The second in Marianne Talbot's series of lectures on Internalism and Externalism in the Philosophy of Mind

1. 1

2. The
Cartesian
Legacy The Cartesian thought
experiment was hugely
influential
The fact that, in 1975, the
‘kneejerk’ theory of mind still
rested on it indicates just how
influential

3. The
Cartesian
Legacy
The Cartesian picture of the mind
rests on a gap between:
• the mind – constituted of
subjective states that can be
known directly by inwards gaze
• the world - constituted of
objective objects that can be
known only as the causes of our
subjective states

4. The
Cartesian
Legacy
The Cartesian picture of the mind
had been updated by 1975 but there
was still a gap between:
• the mind – now constituted of
states of the brain, thought of as
having subjective properties that
can, as before, be known directly
by inwards gaze
• the world - still constituted of
objective objects that can be
known only as the causes of our
subjective states

5. The
Cartesian
Legacy
For 344 years philosophers had
accepted this Cartesian gap
They saw their job as trying to span
the gap by showing that it is possible
to justify the claim that our beliefs
about the external world are true
They tried to do this by analysing
our beliefs about the external world
in terms of beliefs about our
subjective states, the states we could
know for certain

6. The
Cartesian
Legacy
On this picture we know for certain (by
inwards gaze)
• our experiences and the qualities
they have
• what we believe about our
experiences (i.e. what we believe
they are experiences of)
• what we have done to ensure that
these experiences are veridical
• whether our beliefs about the
external world are justified in terms
of these experiences

7. The
Cartesian
Legacy
What we do not know for certain is:
• whether our experiences are
veridical
• whether our beliefs about the
external world are true
We take ourselves to know that
however hard we try to justify our
claims that they are true, that pesky
demon might still be at work

8. A problem
for the
Cartesian
Legacy
All this philosophical effort
assumed, with Descartes, that in a
demon world our problem would
be knowing the truth-value of our
beliefs about the external world
A problem that was ignored was
the problem of what our beliefs
would be in a demon world
But this is the problem of
externalism

9. A problem
for the
Cartesian
Legacy
The externalist is not going to
assume that in a demon world our
beliefs would be just the beliefs
they are here
An externalist believes that beliefs
are a function of the environment
of the believer
In a demon world, on an
externalist view, our beliefs would
be quite other than they are here

10. A problem
for the
Cartesian
Legacy
It looks as though the Cartesian
thought experiment simply
assumes that, in a demon world,
the beliefs we’d have would be the
same beliefs we have here
If this is right then Descartes’
thought experiment is not an
argument for internalism
Descartes’ thought experiment
begs the question against
externalism

11. A problem
for the
Cartesian
Legacy
Anyone who thinks the Cartesian
thought experiment supports
internalism seems to be conflating:
the question of evaluating our
actual beliefs in a counterfactual
situation
and
the question of determining
which beliefs we would have in
that counterfactual situation

12. The issue at
stake between
internalism
and
externalism
The issue of externalism versus
internalism is the issue of:
which beliefs we would have in a
given counterfactual situation
It is not the issue of:
how, given the beliefs we actually
have, they should be evaluated in a
given counterfactual situation
The issue of externalism is left wide
open by the Cartesian thought
experiment

13. Does this
make
externalism
more
plausible?
Suddenly we are without an
argument for internalism
Does this make externalism
more plausible
Let’s reconsider it now the
Cartesian thought experiment
has been stripped of its
internalist power

14. Does this
make
externalism
more
plausible?
Putnam claimed that our beliefs are the
beliefs that they are because we have
learned our language and acquired our
concepts by being in causal contact with
mind-independent external objects
Putnam denies, that is, that the
Cartesian gap between mind and world
can even open
Our beliefs are the beliefs they are
because we inhabit the objective world
that we inhabit (whichever objective
world we inhabit)

15. Does this
make
externalism
more
plausible?
Surely there is something very plausible
about this:
Could we have the concept [red]
without having had causal contact
with red objects?
Is our concept [red], the concept of a
quality of a subjective experience, or
the concept of a property of the mind-
independent objects from which we
acquired our concept?

16. Does this
make
externalism
more
plausible?
Could we have beliefs about J.K.Rowling without
having had (mediated) causal contact with
J.K.Rowling?
Would beliefs about J.K.Rowling even be possible
in a world in which J.K.Rowling didn’t exist?
If, whilst you are here, your spouse were swapped
for a molecule for molecule twin would the
thoughts you have about this twin tonight be
thoughts about your spouse?
The final question here suggests that the
phenomenological identity of A and B is not
sufficient to make a thought about A a thought
about B – which brings us to the second
interpretation of your objection to Putnam

17. Another
interpretation
of your
objection to
Putnam: the
externalist
version
Perhaps you believe that, as the observable
properties of water and twin water are the same, the
twins’ experiences will be the same?
Perhaps you believe that because the twins’
experiences are the same, their beliefs about their
experiences will be the same?
Perhaps, given that you believe the twins’ beliefs
about their experiences are the same, you also
believe that their beliefs about the external world
will be the same, as will the meanings of the
utterances in which they express those beliefs?
You therefore want to ask: how can the truth-
values of the twins’ beliefs and utterances be
different?

18. Another
interpretation
of your
objection to
Putnam: the
externalist
version
This interpretation of your objection is very
different from the first interpretation (though it
might not seem it)
It is not another attempt to close the Cartesian gap
by analysing the twins’ beliefs about the objective
world into their beliefs about their subjective
experiences
Instead you are assuming externalism (as evidenced
by mention of the ‘observable properties’ of water
and twin water)
You are saying that ‘water’, in both English and
Twin English, can be analysed in terms of the
observable mind-independent properties of the
liquid that flows in rivers, falls from the sky and
comes out of the taps on both Earth and Twin
Earth

19. Another
interpretation
of your
objection to
Putnam: the
externalist
version
If this is the force of your objection to Putnam, it is
not Putnam’s externalism you are objecting to - you
are accepting externalism
The target of your objection, on this interpretation,
is just Putnam’s thought experiment
You are allowing everything up to the point at
which Putnam assumes that, even before 1750, the
twins’ word ‘water’ and the concepts expressed by
it, would be different
Presumably you would allow (as Putnam would
also admit) that after 1750 we would have a choice
about whether to say the twins’ words differed in
meaning or were the same?

20. Another
interpretation
of your
objection to
Putnam: the
externalist
version
Choice One: Their Meanings/Contents Are
Different
• We might say that after they learn the molecular
structure of the liquid that flows in the rivers,
falls from the sky and comes out of the taps,
then the meaning of ‘water’ would start to
diverge for the twins
• Certainly the twins’ water–related behaviour
would start to differ
• They would start to defer to chemists, to insist
they couldn’t be sure the liquid in the glass is
water until they had tested it etc
• This would give us reason to think the
meanings, post-1750, would be different

21. Another
interpretation
of your
objection to
Putnam: the
externalist
version
Choice Two: Their Meanings/Contents Are
The Same
• Or we could take advantage of our
perspective as observers and argue that
we can see that were space-travel
invented, so the twins could travel
between Earth and Twin Earth, we
should just say that, given the very
similar properties of H20 and XYZ,
there are two types of water
• The meaning of ‘water’ would then
become (H20 or XYZ), and the meaning
of the twins’ word ‘water’, and the
concept they express by it, would again
be the same

22. Which
interpretation
was the one
you
intended?
I will leave it to you to decide which
interpretation of your objection is the one
that you intended
Were you assuming internalism or
externalism (or had you not realised there
was a difference, so you might have been
doing both at different times)?
In the next lecture I will be showing what
excellent company you would be in if you
meant the internalist interpretation rather
than the externalist one
But we haven’t finished this lecture yet….

23. Putnam’s
mistake
Putnam’s mistake is to have constructed a
hugely complex thought experiment to make a
relatively simple point
The complexity of his thought experiment
obscured a hugely plausible claim with an
illustration of that claim that baffles everyone
(and really gets up the nose of the scientifically
inclined)
But given the hugely important insight
Putnam was expressing I think he should be
forgiven
This insight was, after 344 years, to overturn
the almost universally assumed Cartesian
picture of the mind

24. Does this
make
externalism
more
plausible?
The idea of an unspannable Cartesian gap
between mind and world is actually rather
odd, isn’t it?
Why were philosophers so easily convinced
that such a gap exists?
Surely it is more plausible to think that there
is no gap between mind and world because
information is constantly being exchanged
between our minds and the world?

25. Does this
make
externalism
more
plausible?
If you are now thinking that externalism
seems plausible you might be wondering
why internalism ever seemed plausible
Is there any support for internalism, we
might think, that does not derive from the
Cartesian thought experiment?
In the rest of this lecture (and in the
lecture tomorrow) I will consider some
arguments for internalism, and how the
externalist might counter them

26. (i) The
Argument
from First
Person
Authority
Assume with the externalist, that our
beliefs would be different if we were in a
demon world
Problem: given we do not know which
world we are in, doesn’t this mean we do
not know what our beliefs are?
Are they the beliefs we think we have, or
are they demon-world beliefs (whatever
they would be)?
Either way we have lost first person
authority about the nature of our beliefs

27. (i) The
Argument
from First
Person
Authority
This is radical ignorance – in fact we have
gone from the impossibility of knowing for
certain anything about the world, to the
impossibility of knowing for certain
anything about our own minds!
It would seem we have a choice – we can
accept internalism and the possibility of
radical ignorance about the world, or we
can accept externalism and radical
ignorance about our own minds
But this is ridiculous, we know we have
first person authority about our own
minds, so internalism must be correct

28. Externalism
and first
person
authority
But the externalist will simply accept that we have
first person authority over the contents of our
beliefs
He will insist, indeed, that we would have first
person authority over the content of our beliefs
whichever world we are in
If we were in the demon world, for example, we
would also have first person authority over the
contents of our beliefs
The only thing externalism rules out is knowledge
of which beliefs we would have if we were in the
demon world.
Our first person authority does not extend to
knowledge of the content of beliefs we do not have

29. Externalism
and first
person
authority
It would seem that the
argument from first person
authority does not entail
internalism

30. (ii) The
Argument
from
Hallucination
If we have do have first person authority over the
nature of our experiences, but we do not know
whether these experiences are veridical or
hallucinatory, doesn’t this mean that our
experiences are the same whether they are veridical
or hallucinatory?
But this must surely mean, we might think, that an
experience must be the state it is quite
independently of the environment?
If we do not have first person authority over
whether our experience is veridical or
hallucinatory, but we do have first person authority
over the nature of this experience, then surely the
nature of this experience must be determined from
within?

31. Externalism
and
hallucination
This argument infers from the fact that we do not
know whether experiences are veridical or
hallucinatory, to the claim that hallucinatory and
veridical experiences must be states of the same
kind
But this claim can only be made from a first person
perspective, from the perspective of a Cartesian
subject gazing inwards
If we adopt a third person perspective then we can
say that hallucinations and veridical experiences
are very different experiences
Imagine that for the last few hours I have been
hallucinating this glass of water - my behaviour
would have seemed extremely odd

32. Externalism
and
hallucination
It is certainly the case that had I been hallucinating
this glass of water I would not have been able to tell
By gazing inwards we cannot see the difference
between a veridical perception of the glass and a
hallucination of the glass
But this tells us only that, from the first person
perspective, perceptions and hallucinations appear
to be states of the same kind
It doesn’t tell us that perceptions and
hallucinations are states of the same kind
From the point of view of the interpreter they are
states of very different kinds – one fits into a
continuing narrative of me as a sensible person -
the other makes it look as if something has gone
badly wrong

33. Externalism,
first person
authority and
hallucination
Neither the recognition of our first person
authority, therefore, or our inability to distinguish
between veridical perceptions and hallucinations
from a first person perspective, can threaten the
externalist
To the externalist the first person perspective is not
privileged as it is to the internalist (and especially
to the Cartesian)
The externalist can accept, as the Cartesian can’t,
that we can be wrong about our own subjective
states
We can be wrong to think that an experience is an
experience of a glass, because we can allow that
that experience might only seem to be about a glass

34. (iii) The
Coherence of
Scepticism
Is the externalist saying, we might ask, that
whichever world we are in, we will know that we
are in it because our beliefs will be about this world
and, thanks to first person authority, we know that
that our beliefs are about this world?
If so then surely the externalist is saying that
scepticism is incoherent?
The externalist is saying, pace Descartes, that we
know that we inhabit the world of lecterns, chairs,
pens, books and cats because we know that our
beliefs are about lecterns, chairs, pens, books and
cats
But if so then it could not be the case that all our
beliefs about the external world are false. Radical
error is impossible. We know that we are not being
manipulated by the evil demon

35. (iii) The
Coherence of
Scepticism
But for centuries philosophers have been trying to
deal with scepticism
It has seemed to them that, for all we know, it could
be the case that we are manipulated by the evil
demon
Now the externalist is saying that the solution was
right here in front of our eyes the whole time
If we insist that our beliefs are the beliefs that they
are only because our environment is the way it is,
than it cannot be the case that all our beliefs about
the external world might be false
But surely one thing of which we can be certain is
that scepticism is coherent?
So externalism must be wrong

36. Externalism
and The
Coherence of
Scepticism
This is another argument that doesn’t bother the
externalist who will simply nod and accept that
scepticism is incoherent
Scepticism, he will say, is a legacy of the Cartesian
gap: once we have retreated into the mind,
believing that we can be certain about the objective
world only if we can analyse our beliefs about the
objective world into beliefs about our subjective
experiences, then the objective world has gone for
good
We cannot build an objective world from subjective
material, but that is what the Cartesian picture
requires of us

37. Externalism
and The
Coherence of
Scepticism
If, however, we consider the way we
actually learn language and acquire
the concepts expressed by the
language we learn, we will see that
Descartes’ picture of the mind
makes a mystery of how the mind
represents the world at all
Let’s look more closely at this claim

38. Externalism
and The
Coherence of
Scepticism:
the process of
language
learning and
concept
acquisition
The process of language learning and concept-
acquisition demands a learner, a competent
speaker, and a world of objects (lecterns,
chairs, pens, books and cats)
The competent speaker, making sure the
learner can see and hear her, will demonstrate
a cat whilst uttering the word ‘cat’
She’ll do this again and again with a variety of
cats under different circumstances
After a while the learner will start herself to
utter ‘cat’ whilst pointing at a cat
Now the test phase can start – is the learner
learning the correct meaning, expressing the
correct concept?

39. Externalism
and The
Coherence of
Scepticism:
the process of
language
learning and
concept
acquisition
Now our competent speaker points to a cat and
utters ‘cat?’ Occasionally she points to dogs or
rabbits whilst uttering ‘cat?’
She is hoping the child will assent to her utterances
of ‘cat?’ when she is pointing to a cat, and dissent
from her utterances of ‘cat?’ when she is pointing
to a dog or a rabbit
If the learner does this then she demonstrates that
she has successfully acquired both the concept [cat]
and the meaning of the word ‘cat’
The learner has demonstrated in her observable
behaviour that she grasps the conditions under
which an utterance of the word that (in English)
expresses the concept [cat] is true, and those under
which such an utterance would be false

40. Externalism
and The
Coherence of
Scepticism:
the process of
language
learning and
concept
acquisition
It is only one who is appropriately related to
cats, and whose visual and cognitive systems
are intact, can learn the meaning of a word
that, in some natural language, expresses the
concept [cat]
Only such a person can learn to see cats as cats
The behaviour of a learner all of whose beliefs
about the objective public world in which cats
exist were false would be completely baffling
to any competent speaker of a language
It is unlikely that anyone would even attempt
to teach her language, never mind that she
would be able to learn it

41. Externalism
and The
Coherence of
Scepticism:
the process of
language
learning and
concept
acquisition
On the basis of this account of language-
acquisition falsehood can make sense only
against a background of truth
Once the learner is a competent user of
language, then we can make sense of her
misusing a word of that language (of applying
a word that means ‘cat’ to a dog)
We do so by saying that she has mistaken a
dog for a cat, that her word ‘cat’ means ‘cat’
even though she has misapplied it to a dog
We can do this only because we have every
reason to think that most of the time she
correctly uses the word ‘cat’ to mean cat

42. Externalism
and The
Coherence of
Scepticism:
the process of
language
learning and
concept
acquisition
So the externalist rejects the idea that all our beliefs
about the external world might be false, whilst
explaining how some of our beliefs about the
external world can be false
The externalist notes that the more careless we are
about the circumstances in which we believe we are
justified in applying a word, the more often we will
misapply that word (the more often we will get it
wrong)
But none of us could be as radically wrong as
Descartes suggests
The possibility of such radical error conflicts with
everything we know about how language is actually
learned, and how concepts are acquired

43. Conclusion In this lecture I have argued that the Cartesian
thought experiment begs the question against
externalism
As a result for three centuries internalism was
simply assumed!
Putnam’s thought experiment triggered a
recognition of the plausibility of externalism
A thought-out externalism is proof against any of
the arguments we have so far examined
We’ll look at such an account in tomorrow’s lecture
In the next lecture I will illustrate how
comprehensively philosophy was misled by
Descartes