Below is my development of Paul Churchalnd’s development of Wilifred Sellars’ account of introspection. I used to call it “Churchlandish” until David Rosenthal suggested “Churchlandik”. For a longer version see my 2006 paper The Introspectability of Brain States as Such. In Brian Keeley, (ed.) Paul M. Churchland: Contemporary Philosophy in Focus. Cambridge: Cambridge University Press.
The Churchlandik account of introspection depends on a particular view of perception and an analogy between perception and introspection. The view of perception at play here is that â€œperception consists in the conceptual exploitation of the natural information contained in our sensations or sensory states.â€ (Churchland 1979, Scientific Realism and the Plasticity of Mind, p. 7). Analogously then, introspection is the conceptual exploitation of natural information that our sensations or sensory states contain about themselves. Fleshing out these views of perception and introspection requires us to flesh out what Churchland thinks the conceptual exploitation of natural information is. Crucial here is a distinction Churchland draws between two kinds intentionality that sensations can have, that is, two ways in which a sensation can be a sensation of something. A sensation can have â€œobjective intentionalityâ€ as well as â€œsubjective intentionalityâ€ or, in other words, a sensation can be a sensation of X in an objective sense and in a subjective sense. Adapting Churchland’s formulations (from ibid, p. 14) yeilds:
A given (kind of) sensation one has is a sensation of X (in the objective sense of “of”) if and only if under normal conditions, sensations of that kind occur in one only if something one’s perceptual environment is indeed X.
A given (kind of) sensation one has is a sensation of X (in the subjective sense of “of”) if and only if under normal conditions, one’s characteristic non-inferential response to any sensation of that kind is some judgment to the effect that something or other is X.
The objective intentionality of sensations is the information that sensations actually carry about the environment regardless of whether or not we exploit that information. The objective intentionality of sensations determines what it is that we are capable of perceiving. What we actually do perceive depends on subjective intentionality. That is, what we actually do perceive depends on what concepts we bring to bear in the judgments that our sensations non-inferentially elicit. So, for example, whether I am capable of seeing the tiny insect on the far side of the room depends on whether I have states of my visual system that reliably co-vary with the presence of that object, and if my eyesight is insufficiently acute, I will lack such states. Whether I actually do perceive that object depends on more than just good eyesight. It depends on whether I actually do employ my conceptual resources to interpret my visual sensations as indicating the presence of an insect.
The crucial aspects of this account of perception are those that allow for the reconstruction of the distinction between what is perceived without inference and what is inferred but not perceived.
Let us consider the following situation to illustrate this distinction. Two friends, George and John, are lunching in a well lighted location when, as part of some publicity stunt, a man in a realistic gorilla suit runs through the area. Suppose that both gorilla suit and gorilla act are quite realistic and convincing to the untrained eye. George, being a special effects expert for the film industry, is not fooled and can see quite clearly that this is indeed a man in a costume. John, however, is a novice and cannot help but be fooled: he sees this as a genuine gorilla, perhaps escaped from the nearby zoo. In fact, John the novice continues to see this individual as a genuine gorilla even after George the expert assures him that it is in fact a suited man. John may even come to believe Georgeâ€™s testimony for he trusts Georgeâ€™s expertise, but John cannot shake the impression that it is a real gorilla that is causing a ruckus in the restaurant.
There is a sense in which both John and George see the same thing. But only George sees that thing as a man in a suit. They both know that it is a man in a suit. However, in spite of his knowledge, John is incapable of seeing it as a man in a suit. John and George both have visual sensations with the same objective intentionality. They both have states of their visual system that causally co-vary with, for example, the distinctive way that a man in a gorilla suit moves. But only George is able to automatically (without an intervening inference) apply the concept of a man in a gorilla suit to the thing causing his current visual sensation and thus only Georgeâ€™s sensations have the subjective intentionality indicating the presence of a man in a gorilla suit. Unlike George, John is incapable of automatically (without an intervening inference) applying the concept of a man in a gorilla suit to the thing causing his current visual sensation, and thus Johnâ€™s sensations lack the subjective intentionality indicating the presence of a man in a gorilla suit.
The appropriate analogy, then, to introspection would be the following. If a person knew that their mental states were identical to brain states, but was incapable of automatically applying the concept a brain state to a mental state, then in spite of their knowledge they would be incapable of introspecting their brain states as brain states. In contrast, if they were able to automatically apply the concept of a brain state to their brain states then they would be introspecting their brain states as such: their brain states would seem like brain states to them.