PURPOSE, EVOLUTION AND MENTAL CONTENT

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Topic 2

• PURPOSE, EVOLUTION AND MENTAL CONTENT

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NATURALISM

• Cf. supernatural
• The Enlightenment natural and natural science
• All which qualities, called sensible, are
  nothing in the object, but so many several
  motions of the matter, by which it presseth our
  organs diversely. Neither in us that are pressed,
  are they anything else, but diverse motions for
  motion produceth nothing but motion (Hobbes)

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THE MIND

• Dualists
• Substance and property dualists
• Naturalists
• Whats to be explained by science?

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MENTAL STATES

• Folk psychology
• Beliefs, desires, perceptions, sensations, hopes
• Such mental states have two important properties,
  two properties that at first glance would seem to
  pose difficulties for naturalism
• 1. Intentionality or aboutness
• 2. consciousness

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INTENTIONALITY

• Aboutness
• Latin intendere, meaning to aim
• cf. other senses of intention
• Beliefs are about the world
• I believe that the rabbit is on the grass

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INTENTIONAL CONTENT

• Beliefs have intentional content
• Intentionality
• Belief about rabbit and the grass
• Intentional content
• That there is a rabbit on the grass
• Want to explain this in naturalistic terms
• A naturalized account of intentionality

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• I suppose that sooner or later the physicists
  will complete the catalogue theyve been
  compiling of the ultimate and irreducible
  properties of things. When they do, the likes of
  spin, charm, and charge will perhaps appear upon
  their list. But aboutness surely wont
  intentionality simply doesnt go that deep. Its
  hard to see, in face of this consideration, how
  one can be a Realist about intentionality without
  also being, to some extent or other, a
  Reductionist. If the semantic and the
  intentional properties of things are real
  properties of things, it must be in virtue of
  their identity with (or maybe of their
  supervenience on?) properties that are themselves
  neither intentional nor semantic. If aboutness
  is real, it must be really something else.
  (Fodor, Psychosemantics, p. 97)

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• I want a naturalized theory of meaning a theory
  that articulates, in nonsemantic and
  nonintentional terms, sufficient conditions for
  one bit of the world to be about...another bit.
  (Ibid., p. 98)

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NORMATIVITY

• Thinking is normative
• Particular thoughts are correct or justified
• There are certain thoughts I should have
• Cf. pragmatic should
• Mechanical should
• Ethical should

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NORMATIVITY AND INTENTIONALITY

• Interdependent on each other
• (i) Normativity presupposes intentionality
• Certain thoughts are justified given that I am
  aiming to have correct thoughts about the world
• (ii) intentionality is essentially normative
• We focus on the world by being able to have
  justified thoughts about it

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• To make sense of the idea of a mental state's or
  episode's being directed towards the world....we
  need to put the state or episode in a normative
  context. A belief or judgment to the effect that
  things are thus and so...must be a posture or
  stance that is correctly or incorrectly adopted
  according to whether or not things are indeed
  thus and so.... This relation between mind and
  world is normative, then, in this sense thinking
  that aims at judgement, or at the fixation of
  belief, is answerable to the world ? to how
  things are ? for whether or not it is correctly
  executed. (McDowell, Mind and World, p. xi-xii)

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• Thus we shall approach a naturalized account of
  intentionality by focusing on normativity
• By providing an account of how we should think
  about rabbits in certain circumstances, we are
  providing an account of how our thoughts
  represent that bit of the world

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The problem of normativity

• Naturalistic accounts would seem to provide
  descriptions of what
• Thoughts we actually have
• Thoughts we are disposed to have
• But an account is required of which thoughts we
  should have
• Which thoughts are correct

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• What is required is a naturalistic account of
  correctness conditions
• Of when we should have certain thoughts
• If we can give an account of when we should think
  about rabbits
• then we have an account of how we think about
  that part of the world, that is, rabbits
• We have an account of intentional content and
  intentionality

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PROPER FUNCTION

• Bottle openers have a function they open bottles
• They can function correctly and incorrectly
• Biological entities also have a function
• Hearts, chlorophyll molecules, rods and cones

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• Hearts do many things
• Move the chest cavity, pump blood, make a
  soothing sound
• There is a reason why we have hearts
• And thats because they pump blood
• Thats what they were designed to do
• By natural selection

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• Pumping blood is the hearts proper function
• Describes what an organ should do
• Not necessarily what it does
• Dandelion seeds, malformed eyes, spermatozoa

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MENTAL REPRESENTATIONS

• Things in the brain (MRs) represent things out in
  the world
• MRs are about rabbits
• How?
• MRs have an evolutionarily selected function
• MRs have a proper function
• they were designed to be present in the mind in
  the presence of certain things in the world

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• The reason we have MR(X) is because having MR(X)
  in the presence of Xs in the past has aided our
  survival
• We have the MR WATER when in the presence of
  water, yet also sometimes in the presence of
  mirages or vodka
• But we should only have WATER thoughts in the
  presence of water, because this explains the
  presence of WATER thoughts in our mental economy

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• WATER thoughts in the presence of water ?
  biological success
• WATER thoughts in the presence of a mirage or
  vodka do not ? biological success
• A cognitive state that is evolutionarily selected
  to be sensitive to an environmental feature X has
  the content X

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ANIMALS AND INTENTIONALITY

• Millikan and the dance of the bumble bee