Lecture 3 Anomalous Monism Philosophy of Mind Lecture 3  Anomalous Monism

Anomalous Monism Donald Davidson presented an argument for a physicalist theory labelled ‘anomalous monism’. It is a token-identity physicalist theory – and the argument he presents for this theory purports to show, a priori, that a type-identity physicalist theory cannot be correct. Davidson’s view is sometimes referred to as a non-reductive physicalist view.

Background: Davidson’s conception of the mental: Davidson is concerned with events and states associated with propositional attitudes. Mental events / states with propositional contents. Beliefs, desires, intentions that p. (So his view doesn’t seem to address the status of mental events such as sensations – pains, tickles etc.)

Propositional Attitudes These mental states/events – our propositional attitudes – are mental states/events that we cite in a distinctive form of explanation of a distinctive kind of event – namely our intentional actions.

Davidson on Action A bodily movement can be something one does – an action that one performs – or something that merely happens to one. What makes a bodily movement of mine something that I do – an action - as opposed to a mere happening or occurrence? E.g. the difference between my arm’s rising (when this is an involuntary twitch) and my raising it?

Davidson on Action According to Davidson, a subject’s bodily movement is an action only if that bodily movement is caused by a reason that the subject has for so moving (under some description). The reason cited is one that justifies (rationalises), as well as causes, the bodily movement (under some description).

Why “under some description”? Davidson holds that events, including actions, are particulars that can be referred to and re-described in different ways. The contracting of muscles, the pulling of the trigger, the killing of Jack, can all be different ways of picking out one and the same action. My reason for the action may not have been simply to contract my muscles, or to kill Jack. It may have been to start the race.

According to Davidson a reason for acting consists of a desire (or some other ‘pro’ attitude) and belief – your wanting something and your belief that doing something will bring about what you want. So our reasons for action consist in our propositional attitudes. Our propositional attitudes rationalise, as well as cause, our actions. E.g. I want to know the time. I believe that looking at my watch will result in my knowing the time. These two attitudes cause me to look at my watch. They are also my (justifying) reasons for looking at my watch. And because I engage in this behaviour for reasons, I make it happen. It’s something I do, and not something that merely happens to me.

We explain the notions of our propositional attitudes and intentional actions in terms of one another. An event is an intentional action only if it is caused by propositional attitudes that justify/rationalise it. Propositional attitudes are the mental states we cite in justifying/rationalising explanations of those events which are our intentional actions.

Note that it is part of Davidson’s theory that our propositional attitudes cause, as well as justify/rationalise our actions. Davidson issues a challenge to those who would deny this: If a subject acts for reasons when she acts intentionally, what determines which of her reasons are her reasons for acting, if not the fact that those reasons are causally responsible for her acting?

Davidson’s conception of the physical: The Physical: “physical theory promises to provide a comprehensive closed system guaranteed to yield a standardized, unique description of every physical event couched in a vocabulary amenable to law”. There is an assumption here about the completeness of physics, and the capacity of the physical to feature in strict laws.

Davidson’s argument for Physicalism:   Principle of Causal Interaction: All mental events causally interact with physical events. (E.g. Events in the physical world cause us to change our beliefs, and our beliefs and desires cause us to act, and these actions have effects in the physical world.)

Note that the claim that the mental causally interacts with physical follows from his claim that we need to accept that our propositional attitudes cause our actions.

Davidson’s argument for Physicalism: 2. The Nomological Character of Causality: Events related as cause and effect are covered by strict laws. A ‘strict’ law is one that makes use of no open-ended clauses, such as ‘other things being equal’. Thus such laws must belong to a closed system: whatever can affect the system must be included in it.

Does the notion of strict law assume that the laws of physics must be deterministic? Can there be exceptionless, strict probablistic/indetermitsic laws?

Davidson’s argument for Physicalism: 3. The Anomalism of the Mental: There are no strict laws on the basis of which mental events can predict, explain, or be predicted or explained by other events

Davidson’s argument for Physicalism: Given (2), there must be strict laws covering the interaction between mental and physical events cited in (1). But the anomalism principle (3) entails that there are no strict psychophysical laws. If particular physical event p1 causes particular mental event m1, there must be some strict law covering this interaction. But there is no strict law of the form ‘P1 → M1’.

Davidson’s argument for Physicalism: If particular physical event p1 causes particular mental event m1, then there must be some strict law covering this interaction. Since there is no strict law of the form ‘P1 → M1’, then there must be some other law, ‘?1 → ?2’, which covers the causal relation between p1 and m1. Davidson suggests that the way to resolve the tension is to hold that the strict laws covering the causal interaction between mental and physical events must be physical, since only physics holds out the promise of a closed system of strict laws.

Davidson’s argument for Physicalism: Therefore, mental events must be (token identical with) physical events. Hence, the Monism: Every causally interacting mental event is token-identical to some physical event. A key claim in the argument is that there are no strict psycho-physical laws, hence ‘anomalous monism’.

Davidson’s Monism: On the Identity between mental events and physical events: Davidson holds that events are particulars that can referred to and described in different ways. Whenever there is an event that has a mental description (say, ‘Fred remembering where he left the car keys’) the same event also has a physical description (say, ‘electrochemical process y happening in Fred’s brain’).

Yet, an event’s mental description cannot be reduced to its physical description. That is to say, it is not in general true that two events falling under the same mental description also fall under the same physical description. So this is a form of ‘non-reductive’ physicalism.

Supervenience Mental events are identical with physical events, and more generally, the mental supervenes on the physical. In the literature one can find different supervenience views, expressed with varying degrees of modal force.

Davidson on supervenience Davidson expresses his superveneience thesis in terms of mental and physical predicates. Predicate p supervenes on a set of predicates S ‘if and only if p does not distinguish any entities that cannot be distinguished by S’ (‘Thinking Causes’). That is, events that cannot be distinguished under some physical description cannot be distinguished under a mental description either. Note that this does not commit him to the claim that a subject who has type-identical physical states to mine will be in the same mental states as me.

The Anomalism of the Mental: The anomalism of the mental rules out two forms of reductionism: reduction of the mental to the physical by explicit definition of mental predicates in physical terms, and reduction by way of bridging laws that connect mental with physical predicates. So the anomalism of the mental involves a rejection of type-type identity physicalism. But the monism implies that “mental entities do not add to the physical furniture of the world”.

Argument for the anomalism of the mental? It is the rational status of our propositional attitudes that is supposed to establish that there are no strict psycho-physical laws. Our propositional attitudes justify/rationalise/make rationally intelligible our intentional actions. That is what our propositional attitudes are – states that play that distinctive sort of justifying/rationalising explanatory role.   But how exactly is the argument for the anomalism of the mental supposed to go?

Propositional attitudes cannot exist in isolation Propositional attitudes cannot exist in isolation. (The Holism of the mental). Individual beliefs, desires intentions etc. owe their identities to their position in a large network of further such attitudes. Relations among propositional attitudes are essentially ‘logical’. This places a normative constraint on the correct attribution of aptitudes – e.g. the pattern of attitudes in an individual must involve a large degree of coherence. (The possibility of irrationality depends upon a background of rationality).

So our ascriptions of propositional attitudes are constrained by a normative notion: rationality – e.g. what a subject ought (rationally) to believe given his / her other beliefs, and also what makes rationalising sense of what he/she does.

If strict psychophysical laws existed, this would, in principle, open up the possibility of reading people’s beliefs and desires off their brains (or what physical states they are in). We could in principle determine whether a person has a certain belief by ascertaining which neural (or physical) state she is in, independently of the question as to whether the person is rational or not.

Yet, attributions of attitudes like belief or desire are controlled by a requirement for rationality and coherence. Unless we assume that a person is rational, it does not seem to be possible to say what the significance is of ascribing any particular belief or desire to her.

Unless she does things that such propositional attitudes rationalise, she can’t be rationally interpreted as having such propositional attitudes. And if she can’t be rationally interpreted as having such propositional attitudes, then she doesn’t have them. That is, our very idea of what it is for a person to have a certain belief or desire cannot be divorced from the idea that they play a role in justifying/rationalising other beliefs, desires, and actions that the subject engages in.

Davidson: “there cannot be tight connections between the realms [of the mental and the physical] if each is to retain allegiance to its proper source of evidence”.

So there cannot be strict psycho-physical laws relating the mental and the physical, and there cannot be bridge laws linking propositional attitudes and physical states. So the type identity theory cannot be correct for our propositional attitudes.

Anomalism of the Mental and Supervenience Is the anomalism of the mental inconsistent with the supervenience thesis? It may be inconsistent with certain versions of a supervenience thesis.

But note that Davidson holds a very weak supervenience claim: Predicate p supervenes on a set of predicates S ‘if and only if p does not distinguish any entities that cannot be distinguished by S’ (‘Thinking Causes’). That is, events that cannot be distinguished under some physical description cannot be distinguished under a mental description either.

The Epiphenomanlism Objection On Davidson’s view, mental events are token-identical with physical events. This is supposed to preserve the idea that the mental causally interacts with the physical (premise 1 of his argument for physicalism). But do such events have their physical effects in virtue of their mental properties, or their physical properties?

The Epiphenomanlism Objection The fact that one can refer to event under some mental description doesn’t mean that the mental properties of the event are playing a role in causing the physical effect. (Compare: The cause of the window smashing was my throwing of a brick. The latter event can be described as the throwing of something red. But it wasn’t the redness of the brick that caused the window to break.)

The Epiphenomanlism Objection Don’t the physical properties of the relevant events do all of the causal work? Leaving the mental properties of the events causally inert? So doesn’t this view make the mental properties of events epiphenomenal?

Davidson’s response: Properties don’t cause anything, and so can be neither causally relevant or irrelevant. It is events that are the relata of the causal relation. That extensional relation obtains between events no matter how they are described. It’s a mistake to think that an event causes its effect in virtue of its possessing some properties and not others. However, some descriptions of the event that is the cause will offer a better causal explanation of the effect, than other descirptions.

Causation and Explanation: The claim that events are particulars that can be picked out and described in different ways is relevant to a distinction he draws between explanation and causation. Explanation is sensitive to how events are described, whereas causation is an extensional relation, obtaining between pairs of events independently of how they are described. Causes and effects can be accurately picked out using a variety of expressions, many of which are not explanatory.

Why are some descriptions of events that are causes better than others when it comes to explaining their effects? From a good explanation we expect a description of the event that can explain why the effect occurred given some true generalisation - a generalisation linking that kind of cause, so described, with the effect (under the relevant description).

Note that although Davidson denies that there are strict psycho-physical laws, he accepts that there are true generalisations linking the psychological and bodily events and behaviour. (Psychology is like other special sciences in this regard, and can invoke non-strict laws).

But if the laws of physics are strict, and the generalisations of psychology are not, won’t it always be the case that physics offers the best explanation of any physical effect?

Davidson may say that physics can offer the best explanation of physical effects when those physical effects are characterised using the vocabulary of physics. But our intentional bodily actions are not ones we tend to characterise using the vocabulary of physics. So our bodily actions, described as such, may be best explained using the vocabulary of psychology.