Causal Theories of Intentionality

Asymmetric Dependence

In the human case, mental representations most likely take physical form in the neural system, and of course, these neural structures participate in the natural order of causes and effects. This suggests a straightforward causal account of intentional content: A mental representation is about whatever causes its activation (where activation might amount to increased rates of neural firings). For instance, when one sees a cow, this activates the collection of neurons heightened firing of which constitutes the activation of a mental representation—the representation of cows.

We should, however, want to identify a persisting representation of cows, one that can be activated in a variety of contexts, on each occasion serving as a vehicle for the subject's thoughts about cows. This desideratum introduces a complication. We should want standing representations partly because humans [Page 141]often think about cows in the absence of cows—that is, even when a cow has not, on the occasion of the subject's thought, directly caused the activation of any of his or her mental representations. This is especially clear in cases of misrepresentation, in which something other than a cow—say, a horse in the fog—causes a subject to think about cows, because, as we would normally put it, the person has mistaken the horse for a cow. Thus, we require a more discerning causal theory, one that does not simply identify the intentional content of a mental representation with whatever causes its activation. For the simple theory does not seem to allow for misrepresentation; rather, it entails that any cause of the activation of a given mental representation is correctly characterized by the intentional content of that representation.

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