Do our thoughts and ideas cause us to act?

Is our conscious will the cause of our behaviour?
For example, I may choose to drive a different way to work, select an apple rather than an orange, decide to vote for a particular party in an election. We usually think that such decisions cause us to act in the ways chosen. But do they? When we begin to analyse what actually happens in cases like these, the idea that our conscious states are the causes of our actions begins to look more problematic.

In these pages I intend to examine these claims (which I will call more technically conscious-to-physical causation). under the following headings:

1. a nomological theory of causation
2. a counterfactual theory of causation
3. the extrinsic nature of mental states
4. the causal closure of the physical domain
5. the supervenient model of the mind-body relationship
6. an argument from experimental psychology
7. an argument from psychological research.

('Nomological' means 'following a law'.)
According to this view of causation we can say that x causes y if there is a general rule that x type events are regularly followed by y type events. For example, we can say that x, a brick thrown hard at a window, causes y, the glass shattering, on the grounds that generally when x events (hard objects striking brittle objects with force) occur, then y events (the brittle objects breaking) occur. In other words, it is a general rule or even a law that such a sequence of events regularly happens.

Is there a general rule that covers conscious events causing physical events? I think not. Take a conscious event such as my desire not to eat chocolate; sometimes it is followed by my avoiding the sweet shop and sometimes it isn't. And again in the case of another conscious event, a strong dislike in me stirred up by the appearance of certain TV celebrities - sometimes it is followed by swearing at the TV, sometimes by a sigh, sometimes by silent resignation. There doesn't seem here to be any fixed sequence of events of particular types of conscious events regularly followed by particular types of physical events that looks remotely like a general rule. For this reason it seems that we cannot fit the idea of the conscious as a cause of the physical into the nomological category of causal relationships.

According to this view of causation when we say that x is the cause of y, we mean the following, that if x had not happened, then y would not have happened. For example, we can take the sentence:
The dropped cigarette caused the fire
and put it into counterfactual terms:
If the cigarette had not been dropped, there would not have been a fire.

Do we have a clearer idea of the conscious causing the physical if we rephrase the situation in counterfactual terms? Suppose we use as an example a case of someone slamming a door because of anger. So we have the conscious event, the anger, as the apparent cause of the physical act of slamming. Now turn this into a counterfactual. It becomes: if he had not been angry, he would not have slammed the door. But are we entitled to say this? There is one very good reason why we are not. As we shall see in Section 4, (THE CAUSAL CLOSURE OF THE PHYSICAL DOMAIN), there are strong grounds for believing that every physical event is caused by a previous physical event. If this theory is true, then we can explain the act of slamming purely in terms of physical causes, in other words of the brain events and the impulses in the nerves that make the hand have contact with the door. So it isn't the case that if he had not been angry, he would not have slammed the door. The translation of the causal sentence into a counterfactual has not helped us to have a better understanding of the idea of the conscious causing the physical. But if you are not convinced by this, you might to look at Section 4 of this summary discussion.

For this argument let us suppose that every time there is a conscious event, a taste, a smell, a feeling of emotion or whatever, there is a corresponding physical event. So whenever there is a state of consciousness, there is always something going on in the brain and this is likely to be a particular pattern of neurons (among the 100 billion of them in the brain) firing electrically. Now as a thought experiment let us imagine that the same pattern of firing neurons is found in the brains of several people. Now it is quite conceivable that the conscious state corresponding with this brain state in one person is the taste of olives, in another person the sound of a fighter plane and in another person a feeling of disgust. The point here is that only the physical thing, the pattern of neurons firing, is involved with the causal process. The conscious state, whatever it may be, is quite irrelevant to what is going on in the body. This is what is meant by the term, 'extrinsic nature' when applied to consciousness. The content of the conscious state can be anything from pondering over a difficult problem in maths to the smell of smoke. Whatever it is, it doesn't make any difference to the causal processes going on in the brain. Changes in the brain which are the causes of our actions are determined by physical influences brought to bear on the brain. What is in the conscious experience is outside the loop of these causes and effects.

Think of two keys that both open the same lock. One may be an antique, once owned by a king; the other is a copy made yesterday in the town centre. The only factors that affect whether the key turns in the lock are to do with the keys' physical shape and solidity; their history, the story that can be told about each key, is quite irrelevant to the key causing the lock to open. In a similar way the only factors that are involved in the causal connections between neurons are the physical, chemical and electrical condition of those neurons. It makes not slightest difference what conscious state is associated in some way with the pattern of neurons.

The idea here is that as far as we know every physical event has a physical cause. Take any physical event, identify its cause and trace the cause of that and so on as far as it is possible to go. You will always find another physical event. The causal chain of physical events just goes on and on and we never find a non-physical event as a cause. If this is true, then there does not seem to be room for conscious events to be the cause of physical events. (What we mean specifically by a physical event here, of course, is something going on in the brain.)

Suppose we want to insist that, while accepting that the causal closure of the physical domain makes a good deal of sense, still in some way consciousness is also a cause of physical events. If there can be two causes in the ordinary run of events, then why not here? Hamlet was killed by both a stab wound and poison: each cause was sufficient to kill him. Why cannot my actions be caused by both my conscious feelings, say my anger, and by physical events in my brain, a set of neurons firing? The problem now is that each cause is sufficient on its own to cause the effect. Hamlet would have died of poison if he had not had the stab wound and he would have been killed by the stab wound if he had not been poisoned. Whichever way it is, Hamlet is dead. Similarly, in our case we have to admit that if there had been no conscious event, if I had not been in a conscious state of anger, then the physical event, the neuron pattern would have caused the action anyway. So, if we want to hold on to consciouseness as a cause, we can do so but only at the price of it being an unnecessary one.

What is the 'supervenient model'? Think of the tune to the national anthem. It is a melody made up of particular notes of music in a particular order. You will not find the melody at the level of the particular notes analysed closely. It is not in this crochet or that bar line. And yet, at the same time, the melody is completely made up of those notes, bar lines and so on. It is in this sense that the melody is said to 'supervene' on the details of the musical notation.

In a similar way, the supervenient model of the relationship between consciousness and the brain holds that conscious states are not found at the level of individual neurons but that just as the melody is totally made up of the notation but at the same time not reducible to the notation, the conscious states are totally made up of the neurons but not reducible to them. However, the supervenient model of the relationship between consciousness and the brain confronts the same problem we met in Section 4.

In the 1980s an American experimental psychologist, Benjamin Libet, carried out some remarkable experiments. He wired the brains of some people up to electrodes and asked them at a time of their own choosing to flick a finger. He took three measurements:

1. the time of what he called the 'readiness potential', when the brain processes begin to set the act in motion
2. the time of the conscious willing of the act, i.e., when the person chose to move the finger
3. the time of the beginning of the act when the muscles react

What he found was that the readiness potential occurred several milliseconds before the conscious choice. The conclusion drawn from his experiments was that in situations in which we think that our conscious will is the cause of our actions, in fact, the brain starts the actions first. And this means that this particular conscious event, one of choosing or willing, is not the cause of our actions.

In his 2002 book, The Illusion of Conscious Will Harvard psychologist, Daniel M Wegner, attempts to explain why we believe that our conscious will is the cause of our actions. We certainly have the experience of choosing an action and on many occasions the body immediately performs the chosen action. But why do we think that the conscious experience is the cause of the action. Wegner shows us that the two can be separated: there are occasions when there is conscious willing and no related action and cases when there is what to any observer very much looks like but is not consciously willed action. One explanation is that the mind, because it cannot cope with the complexity of the chain of physical causation, seizes on the simplest answer to the problem just as to the audience at a magic show it seems that the conjuror's words caused the rabbit to come out of the hat. In both cases the mind cannot cope with the actual complexity. Secondly, we require three conditions to be met before we believe in an act being caused by a conscious choice: a) priority, b) consistency and c) exclusivity. (a=the conscious intention occurs before the action; b=e.g., the intention to leave the motorway at the next exit is followed by the action of leaving the motorway at the next exit; c=we can excude other 'causes' such as blind rage or habit.

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