Meaning and Mental Representation Chapter 4

General intro to problems confronting covariance theories:
(L1) x represents y in LOCKE = x is a punch pattern that occurs in a percept when, only when, and because LOCKE is confronted by y (whiteness, a cat, whatever)
Positive aspect of this theory: proposes that the things that mediate cat recognition in the system must be the cat representations.
Another positive aspect of this theory: Does away with resemblance as the ground of represenation, and solves the problem of abstraction (nothing can resemble all and only the blue things, but something can be the regular and natural effect of blue on the system, and hence occur in the system's percepts when and only when blue is present to it).
The fundamental difficulty facing Lockean theories is to explain how misrepresentation is possible; for suppose LOCKE is confronted by a cat but generates a dog percept D- then it is not true that D occurs in a percept when, only when, and because a dog is present, since no dog is present and the current percept has feature D.
The covariance theory strategy for dealing with the problem of misrepresentation is via idealization- either idealizing away from malfunctions, or idealizing away from suboptimal conditions of perceptual recognition.
General problem for idealization solutions: The idea that one can idealize away from cognitive error is incompatible with a fundamental finding of CTC- error is essential to a well-designed cognitive system with finite resources, because in order to succeed it must take short cuts. [I like this quote- "Epistemology for God and epistemology for us are two different things. God never had to worry about recognizing tigers in time to evade them]
Specific problems for idealization solutions:
(L2) [idealizing away from malfunction] x represents y in LOCKE = were LOCKE functioning properly, punch pattern x would occur in a percept when, only when, and because LOCKE is confronted by y.
Problem: The most obvious/everyday cases of perceptual misrepresentation- illusions- are not cases of malfunctions, but cases of proper functioning in abnormal circumstances.
(L3) [idealizing away from suboptimal conditions of perceptual recognition] x represents y in LOCKE = were LOCKE functioning properly and circumstances ideal, x would occur in a percept when, only when, and because LOCKE is confronted by y. [the basic idea here is that something is a representation of a cat in virtue of having some feature that is, in percepts, an effect of cat presence and not of anything else]
Problem: Any specification of ideal circumstances will lead us in a circle. For according to this theory, we're going to have covariance only when the epistemological conditions (e.g. ideal circumstances) are right. And specifying those conditions will already presuppose content assignments to states of the cognitive system, because in order for the system to "get it right", it means that it has representations with the right content. So, to avoid being circular, Lockeans must specify ideal conditions in a way that does not presuppose content assignments to states of the cognitive system.
[At this point in the chapter, Cummins starts getting into possible strategies for the Lockean, involving inexplicit content, and I don't really understand it. I think further reading would be required to really get the inexplicit content stuff. However, I think that the main gist of the chapter can be captured without getting into that stuff, because Cummins concludes the chapter by reiterating what I have called the general problem for idealization solutions, and the specific problem for idealizing away from suboptimal conditions of perceptual recognition.]