Phenomenal Concepts and the Private Language Argument - mm

Document Sample
Phenomenal Concepts and the Private Language Argument - mm Powered By Docstoc
					 Phenomenal Concepts and
     Private Languages

                  David Papineau

          British Postgraduate Philosophical
                   KCL July 14 2009
Phen Concepts and PLA   1 Mary and Phen Concepts   1
                        The Plan
1 Mary and Phenomenal Concepts

2 Are Phenomenal Concepts inconsistent
  with the PLA?

3 If so, is this bad for Phenomenal
  Concepts, or bad for the PLA?

Phen Concepts and PLA   1 Mary and Phen Concepts   2
        Conceivability Arguments for
We can conceive of a being who is
   physically just like us, but has no
   conscious feelings (a ‘zombie’).
So conscious feelings are extra to the
   material realm.

We might all agree that this is not a good
  argument. But what exactly is wrong
  with it?
Phen Concepts and PLA   1 Mary and Phen Concepts   3
                Type-A Physicalism
Back in the 1970s and 1980s we responded to this
   argument by denying the conceivability premise.
   Maybe we can conceive of C-fibres without
   pains. But once you fill the rest of the physical
   framework, as with a zombie, the absence of
   feelings ceases to be conceivable.
(If it walks like a conscious person, and talks like a
   conscious person, . . .)
But Jackson’s Mary argument undermined this

Phen Concepts and PLA   1 Mary and Phen Concepts     4
         Frank Jackson’s Knowledge
Mary is an omniscient colour vision scientist who has never
   had any colour experiences herself—until one day she
   sees a red rose.
Jackson's argument:
(a) Before that day, Mary knew about all physical aspects
   of colour experience
(b) The she learns about another aspect--what it is like to
   see something red
(c) There is at least one non-physical aspect of colour
Phen Concepts and PLA   1 Mary and Phen Concepts          5
  Type-A Physicalism Kyboshed
This looks in tension with the Type-A line. Mary knew everything
  there is to know about how conscious persons walk and talk,
  but didn’t yet know what it was like for them. It looks as if the
  facts about brains and behaviour leaves it conceptually open
  what if anything is going on consciously.

Sure, 'Type-A' physicalists--Dennett, Ryleans, neo-behaviourists,
  David Lewis, Analytic Functionalists, Wittgensteinians?—may
  try to deny premise (b) which says that Mary acquires some
  new knowledge. (She may not have had the experience
  before, but she didn’t then lack any knowledge.)

But this is highly implausible, for reasons that will become even
  more clear later on.

Phen Concepts and PLA   1 Mary and Phen Concepts                    6
            Phenomenal Concepts
So 'Type-B' Physicalists allow that Mary
 does acquire new knowledge, but only at
 the level of concepts.

Mary gets a new 'phenomenal' concept, Ø,
 which refers to the same state as her old
 physical concept seeing redly.

Phen Concepts and PLA   1 Mary and Phen Concepts   7
                  What Mary Learns
So now she knows ripe tomatoes cause Ø, where before
  she only knew ripe tomatoes cause seeing redly.

But this doesn't involve knowledge of a new dualist mental
  property, anymore than learning Bristol is the birthplace
  of Cary Grant, when previously you only knew Bristol is
  the birthplace of Archie Leach, involves knowledge of a
  new person.

By the same coin, Mary now knows that seeing redly = Ø,
  when before she only knew seeing redly = seeing redly.
  But no new dualist property is required.

Phen Concepts and PLA   1 Mary and Phen Concepts              8
     Phenomenal Concepts Rule

Contemporary dualists (Chalmers, Bealer, old Jackson)
  agree about the phenomenal concepts, but use a
  contentious semantic premise to argue that the a
  posteriority of seeing redly = Ø entails its falsity.
So pretty much everybody in this debate now accepts
  phenomenal concepts. There are scarcely Type-A
  physicalists left. Dennett. And Jackson himself. (He
  became embarrassed about being a dualist, and so had
  to deny either (i) Mary gets a new phenomenal concept
  or (ii) the dodgy semantic premise. Amazingly, he is so
  attached to the latter that he (alone) has joined Dennett
  in denying his own knock-down argument for
  phenomenal concepts.)

Phen Concepts and PLA   1 Mary and Phen Concepts              9
Does Mary have Private Terms?

So—is there something about Mary that Wittgenstein wouldn't

After all, her ‘phenomenal concept’ is posited as applying
   specifically to a kind of sensation. Moreover, it is a concept
   that can only be possessed by people who have had that
   sensation themselves.

But it’s not immediately clear why Mary should be ruled out by
  the PLA. I take it that Wittgenstein did not wish to deny that
  we can refer to sensations in the direct way Mary now can.
  Nor is it clear that he would wish to deny that having had the
  sensation yourself is necessary for such reference.

Phen Concepts and PLA   2 PLA -> No Phen Concepts?                  10
               Phenomenal Concepts

Maybe we were to quick to say that Mary
 acquired a special new concept for her own
 private sensation.

Perhaps on coming out the room, Mary simply
 gets better at applying the public concept of
 seeing redly that she already shared with
 the general community. (Cf the ‘ability

Phen Concepts and PLA   1 Mary and Phen Concepts   11
Mariana and the Piece of Paper
But now consider this variant. Mariana isn't
  shown a red rose, but a coloured piece of
  paper—and isn't told what colour it is. I say
  she too will form a concept of the type of
  experience she then had.
After all—she may conjecture I'll have Ω
  again today, or Ω is caused by lush
  grass—and these conjectures will surely
  be true or false.

Phen Concepts and PLA   2 PLA -> No Phen Concepts?   12
  Let’s assume the child is a genius
But note that Mariana won't know in any
 public terms which colour experience Ω is.
So any word—’seeso', say—that she coins
 to express it will be private, at least in the
 sense that its meaning will be
 incommunicable to anyone else. ('Well,
 let's assume the child is a genius and itself
 invents a name for the sensation. . .')

Phen Concepts and PLA   2 PLA -> No Phen Concepts?   13
                 ‘Private’ ≠ ‘Solitary’
Still, perhaps this incommunicability is
  superficial, like that of an as-yet unrescued
  Crusoe who hasn't had a chance to
  explain his terminology to anybody.
That is, maybe Mariana's term isn't
  necessarily private. Maybe 'seeso' has
  been assigned meaning in way that
  satisfies the appropriate standards of
  checkability, etc, but Mariana simply hasn't
  yet had a chance to explain it to anyone.

Phen Concepts and PLA   2 PLA -> No Phen Concepts?   14
 Mariana makes herself understood
Now, I myself certainly think that, given
 propitious circumstances, Mariana will be
 able to communicate her meaning to
Suppose that it becomes common
 knowledge between her and others that
 the piece of paper was green. Then they
 will all know that 'seeso' refers to: seeing

Phen Concepts and PLA   2 PLA -> No Phen Concepts?   15
   Identifying Mariana’s Referent

But let's look a bit more closely at what is going on

Mariana and her friends know that there is a publicly
 accessible kind of experience (maybe physical,
 maybe functional role, maybe even non-physical
 functional realizer) called 'seeing greenly', which is
 typically caused by green things.

And they figure out that Ω = seeing greenly/'seeso =
  seeing greenly'. And so everything is fine.

Phen Concepts and PLA   2 PLA -> No Phen Concepts?        16
  An Argument for Physicalism?
But is it fine for Wittgenstein? Some would
 argue at this point that it is indeed fine for
 him precisely insofar as the referent of
 Ω/'seeso' turns out to be a publicly
 accessible item.
Thus my colleague Jim Hopkins holds that
 Wittgenstein has an argument for
 physicalism here (otherwise Mariana-style
 references wouldn't be to anything public).

Phen Concepts and PLA   2 PLA -> No Phen Concepts?   17
  Meaning needed from the start

But I doubt that this general story would be all right
  for Wittgenstein. Note crucially that the
  discovery that Ω = seeing greenly/'seeso =
  seeing greenly' is a posteriori for Mariana and
  her friends. And this surely requires that
  Ω/'seeso' already had a determinate meaning
  prior to their knowledge of the greenness of the

Phen Concepts and PLA   2 PLA -> No Phen Concepts?   18
    Seeming Right is Being Right
How did that happen?
Mariana looked inwards and gave the name
    Ω/'seeso' to her sensation.
At that stage there was no possibility of any
    check on later uses of Ω/'seeso' being
    used with the same meaning.
And so no such checkable difference
    between being right and seeming right in
Phen Concepts and PLA   2 PLA -> No Phen Concepts?   19
                    A Beetle in a Box
When we later correlate uses of Ω/'seeso'
  with something publicly accessible,
  surely that's just like correlating 'S' with
  movements of the manometer.
And for Wittgenstein this doesn't vindicate
  the prior usage of 'S' as referring to
  anything, but simply renders it a new
  public term for which any prior supposed
  referent has become irrelevant.

Phen Concepts and PLA   2 PLA -> No Phen Concepts?   20
                        Two Ways to Go
Assuming there is an incompatibility between
   Phenomenal Concepts and the PLA, there are
   two ways to go.

(a)The PLA shows that Mariana does not have a
    contentful concept.

(b) Mariana refutes the PLA.

Let me broaden out the issues.
Phen Concepts and PLA      Phen Concepts OR PLA   21
              Judgement and Rules
I take it that behind the PLA lies a broader picture
     of contentful judgement.
Judgements are constituted by rules. You can
     judge that p insofar as you are sensitive to a
     rule governing such judgements.
The nature of such rules is not straightforward, but
     at the least they require some kind of public
     checkability, some answerability to public
     standards that ensure a difference between
     seeming right and being right.

Phen Concepts and PLA   Phen Concepts OR PLA       22
                        No Rules
Here is an alternative view of contentful judgement.
We have a stock of concepts that are designed to lock onto
    entities in our environment.
Thus when confronted with a zebra I might take an animal
    species concept from the shelf, so to speak, and then
    from then on this concept refers to the species: zebra.
Nothing more is needed. In particular no rules are needed
    to bring it about that I can re-use the term with the
    same meaning on future occasions. Next time I judge
    zebra I will be right if it is a zebra (the species I locked
    on to) and not otherwise.
Similarly I can form concepts of individual animals, people,
    metals, houses, . . . and of types of experience.

Phen Concepts and PLA   Phen Concepts OR PLA                  23

Mariana's manifest ability to refer to her
  experience seems to me a powerful
  reason for preferring the second
  view to the first.

Phen Concepts and PLA    Phen Concepts OR PLA   24