Problem of mental causation
Encyclopedia
The problem of mental causation is a conceptual issue in the philosophy of mind
. That problem, in short, is how to account for the common-sense idea that intentional thoughts or intentional mental states are causes of intentional actions. The problem divides into several distinct sub-problems, including the problem of causal exclusion, the problem of anomalism, and the problem of externalism. However, the sub-problem which has attracted most attention in the philosophical literature is arguably the exclusion problem.
To the extent that we do not have to go outside human physiology in order to trace the causal antecedents of any bodily movement, intentional action can be fully causally explained by the existence of these physiological antecedents alone. No mention of mental states need enter into the explanation. This troubles philosophers because, pre-theoretically, it seems that what is crucial in causing a person to act is their mental states (for example, their beliefs and desires). But, given that physiological facts are sufficient to account for action, mental states appear to be superfluous; they are at risk of being causally and explanatorily irrelevant with respect to human action (Yoo 2007, §3b.iii).
Many consider this to be a highly counter-intuitive and undesirable position to take. It ultimately leads to epiphenomenalism
--the view that mental events or states are causally irrelevant, they are merely after effects that play no role in any causal chains whatsoever. Thomas Huxley famously noted that epiphenomenalism treats mental states like the steam coming off a train: it plays no causal role in the train's moving forward, it is merely an "emergent property" of the actual causation occurring in the engine (Walter 2007, §2).
In short, one response has been to deny that psychological laws involving mental states require strict, exceptionless laws. Jerry Fodor (1980) argues that non-basic (or "special") sciences do not in fact require strict laws. In current practice, special sciences (for example, biology and chemistry) have ceteris paribus laws (or laws with "all else being equal" clauses), according to which there are exceptions. However, only in the basic sciences (physics) are there strict, exceptionless laws. Thus, although mental states are anomalous, they can still figure into scientifically respectable laws of psychology.
. According to such a view, mental events and physical events are entirely different things. One main difference is that mental events have no spatial location, yet physical events do. However, the two causally interact nevertheless (see Descartes 1642/1986, especially meditations II & VI).
The major problem that interactionist dualism faces is that of explicating a satisfactory notion of causation according to which non-spatial events, such as mental events, can causally interact with spatially located events. According to the current mainstream scientific world-view, the physical realm is causally closed in that causal relationships only hold among physical events in the physical realm. Given these types of considerations, some argue that it is appropriate to say that the main assumptions in interactionist dualism generate the problem of mental causation rather than solve it (see Yoo 2006, §1a).
or materialism
. But, such views require a particular theory of how mental events are physical in nature. One such theory is behaviorism
. Behaviorists, in general, argue that mental events are merely dispositions to behave in certain ways. Another theory is the identity theory, according to which mental events are (either type- or token-) identical to physical events. A more recent view, known as functionalism
, claims that mental events are individuated (or constituted by) the causal role they play. As such, mental events would fit directly into the causal realm, as they are simply certain causal (or functional) roles. Finally, there is eliminative materialism
, which simply denies that there are any such mental events; thus, there is really no problem of mental causation at all.
Philosophy of mind
Philosophy of mind is a branch of philosophy that studies the nature of the mind, mental events, mental functions, mental properties, consciousness and their relationship to the physical body, particularly the brain. The mind-body problem, i.e...
. That problem, in short, is how to account for the common-sense idea that intentional thoughts or intentional mental states are causes of intentional actions. The problem divides into several distinct sub-problems, including the problem of causal exclusion, the problem of anomalism, and the problem of externalism. However, the sub-problem which has attracted most attention in the philosophical literature is arguably the exclusion problem.
The general problem
The basic problem of mental causation is an intuitive one: on the face of it, it seems that mental events cause physical events (and vice versa), but how can mental events have any causal effect on physical events? Suppose, for example, some person, John, orders dessert after dinner. It seems that at least one cause for such a physical, behavioral event is that John desired to have dessert and believed that by ordering dessert he would be able to soon have dessert. But, how can such mental events as beliefs and desires cause John's mouth to move in such a way that he orders dessert?Exclusion problem
What follows is a summary of the causal exclusion problem in its simplest form, and it is merely one of several possible formulations.To the extent that we do not have to go outside human physiology in order to trace the causal antecedents of any bodily movement, intentional action can be fully causally explained by the existence of these physiological antecedents alone. No mention of mental states need enter into the explanation. This troubles philosophers because, pre-theoretically, it seems that what is crucial in causing a person to act is their mental states (for example, their beliefs and desires). But, given that physiological facts are sufficient to account for action, mental states appear to be superfluous; they are at risk of being causally and explanatorily irrelevant with respect to human action (Yoo 2007, §3b.iii).
Many consider this to be a highly counter-intuitive and undesirable position to take. It ultimately leads to epiphenomenalism
Epiphenomenalism
In philosophy of mind, epiphenomenalism, also known as Type-E Dualism, is a view that "mental" states do not have any influence on "physical" states.-Background:...
--the view that mental events or states are causally irrelevant, they are merely after effects that play no role in any causal chains whatsoever. Thomas Huxley famously noted that epiphenomenalism treats mental states like the steam coming off a train: it plays no causal role in the train's moving forward, it is merely an "emergent property" of the actual causation occurring in the engine (Walter 2007, §2).
Problem of anomalism
Another problem with mental causation is that mental events seem anomalous in the sense that there are no scientific laws that mental states can figure into without having exceptions. There are no "strict" laws, and mental events must factor into strict laws in order to fit respectably into the causal order described by current science (see Davidson 1970).In short, one response has been to deny that psychological laws involving mental states require strict, exceptionless laws. Jerry Fodor (1980) argues that non-basic (or "special") sciences do not in fact require strict laws. In current practice, special sciences (for example, biology and chemistry) have ceteris paribus laws (or laws with "all else being equal" clauses), according to which there are exceptions. However, only in the basic sciences (physics) are there strict, exceptionless laws. Thus, although mental states are anomalous, they can still figure into scientifically respectable laws of psychology.
Problem of externalism
In the latter half of the twentieth century externalism about meaning became espoused by many philosophers. Externalism is roughly the view that certain parts of an individual's environment play a crucial role in the meaning of at least some of an individual's words (see Putnam 1975 and Burge 1979). A thesis about meaning affects the mind insofar as our thoughts are about things in the world. A common view in the philosophy of mind is that at least certain mental states have intentional content in this sense. For example, one's belief that water is wet has the semantic content of water is wet. The thought is about water and the fact that it is wet. But, if externalism is true—if some of the contents of one's thoughts are constituted at least in part by factors external to one's mind—then there is yet another difficulty in explaining how mental states can cause physical states (see Yoo 2006, §3b.ii).Dualist solutions
There are several options for answers to the kinds of questions raised by the basic problem of mental causation. One can simply claim that while the mental and the physical are quite different things, they can nonetheless causally interact with one another. This view is known as interactionist dualismDualism
Dualism denotes a state of two parts. The term 'dualism' was originally coined to denote co-eternal binary opposition, a meaning that is preserved in metaphysical and philosophical duality discourse but has been diluted in general or common usages. Dualism can refer to moral dualism, Dualism (from...
. According to such a view, mental events and physical events are entirely different things. One main difference is that mental events have no spatial location, yet physical events do. However, the two causally interact nevertheless (see Descartes 1642/1986, especially meditations II & VI).
The major problem that interactionist dualism faces is that of explicating a satisfactory notion of causation according to which non-spatial events, such as mental events, can causally interact with spatially located events. According to the current mainstream scientific world-view, the physical realm is causally closed in that causal relationships only hold among physical events in the physical realm. Given these types of considerations, some argue that it is appropriate to say that the main assumptions in interactionist dualism generate the problem of mental causation rather than solve it (see Yoo 2006, §1a).
Physicalist solutions
The other major option is to deny that mental events are non-physical. Views that fall under this general heading are called physicalismPhysicalism
Physicalism is a philosophical position holding that everything which exists is no more extensive than its physical properties; that is, that there are no kinds of things other than physical things...
or materialism
Materialism
In philosophy, the theory of materialism holds that the only thing that exists is matter; that all things are composed of material and all phenomena are the result of material interactions. In other words, matter is the only substance...
. But, such views require a particular theory of how mental events are physical in nature. One such theory is behaviorism
Behaviorism
Behaviorism , also called the learning perspective , is a philosophy of psychology based on the proposition that all things that organisms do—including acting, thinking, and feeling—can and should be regarded as behaviors, and that psychological disorders are best treated by altering behavior...
. Behaviorists, in general, argue that mental events are merely dispositions to behave in certain ways. Another theory is the identity theory, according to which mental events are (either type- or token-) identical to physical events. A more recent view, known as functionalism
Functionalism (philosophy of mind)
Functionalism is a theory of the mind in contemporary philosophy, developed largely as an alternative to both the identity theory of mind and behaviourism. Its core idea is that mental states are constituted solely by their functional role — that is, they are causal relations to other mental...
, claims that mental events are individuated (or constituted by) the causal role they play. As such, mental events would fit directly into the causal realm, as they are simply certain causal (or functional) roles. Finally, there is eliminative materialism
Eliminative materialism
Eliminative materialism is a materialist position in the philosophy of mind. Its primary claim is that people's common-sense understanding of the mind is false and that certain classes of mental states that most people believe in do not exist...
, which simply denies that there are any such mental events; thus, there is really no problem of mental causation at all.