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Today’s Lecture
• A comment about your Third Assignment and final Paper
• Preliminary comments on Functionalism
• Hilary Putnam
A comment about your Third Assignment and final
Paper
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I’m going to take the long weekend to grade your Third Assignments.
I am giving you a bonus day of grace to get your final Paper in to me.
Three things to note about this proposal:
(1) It means that IF you get your paper to me, or the assignment drop box, by 4:00
p.m. on August 11th, THEN you will not receive any late penalties for your paper.
• (2) This extra day of grace only applies to your Paper.
• (3) Technically, this does not change the due date for the paper (which remains
August 8th).
Third in-class quiz
• Do remember that due to my oversight in not giving a third in-class quiz,
and what I imagine would have been your stellar performance in
answering whatever question I would have asked, each of you have
received an automatic ‘2 out of 2’ for that ‘quiz that wasn’t’.
Preliminary comments on Functionalism
• Mind-Brain Identity Theory contends that types of mental states are
nothing more than types of brain states.
• Functionalism contends that an internal state of an individual counts as
a type of mental state if it performs the relevant causal role, in relation to
other states of the central nervous system or non-neuronal physiological
processes, and is causally efficacious in contributing to the subsequent
behavior of the organism that possesses it (see FP, p.391).
Preliminary comments on Functionalism
• What would be an example of a claim made by a Mind-Brain Identity Theorist?
• The most famous is the claim that ‘Pain is the firing of c-fibers’.
• It doesn’t matter what c-fibers are, just think of a particular area of the brain
associated with pain and replace the reference to c-fibers with that.
• What the Mind-Brain Identity Theorist is claiming here is that pain is a physical
state, in particular a physical state of the brain, or central nervous system (see FP,
p.411).
Preliminary comments on Functionalism
• This claim is likened to the claim that ‘Heat is mean molecular kinetic energy’ (see
FP, p.426).
• Heat, that is, is nothing more than mean molecular kinetic energy. Of course this
can’t be quite right, but the point is relatively clear.
• Pain, for the Mind-Brain Identity Theorist is, consequently, a publicly observable
event. Though the feeling of pain is still in some important sense private, the actual
ontic entity is not.
• Thus, if Mind-Brain Identity Theory is right, we would have a way around the
problem of other minds.
Preliminary comments on Functionalism
• Mind-Brain Identity Theory is a way of moving beyond some of the
deficiencies of either Logical or Metaphysical Behaviorism.
• Metaphysical Behaviorism, remember, reduces mental states to
dispositions to act. Logical Behaviorism, remember, reduces talk of
mental states to talk of dispositions to act.
Preliminary comments on Functionalism
• Neither kind of Behaviorism seems to deal well with, among other things, claims of
sensation.
• Consider the claim ‘I’m in pain’. This is not merely, as Metaphysical Behaviorists
would have us believe, a kind of pain behavior, akin to a yelp or wince (see FP,
p.409 for Smart’s discussion of this point). There is something it is like to be in
pain. It is, or involves, a feeling.
• Mind-Brain Identity Theorists do not see this as a good enough reason to
re-embrace Cartesian Dualism … after all there are other, equally difficult
problems with Cartesian Dualism (see Ryle’s discussion of some of these problems
in your readings).
Preliminary comments on Functionalism
• Nor will Mind-Brain Identity Theorists embrace a Property Dualism, where
consciousness is a non-physical property produced by the brain.
• Their reluctance in this regard is harder to justify or motivate. It may be best
explained by their commitment to (metaphysical) Materialism or Physicalism.
• For example Smart, in his essay, claims that “sensations, states of consciousness,
do seem to be the one sort of thing left outside the physicalist picture, and for
various reasons I just cannot believe that this can be so. … The above is largely a
confession of faith” (FP, p.410).
Preliminary comments on Functionalism
• It could also be the case that Property Dualism reintroduces problems of
interactionism, albeit at more ‘localized areas of the brain’ than is true
for Cartesian Dualism.
Preliminary comments on Functionalism
• Functionalism was developed to compensate for the perceived
deficiencies of Mind-Brain Identity Theory.
• Though also a Physicalist theory of mind, functionalism seems to be
better equipped to accommodate kinds of minds that it seems possible to
conceive exist albeit in individuals who do not possess central nervous
systems (e.g. androids, Deities, angels, perhaps clouds of interstellar gas,
et cetera).
Preliminary comments on Functionalism
• Do note, however, that a rejection of type-type Mind-Brain Identity
Theory does not require one to reject a type-token Mind-Brain Identity
theory. In a type-token Identity Theory, mental states are, in the case of
humans and other terrestrial animals, identical to actual states in the
relevant central nervous systems, though they may be instantiated in very
different biological systems or forms of life (i.e. that lack central nervous
systems).
Preliminary comments on Functionalism
• Hilary Putnam’s Functionalism is known as Machine Functionalism. His theoretical
model for understanding mind is the Turing Machine (I’ll explain this in a second).
This is, however, not the only kind of Functionalist Theory of Mind.
• Teleological Functionalism is the view that mental states are individuated based
on their function, purpose, or role in the mental system. Put crudely, to have a
certain belief about your environment is to have a neurophysiological state that
contains information about that aspect of the environment as a part of its function
in, or its place in the ‘design’ of, the neurophysiological processes and mechanisms
responsible for processing incoming data from the body’s various receptors and
then producing a(n appropriate) behavioral response.
Preliminary comments on Functionalism
• Homuncular Functionalism sees the mind broken up into sub-components with
particular functions to play in the overall mental system, with each sub-component
itself broken up into yet smaller components with their own particular functions in
the overall ‘design’ of the system. These sub-components work together to process
incoming data from the body’s receptors and produce a(n appropriate) behavioral
response. Each component is individuated based on its role in the mental system.
• The brain is construed, under this account, as a physical system made up of
sub-components that can be mapped onto the hierarchy of control present in the
proposed mental system.
Preliminary comments on Functionalism
• Hilary Putnam’s Functionalist Theory of Mind is often referred to as
Machine Functionalism. It is so named because Putnam likens the mind
to a Turing Machine ... the mind, under this account, is a complex
computational device.
Preliminary comments on Functionalism
• A Turing Machine is a really simple computational device ... it’s also an abstract
computational device (you can’t go and pick one up at your local computer store).
• Imagine that a Turing Machine travels along an infinite paper tape. This tape is
divided up into squares containing symbols from a finite alphabet or symbol
system. What the Turing Machine does is either move forwards, backwards, erase
the symbol on a given square of tape, write a symbol on a given square of type or
change its internal state relative to its current input (the square on the tape it is
currently reading) and its current internal state (which is a ‘readiness state’ that
consists of a rule that instructs the Machine in what it must do relative to its input)
(see FP, p.421).
Preliminary comments on Functionalism
• For Putnam, the mind is relevantly similar to a Turing Machine in that it too is
responsive to input, and relative to the internal states it is currently in, will respond
to that input in one of a finite set of ways.
• A individuated mental state, according to Machine Functionalism, is a contributing
factor to the overall internal state of an individual that is itself, as a whole,
functionally equivalent to the internal state of a Turing Machine.
• No one mental state is functionally equivalent to the internal state of a Turing
Machine (see Bailey’s discussion of this on pages 422-23 of your FP).
Hilary Putnam
• Hilary Putnam was born in 1926 and died really recently (I’ll look up the
date).
• He worked in, among other things, metaphysics (particularly philosophy
of mind), philosophy of science and philosophy of language.
• Though he is famous for first proposing Functionalism as a Theory of
Mind, he has also contributed a great deal to philosophical analyses of
linguistic meaning and reference, and to the debate over whether we can
sensibly talk of theory-independent truth (see FP, pp.419-20).
“The Nature of Mental States”: I
• This section of Putnam’s paper clarifies what he means by identity.
• Putnam rejects the view that the identity claim “being A is being B” (FP,
p.425) must (1) arise from the meanings of the terms ‘A’ and ‘B’ and (2)
must be philosophically informative by yielding a reductive analysis of
one thing into another, more ontologically basic or primitive, thing (FP,
p.425).
“The Nature of Mental States”: I
• Putnam is rejecting, first, that identity claims must be analytic. He thinks
that we can make philosophically informative identity claims about
things in the world based on experience (believe or not some
philosophers find this claim contentious) (FP, p.426). He also thinks
that, to proffer a philosophically informative identity claim, you need not
seek a reductive analysis (FP, p.427).
“The Nature of Mental States”: I
• The primary point Putnam seems to be making in this section is that the
identity claims of Mind-Brain Identity Theory can be legitimately
assessed using empirical data, and should be primarily assessed using
empirical data (FP, pp.427-28).
“The Nature of Mental States”: II
• Putnam opens up this section with two important claims: (1) Pain is not a
brain state and (2) there is another empirical hypothesis of mind that
does a better job of accommodating what we know of the mind than
Mind-Brain Identity Theory (FP, p.428).
• Putnam suggests that “pain, or the state of being in pain, is a functional
state of the whole organism” (FP, p.428).
“The Nature of Mental States”: II
• Two things of note here: (1) Though the input receptors and motor
output processes or mechanisms are specifiable in the individuals to
whom we ascribe minds, or mental states, (2) the mental states are not to
be thought of as (actually) realized as individual physical or
physiological states in (the central nervous systems of) the relevant
individuals (FP, p.428).
“The Nature of Mental States”: II
• For any given minded organism or individual, we have any number of
possible models or interpretations (i.e. Machine Tables) of that
organism’s mind.
• A Machine Table, remember, contains a list of possible (overall) internal
states (of readiness) that an individual can possess, and instructions for
what it will do relative to both its current state and the received input
(see Bailey’s discussion of a Machine Table on page 421 of your FP).
“The Nature of Mental States”: II
• Each model or interpretation provides a way of understanding and
predicting the behavior of the relevant individual relative to the received
inputs and motor outputs (i.e. behavior).
• There is no concern in this approach to specify how the internal states (of
readiness), and the instructions for what the individual will probably now
do relative to the received data and its current (overall) state (of
readiness), are physically realized in that individual (FP, p.428).
“The Nature of Mental States”: II
• The empirical hypothesis that being in pain is a functional state of the relevant
individual is broken down in the following way:
• (1) The relevant individuals, who is capable of feeling pain, are “Probabilistic
Automata” (FP, p.428) or Turing Machines (FP, p.428).
• (2) The relevant individual, who is capable of feeling pain, possesses a Description
of a certain kind (i.e. can be understood using a particular Machine Table) (FP,
p.428).
• (3) The relevant individual, who is capable of feeling pain, is not composed of parts
that themselves have Descriptions (FP, p.429).
“The Nature of Mental States”: II
• (4) For the relevant individual spoken of in (2), she can be said to be in
pain if, in a Description applicable to her, there is a “subset of the
sensory inputs such that [she] ... is in pain when and only when some of
[her] ... sensory inputs are in that subset” (FP, p.429).
“The Nature of Mental States”: II
• Putnam adds that the relevant individual: (i) Must be able to learn from
experience, (ii) has preferences for certain internal states, (iii) has
receptors that alert the individual to damage to its physical body and (iv)
that the sensory input subsets associated with pain rank low in the list of
the preferences mentioned in (ii) (FP, p.429).
“The Nature of Mental States”: III and IV
• In these next sections Putnam considers and rejects Mind-Brain Identity
Theory and Behaviorism as competing hypotheses to his Machine
Functionalism.
“The Nature of Mental States”: III
• Note that Putnam’s Machine Functionalism is not incompatible with
Dualism and that both the input states and over all internal states (of
readiness) are not physical per se (FP, p.429).
• He contrasts these features of his theory with that of Mind-Brain Identity
Theory (FP, pp.429-30).
• Do note that Putnam is not disavowing physicalism here. Its just that,
even if his metaphysics turns out to be false, his theory of mind may still
survive.
“The Nature of Mental States”: III
• Problems facing the Mind-Brain Identity Theorist:
• (1) They must specify the kind of physical-chemical state that is pain such that, for
any given individual who is in pain, she has the right kind of central nervous
system and is in that right physical-chemical state. This doesn’t seem so bad until
you realize that the Mind-Brain Identity Theorist must have an analysis that is
applicable to every individual who can feel pain, be they mammals, reptiles,
cephalopods, or extra-terrestrials AND not be applicable to those individuals who
can’t feel pain (FP, p.430).
“The Nature of Mental States”: III
• (2) The Mind-Brain Identity Theorist is not just limiting their focus to
pain states...their theory applies to all psychological states (or mental
states). The Mind-Brain Identity Theory will fail, then, if there is only
one case of two individuals possessing a similar psychological state
while differing in the physical makeup of their respective central nervous
systems. Putnam thinks it is highly probable that this will be true
somewhere in the universe (FP, p.430).
“The Nature of Mental States”: III
• The perceived edge in favor of Putnam’s Machine Functionalism:
• We ascribe mental states such as pain based on the similarities of
behavior across species. The analogues that ground the ascription of such
mental states across species are much more likely to evince similarities
in the functional organization of the relevant species’ members than in
their respective central nervous systems (FP, pp.430-31).
“The Nature of Mental States”: IV
• Metaphysical Behaviorism appears to have an important advantage over
Mind-Brain Identity Theory and Machine Functionalism. Because,
according to the Metaphysical Behaviorist, being in pain consists of
possessing a disposition to behave in a certain way, it appears to coincide
with how we ascribe pain to another (e.g. by observing how they behave,
rather than knowing either the particular brain states they are currently
in, or their functional organization) (FP, p.431).
“The Nature of Mental States”: IV
• But this, argues Putnam, is only an apparent advantage. All that is
needed for either Mind-Brain Identity Theory or Machine Functionalism
to succeed is for the relevant markers of pain used by either theorist (to
ascribe pain) to be reliable indicators of the relevant state or property of
the individual in question (FP, p.431).
“The Nature of Mental States”: IV
• Problems facing Metaphysical Behaviorism:
• (1) They need to properly specify the relevant behavioral dispositions for the
relevant psychological state without appealing to the very state itself (FP, p.431).
• (2) It seems conceivable to imagine two individuals, one being in pain while the
other is not in pain, exhibiting relevantly similar behavior (FP, p.432).
• (3) It seems more plausible to explain behavior with reference to internal causally
efficacious psychological states than to identify said states with the behavior itself
(FP, p.432).