Mechanisms of mental causation: An examination of the theories of Anomalous Monism and Direct Realism with regard to their proposals concerning the causal role of human mentality in the natural world. A thesis submitted in partial fulfilment of the requirements of Doctor of Philosophy, School of Psychology, Faculty of Science, University of Sydney. June, 2004. 1 Acknowledgements Throughout the process of writing the present thesis, I have been so fortunate as to spend many happy hours in discussing realist philosophy with my supervisors Joel Michell and Terence McMullen, as well as with Fiona Hibberd. I should like to take this opportunity to express my gratitude to each of these good friends, and to acknowledge the positive influence that they have had on my learning experience. I should also like to thank my parents, Faith Charity and Brian Medlow, for their loving support and the encouragement that they have shown me throughout all stages of my education. Most of all I am grateful to James Palethorpe who has been a fellow student and loving companion throughout the whole. Sharon Medlow 2 Abstract One of the most interesting developments in recent psychological theorising has been a growing appreciation of the need for a viable theory of mental causation. Hitherto, the prospects for reconciling what seems to be the uniquely rational character of human thought and action with the non-rational mechanistic workings of the natural world have appeared to be limited or even illusory, and the pursuit of reconciliation of this sort has therefore formerly been dismissed as being either impossible of completion or inappropriate for contemplation. Much of the scepticism concerning the role of causal processes in human thought and action was dispelled, however, by the philosopher Donald Davidson, who argues that not only is human action capable of being caused by the actor’s thoughts and desires, but that only when such action is so caused, can it be rational. Davidson’s proposal for the reconciliation of human rationality with causal necessitation is articulated in his theory of Anomalous Monism. According to this theory, there exists what may be termed an ontological-conceptual distinction between events themselves and the characters or properties that are attributed to events by human observers, and it is through recognition of this distinction that one discovers how mental events, that is, events that are amenable to description in the psychological vocabulary, are causally efficacious yet free from the constraints typically associated with the necessity and sufficiency of causal laws. Anomalous Monism, if it were workable, would therefore resolve the paradox according to which human mentality is at once integrated in, and yet unconstrained by, the mechanistic natural world, by demonstrating the compatibility of the facts of causation with the intuitions of folk psychology. However, close examination of Anomalous Monism reveals it to rely on logically flawed anti-realist principles concerning the characters of events, properties and causation. It follows from this that the theory itself must be rejected, but the task that it was devised to undertake, the formulation of a viable theory of mental causation, need not be similarly discarded. Rather, what remains is the challenge of delineating an alternative theory, one that withstands logical scrutiny whilst addressing what is characteristic of human mental processes, and thereby what is characteristic of mental causation. 3 The theory of Direct Realism that is derived from the broader philosophical realism of John Anderson provides the materials for meeting this challenge. According to Direct Realism, mental phenomena are relational situations obtaining between certain organisms (including humans) and their environments. As such, mental phenomena are included in the range of phenomena occurring in the natural world and they are therefore subject to all of its ways of working, including its deterministic mechanisms. The particular challenge that a Direct Realist theory of mental causation faces, that of demonstrating that relational situations can be causal, is revealed upon examination of the character of causation to be unproblematic. Furthermore, the seeming incompatibility between human rationality and natural necessitation is resolved when it is acknowledged that, rather than be an inherent feature of thought and action, logical structure is a characteristic of the natural environment that organisms are at times sensitive to, as revealed by its effects on the characters of their thoughts and actions. Far from being remote or illusory, the prospects for reconciling human mentality with the causal mechanisms of the natural world are discovered in the present thesis to be favourable when a realist approach to the characters of both mental events and causation is adopted. 4 CONTENTS I: INTRODUCTION i I.i Human freedom in a determined world i I.ii The purpose of psychology: prediction and control or understanding of meaning? ii I.iii Methodological issues v I.iv Ontological issues vii PART I: DAVIDSON’S THEORY OF ANOMALOUS MONISM 1 Section 1: Establishing the Paradox 1 1.1 Davidson and rationality 2 1.2 Davidson and mental anomalism 10 1.2.1 Strict laws and generalisations 11 1.2.2 Mental anomalism: why strict laws are absent from psychology 18 1.2.2.1 Externalism 19 1.2.2.2 Dispositionality 21 1.2.2.3 Rationality 23 1.3 Davidson’s paradox 25 Section 2: Resolving the Paradox 27 2.1 Characterising events 28 2.1.1 Events as a fundamental ontological category 28 2.1.2 Events as particulars 31 2.2 Constitutive description 33 2.2.1 Theories and their empirical interpretations 34 2.2.2 Mental attributions 37 2.2.3 The Unified Theory and radical interpretation 40 2.3 Causal relations and causal explanations 49 2.3.1 Causal relations and singular causal statements 50 2.3.2 Causal explanations 51 2.4 Physical-mental event token identity 55 2.5 Supervenience 56 2.5.1 Supervenience in ethics and aesthetics 57 2.5.1.1 Subvenient and supervenient properties 57 2.5.1.2 The standard in supervenience 59 2.5.2 Mental supervenience 65 2.5.2.1 Supervenient and subvenient properties in mental supervenience 65 2.5.2.2 The standard in mental supervenience 68 2.5.2.3 The conceptual status of supervenient properties 72 2.6 Resolving the paradox 76 5 Section 3: Criticism of Davidson’s Anomalous Monism 79 3.1 Weak mental supervenience, ‘possible worlds’ and internal inconsistency 80 3.2 Anomalous monism, mental supervenience and mental epiphenomenalism 84 3.3 Anomalous monism and explanatory failure 92 3.4 Mental properties as linguistic artefacts 102 3.4.1 The logic of symbolism 102 3.4.2 Implications of rejecting ‘constitutive description’ 106 3.5 The particularity and universality of events 111 3.6 Concluding remarks concerning Anomalous Monism 117 PART II: A DIRECT REALIST APPROACH TO MENTAL CAUSATION 120 Section 4: Introduction to Direct Realism 120 4.1 Realism 120 4.2 Relational situations 122 4.3 Causal relational situations 125 4.3.1 The referents of causation 125 4.3.2 The relata of causation 128 4.3.3 Causal necessity, sufficiency, laws and priority 129 4.3.4 Causation and mental events 131 4.4 Maze’s Direct Realist theory of mental causation 132 4.4.1 Drives 133 4.4.2 Cognitive relational situations 139 4.4.2.1 The referents of cognition 139 4.4.2.2 The relata of cognition 143 4.4.2.3 The relational character of cognition 145 4.4.3 Maze and mental causation 149 Section 5: Further Development of a Direct Realist Theory of Mental Causation 156 5.1 Maze, ‘relational properties’ and epiphenomenalism 156 5.2 An alternative Direct Realist account of mental causation 162 5.2.1 Why causation and externalism seem to be incompatible: the ‘locality assumption’ 162 5.2.2 The character and location of behaviour 168 5.2.3 The role of cognitive relational situations in behaviour-causation 176 Section 6: Summary and Conclusions 184 References 189 6 I: Introduction I.i Human freedom in a determined world The suggestion that thought and action can be entirely accounted for in terms of the causal mechanisms that operate in the natural world is incompatible with traditional understandings of what it is to think and behave. The widely held conviction that while, as a matter of fact, one’s past courses of action did unravel in certain ways, they could just as well, with the exertion of one’s will, have turned out differently, was famously illustrated in a lecture delivered by William James in 1884. James asked his audience to imagine that at the close of the meeting he, having the option of walking home via either Divinity Avenue or Oxford Street, proceeded through Divinity Avenue only to have the powers of the universe annihilate ten minutes of time and thereby return him to his starting position, ready to begin his journey home. At this point, he argued, although all circumstances were now as they were ten minutes before, he would be free to vary his past course of action by ignoring Divinity Avenue and walking home via Oxford Street instead. The appeal of James’ (1884) argument is partly accounted for by the fact that it accords with what, for many of us, goes without question; the view that we are free to think as we please and act in accordance with our whims and fancies. Despite this, there exists good reason to suppose that thought and behaviour are caused, and it is only if this supposition is correct that the practice of psychological experimentation and therapy can be justified. It is the lot of the psychologist, therefore, to question the freedom of the mind and to either discover a compromise, if such exists, between the liberty of free will and the necessitations of the natural world, or to reject one or the other of these.