Albert Parker
May 3, 2001
Functionalism
Two Camps
Dualist
“Mind is formal and abstract”
 Substance – two radically different
kinds of substances in the universe:
material objects and immaterial minds
(Descartes)
 Property - two radically different
kinds of properties in the universe:
material properties (like weight) and
immaterial properties (like pain)
Materialist
“Mind is the wet and slimy stuff in
our heads”
 Behaviorism
–
mind reduces
behavior or dispositions to behavior
 Physicalism –
mental states are
brain states
 Functionalism –
mental states are
defined by causal relations
 Strong AI –
minds are programs
implemented in computers
(Searle MLS, p46-7 and SA 31)
How do we observe the mind?
Dualist’s Problem: Metaphysical Gap
The mind can be observed through introspection.
that cannot be observed.
It is just the minds of others
Materialist’s Problem: Leibniz Gap
“It must be confessed, moreover, that perception, and that which depends on it, are
inexplicable by mechanical causes, that is, by figures and motions. And
supposing that there were a mechanism so constructed as to think, feel and
have perception, we might enter into it as into a mill. And this granted, we
should find only on visiting it, pieces which push one against another, but
never anything by which to explain a perception. This must be sought in the
simple substance, and not in the composite or in the machine” (CMB, Cummins 4)
Analysis of consciousness bogged down
for lack of analytical tools!
(Psychology crippled and behaviorism was spawned by taking
the mind out of psychology) (6-7)
What to do?
For the materialist, Functionalism provides a bridge over the Leibniz gap: Mental
states are defined in terms of their abstract causal roles within the wider
information processing system. A given mental state is characterized in terms
of its abstract causal relations to environmental input, to other internal states and
to output (Churchland, NP, 351).
Example 1: Pump is a functional kind, being implemented by hearts, propellor and case,
vibrator and one-way valve, centrifuges, piston and sleeve arrangements (MBC, Cummmins 7).
Example 2: Mouse Trap is a functional kind, being implemented by spring traps, cage
traps, a sack of grain attached to a trip wire, a cat or specially bred killer rat
Example 3: Being in pain is a state carried out characterized by its causal relations to:
behavior: wincing and crying out
external input: skin being burned
other internal states: the desire to make the pain go away and belief of what will bring
relief.
Functional kinds are specified by their roles and
not by the material in which they are instantiated. (Churchland, NP, 351).
How does Functionalism Deal
with the Leibniz Gap?
• Functionalism: mental concepts are revealed through function
not in terms of intrinsic features. That is, deal with function, to heck
with the form.
• Leibniz Gap occurs because function can’t be read from form
Hence, Functionalism is a bridge over the Gap.
“…trying to understand perception by studying only neurons is like trying
to understand bird flight by studying only feathers” (Marr 27)
“…once we
have explained the causal basis of consciousness in terms of
the firing of neurons … in the various cortical layers, it seems we still
have a phenomenon left over” (Searle MLS, p55)
Whose Idea was this?
• Emile Durkheim created the functional orientation by codifing
the distinction of structure and function in the social sciences. He
published his functional analysis in a number of empirical studies:
– The Division of Labor in Society (1893)
– The Elementary Forms of Religious Life (1912)
Durkheim recognized the potential problems of functionalism that
critics like John Searle and Patricia Churchland still espouse today in
reaction to neurophilosophical functionalism:
To discover the need that a structure functions to meet does not necessarily reveal its
cause - the sequence of events that created the structure in the first place. To assume it
does puts the cart before the horse. (Turner 17)
• J. Dewey The Reflex Arc Concept in Psychology (1896) is the
“opening shot” of Functionalism in Psychology (Bergmann 678).
• H. Putnam “Minds and Machines” in Dimensions of the Mind
(1960) was the first to argue that minds are things that we can
conceive solely in terms of input, output, and various functional
relations. (Hardcastle 2-3)
Some Functionalist
Achievements
• von Neumann architecture
(1943-1957) – Still used in today’s desk-tops,
lap-tops, calculators and palm pilots that grace every office and half the homes in
America (von Neumann xii)
• Barlow’s First Dogma
(1972) “A description of that activity of a single nerve
cell which is transmitted to and influences other nerve cells and of a nerve cell’s
response to such influences from other cells, is a complete enough description for a
functional understanding of the nervous system” (Barlow 380)
• Theory of the Cellebar Cortex (1969) This “regular
cortical structure is interpreted as a simple but powerful memorizing
device for learning motor skills” (Marr 14)
… something was going wrong
“I was myself caught up in this excitement (of the 60’s). Truth, I also believed, was basically
neutral, and the central aim of all research was a thorough functional analysis of the
structure of the central nervous system … the way seemed clear … but somewhere
underneath, something was going wrong … the cerebellar study … suggested that one
could hope to understand cortical structure in functional terms … but at the same time … it
did not much enlighten one about the motor system - it did not, for example, tell one how
to go about programming a mechanical arm” (Marr 14-15)
“Functionalism looks nice on paper to those who know nothing about how
brains work.” (Freeman 115).
“Functionalism … is merely the last gasp of classical psychology.” (Bergmann 678)
“The
functionalist strategem is a smoke screen for the preservation of error
and confusion … It needs to be revealed for the shortsighted and
reactionary position it is.” (MBC, Churchland 506-7)
“If you are tempted to functionalism, I believe you do not need refutation,
you need help.” (Searle, TRM, 9)
What’s wrong with Functionalism?
• ABSURDITIES CAN BE DEFENDED – for example, alchemy, in
the face of elemental chemistry, can be defended using the
functionalist stratagem, thusly:
“Ensouled in mercury” or “sulphur” is an abstract functional state. “Mercury,” for
example, actually refers to the disposition to reflect light,to liquefy under heat, to unite
with other matter, etc. (these are functional kinds). It is the total syndrome of occurent and
causal properties of a metal or substance that matters, not the corpuscularian details of
the substrate (function matters, not the implementation).
Alchemy, it is concluded,
comprehends a level of organization in reality that is distinct from, and irreducible to,
the organization found at the level of corpuscularian chemistry. (MBC Churchland 507).
• NEED DETAILS! - the success of implementing Neural Networks
illustrates that an elementary understanding of brain microstructure
funds a fertile conception of what cognition really is. (MBC Churchland 198)
• QUALIA can not be reduced to something else, because if you
could they would be something else, and they are not something else.
(Searle, RM 51)
Let’s Patch This Up!
“Oceans of Ink have been spilled in the debate over functionalism …”
(Hasker 29)
• Valerie Hardcastle: “Functionalism is neither very strong nor very
controversial.”
• Jaegwon Kim: global reductionism is not possible, but some local
reductions are: “qualia are intrinsic properties if anything is, and to
functionalize them is to eliminate them as intrinsic properties.” (Hardcastle 29).
• Elliot Sober: “Functionalism got off on the wrong foot. The problem is
that function is ambiguous … ” (97)
New Paradigm or Paradigm Shift?
• John Searle: “Most of the recently fashioned materialist concepts of the mind – such
as behaviorism, functionalism and physicalism – end up denying that there are any such
things as minds as we ordinarily think of them … Now, why do they do that? (MBS
15). (We need to stop using) the antique and obsolete vocabulary of “mental” and
“physical”, “mind” and “body” (MLS 47). Any satisfactory account of the mind must take
into account: consciousness, intentionality, subjectivity, and mental
causation” (MBS 17).
Reactions: “Many of them, especially the younger
generation, agree with me, but I am amazed at the
number and vehemence of the defenders” (SA 29)
• David Marr: “Almost never can a complex system of any
kind be understood as a simple extrapolation from the
properties of the individual components … (there are three)
levels at which an information processing device must be understood (24-5):
Computational
Theory
Representation and
algorithm
What is goal of computation
and logic of the strategy?
What is representation of the input
and output and the algorithm
map?
Hardware
Implementation
How are the representation
and the algorithm realized
physically?
My Take
• Cummins states that if a theory is any good, it must be explanative in
and of itself. Some functionalist defenses to attacks sound like the
non-intuitive “hook-hook” argument illustrated on page 3 of MBC
handout.
• Functionalism has problems in its pure form (everything is function,
defined in terms of inputs and outputs). NOTE: The new paradigms
presented here (at least Marr’s) have functionalist components.
• Searle’s paradigm may be a new one. Marr’s is a shift.
References
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H. B. Barlow. “Single snits and sensation: a neural doctrine for perceptual psycology?” Perception 1.
G. Bergmann. “The Contribution of John B. Watson.” J. M. Scher editor. Theories of the Mind. The
Free Press. New York, 1962.
P. S. Churchland. Neurophilosophy. The MIT Press. Cambridge, 1986.
R. Cummins and D. D. Cummins. Minds Brains and Computers: The Foundations of Cognitive
Science. Blackwell Publishers. Malden, MA, 2000.
W. J. Freeman and C. A. Skarda. “Mind/Brain Science: Neuroscience on Philosophy of Mind.” E.
Lepore and R. V. Gulick editors. John Searle and His Critics. Basil Blackwell. Cambridge, 1991.
V. Hardcastle. How to Build a Theory in Cognitive Science. State University of New York Press. New
York, 1996.
W. Hasker. The Emergent Self. Cornell University Press. Ithaca, 1999.
D. Marr. Vision. W.H. Freeman and Company. New York, 1982.
J. von Neumann. The Computer and the Brain. Yale University Press. New Haven, 2000.
J. Searle. “Is the Brain’s Mind a Computer Program?”. Scientific American. Jan 1990, p 118.
J. Searle. Minds, Brains and Science. Harvard University Press. Cambridge, 1984.
J. Searle. Mind, Language, and Society. Basic Books. New York, 1998.
J. Searle. Rediscovery of the Mind.. The MIT Press. Cambridge, 1992.
E. Sober. “Putting the Function Back into Functionalism.” W. G. Lycan editor. Mind and Cognition.
Basil Blackwell. Cambridge, 1990.
J. H. Turner and A. Maryanski. Functionalism. The Benjamin/Cummings Publishing Company.
Menlo Park, CA, 1979.