Download A Defense of Epiphenomenalism

2012 Spring semester
Philosophy of mind
Final term paper
A Defense of Epiphenomenalism
20090918 Jo, HyeongChan
Contents
I. Introduction
II. What the opponents of epiphenomenalism had missed
III. The scientific evidences for supporting epiphenomenalism
IV. Epiphenomenalism from Philosophical Viewpoints
V. Conclusion
I. Introduction
What is consciousness? People always have been thinking about this question. Since the time of
Descartes, philosophers have struggled to identify and comprehend the nature of consciousness, and
tried to find out its essential properties.1 According to John Searle, consciousness is subjective states
of sentience or awareness that begin when one awakes in the morning from a dreamless sleep and
continue throughout the day until one goes to sleep at night, or falls into a coma, or dies, or otherwise
becomes as one would say, ‘unconscious’.2 Then, how can we be conscious about something? How
can we recognize something? What is consciousness anyway?
Epiphenomenalism, in the field of philosophy of mind, is a doctrine that provides some answers to
those questions. This theory insists that mental phenomena are caused by physical processes in the brain,
or that both mental and physical activities are effects of a common cause, as opposed to pure mental
phenomena controlling the physical mechanism of the brain; that is, although all mental events are
caused by physical events, mental event itself cannot evoke any physical events.3,4 This is the main
thesis of epiphenomenalism.
However, many people think that we don’t have any reason to believe epiphenomenalism; they
believe that mental phenomena bring about the physical activities of the brain and the body, because it
is more intuitive and easier to understand. Philosophers like John Searle and Daniel Dennett are the
examples of people who are against the idea of epiphenomenalism. Indeed, they suggested counter
arguments about epiphenomenalism. According to them, epiphenomenalism has following problems:
(1) It has a restrictive, dualistic assumption, which insists that psychological things like consciousness
1
Open University Course Team, Challenging Psychological Issues, The Open University, 2002
2
John Searle, Mind, Language and Society: Philosophy in the Real World, Basic Books, 1999
3
Amitabh Kumar, Encyclopedia of Consciousness, Focal Press, 2010
4
Robert A. Wilson and Frank C. Keil, The MIT Encyclopedia of the Cognitive Sciences, MIT Press, 2001
1
are not a part of physical world.5
(2) Being able to understand some causal relations in a microscopic way does not necessarily mean
that original, macroscopic understanding is wrong.6
(3) The claim that the mind is an epiphenomenon of brain activity is inconsistent with the theory of
evolution, because if the mind does not have any function, it would have disappeared due to
evolution.7
Then, here is the question: Is there no way to solve these problems of epiphenomenalism? Do we
really have no reason to believe epiphenomenalism? In this paper, we will think about these issues. In
what follows, we will deal with what the opponents of epiphenomenalism had missed, and what
would be the supportive facts for epiphenomenalism. By doing this, we can show that
epiphenomenalism is more plausible than a number of philosophers had supposed.
II. What the opponents of epiphenomenalism had missed
In order to examine the plausibility of epiphenomenalism, we should know what opponents had
pointed out and what they had missed. And by figuring out the blind spots of counter arguments, we
can show the plausibility of epiphenomenalism. In this section, therefore, we will focus on the counter
arguments that philosophers like John Searle and Donald Symons had suggested. We will find out
what these opponents had missed.
First of all, epiphenomenalism does not necessarily mean that consciousness is not a part of physical
world. The main concept of epiphenomenalism is that consciousness is an epiphenomenon of physical
interactions of neurons. According to that view, consciousness cannot cause physical phenomena in the
brain or the body. However, the point is that this statement does not claim that consciousness is not a part
5
John Searle, Mind, Language and Society: Philosophy in the Real World, Basic Books, 1999
6
John Searle, Mind, Language and Society: Philosophy in the Real World, Basic Books, 1999
7
Donald Symons, The Evolution of Human Sexuality, Oxford University Press, 1979.
2
of physical world, although some supporters for epiphenomenalism actually believe so. I believe it is not
necessary to exclude consciousness from physical world, even in epiphenomenalism.
One of the examples that can help you understand the claim above is a light from a light bulb in an
electric circuit. In this case, the electric current in the circuit makes the light bulb emit lights. Then, let’s
think about this question: Does this light, emitted from the light bulb, have any effects on the circuit?
The answer is, of course, “no.” The current causes the light to be emitted. The emitted light, however,
does not have any effects on the circuit, as it is just a consequence of the current; even though it actually
exists.
We can consider the mind, or consciousness, as a light in this example. The light itself does not affect
the circuit. However, we cannot deny the fact that the light actually exists. Likewise, the claim that mind
does not have any causal power in the physical world does not mean that it doesn’t belong to physical
world. It can be a part of physical world, like entropy and gravity; it may be abstract, but it can be physical.
Secondly, the claim that “being able to understand some causal relations in a microscopic way
does not necessarily mean that original, macroscopic understanding is wrong” is not a proper counter
argument about epiphenomenalism. From the viewpoint of the opponents of epiphenomenalism,
macroscopic understanding here would be the causal relationship between mind and body, while
microscopic understanding would be all the neural mechanism related to bodily changes. As they
believe that these two different understandings are focused on the same thing, they deny
epiphenomenalism, saying that microscopic understanding cannot falsify macroscopic understanding.
I also agree with the original statement above. Macroscopic and microscopic understanding
about something can coexist; one of these understandings cannot be used to prove the inconsistency of
the other. However, it will be an appropriate counter argument about epiphenomenalism only if both
the understanding of the mind from an epiphenomenalistic viewpoint and the understanding of it from
an ordinary viewpoint are just microscopic and macroscopic understanding about one common thing,
i.e. the mind. However, I believe it is not.
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Fig.
1. Relationship structures of micro & macroscopic events
Fig. 1 shows possible relationship structures of micro and macroscopic events. In the paper of
John Searle, the philosopher who suggested the counter argument shown above, he gave us an
example of engine. In that example, macroscopic understanding would be about a piston, an ignition
system, a cylinder, and the explosion inside the cylinder. The microscopic understanding, on the other
hand, would be related to something more detailed and minute, such as electricity that makes a spark,
and an oxidation reaction of fuels. In this case, people can explain the function of an engine by using
either group of terms; both of them are correct. We cannot say that macroscopic understanding is
wrong because microscopic understanding is possible; the existence of microscopic understanding
cannot falsify the macroscopic understanding of things. This is what Searle had mentioned in his
paper, to show the inconsistency of epiphenomenalism.
However, the point is that this claim is restricted to the structure shown in Fig. 1-1; that is, things
like piston, ignition system, and cylinder, would constitute macroscopic events A and B, while those
things like electricity and oxidation reaction would compose microscopic events a, b, and c, which
can help explaining the connection between macroscopic events. But this structure is totally different
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from the relationship structure of epiphenomenalism; it has the structure shown in Fig. 1-2, rather than
the structure in Fig. 1-1. Here, A´ and B´ would be brain state and physical action, respectively,
while C´ would be mind or consciousness. The known microscopic events like action potentials,
neural connections, and synaptic transductions are relating A´ and B´, not C´ and B´. We do not
know the connection between B´ and C´ yet; epiphenomenalism insists that C´ is an epiphenomenon
of A´, while other doctrines deny this.
This is the reason why John Searle’s argument against epiphenomenalism is not appropriate. If
epiphenomenalism has the structure shown in Fig. 1-1, then his argument is right; we cannot deny the
connection between the mind and the physical action, based on the microscopic events like neural
transduction. However, the important thing is that we do not know the connection between mind and
brain state, while the microscopic events mentioned above can only explain the connection between
brain state and physical action. This is the reason why John Searle’s counter argument about
epiphenomenalism, which is presented in the statement “being able to understand some causal
relations in a microscopic way does not necessarily mean that original, macroscopic understanding is
wrong”, is not proper.
Lastly, epiphenomenalism does not conflict with the concept of evolution. Some people believe
that the fact we actually have a mind and consciousness proves that it helps us to survive; if the mind
cannot cause any physical phenomena, then it would have been disappeared long time ago, due to
evolution.
However, we should notice that “mind cannot cause any physical phenomena” does not
necessarily assert that “mind should’ve been disappeared through evolution.” Deletion of certain
organ or function in evolution occurs when that organ or function is not necessary and consumes
resources.
According to epiphenomenalism, however, mind is a natural consequence of physical
phenomena in the brain. There is no reason to delete this function, as it does not consume energy; it is
just a natural epiphenomenon from logical circuits in the brain. Deleting this function will cause even
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more energy consumption.
Let’s say, for example, that a cheetah had developed an ability to chase after something. Then,
we can say that it would be also good at running away, as it is a natural consequence of being good at
chasing something. With respect to this, being good at running away may be construed as an
epiphenomenon of being a good chaser. And there is no reason to delete the escaping ability by
evolution, as it does not consume energy to be developed. If this unnecessary function consumes
much energy and resources to be developed, then it will be disappeared through evolutionary process,
because the organism can save a lot of energy by deleting it. However, there is no reason to delete the
epiphenomenon, as it is a natural consequence; it does not need an additional energy.
Mind, from the epiphenomenalistic view point, also does not have any reason to be disappeared
by evolutionary process. As it is a natural epiphenomenon of high information processing ability of
neural system, which does not need an additional energy or resource, it will be maintained. It may be
even more developed, due to the development of information processing ability of neural circuitry,
through evolution.
III. The scientific evidences for supporting epiphenomenalism
So far, we have been dealing with the blind spots of the opponents of epiphenomenalism. To support
epiphenomenalism more firmly, however, we will need some direct evidence for epiphenomenalism,
because falsifying the counter arguments does not mean that original argument is correct; we need to
add more credibility through suggesting more evidences. Indeed, there are many scientific evidences
for epiphenomenalism. Hence, in this section, we will deal with some scientific evidence for
epiphenomenalism.
The first one is Bereitschaftspotential, or readiness potential. According to neurobiological
experiments, electrical activity related to voluntary actions can be recorded up to two seconds before
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the subject is aware of making a decision to perform the action.8 This electrical activity, or action
potential, is called Bereitschaftspotential, or readiness potential. The existence of this potential means
that even before we actually decide to do something, physical phenomena in the brain that are related
to that action occurs.
Surprisingly, many experiments support this result. A typical example would be Benjamin Libet’s
experiment, which also showed the existence of readiness potential. In that experiment, the readiness
potential was shown about 300ms before the subjects are actually conscious about his decision.9,10
Even in the experiments which were conducted after his research, the same result have been obtained,
which means that Libet’s research and the existence of readiness potential is quite credible. This
temporal order – action potential occurs first, and human realizes later – supports the concept of
epiphenomenalism.
However, some people might say, “Okay, I understand the short-term decision. Then, how about
the long-term decision? We can make up our mind and plan something. In this case, mind can affect
the action in the future. How can you explain this with epiphenomenalism?”
Yes, some may think that long-term decision and planning could be one of the good examples
that human minds affect the future behavior. However, it also has physical changes in our brain;
learning, planning, and making up our mind change neuronal connections, synaptic strength, and other
neuronal configurations. This is how we memorize something. If we think about readiness potential,
this would happen before we actually realize that we made up our minds; and in case of retrieving,
8
Natasha Maurits, From Neurology to Methodology and Back: An Introduction to Clinical
Neuroengineering, Springer, 2011
9
Libet, B., Gleason, C. A., Wright, E. W., and Pearl, D. K, “Time of conscious intention to act in relation to
onset of cerebral activity (readiness-potential). The unconscious initiation of a freely voluntary act.” Brain, Vol.
106, pp. 623-642, 1983
10
Libet, B., “Unconscious cerebral initiative and the role of conscious will in voluntary action”, Behavioral and
Brain Sciences, Vol. 8, pp. 529-566, 1985
7
change of behavior or physical state will appear even before we actually remind the plan that we made
in the past. Thus, we can even explain the long-term decision with epiphenomenalism.
Another example is an electric current that stimulates laughter. According to Itzhak Fied et al., an
electric current in certain part of the brain can cause the subject to laugh.11 Here, the interesting thing
is, when the experimenter asked for the reason why they laughed, they just said it was because of
sudden remembrance of hilarious happening. And when they were asked for the details of those
happenings, then they just started to think about the details; that is, they laughed at first, and then they
started to think about the reason why, making up a proper reason. However, interestingly, the subjects
did not think that it is awkward or strange to think about the reason for laughter even after laughing;
they just behaved naturally.
This example also supports epiphenomenalism, as it shows that conscious interpretation can
occur after physical change, without feeling of awkwardness. As you can see here, in the first and
second examples, recognition that occurs after physical change is not an odd phenomenon. Even
though we think that our mind and our decision determine the physical states of our bodies, many
experimental result shows that it is not the case; instead, physical states determine our mind. The
reason why we cannot understand this in common sense would be because of the short temporal
interval between our decisions and physical actions. Due to its short time interval, we may not
recognize that physical states precede our minds.
The last evidence is a blind sight. Some patients have blind sight; even though their eyes are
working well, they cannot see anything on the one side of the sight; they only can see the objects from
the other side of the sight. However, the interesting fact is that they can respond to the signals from
the blinded side, although they cannot see them consciously. The physical phenomena related to visual
processing occur well in the brain, without consciousness.
Here, we can see that consciousness may be a result of physical phenomena in the brain, not the
“cause” of physical phenomena. Even without consciousness, the system can work well. There are
other examples which support this fact, such as sleepwalking. As you can see here, consciousness is
11
Itzhak Fied et al., “Electric current stimulates laughter”, Nature, Vol. 391, pp. 650, 1998
8
not everything. There is much more behind consciousness.
IV. Epiphenomenalism from Philosophical Viewpoints
So far, we considered the scientific evidence for epiphenomenalism. However, scientific experiment
or theory could have a hypothetical character. Mere considerations of scientific experiments are not
very proper for philosophical investigations. We should also think about other philosophical stances,
issues, and thought experiments. Thus, in this part of the paper, philosophical viewpoints toward
epiphenomenalism will be considered.
Before we directly think about epiphenomenalism, I would like to deliberate a problem related to
artificial intelligence. Let’s assume that there is a machine, which is exactly the same as someone’s
brain, from its neuronal configuration to its network character. Then, will it work as a human mind?
In my opinion, the answer is “yes.” Because it is the same as original human brain, there will be
no difference between them. At least, its functions or behaviors would be the same. Nothing can cause
the difference.
Then, let’s change the situation a little bit. Let’s assume that we already know something about
someone’s brain, including its neuronal characteristics and network status, as mentioned above. In
addition, let’s say that we can know the status of the brain, from the membrane potential to action
potential, at any given moments. Then, we will be able to expect what he or she will do next, by
simulating the artificial intelligence. That is, with all the information about someone’s brain, we can
construct his or her brain as an artificial intelligence, as mentioned above. Then, by applying the
current status of the brain, like electrical signals, we may forecast what will happen next, and what he
or she is going to do, by simulating the artificial intelligence. Then, in this case, can we say that our
mind determine our behavior? Maybe not. According to this scheme, we can predict any behavior, any
action, and any decision that a person would make through simulation. Of course, we cannot be sure
about its inner state, but we cannot say that it is just a result of our mind and consciousness.
Of course, people may say that it is a result of copied mind; that is, if we say that the machine
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also has an identical mind with the original brain, then we can assert that human mind determines our
behavior. However, the statement that “the machine also has an identical mind with the original brain”
means that mind is based on physical characteristic of the brain, which supports epiphenomenalism.
In either way, therefore, it can be used to support epiphenomenalism.
This is the starting point of my belief in epiphenomenalism. According to this thought
experiment, the mind does not determine physical states; instead, physical states determine our mind.
Then, if it is correct, why do we believe that our mind determines our behavior?
I believe, as mentioned above, that it is because of short time interval between our decisionmaking and physical action that appears. Let’s look at Fig. 2.
Fig. 2. Connections between brain states, physical action, and mind
According to epiphenomenalism, brain states cause both physical action and mind. However, mind
itself cannot evoke physical action. The reason why the mind seems to have a causal effect on
physical action is because it has a correlation with behavior.
Ancient people forecasted weather by observing wild animals’ behavior. When sparrows fly
close to the ground, for example, people expected raining. Although both the sparrow which flies near
the ground and the raining are caused by high humidity, it seems like they have direct causal
relationship. This is called the third variable problem, or the correlation-implies-causation fallacy.
Mere temporal correlation does not imply causation, even though we usually think so in common
sense.
This is what happens in the causal relation between brain states, physical action, and mind. In
common sense, physical action and mind seem to have a direct causal relationship. However,
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according to epiphenomenalism, it is not. As you can see in Fig. 2, from the epiphenomenalistic
viewpoint, both physical action and mind are caused by brain states. Due to this common causation,
physical action has a high temporal correlation with the mind. This is the main reason why we think
that the mind can cause physical behaviors; we tend to interpret the correlation as a form of causation.
In reality, the mind and the behaviors only have a correlation, mediated by brain states, not a direct
causal relationship.
Hence, from epiphenomenalistic viewpoints, the reason why we think that our action is
determined by our mind is due to complex effects of both the third variable problem and the short
temporal gap between physical action and the mind. This interpretation can logically explain a lot of
things about our mind and our thought about mind, even though it might be difficult to understand in
common sense.
V. Conclusion
In summary, the opponents of epiphenomenalism are missing the following points: (1)
Epiphenomenalism does not necessarily mean that consciousness is not a part of physical world. (2)
The claim that “being able to understand some causal relations in a microscopic way does not
necessarily mean that original, macroscopic understanding is wrong” is not a proper counter argument
about epiphenomenalism; epiphenomenalism is not a mere microscopic view toward the mind. (3)
Epiphenomenalism does not conflict with the concept of evolution.
Also,
there
are
many
scientific
facts
supporting
epiphenomenalism,
such
as
Bereitschaftspotential, electric current that evokes laughter, and blind sight. These examples show that
conscious experience actually occurs after the change in brain states, and our brain can work well
even without consciousness – there are a lot of things behind consciousness.
Furthermore, we have handled the thought experiment which is about artificial intelligence. In
this thought experiment, we have considered a machine which have an identical configuration with a
real human brain, and able to figure out the current status of the brain at any given moment. The
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conclusion we obtained from this experiment was that this machine may predict every single action of
the subject through simulation, which supports the stance of epiphenomenalism. Also, we have dealt
with the possible reasons why we think that our minds can evoke physical actions. One of these
reasons would be the short time interval between the physical state of the brain and the mind or action;
and another one would be the third variable problem.
From these results, we can see that epiphenomenalism is also a plausible theory. Even though
many philosophers like John Searle and Donald Symons are opposed to epiphenomenalism and insists
that there is no reason to believe it, it also has many supportive backgrounds and evidence.
However, some people may say, “Epiphenomenalism admits the existence of the mind in a ‘hard
way’, which considers mind to be an entity without any practical function, especially the causal power.
But we can also admit it in an ‘easy way’. What is the significance of this complicated interpretation?”
Surely epiphenomenalism is a very complex doctrine in philosophy of mind. It is difficult to
understand. There seems to be no reason to believe this, because there are simpler, more intuitive
philosophical positions about the mind.
Then, let me ask a question. There had been several philosophical positions toward the origin of
the universe. The Big Bang theory was one of these positions. It was a complicated, unintuitive stance,
because it insists that the whole universe was once a tiny little point. But now many people believe it,
despite of its complexity. Why would they do that? Can’t we just believe, intuitively, that the universe
in the past was just the same as in nowadays?
I believe that epiphenomenalism is just like the Big Bang theory. It is hard to understand, but it is
very important because it integrated the scientific evidence and philosophical positions. People always
have been thinking about their intellectual abilities, consciousness, free will, and mind.
Epiphenomenalism may be one of the ways to help people get the answers for these questions. Of
course, we cannot say that epiphenomenalism is “the truth” in philosophy of mind. However, what I
want to say here is its significance. We cannot assure its truth yet, but its significance cannot be
denied.
Although epiphenomenalism was originally suggested by post-Cartesian attempts to solve the
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problem of Cartesian dualism, which is about how the mind and body could interact, there are many
strong points in epiphenomenalism as mentioned above. Even from the viewpoints of materialists or
physicalists like me, it is very significant as it combines the philosophical positions with scientific
backgrounds. Supporting scientific evidence is well-organized, and the opponents’ arguments against
epiphenomenalism have many blind spots. Nowadays, there are few philosophers who believe in
epiphenomenalism. However, as one of those people who adopt epiphenomenalistic viewpoints, I am
expecting that one day, a philosophical doctrine like epiphenomenalism, or another doctrine which
adopts the strong points and main components of epiphenomenalism, will be flourished once again.
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References
[1] Open University Course Team, Challenging psychological issues, The Open University, 2002.
[2] John Searle, Mind, Language and Society: Philosophy in the Real World, Basic Books, 1999.
[3] Amitabh Kumar, Encyclopedia of consciousness, Focal Press, 2010.
[4] Robert A. Wilson and Frank C. Keil, The MIT Encyclopedia of the Cognitive Sciences, MIT Press,
2001.
[5] Donald Symons, The Evolution of Human Sexuality, Oxford University Press, 1979.
[6] Natasha Maurits, From Neurology to Methodology and Back: an Introduction to Clinical
Neuroengineering, Springer, 2011.
[7] Libet, B., Gleason, C. A., Wright, E. W., and Pearl, D. K, “Time of conscious intention to act in
relation to onset of cerebral activity (readiness-potential). The unconscious initiation of a freely
voluntary act.” Brain, Vol. 106, pp. 623-642, 1983.
[8] Libet, B., “Unconscious cerebral initiative and the role of conscious will in voluntary action”,
Behavioral and Brain Sciences, Vol. 8, pp. 529-566, 1985.
[9] Itzhak Fied et al., “Electric current stimulates laughter”, Nature, Vol. 391, pp. 650, 1998.
14