EECS 690 (PowerPoint) by dffhrtcv3


									EECS 690

  April 5
                  Type identity
• Is a kind of physicalism
• Every mental event is identical with a physical event
• In each case where two minds have something mental in
  common, they have something physical in common.
• A note about the notation: ‘(x)’ prior to an expression
  indicates that it is a universal quantifier over x. ‘’ is
  the symbol for the biconditional. So read (x) (Mx  Px) as
  “For all of x, x is a mental event if and only if x is a
  physical event.” What this means is that for every
  mental predicate, there is a corresponding physical
    Problems with type identity
• The second claim it makes is hopelessly too
  strong. There are small but noticeable
  differences between individual persons’ brains
  that don’t lead us to attribute different mental
  predicates altogether to them.
• Also, type identity theory is what has been called
  a chauvanist theory, namely that it defends the
  claim that only (human) brains are minds.
    Turing Machine Functionalism
• Substance dualism is still denied here
• Instead of some particular physical state type
  being identical with each mental state type, each
  mental state has a functional description such
  that an indefinite number of physical setups
  could be made to perform the function.
• In this case, mental predicates “bottom out” in
  their specification as a specific state of a
  universal Turing machine (a digital computer).
         Problems with TMF
• Though there are still plenty of TMFers
  kicking around, it is probably still too
  strong a claim to say that what two people
  have in common when they both believe
  that snow is white is to be realizing the
  same discrete machine state. This still
  requires that our minds work in some
  sense in the exact same ways as each
         Token functionalism
• This is the more relaxed form of functionalism
  that we have been operating with for the past
  couple of weeks.
• In a sense, this approach is born out of a
  reluctance to reduce mental predicates either to
  specific brain states or to specific discrete
  machine states.
• Token functionalism isn’t, by itself, a complete
  theory, but is an hypothesis adopted by many
  otherwise different theories of the mind.
  Dennett’s Move (type intentionalism)

• “[E]very mental event is some functional,
  physical event or other, and the types are not
  captured by any reductionist language, but by a
  regimentation of the language we already use.”
• His illustration about the society who talks about
  “fatigues” as mental entities is supposed to
  illustrate how unregimented our own use of
  intentional idioms are, and how little the physical
  facts detract from the usefulness of intentional
Three ways of talking (and thinking)
     about different systems
• Theories are only useful and valid insofar
  as they can aid in prediction. Dennett
  identifies three distinct stances that we
  can take to aid us in prediction. Each
  stance involves the use of different
  theories and considerations. Note that
  any system can be approached via any
  stance at any time, but it is typically
  obvious to us when one stance is more
  useful than the others.
         The Physical Stance
• “From this stance our predictions are based on
  the actual physical state of the particular object
  and are worked out by applying whatever
  knowledge we have of the laws of nature.”
• This is the stance typically used to describe
  malfunction (which is why that can be so difficult
  to explain in complex systems)
• Statements and predictions from the physical
  stance tend to be very fine-grained.
            The Design Stance
• “Different varieties of design stance predictions can be
  discerned, but all of them are alike in relying on the
  notion of function which is purpose-relative or
  teleological. That is, a design of a system breaks it up
  into larger or smaller functional parts, and design stance
  predictions are generated by assuming that each
  functional part will function properly.”
• We generally adopt the design stance when predicting or
  describing the behavior of mechanical objects, though
  many sciences routinely make use of the design stance,
  (e.g. Biology)
       The Intentional Stance
• “One predicts behavior in such a case by
  ascribing to the system the possession of certain
  information and supposing it to be directed by
  certain goals, and then by working out the most
  reasonable or appropriate action on the basis of
  these ascriptions and suppositions.”
• “One will arrive at the same predictions whether
  one forthrightly thinks in terms of the computer’s
  beliefs and desires, or in terms of the computer’s
  information-store and goal-specifications.”
• The theoretical commitments of the intentional
  stance include beliefs, desires, and rationality.

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