“Big” essays are due next Wednesday.
(Don’t try to write them next Tuesday!)
Overview of the Course:
Five Topics (“Units”)
1) Arguments / Methods
1) Phil of Religion
1) Epistemology / Phil of Science
2) Free Will
1) Phil of Mind
Overview of the Course:
Five Topics (“Units”)
1) Arguments / Methods
1) Phil of Religion
1) Epistemology / Phil of Science
2) Free Will
1) Phil of Mind
Philosophy of Mind
What’s the difference between philosophy
of mind and psychology?
Only 150 years ago, there was no difference.
Psychology didn’t exist yet, so all questions about the
mind were viewed as philosophical questions.
Psychology vs. Philosophy of Mind
Psychology is a scientific discipline; it asks
questions that can be answered by the
scientific method.
As a result, psychology is all about
prediction (like the rest of science).*
Psychology vs. Philosophy of Mind
Psychology is a scientific discipline; it asks
questions that can be answered by the
scientific method.
As a result, psychology is all about
prediction (like the rest of science).*
* Explanation is also important, but only because it helps
with prediction.
Psychology vs. Philosophy of Mind
Philosophy is wider in scope.
Questions of prediction fall within its scope, but
it isn’t limited to questions of prediction.
Psychology vs. Philosophy of Mind
Since all science is ultimately about prediction,
scientific fields are defined by the types of
observation they try to predict (and explain).
Psychology vs. Philosophy of Mind
Since all science is ultimately about prediction,
scientific fields are defined by the types of
observation they try to predict (and explain).
What observations define psychology,
as a scientific field?
Philosophy of Mind
Psychology is not “the science of the mind”
(strictly speaking).
Philosophy of Mind
Psychology is not “the science of the mind”
(strictly speaking).
You can’t observe minds.
Philosophy of Mind
Psychology is not “the science of the mind”
(strictly speaking).
You can’t observe minds.
Psychology is the prediction and
explanation of behavior.
Philosophy of Mind
Concepts of the mind explain
observations of behavior, but scientific
fields aren’t defined by the explanations
they
provide.
Newton
and Einstein gave different explanations for
the same observations, but they were both
physicists.
Physics is defined by what it tries to explain, not by
the explanations it actually offers.
Philosophy of Mind
Concepts of the mind explain
observations of behavior, but scientific
fields aren’t defined by the explanations
they
Forprovide.
the same reason, psychology is not the science
of the mind:
the mind is the explanation,
not the thing being explained.
Philosophy of Mind
Psychology focuses specifically on how
the mind explains behavior.
Philosophy of mind doesn’t have this
focus.
It’s open to any (theoretical) question about
the mind.
Philosophy of Mind
The central issue in philosophy of mind is
the mind/body problem.
If the mind is just the body,
then when we die, that’s it. You have no soul. There
is no life after death.
Philosophy of Mind
The central issue in philosophy of mind is
the mind/body problem.
If the mind is just the body,
then when we die, that’s it. You have no soul. There
is no life after death.
But if the mind is not just the body,
how is it possible to get drunk?
Philosophy of Mind
And even if the mind is just the body,
some difficult questions arise...
Exercise:
Define the emotion of homesickness in
terms of the body.
Suppose someone claims to be homesick.
If the mind is just the body, this claim implies facts
about this person’s body.
What would we have to observe about a person’s
body in order to observe her homesickness?
The Mind/Brain Identity Theory
Water = H2O
Mind = Brain
Leibniz’s Law:
If two things are identical, they must
share all their properties.
(There aren’t really two things, after all. There’s just
one thing, with one set of properties.)
If water is identical to H2O, it’s impossible for
water to have a property that H2O doesn’t
have.
Descartes’ First Argument for Dualism:
1) It’s possible to doubt the existence of
your body.
1) People often have false experiences and
sensations.
2) It’s at least possible that your beliefs about your
body are all based on false experiences.
So it’s possible to doubt that your body actually
exists.
Descartes’ First Argument for Dualism:
2) It’s not possible to doubt the existence of
your mind.
In order to doubt anything, you must have a mind
to do the doubting. Even if all your experiences are
false, you have to have a mind to have false
experiences.
(“I think, therefore I am.”)
Descartes’ First Argument for Dualism:
1) It’s possible to doubt the existence of your body.
2) It’s not possible to doubt the existence of your
mind.
3) Your body has a property your mind doesn’t have.
4) If your body has a property your mind doesn’t
have, your body can’t be identical to your mind.
Your body can’t be identical to your mind.
Descartes’ First Argument for Dualism:
1) It’s possible to doubt the existence of your body.
2) It’s not possible to doubt the existence of your
mind.
3) Your body has a property your mind doesn’t have.
4) If your body has a property your mind doesn’t
have, your body can’t be identical to your mind.
Your body can’t be identical to your mind.
What do you think of this argument?
Descartes’ First Argument for Dualism:
1) It’s possible to doubt the existence of your body.
2) It’s not possible to doubt the existence of your
mind.
3) Your body has a property your mind doesn’t have.
4) If your body has a property your mind doesn’t
have, your body can’t be identical to your mind.
Your body can’t be identical to your mind.
Descartes claims that the mind has the
property of indubitable existence, while
the body does not.
Is indubitable existence a property of the
mind?
Doubt is a form of thinking, a cognitive
activity. (That’s why it requires a mind, as Premise
2 says.)
As a result, what can or cannot be doubted
depends upon the cognitive abilities of the
agent doing the doubting.
Even if all cognitive agents are incapable of
doubting something about the world, that’s a
property of the agents, not of the things their
doubts are about.
Even if all cognitive agents are incapable of
doubting something about the world, that’s a
property of the agents, not of the things their
doubts are about.
If I doubt it will rain tomorrow, that’s not a property
of the weather. It’s a property of my thoughts about
the weather.
Even if all cognitive agents are incapable of
doubting something about the world, that’s a
property of the agents, not of the things their
doubts are about.
If I doubt it will rain tomorrow, that’s not a property
of the weather. It’s a property of my thoughts about
the weather.
If I’m unable to doubt that I have a mind, that’s a
property of my thoughts about my mind. It’s not a
property of my mind.
Descartes’ First Argument for Dualism:
1) It’s possible to doubt the existence of your body.
2) It’s not possible to doubt the existence of your
mind.
3) Your body has a property your mind doesn’t have.
4) If your body has a property your mind doesn’t
have, your body can’t be identical to your mind.
Your body can’t be identical to your mind.
Descartes’ Second Argument for Dualism:
Descartes’ Second Argument for Dualism:
1) Bodies have extension. (They take up space, and
have locations in space.)
Descartes’ Second Argument for Dualism:
1) Bodies have extension. (They take up space, and
have locations in space.)
2) Minds don’t have extension.
Descartes’ Second Argument for Dualism:
1) Bodies have extension. (They take up space, and
have locations in space.)
2) Minds don’t have extension.
3) Bodies have a property that minds don’t have.
4) If bodies have a property that minds don’t have,
bodies can’t be identical to minds.
Bodies can’t be identical to minds.
Descartes’ Second Argument for Dualism:
1) Bodies have extension. (They take up space, and
have locations in space.)
2) Minds don’t have extension.
3) Bodies have a property that minds don’t have.
4) If bodies have a property that minds don’t have,
bodies can’t be identical to minds.
Bodies can’t be identical to minds.
Where’s the flaw in this argument?
Descartes’ Second Argument for Dualism:
1) Bodies have extension. (They take up space, and
have locations in space.)
2) Minds don’t have extension.
3) Bodies have a property that minds don’t have.
4) If bodies have a property that minds don’t have,
bodies can’t be identical to minds.
Bodies can’t be identical to minds.
It’s not clear that this premise is false, but
there is definitely a problem. What is it?
Descartes’ view is called substance dualism,
because he considers minds and bodies to
be different kinds of substances.
Physical substance is extended in space.
Mental substance has no spatial properties.
Descartes’ view is called substance dualism,
because he considers minds and bodies to
be different kinds of substances.
Physical substance is extended in space.
Mental substance has no spatial properties.
There’s one GLARING objection to this
view. What is it?
Logical Behaviorism
Logical Behaviorism
Since it isn’t possible to observe minds,
some have proposed simply dropping the
whole idea of the mind. That’s behaviorism.
Logical Behaviorism
Since it isn’t possible to observe minds,
some have proposed simply dropping the
whole idea of the mind. That’s behaviorism.
Logical behaviorism proposes that we
translate all mental concepts into physical
concepts about behavior.
Logical Behaviorism
Mentalistic Concepts
-Thoughts
-Beliefs
-Intentions
-Desires
-Emotions
-Doubts
-Wishes
-Hopes
-Etc.
Logical Behaviorism
Mentalistic Concepts
-Thoughts
-Beliefs
-Intentions
-Desires
-Emotions
-Doubts
-Wishes
-Hopes
-Etc.
Behavior
Logical Behaviorism
Mentalistic Concepts
-Thoughts
-Beliefs
-Intentions
-Desires
-Emotions
-Doubts
-Wishes
-Hopes
-Etc.
Behavior
Behavior
Logical Behaviorism
Mentalistic Concepts
-Thoughts
-Beliefs
-Intentions
-Desires
-Emotions
-Doubts
-Wishes
-Hopes
-Etc.
Behavior
Behavior
Behavior
Logical Behaviorism
Mentalistic Concepts
-Thoughts
-Beliefs
-Intentions
-Desires
-Emotions
-Doubts
-Wishes
-Hopes
-Etc.
Behavior
Behavior
Behavior
Behavior
Behavior
Behavior
Behavior
Behavior
Behavior
It’s called Logical Behaviorism because it’s a
claim about what mentalistic concepts
mean.
-Thoughts
-Beliefs
-Intentions
-Desires
-Emotions
-Doubts
-Wishes
-Hopes
-Etc.
Behavior
Behavior
Behavior
Behavior
Behavior
Behavior
Behavior
Behavior
Behavior
Logical Behaviorism
Negative Thesis:
The common sense view of the mind is
based on a myth: the myth of the ghost in
the machine.
Positive Thesis:
The mind is just the activity of the
machine.
The Negative Thesis
Ryle rejects two features of the common
sense concept of the mind: mentalism and
dualism.
Mentalism: mental states are internal
causes of behavior.
Dualism: the mind is a thing, and it’s not
the same thing as the body.
The Negative Thesis
The Myth of
The Ghost in the Machine
The body is a physical system, like a machine.
Mental states are causes of this system’s
activities, but they aren’t part of the physical
system.
Mentalism: the ghost is in the machine.
Dualism: the ghost isn’t part of the machine.
The Negative Thesis
These days...
Mentalism: mental states are internal
✔
causes of behavior (but there’s no ghost).
Dualism: the mind is a thing, and it’s not
the same thing as the body.
✗
The Negative Thesis
Why did Ryle reject mentalism?
Mentalism: mental states are internal
causes of behavior.
The Negative Thesis
Why did Ryle reject mentalism?
Mentalism: mental states are internal
causes of behavior.
He thought it led to third-person
skepticism:
We can know about our own mental states, but not
other people’s.
The Negative Thesis
Ryle’s argument against mentalism:
1) If mental states were inner causes of behavior, we
wouldn’t have knowledge of others’ mental states.
2) We do have knowledge of others’ mental states.
So mental states are not inner causes of behavior.
The Negative Thesis
Ryle’s argument against mentalism:
1) If mental states were inner causes of behavior, we
wouldn’t have knowledge of others’ mental states.
2) We do have knowledge of others’ mental states.
So mental states are not inner causes of behavior.
The Negative Thesis
Ryle’s argument against mentalism:
1) If mental states were inner causes of behavior, we
wouldn’t have knowledge of others’ mental states.
Ryle is relying on the problem of other
minds: since we never observe others’ minds,
how do we even know they have minds?
The Negative Thesis
Ryle’s argument against mentalism:
The traditional solution to the problem of
other minds was an argument from analogy:
When I say “ouch!”, I’m feeling pain.
Other people must experience the same mental
state when they exhibit the same observable
behavior.
The Negative Thesis
Ryle’s argument against mentalism:
The traditional objection to this argument is that
it’s based on a terrible inductive inference
drawn from a sample of one. Compare:
Since I prefer dijon mustard, probably everyone
prefers dijon mustard.
The Negative Thesis
Ryle’s argument against mentalism:
Ryle understandably rejected the argument
from analogy, so he thought mentalism still led
to the problem of skepticism about others’
minds.
The Negative Thesis
Ryle’s argument against mentalism:
Ryle understandably rejected the argument
from analogy, so he thought mentalism still led
to the problem of skepticism about others’
minds.
However, there’s another solution to the
problem of other minds:
use abduction, not induction.
The mind is a postulate in a theory that
provides the best explanation for our
observations of behavior.
The mind is an unobservable that explains
what we actually observe.
The mind is a postulate in a theory that
provides the best explanation for our
observations of behavior.
The mind is an unobservable that explains
what we actually observe.
This happens all the time in science:
unobservable entities are postulated, then
verified by abduction.
Unobservables:
Newton couldn’t observe gravity.
Mendel couldn’t observe genes.
Physicists recently spent billions of dollars to observe
the Higgs boson, but interest in this particle is due to
more fundamental interest in something that can’t be
observed: a “field” that “permeates the universe and
gives energy to the vacuum” (Science, 2012).
Unobservables:
Newton couldn’t observe gravity.
Mendel couldn’t observe genes.
Physicists recently spent billions of dollars to observe
the Higgs boson, but interest in this particle is due to
more fundamental interest in something that can’t be
observed: a “field” that “permeates the universe and
gives energy to the vacuum” (Science, 2012).
The mind is just another unobservable
postulate.
The Negative Thesis
Ryle’s argument against mentalism:
1) If mental states were inner causes of behavior, we
wouldn’t have knowledge of others’ mental states.
2) We do have knowledge of others’ mental states.
So mental states aren’t inner causes of behavior.
We have knowledge about minds in the same
way that we know about gravity.
The Positive Thesis
The positive claim of logical behaviorism
is that mentalistic concepts can be
translated into dispositions to behave.
To be thirsty is just to have a disposition to drink
water.
The Positive Thesis
The problem with this analysis of mental
concepts is that mental states always interact
with other mental states in causing behavior.
The effects of being thirsty on behavior will depend
on what other beliefs and desires the person has at
the time.
The Positive Thesis
The problem with this analysis of mental
concepts is that mental states always interact
with other mental states in causing behavior.
The effects of being thirsty on behavior will depend
on what other beliefs and desires the person has at
the time.
Thus, you can’t map any particular type of
mental state onto any particular way of
behaving.
The Positive Thesis
Also note:
the dispositional analysis of mental state
terms would still be consistent with
mentalism.
Even if being thirsty is just a disposition to drink
water, that disposition could be explained by
more specific dispositions of internal systems in
the mind.
Logical Behaviorism
Since it isn’t possible to observe minds,
some have proposed simply dropping the
whole idea of the mind. That’s behaviorism.
Logical behaviorism proposes that we
translate all mentalistic concepts into
physicalistic concepts of behavior.
Methodological Behaviorism
Since it isn’t possible to observe minds,
some have proposed simply dropping the
whole idea of the mind. That’s behaviorism.
Methodological Behaviorism
Since it isn’t possible to observe minds,
some have proposed simply dropping the
whole idea of the mind. That’s behaviorism.
Methodological behaviorism proposes that
we just drop mentalistic concepts from our
explanations of behavior.
Logical behaviorism says common sense
gets the meaning of mental concepts wrong.
The right meaning is in terms of dispositions to
behave.
Methodological behaviorism doesn’t
disagree with the meaning of these
concepts, it just says they’re useless.
We don’t need internal states to explain behavior.
Logical behaviorism wants us to change
mental concepts into behavioral concepts.
Methodological behaviorism wants us to just
drop mental concepts (at least in science).
Methodological behaviorism: even if internal
states exist, we can explain behavior better
by appealing to the history of conditioning
for the individual.
Methodological behaviorism: even if internal
states exist, we can explain behavior better
by appealing to the history of conditioning
for the individual.
Objection #1 (p. 224-5):
How to explain novel behaviors, which
haven’t been conditioned?
Which of your past behaviors are relevant when
explaining new behaviors?
Methodological behaviorism: even if internal
states exist, we can explain behavior better
by appealing to the history of conditioning
for the individual.
Objection #2:
What about the role of genes, since
conditioning is an environmental factor?
Example: The Garcia Effect
In theory, methodological behaviorism could
be justified by abduction, just as mentalistic
accounts of behavior are justified.
In practice, however, explanations appealing
to internal states are better. They explain
things that behaviorism can’t explain.
In theory, methodological behaviorism could
be justified by abduction, just as mentalistic
accounts of behavior are justified.
In practice, however, explanations appealing
to internal states are better. They explain
things that behaviorism can’t explain.
The horse raced past the barn fell.