Teleology and the nature of mental states.

JENNIFER expresses a desire for coffee, walks to the kitchen and soon returns with a cup of coffee in hand. Without tremendous difficulty, we surmise that Jennifer went to the kitchen because she wanted coffee. We have thereby explained Jennifer's action by citing a relevant mental state, her desire for coffee. Such ordinary explanations of action, and the mental states postulated by those explanations, constitute central subjects of inquiry for philosophy of mind. Moreover, there is a developing philosophical orthodoxy concerning both topics. The orthodoxy sees ordinary action explanation as a species of causal explanation: in saying that Jennifer went to the kitchen because she wanted coffee, it is implied that her desire for coffee caused her behavior of going to the kitchen. This causal theory of action explanation in turn motivates functionalism, the second part of the orthodox view of the mental. According to functionalism, mental states are causally individuated states of the agent: mental kinds are implicitly defined or specified by a common sense theory consisting of causal generalizations relating mental states to one another and to behavior.(1)

It is time to overthrow this orthodoxy within the philosophy of mind, although a complete case for that will not be made within the scope of this paper. Instead, after some background discussion of the causal theory of action and functionalism, the paper defends two theses. First, a teleological account of action explanation provides a plausible alternative to the causal theory of action, an alternative that can answer the only argument offered in favor of the causal view. Second, the teleological alternative provides strong grounds for rejecting the functionalist account of the nature of mental states.

1. THE CAUSAL THEORY AND FUNCTIONALISM

Put in more general terms, the explanation of Jennifer's action is an instance of a relatively standard form of psychological explanation:

A [phi]'d because she desired [psi] and believed that

by [phi]ing she could [psi]. We can call such explanations of action reason explanations or intentional explanations. The causal theory of action asserts that explanations of this form typically presuppose that the agent's desire and her instrumental belief caused her [phi]ing. This theory of action currently enjoys wide acceptance within the philosophical literature, frequently without any suggestion that the claim requires argument. Non-causal views of action were prevalent through the early 1960's,(2) but they seem to have all but disappeared from the philosophical scene today.(3) This general acceptance of the causalist view seems to have begun with Donald Davidson's seminal article, "Actions, Reasons and Causes" (1963). In that article, Davidson offers as his only argument this challenge: if reason explanations are not causal, what else accounts for their explanatory force? Lacking a satisfactory alternative construal, we should, Davidson claims, assume that reason explanations are a species of causal explanation. Davidson's challenge has appeared compelling to a generation of philosophers, and the causal theory has become firmly entrenched as the orthodox view of action explanation. After a presentation of the alternative, teleological account of action explanation, we will return for a more detailed look at the Davidsonian challenge.

Alongside our ordinary explanations of individual actions, we have a vast body of common sense platitudes or generalizations relating mental states and behavior. For example, we presumably believe that,

Agents who desire coffee and believe that cof-

fee can be obtained in the kitchen will, ceteris

paribus, go to the kitchen. Given the causal theory of action explanation, the causalist will naturally read this as making a causal generalization. In other words, the causalist will construe it as:

If an agent has a desire for coffee and a belief

that coffee can be obtained in the kitchen,

then, ceteris paribus, the desire and belief will

cause her to go to the kitchen. The causalist will then likely construe the conjunction of all such causally construed folk platitudes as constituting a folk theory of the mind. On this view, mental states are the theoretical posits of this folk theory, and the folk theory implicitly specifies mental types as types of causal role. Desires for coffee, for example, are the states that play the causal role specified by the folk theory. Thus there is a natural slide from the causal theory of action to a functionalist theory of the nature of mental states.(4)

2. THE TELEOLOGICAL ALTERNATIVE

The general acceptance of the Davidsonian challenge notwithstanding, there does seem to be an obvious alternative to the causal account: when we say that Jennifer went to the kitchen because she wanted coffee, the explanation could well be teleological in form. In The Intentionality of Human Action, George Wilson (1989) presents a theory of this sort. Section 2.1 below presents an account based on Wilson's; section 2.2 elaborates on Wilson's proposal, and in 2.3 and 2.4 it is argued that this account suffices to meet the Davidsonian challenge and provides a plausible alternative to causalism.

2.1 Outline of the Proposal

In giving a teleological explanation of an agent or system's behavior, we answer a certain type of "why" question about the behavior, namely, an inquiry concerning the purpose or goal of the behavior. Typical examples of teleological explanations include:

The spider ran across its web in order to collect

the trapped prey.

The rabbit ran into its burrow in order to es-

cape the dog.

The Supreme Court cut back the habeas cor-

pur rights of prisoners in order to reduce the

role of the Federal judiciary.

The batter bunted in order to move the runner

to …