This aim will be met through the identification and brief discussion of some (...) key points on which Aristotle’s theory differs from teleology as still commonly understood. The positive aim is more controversial as it proposes that we take an ontology of life as the proper context for understanding the significance and nature of final causation in Aristotle. The argument for final causation, in other words, is that, without it, we would lose the phenomenon of life and, indeed, of nature altogether, reducing nature to the inanimate and mechanical. (shrink)

The range of this volume, and thus the task especially of its editor, is enormous: to confront the question of teleology from Plato through Aristotle, Maimonides, Aquinas’s commentaries on the Physics, Copernicus, Machiavelli, Bacon, Galileo, Descartes, Spinoza, and Newton, to Kant, Hegel, and then to Einstein, and to recent theories of anthropic-principle cosmology or else versions of the many-worlds cosmology of chance and necessity, and then to Niels Bohr and quantum mechanics, and finally to the problem of current molecular-biological theories (...) of evolution. (shrink)

Polanyi’s vision of the cosmic process as undergirded by a logic of emergence common to both the mental life of human beings and the processes of non-human nature can be vindicated if one is prepared to make certain adjustments in the notion of morphogenetic fields with an active center or organizing principle. Given the author’s field-oriented interpretation of Whiteheadian societies, it should be possible to think of entelechies or final causes in developmental rather than strictly Aristotelian terms. That is, (...) the “common element of form” or organizing principle of a Whiteheadian society depends for its own existence on the spontaneous activity of previous sets of actual occasions and yet serves as the ongoing principle of formal and final causality for the present set of actual occasions and still others to follow it. In Aristotelian language, matter and form thus dialectically condition one another and neither is ontologically superior to the other. (shrink)

The great philosopher and historian of philosophy, Etienne Gilson, sets out to show that final causality or purposiveness and formal causality are principles for those who think hard and carefully about the world, including the world of biology. Gilson insists that a completely rational understanding of organisms and biological systems requires the philosophical notion of teleology, the idea that certain kinds of things exist and have ends or purposes the fulfillment of which are linked to their natures-in (...) other words, formal and final causes. His approach relies on philosophical reflection on the facts of science, not upon theology or an appeal to religious authorities such as the Church or the Bible. (shrink)

In this paper, I argue that it is in the fourteenth century that the problem of the compatibility or unity of efficient and final causality emerges. William Ockham and John Buridan start to flirt with a mechanized view of nature solely explainable by efficient causality, and they hence push final causality into the human mind and use it to explain for example action, morality and the good. Their argumentation introduces the problem of how to give (...) a unified account of the world, that is, how are nature and freedom compatible. In the paper, I set up the discussion by going through some of the problems associated with final causality in the seventeenth century and show that Ockham and Buridan's problems are similar. I then argue using a formulation from Leibniz's Monadology that the problems here traced should be seen as versions of the mind/body problem. (shrink)

The paper examines Walter Chatton’s rejection of final causality. At the core of Chatton’s theory lies the claim that there are four kinds of cause, but only three kinds of causality, because final causality should in a sense be reduced to efficient causality. The author begins by situating Chatton’s theory in the context of the fourteenth-century discussions concerning the problematic status of ends as causes. After that, the paper reconstructs Chatton’s rejection of the opinio (...) communis of his time, according to which both final causes and final causality must be posited. The author claims that Chatton’s objections employ three main arguments, based on ontological parsimony, possible non-existence of ends, and the efficient character of love and desire. Then, Chatton’s own theory is presented. The author’s exposition is focused on Chatton’s thesis that final causes are said to be causes only in a metaphorical sense. The final part of the article examines William of Ockham’s reaction to Chatton’s theory. Arguing against Chatton’s teleology, Ockham wants to prove that we have good reasons to retain both final causes and final causality. (shrink)

In his commentary on Aristotle’s Physics, John Buridan (c. 1300–1361) presents his well-known rejection of final causality. The main problem he sees with it is that it requires the cause to exist before the effect. Despite this, he retains the terminology of ends. This has led to some difficulty interpreting Buridan’s view. In this article, I argue that one should not misunderstand Buridan’s terminology and think that he still retains some use or explanatory function for final (...) class='Hi'>causality in nature. To make this point, I look first at Buridan’s text, but then also at three thinkers who discuss Buridan’s view in detail: Albert of Saxony (d. 1390), Paul of Venice (d. 1429), and Luis Coronel (d. 1531). They all have a very clear idea of what Buridan’s view was and understand that it entails a rejection of final causality, but they also all preserve his distinctive terminology. Paul of Venice especially discusses and criticizes Buridan’s view in detail. Besides confirming my interpretation of the rejection of final causality, this study also shows that the view was extremely influential well into the sixteenth century and attributed to Buridan throughout two centuries. (shrink)

Bracken synthesizes Polanyi’s notion of morphogentic field and Whitehead’s notion of societies of actual occasions. These comments emphasize the implications of the metaphors involved in these notions. The rnetaphor of plants growing in afield lies beyond the concept of a morphogenetic field, and the metaphor of a society of interacting persons lies behind the concept of a society of actual occasions. I suggest that one of the implications of this metaphor is that there is not, as Bracken argues, a problem (...) of continuity in Whitehead’s metaphysics of events. (shrink)

Bracken synthesizes Polanyi’s notion of morphogentic field and Whitehead’s notion of societies of actual occasions. These comments emphasize the implications of the metaphors involved in these notions. The rnetaphor of plants growing in afield lies beyond the concept of a morphogenetic field, and the metaphor of a society of interacting persons lies behind the concept of a society of actual occasions. I suggest that one of the implications of this metaphor is that there is not, as Bracken argues, a problem (...) of continuity in Whitehead’s metaphysics of events. (shrink)

Norton has recently argued that causation is merely a useful folk concept and that it fails to hold for some simple systems even in the supposed paradigm case of a causal physical theory – namely Newtonian mechanics. The purpose of this article is to argue against this devaluation of causality in physics. My main argument is that Norton’s alleged counterexample to causality within standard Newtonian physics fails to obey what I shall call the causal core of Newtonian mechanics. (...) In particular, I argue, Norton’s example is not in conformity with Newton’s first law. Moreover, Norton’s reformulation of this first law seems insufficient as a replacement for the original version since the notion of inertial frames in the resulting reformulated theory lacks a physical justification, and since an intelligible notion of time in Newtonian mechanics appears to be closely tied to Newton’s first law in its standard form. I will finally suggest how, given a plausible relationist account of time, the causal core of Newtonian mechanics may play a central role also in relativity and quantum theory. (shrink)

Becoming is a process in which a thing moves from one state to another. In Section 1, the study will elaborate on the discussion of the Aristotelian causes taken broadly, primarily focusing on the relation between efficient and final causes. In Section 2, the study discusses the implications of Scotus’s conception of freedom, as it is reflected in the relation of the future to the past, for the efficient and final causalities. Similarly in Section 3 an examination of (...) Scotus’s conception of matter is conducted. Based on the ideas established in these sections, the study attempts to present an initial Scotistic view of becoming. -/- . (shrink)

A new approach for defining causality and such related notions as degree of responsibility, degrees of blame, and causal explanation. Causality plays a central role in the way people structure the world; we constantly seek causal explanations for our observations. But what does it even mean that an event C "actually caused" event E? The problem of defining actual causation goes beyond mere philosophical speculation. For example, in many legal arguments, it is precisely what needs to be established (...) in order to determine responsibility. The philosophy literature has been struggling with the problem of defining causality since Hume. In this book, Joseph Halpern explores actual causality, and such related notions as degree of responsibility, degree of blame, and causal explanation. The goal is to arrive at a definition of causality that matches our natural language usage and is helpful, for example, to a jury deciding a legal case, a programmer looking for the line of code that cause some software to fail, or an economist trying to determine whether austerity caused a subsequent depression. Halpern applies and expands an approach to causality that he and Judea Pearl developed, based on structural equations. He carefully formulates a definition of causality, and building on this, defines degree of responsibility, degree of blame, and causal explanation. He concludes by discussing how these ideas can be applied to such practical problems as accountability and program verification. Technical details are generally confined to the final section of each chapter and can be skipped by non-mathematical readers. (shrink)

This paper argues that reliabilism can handle Gettier cases once it restricts knowledge producing reliable processes to those that involve a suitable causal link between the subject’s belief and the fact it references. Causal tracking reliabilism (as this version of reliabilism is called) also avoids the problems that refuted the causal theory of knowledge, along with problems besetting more contemporary theories (such as virtue reliabilism and the “safety” account of knowledge). Finally, causal tracking reliabilism allows for a response to Linda (...) Zagzebski’s challenge that no theory of knowledge can both eliminate the possibility of Gettier cases while also allowing fully warranted but false beliefs. (shrink)

Recent attempts to resolve the Paradox of the Gatecrasher rest on a now familiar distinction between individual and bare statistical evidence. This paper investigates two such approaches, the causal approach to individual evidence and a recently influential (and award-winning) modal account that explicates individual evidence in terms of Nozick's notion of sensitivity. This paper offers counterexamples to both approaches, explicates a problem concerning necessary truths for the sensitivity account, and argues that either view is implausibly committed to the impossibility of (...) no-fault wrongful convictions. The paper finally concludes that the distinction between individual and bare statistical evidence cannot be maintained in terms of causation or sensitivity. We have to look elsewhere for a solution of the Paradox of the Gatecrasher. (shrink)

This article compares causal and constitutive explanation. While scientific inquiry usually addresses both causal and constitutive questions, making the distinction is crucial for a detailed understanding of scientific questions and their interrelations. These explanations have different kinds of explananda and they track different sorts of dependencies. Constitutive explanations do not address events or behaviors, but causal capacities. While there are some interesting relations between building and causal manipulation, causation and constitution are not to be confused. Constitution is a synchronous and (...) asymmetric relation between relata that cannot be conceived as independent existences. However, despite their metaphysical differences, the same key ideas about explanation largely apply to both. Causal and constitutive explanations face similar challenges (such as the problems of relevance and explanatory regress) and both are in the business of mapping networks of counterfactual dependence—i.e. mechanisms—although the relevant counterfactuals are of a different sort. In the final section the issue of developmental explanation is discussed. It is argued that developmental explanations deserve their own place in taxonomy of explanations, although ultimately developmental dependencies can be analyzed as combinations of causal and constitutive dependencies. Hence, causal and constitutive explanation are distinct, but not always completely separate forms of explanation. (shrink)

During the past decade, social mechanisms and mechanism-based ex- planations have received considerable attention in the social sciences as well as in the philosophy of science. This article critically reviews the most important philosophical and social science contributions to the mechanism approach. The first part discusses the idea of mechanism- based explanation from the point of view of philosophy of science and relates it to causation and to the covering-law account of explanation. The second part focuses on how the idea (...) of mechanisms has been used in the social sciences. The final part discusses recent developments in analytical sociology, covering the nature of sociological explananda, the role of theory of action in mechanism-based explanations, Merton’s idea of middle-range theory, and the role of agent-based simulations in the development of mechanism-based explanations. (shrink)

In this dissertation, I develop and defend a model of causation that allows for dualist mental causation in worlds where the physical domain is physically complete. In Part I, I present the dualist ontology that will be assumed throughout the thesis and identify two challenges for models of mental causation within such an ontology: the exclusion worry and the common cause worry. I also argue that a proper response to these challenges requires a thoroughly lightweight account of causation, i.e. an (...) account that allows for causes to be metaphysically distinct from the phenomena that produce or physically necessitate their effects. In Part II, I critically evaluate contemporary responses to these challenges from the philosophical literature. In particular, I discuss List and Stoljar’s criticism of exclusion worries, Kroedel’s alternative dualist ontology, concerns about the notion of causal sufficiency, and Lowe’s models of dualist mental causation. I argue that none of these proposals provide independent motivation for a thoroughly lightweight account of causation and therefore leave room for improvement. In the first four chapters of Part III, I develop a thoroughly lightweight model of causation, which builds on interventionist approaches to causation. First, I explain how so-called ‘holding fixed’-requirements in standard interventionist accounts stand in the way of dualist mental causation. I then argue that interventionist accounts should impose a robustness condition on causal correlations and that, with this condition in place, the ‘holding fixed’-requirements can be weakened such that they do allow for dualist mental causation. I dub the interventionist model with such weakened ‘holding fixed’-requirements ‘insensitive interventionism’, argue that it can counter the exclusion worry as well as the common cause worry, and explain under which circumstances it would predict there to be dualist mental causation. Importantly, these circumstances might, for all we know, hold in the actual world. In the final three chapters of Part III, I defend insensitive interventionism against some objections. I consider the objection that causation must be productive, the objection that causes must physically necessitate their effects, and the objection that insensitive interventionism is too permissive. I respond by drawing from the literature on causation by absences and on the relation between causation and fundamental physics. Overall, insensitive interventionism performs as well as standard interventionist accounts. I conclude that insensitive interventionism is a credible model of causation. (shrink)

Invariance is one of several dimensions of causal relationships within the interventionist account. The more invariant a relationship between two variables, the more the relationship should be considered paradigmatically causal. In this paper, I propose two formal measures to estimate invariance, illustrated by a simple example. I then discuss the notion of invariance for causal relationships between non-nominal (i.e., ordinal and quantitative) variables, for which Information theory, and hence the formalism proposed here, is not well suited. Finally, I propose how (...) invariance could be qualified for such variables. (shrink)

This article is intended to provide insight into aspects of Ibn Sīnā’s natural philosophy. It will summarize his interpretation of the Aristotelian four causes, explicate his theory of efficient and necessary causal linkage, and analyze his arguments for causal efficacy. Finally, it will discuss Ibn Sīnā’s views on chance happenings in nature.

The finding of fractal scaling (FS) in behavioral sequences has raised a debate on whether FS is a pervasive property of the cognitive system or is the result of specific processes. Inferences about the origins of properties in time sequences are causal. That is, as opposed to correlational inferences reflecting instantaneous symmetrical relations, causal inferences concern asymmetric relations lagged in time. Here, I integrate Granger‐causality with inferences about FS. Four simulations illustrate that causal analyses can isolate distinct FS sources, (...) whereas correlational techniques cannot. I then analyze three simultaneous sequences of responses from a database of word‐naming trials. I find that two, or perhaps three, distinct sources account for the presence of FS in these sequences, but FS is not a general property of the system. This suggests that FS arises due to the properties of a limited number of identifiable psychological and/or neural processes. Finally, I reanalyze a previously published dataset of acoustic frequency spectra using the new tools. The causality/criticality combination introduced here offers a new important perspective in the study of cognition. (shrink)

In this thesis, I give a metascientific account of causality in medicine. I begin with two historical cases of causal discovery. These are the discovery of the causation of Burkitt’s lymphoma by the Epstein-Barr virus, and of the various viral causes suggested for cervical cancer. These historical cases then support a philosophical discussion of causality in medicine. This begins with an introduction to the Russo- Williamson thesis (RWT), and discussion of a range of counter-arguments against it. Despite these, (...) I argue that the RWT is historically workable, given a small number of modifications. I then expand Russo and Williamson’s account. I first develop their suggestion that causal relationships in medicine require some kind of evidence of mechanism. I begin with a number of accounts of mechanisms and produce a range of consensus features of them. I then develop this consensus position by reference to the two historical case studies with an eye to their operational competence. In particular, I suggest that it is mechanistic models and their representations which we are concerned with in medicine, rather than the mechanism as it exists in the world. -/- I then employ these mechanistic models to give an account of the sorts of evidence used in formulating and evaluating causal claims. Again, I use the two human viral oncogenesis cases to give this account. I characterise and distinguish evidence of mechanism from evidence of difference-making, and relate this to mechanistic models. I then suggest the relationship between types of evidence presents us with a means of tackling the reference-class problem. This sets the scene for the final chapter. Here, I suggest the manner in which these two different classes of evidence become integrated is also reflected in the way that developing research programmes change as their associated causal claims develop. (shrink)

Knowledge of causal laws is expensive and hard to come by. But we work hard to get it because we believe that it will reduce contingency in planning policies and in building new technologies: knowledge of causal laws allows us to predict reliably what the outcomes will be when we manipulate the factors cited as causes in those laws. Or do they? This paper will argue that causal laws have no special role here. As economists from JS Mill to Robert (...) Lucas and David Hendry stress, along recently with philosophers like James Woodward and Sandra Mitchell, they can do the job only if they are invariant under the manipulations proposed. But then, I shall argue, anything that is invariant under the proposed manipulations will do this job equally well. There seems to be nothing special about causal-law knowledge in and of itself that makes it particularly valuable for policy and technology prediction. What seems to matter is invariance alone, not causality. But what guarantees invariance and how do we know when it will obtain? Here certain kinds of causal laws do have a special place – those underwritten either by what I have called ‘nomological machines’ or by what I have called ‘capacities’. Capacities and nomological machines have a double virtue that makes them invaluable for policy planning. First, the causal laws they give rise to will be invariant so long as they obtain; and second, they typically have visible markers we can come to recognize that tell us when they obtain. The markers for nomological machines are shakier than those for capacities, though, since capacities are often tied to markers by well-established empirical laws. Capacities have their own drawback however, which is the final topic of this paper: the causal laws that are guaranteed by a capacity connect the obtaining of a capacity with its exercise. But Hume argued that no distinction can be made between the obtaining of a power and its exercise. (shrink)

This article initially discusses reasons why Freud researchers turn to critical realism since this is what led me to compare causality in the two traditions in the first place. Three arguments on causality follow. First, it is argued that Freud's analyses of unconscious processes merit closer attention by critical realists, focusing on the relation between causal unconscious processes and rationality, and causal unconscious processes and social change. It may be objected that this does not concern the discussion of (...) causality proper, to which I would reply that what we consider to be causally efficacious ultimately is relevant to our conception of causality. The second argument, which is the centrepiece, outlines Freud's conception of causality, his idea of overdetermination and his treatment of motives and reasons as causes. His notions of causality are compared to those of critical realism. Freud's idea of retroactive causality is discussed in relation to delayed causality in critical realism and the idea of disembedded space-time components. Finally, Freud's concept of determinism and the related concepts of repetition and chance are discussed and compared to ubiquity determinism in critical realism and the distinctions between causal and non-causal correlations and necessary and accidental sequences of events. While the first argument concerns presuppositions for the discussion of causality in psychoanalysis and its relevance for critical realism, the third concerns implications and/or applications of the two views on causality. It is my contention that the second argument needs to be placed in context of the other two in order for the two conceptions of causality to be understood adequately and most revealingly compared. (shrink)

It is generally agreed upon that Grice's causal theory of perception describes a necessary condition for perception. It does not describe sufficient conditions, however, since there are entities in causal chains that we do not perceive and not all causal chains yield perceptions. One strategy for overcoming these problems is that of strengthening the notion of causality. Another is that of specifying the criteria according to which perceptual experiences should match the way the world is. Finally, one can also (...) try to provide sufficient conditions by elaborating on the content of perceptual experiences. These different strategies are considered in this paper, with the conclusion that none of them is successful. However, a careful examination of their problems points towards the general solution that we outline at the end. (shrink)

There are cases of ineffable learning — i. e., cases where an agent learns something, but becomes certain of nothing that she can express — where it is rational to update by Jeffrey conditionalization. But there are likewise cases of ineffable learning where updating by Jeffrey conditionalization is irrational. In this paper, we first characterize a novel class of cases where it is irrational to update by Jeffrey conditionalization. Then we use the d-separation criterion to develop a causal understanding of (...) when and when not to Jeffrey conditionalize that bars updating by Jeffrey conditionalization in these cases. Finally, we reflect on how the possibility of so-called “unfaithful” causal systems bears on the normative force of the causal updating norm that we advocate. (shrink)

Decision-making typically requires judgments about causal relations: we need to know the causal effects of our actions and the causal relevance of various environmental factors. We investigate how several individuals' causal judgments can be aggregated into collective causal judgments. First, we consider the aggregation of causal judgments via the aggregation of probabilistic judgments, and identify the limitations of this approach. We then explore the possibility of aggregating causal judgments independently of probabilistic ones. Formally, we introduce the problem of causal-network aggregation. (...) Finally, we revisit the aggregation of probabilistic judgments when this is constrained by prior aggregation of qualitative causal judgments. (shrink)

Causal refutations of external-world scepticism start from our ability to make justified judgements about the order of our own experiences, and end with the claim that there must be perceptible external objects, some of whose states can be causally correlated with that order. In a recent paper, I made a series of objections to this broadly Kantian anti-sceptical strategy. Georges Dicker has provided substantive replies on behalf of a version of the causal refutation of idealism. Here I offer a few (...) final remarks about issues at the heart of our disagreement. -/- . (shrink)

Scientific models describe natural phenomena at different levels of abstraction. Abstract descriptions can provide the basis for interventions on the system and explanation of observed phenomena at a level of granularity that is coarser than the most fundamental account of the system. Beckers and Halpern (2019), building on work of Rubenstein et al. (2017), developed an account of abstraction for causal models that is exact. Here we extend this account to the more realistic case where an abstract causal model offers (...) only an approximation of the underlying system. We show how the resulting account handles the discrepancy that can arise between low- and high-level causal models of the same system, and in the process provide an account of how one causal model approximates another, a topic of independent interest. Finally, we extend the account of approximate abstractions to probabilistic causal models, indicating how and where uncertainty can enter into an approximate abstraction. (shrink)

Causal theories of mental content (CTs) ground certain aspects of a concept's meaning in the causal relations a concept bears to what it represents. Section 1 explains the problems CTs are meant to solve and introduces terminology commonly used to discuss these problems. Section 2 specifies criteria that any acceptable CT must satisfy. Sections 3, 4, and 5 critically survey various CTs, including those proposed by Fred Dretske, Jerry Fodor, Ruth Garrett Millikan, David Papineau, Dennis Stampe, Dan Ryder, and the (...) author himself. The final section considers general objections to the causal approach. (shrink)

Knowledge of causal laws is expensive and hard to come by. But we work hard to get it because we believe that it will reduce contingency in planning policies and in building new technologies: knowledge of causal laws allows us to predict reliably what the outcomes will be when we manipulate the factors cited as causes in those laws. Or do they? This paper will argue that causal laws have no special role here. As economists from JS Mill to Robert (...) Lucas and David Hendry stress, along recently with philosophers like James Woodward and Sandra Mitchell, they can do the job only if they are invariant under the manipulations proposed. But then, I shall argue, anything that is invariant under the proposed manipulations will do this job equally well. There seems to be nothing special about causal-law knowledge in and of itself that makes it particularly valuable for policy and technology prediction. What seems to matter is invariance alone, not causality. But what guarantees invariance and how do we know when it will obtain? Here certain kinds of causal laws do have a special place – those underwritten either by what I have called ‘nomological machines’ or by what I have called ‘capacities’. Capacities and nomological machines have a double virtue that makes them invaluable for policy planning. First, the causal laws they give rise to will be invariant so long as they obtain; and second, they typically have visible markers we can come to recognize that tell us when they obtain. The markers for nomological machines are shakier than those for capacities, though, since capacities are often tied to markers by well-established empirical laws. Capacities have their own drawback however, which is the final topic of this paper: the causal laws that are guaranteed by a capacity connect the obtaining (or triggering) of a capacity with its exercise. But Hume argued (mistakenly I suggest) that no distinction can be made between the obtaining of a power and its exercise. (shrink)