' Groundwork: A representation itself
is semantically not epistemically assessable (i.e. doesn't have or determine
epistemic liasons except as part of an attitude). That is, representations are
justified, warranted, etc. Also, you can't just identify attitude content with
epistemic liasons because the belief that p and the desire that p
will have different content although both use the same p. So what's the
content of p?
' Start with just attitudes. Epistemic
liasons: the set of paths in state space that intersect at cA
are liasons of A in the context of cA. (Total) Conceptual
role: set of A's conceptual roles realtive to c for each state in
which A can occur.
' Now we need representational
content: Identify the conceptual role of r with the set of attitudes it
enables. Thus the meanin of r is identifies with the paths through
cognitive space that are made possible by its availability to the cognitive system.
' Result: epistemic relations
determined by r are insensitive to which other beliefs a system actually
has. Therefore no meaning-incomparability. (Because what you mean doesn't
depend on what you currently believe, it depends on the set of possible states
licensed by the inclusion of that representation in your system).
' See
p. 38-9 bottom to top. Result: E2 is empty as an explanation of D
because it entails D. Why isn't entailment explanation? Because: 1.
self-explanation 2. weak premises 3. irrelevant information 4. causal order.
' So
what? CRS gives a 'valence theory' of content. I.e., it takes content to be a
useful fiction that simply stands in for talk of complex epistemic relations
(like 'valence' in bonding in chemicals; claims you can't explain why O and H
bond 1 to 2 by appeal to valence. Agree?).
' Why
not think content is causally inert? Just look and see. We can tell that
representational error, getting content wrong, results in problematic behavior.
CRS response: We can tell, but what about the system? The only way we
know it has a problem is because it results in bad behavior, and
behavior just is the result of epistemic liasons. C:Well at least we know CRS will be wrong if we can show
that content has a genuine explanatory role.
'
CRS and Error:
' CRS can't distinguish wrong moves in
chess from right moves in schess. This is because CRS assigns content
determinations without intepretations, so we don't know if their directed at
chess or schess. In other words we know how to get the content but we don't kow
what it is (chess e.g.). p. 41.
' We can't distinguish what the system
uses a representation to represent and what it actually represents (content) so
we can't explain error (since there isn't any). CRS defines the content of RP3
as (in part) the actual use of RP3 in the system, so it must always be
correctly used.
' How to fix this? Appeal to ideal use
rather than actual use for content fixation. But
it tends to be circular:
1. Ideal
use is correct use requires a criterion of error.
2. Ideal
use as successful use can't evaluate success without an interpretation.
3. Ideal
use as rational use but rationality can't be specified in a way independent of
how cognitive systems actually work so it isn't independent of actual use.
4. Ideal use is competent use.
Competence/performance is based on breakdown or limited resources but these don't
explain representational error (rather because of incomplete information). So
you couldn't distinguish correct use from justified use.
5. Ideal use as adaptive use but
correctness and adaptivness easily come apart. Some repns are adaptive but not
correct (fast predator detection) others are correct but not adaptive (trout
with true position of flies but reactions that compensate for diffraction).
Also explanatory order is wrong: representations are adaptive because
they represent what they do.
' Totally different strategy: relativize
to interpretations. (It's playing chess wrt one interpretation and schess wrt
another). But this dispenses with CRS because we've already fixed contents in
advance!
' Nontriviality of representational
explanation
' Granted CRS will give an accurate
picture of the causal story of interest. But, the explanatory role of content is not found in causal
role, it's in the ability to talk of representational error.
' With error you can note that faster
systems with many false positives can be better than slower more accurate ones.
Use theories undermine the accuracy/effectiveness distinction and thus can't
make such claims.
' With error you can describe the
debate between Piagetians and others that error during development is forced or
unforced (i.e. due to representational changes or processing changes). In
general (Kant example, p. 48) use theories can't have forced error because that
requires representations that never correctly apply (e.g. Euclidean space).
Response: The Kant case is just that the theory is wrong regarding our
perceptual content (i.e. it is non-euclidean and not euclidean). Reply: Really
want to say it's a euclidean approximation, but you can't because 'always being
in error' isn't acceptable; no systemmatic misrepresentations!
' So why do we need representation?
1.
Because
it allows dimension shifts: Explanations by appeal to computation need semantic
interpretations of their objects; hence representations. CRS gets you this far.
2.
It
permits the distinction between reasoning errors from representational errors. CRS
can't support this.
1. Specify epistemological conditions
when detectors apply representations correctly
2. Teleological theories that say
detectors are right when properly functioning
3. Asymmetric dependence theories that say
successful detection are cases in which a special law obtains.
' Problem 1: Foolproof detectors
(when? Never!)
1.
E-theories:
Fact of life that even under optimal conditions detectors fail (why are the
conditions optimal then?). C suggests you can save this view by becoming an
antirealist (identify what there is to detect with what actually is detected).
But this is 'perverse' because you started with a theory that supposed there
were properties out ther causing things inside to detect them.
2.
T-theories:
Distinguish a) psychological proper functioning from b) semantic proper
functioning. A) is when it's playing the right cognitive role b) is when it is detecting
correctly. A detector could be a) and not b). This is a problem for T-theories
because they try to define b) in terms of a)! That is, according to C: 'TRUE-OF
doesn't reduce to GOOD-FOR any more than TRUE reduces to GOOD.' P. 57.
3.
AD-theories:
(p. 57) The basic idea is that connections between properties and
representations are correct when they are basic (not AD). C claims that AD must
assume that every instance of a basic law of detection is a case of correct
representation. This is, of course, true (not by assumption but by assertion).
When a law is violated is when you get error, that's the point. C provides a
case where a Pavlov's dog has his olfactory nerve cut to put pressure on AD.
However, Fodor has 'normal conditions' clauses in his formulation of AD, so
this is 'sort of' cheating (though we may think Fodor has no right to such
clauses). Also, on p. 60 C claims that 'the idea that every basic law is a law
governing detection is radically implausible' is perfectly fine because AD is
only concerned with basic laws of detection. C himself points this out 2
pages earlier (?). This is really a poor discussion of AD. His second attack is
better motivated when he points out that AD has to show that representational
error is never a basic feature of detection architecture (recall cartesian
example). AD is commited, as C points out, to idealizing away from resource constraints
in detection. This seems highly unusual given that cognitive systems are
severely resource limited. Cummins pushes the point by claiming that natural mechanisms
are designed with such constraints in mind and that changing resources won't
change detection properties. This is because they simply key to one feature
(imperfectly correlated) to perform detection, more resources won't change this
mechanism. Response: There is another system (reason) that takes the output
from those detectors and can always get it right with unlimited resources.
Reply: There is no guarantee that we'll always get it right even with unlimited
resources (begins to seem like intution mongering). C then claims that if getting
more resources improves your detection ability, obviously you are relying on a
nondemonstrative inference. But this isn't true (e.g. Turing Machines). He
shouts 'anti-realism' at those who deny this. Why?
' Problem 2: Content/Attitude
Distinction
' Like CRS, CT suffers from putting it's
efforts in understanding attitude content, not representational content.
' This is because detections are
attitudes: To detect H is to token an attitude whose content is that there is H
present in response to H's being present.
' But, we can have such an attitude, C
claims, without being able to represent H! Provides 'food-status' example. The
constituent representation means 'present' not 'food'. Thus we can construct
two systems with the same attitudes but different representations. You can't,
in other words, infer representational content from attitude content.
' C says that this happens because
having an attitude that p isn't standing in a relation to a representation p.
He says any theory that does this will not allow a distinction between targets
and contents. Why?
' Problem 3: Explanation
' We want CT to tell us why
representations tokened by detections should matter to understanding cognition.
' Any explanatory plausiblity that CT
does have comes from its use of the notion of information. Detectors token
representations that carry information about the world; having information is
useful; so representations indicate their contents and are useful. But
representing and indicating are different.
' Furthermore, information processing
according to CT doesn't preserve information. Complex representations are
functions of their constituents, but their information isn't a function of the
information of constituents (p. 65). As a result, |food| does not carry the
information that food is around when it is the result of |bell&(bell->food)|.
(Is that the right information content?). This is a more typical case of where
|food| comes from.
' So we have a dillema: CT derive
plausibility from the idea that a basic case of representing is carrying information
but they don't (and can't) think representing is carrying information!
' This, says C, is because information
and symbolic constituency don't mix. The idea that computing over
representations is information processing is thus abandoned by CT.
' How is content relevant then?
Standard story: content mirrors form and form is processed by underlying mechanisms
('tower bridge').
' C thinks this initial correlation
won't stand up. He uses the argument against 2-factor theories from Fodor and
others to show that content, fixed causally, need not track form. Response:
alignment is contingent, but systems that don't respect it will get into
problems. Reply: No way. Confusing |cow| with |ungulate| or |cow or apparent
cow| just won't matter. Such a system would get into the problems that we
actually get into. So misalignment won't be rare.
' This is because symbols are
arbitrary according to LOT (and CT). thus as far as intrinsic properties of a
representation are concerned it's not clear whether detection or processing has
gone wrong. This is because r counting as a |horse| can't be read off of
intrinsic properties. If you read it off detection, processing is wrong
but if you read it off conceptual role, detection is wrong. Either way it is your
theory that fixes the problem, there's no fact of the matter.
' From this C concludes that it is
probably a representations structure that matters, not it's role in detection
(foreshadowing).
' CT entails LOT: CT implies
representations are abitrary because it's causal connections that matter. This
is how primitive representations are fixed complex representations get meaning
from combinatorial semantics. Voila.
' Thus, there are 3 ways for symbols
to help explanation: 1) as triggers 2) as cues to knowledge 3) as constituents
of complex representations. None of these is that interesting; i.e., none
addresses the fact that representations of cows tell you something about cows!
' Since representations just trigger
knowledge (ITT-internal tacit theories) it is theories doing all the work, but
1) theories as sentences have computationally relevant structure that
semantically irrelevant and 2) no one thinks complex mental representations are
sets of sentences. Thus whole ranges of problems will be intractable to one
system and tractable to another even though they have semantically
equivalent theories according to CT.
' From 2) CT can't accommodate context
sensitive representations (e.g. faces). Why? Only faces have independently
specifiable content so 1) no semantic complexity and 2) primitives are
infinite. Furthermore, such representations are common, even in standard
symbols systems (see map e.g. p. 73)!
' We have good reasons to be suspicious
of any theory (CT or CRS) that suggests that all representational content is
intrinsically holistic or atomistic because we should accept the 'obvious' fact
that representational schemes are both. (Descartes even showed that holistic
and atomistic representations can represent the same functions).
' Thus we need a theory that makes content
holistic in holistic schemes and atomistic in atomistic schemes.
' Question: Is C conflating content
and representational schemes? Could one be holistic and the other either holistic
or atomistic? Do the definitions apply to each? Yes.
' You could argue that the scheme of mental
representation is atomistic or holistic and all representation is parasitic on
mental representation. But this won't work because
1. You have to show that mental meaning
has to be atomistic (holistic). You could try to do this as Fodor has
using the essential feature strategy (identify some property X that all minds
must have and show that only atomistic schemes could have X). Fodor uses
systematicity and productivity (p. 80). Unfortunately one of Fodor's premises
is false (because of cartesian representations). But this doesn't generalize
and C says he can't make it do so. But, he considers another argument (p. 81).
This also turns on a false premise (that acquiring new beliefs changes meaning --
but not by fCRS). (It seems that, in fact, changing representational power
doesn't come through learning but maturation or trauma.) C. claims this is a
pattern: any arg that a crucial feature requires atomism will undermine the
claim that it is essential.
2. It seems to be contingent even if
true what the structure of our mental schemes is. If it's contingent, a theory
of representational content should leave it an open question but CRS and CT don't.
Thus need a representational theory that avoids this consequence' see next
week.