Online research in philosophy

The systems studied in the special sciences are often said to be causally autonomous, in the sense that their higher-level properties have causal powers that are independent of those of their more basic physical properties. This view was espoused by the British emergentists, who claimed that systems achieving a certain level of organizational complexity have distinctive causal powers that emerge from their constituent elements but do not derive from them.2 More recently, non-reductive physicalists have espoused a similar view about the causal autonomy of specialscience properties. They argue that since these properties can typically have multiple physical realizations, they are not identical to physical properties, and further they possess causal powers that differ from those of their physical realizers.3 Despite the orthodoxy of this view, it is hard to find a clear exposition of its meaning or a defence of it in terms of a well-motivated account of causation. In this paper, we aim to address this gap in the literature by clarifying what is implied by the doctrine of the causal autonomy of special-science properties and by defending the doctrine using a prominent theory of causation from the philosophy of science. The theory of causation we employ is a simplified version of an “interventionist” theory advanced by James Woodward (2003, forthcoming a, b), according to which a cause makes a counterfactual difference to its effects. In terms of this theory, it is possible to show that a special-science property can make a difference to some effect while the physical property that realizes it does not. Although other philosophers have also used counterfactual analyses of causation to argue for the causal autonomy of special-science properties,4 the theory of causation we employ is able to establish this with an unprecedented level of precision..

Among the many philosophers who hold that causal facts1 are to be explained in terms of—or more ambitiously, shown to reduce to—facts about what happens, together with facts about the fundamental laws that govern what happens, the clear favorite is an approach that sees counterfactual dependence as the key to such explanation or reduction. The paradigm examples of causation, so advocates of this approach tell us, are examples in which events c and e—the cause and its effect—both occur, but: had c not occurred, e would not have occurred either. From this starting point ideas proliferate in a vast profusion. But the remarkable disparity among these ideas should not obscure their common foundation. Neither should the diversity of opinion about the prospects for a philosophical analysis of causation obscure their importance. For even those philosophers who see these prospects as dim—perhaps because they suffer post-Quinean queasiness at the thought of any analysis of any concept of interest—can often be heard to say such things as that causal relations among events are somehow “a matter of” the patterns of counterfactual dependence to be found in them. It was not always so. Thirty-odd years ago, so-called “regularity” analyses (so-called, presumably, because they traced back to Hume’s well-known analysis of causation as constant conjunction) ruled the day, with Mackie’s Cement of the Universe embodying a classic statement. But they fell on hard times, both because of internal problems—which we will review in due course—and because dramatic improvements in philosophical understanding of counterfactuals made possible the emergence of a serious and potent rival: a counterfactual analysis of causation resting on foundations firm enough to be repel the kind of philosophical suspicion that had formerly warranted dismissal..

The paper proposes an explication of causation in terms of laws and their explanatory systematization. A basic notion is "nomic dependence". The definition given by David Lewis is suitable for deterministic laws, and a general definition drawing on Wesley Salmon's statistical-relevance model of explanation is proposed. A test is offered for establishing that one chain of nomically dependent events is more direct than another that ends with the same event by considering the relationship between the two chains when an explanation in terms of more basic laws is sought. The chain to an event can be defined as causal if it is the most direct nomically linked chain leading up to that event.

Orthodox physicalism has a problem with mental causation. If physics is complete and mental events are not identical to physical events (as multiple-realisation arguments imply) it seems as though there is no causal work for the mental to do. This paper examines some recent attempts to overcome this problem by analysing causation in terms of counterfactuals or conditional probabilities. It is argued that these solutions cannot simultaneously capture the force of the completeness of physics and make room for mental causation.

In this paper I wish to argue that counterfactual analyses of causation are inadequate. I believe the counterfactuals that are involved in counterfactual analyses of causation are often false, and thus the theories do not provide an adequate account of causation. This is demonstrated by the presentation of a counterexample to the counterfactual analyses of causation. I then present a unified theory of causation that is based upon probability and counterfactuals. This theory accounts for both deterministic and indeterministic causation, and is not subject to many of the traditional problems facing theories of causation.

The paper argues for four claims: (1) The problem of mental causation and the argument for its solution in terms of the identity of mental with physical causes are independent of the theory of causation one favours. (2) If one considers our experience of agency as described by folk psychology to be veridical, one is committed to an anti-Humean metaphysics of causation in terms of powers that establish necessary connections. The same goes for functional properties in general. (3) A metaphysics of causation in terms of powers is compatible with physics. (4) If combined with the argument for mental causes being identical with physical causes, that metaphysics leads to a conservative reductionism.

Several different approaches to the conceptual analysis of causation are guided by the idea that a cause is something that makes a difference to its effects. These approaches seek to elucidate the concept of causation by explicating the concept of a difference-maker in terms of better-understood concepts. There is no better example of such an approach than David Lewis’ analysis of causation, in which he seeks to explain the concept of a difference-maker in counterfactual terms. Lewis introduced his counterfactual theory of causation with these words: 'We think of a cause as something that makes a difference, and the difference it makes must be a difference from what would have happened without it. Had it been absent, its effects—some of them, at least, and usually all—would have been absent as well.' (Lewis 1973b: pp. 160-1) According to Lewis, a cause c makes a difference to an effect e in the sense that if the cause c had not occurred, the effect e would not have occurred either. All we shall see in section 2, Lewis’ theory says there is more to the concept of causation than this counterfactual condition. Lewis is on the right track, I think, in saying that we think of a cause as something that makes a difference and that this thought is best explicated in terms of counterfactual concepts. However, I shall argue that the particular way in which Lewis spells out the concept of a cause as difference-maker is unsatisfactory. For Lewis’ articulation of this concept is distorted by a specific metaphysical assumption: specifically, that causation is an absolute relation, specifiable independently of any contextual factors. The distortion induced by this assumption is reflected in the undiscriminating manner in which his theory generates countless causes for any given effect. However, commonsense judgement is much more discriminating about causes than Lewis’ theory. Accordingly, I claim that Lewis' analysis faces the problem of profligate causes and I outline some specific problem cases in section 3..

If we seek to analyse causation in terms of counterfactual conditionals then we must assume that there is a class of counterfactuals whose members (i) are all and only those we need to support our judgements of causation, (ii) have truth-conditions specifiable without any irreducible appeal to causation. I argue that (i) and (ii) are unlikely to be met by any counterfactual analysis of causation. I demonstrate this by isolating a class of counterfactuals called non-projective counterfactuals, or NP-counterfactuals, and indicate how counterfactual analyses of causation must appeal to them to account for the correct causal judgements we make. I show that the truth-conditions of NP-counterfactuals are specifiable only by irreducible appeal to causation. A dilemma then holds: if counterfactual analyses of causation eschew appeal to NP-counterfactuals they are empirically inadequate, but if they appeal to NP-counterfactuals they are circular and thus conceptually inadequate.

Causation has traditionally been analyzed either as a relation of nomic dependence or as a relation of counterfactual dependence. I argue for a third program, a physicalistic reduction of the causal relation to one of energy-momentum transference in the technical sense of physics. This physicalistic analysis is argued to have the virtues of easily handling the standard counterexamples to the nomic and counterfactual analyses, offering a plausible epistemology for our knowledge of causes, and elucidating the nature of the relation between causation and physical science.

The basic idea of counterfactual theories of causation is that the meaning of causal claims can be explained in terms of counterfactual conditionals of the form “If A had not occurred, C would not have occurred”. While counterfactual analyses have been given of type-causal concepts, most counterfactual analyses have focused on singular causal or token-causal claims of the form “event c caused event e”. Analyses of token-causation have become popular in the last thirty years, especially since the development in the 1970's of possible world semantics for counterfactuals. The best known counterfactual analysis of causation is David Lewis's (1973b) theory. However, intense discussion over thirty years has cast doubt on the adequacy of any simple analysis of singular causation in terms of counterfactuals. Recent years have seen a proliferation of different refinements of the basic idea to achieve a closer match with commonsense judgements about causation.