Abstract

In the movie, Memento, the hero, Leonard, suffers from a form of anterograde amnesia that results in an inability to lay down new memories. Nonetheless, he sets out on a quest to find his wife’s killer, aided by the use of notes, annotated polaroids, and body tattoos. Using these resources he attempts to build up a stock of new beliefs and to thus piece together the puzzle of his wife’s death. At one point in the movie, a character exasperated by Leonard’s lack of biological recall, shouts: “YOU know? What do YOU know. YOU don’t know anything. In 10 minutes time YOU won’t even know you had this conversation” Leonard, however, believes that he does, day by day, come to know new things. But only courtesy of those photos, tattoos, tricks and ploys. Who is right?These are the kinds of question addressed at length in the paper ‘The Extended Mind’. Is the mind contained in the head? Or does the notion of thought allow mental processes to inhere in extended systems of body, brain and aspects of the local environment? The answer, we claimed, was that mental states, including states of believing, could be grounded in physical traces that remained firmly outside the head. As long as a few simple conditions were met, Leonard’s notes and tattoos could indeed count as new additions to his store of long-term knowledge and dispositional belief. In the present treatment I revisit this argument, defending our strong conclusion against a variety of subsequent observations and objections. In particular, I look at objections that rely on a contrast between the intrinsic content of neural symbols and the merely derived content of external inscriptions, at objections concerning the demarcation of scientific domains via natural kinds, and at objections concerning the ultimate locus of agentive control and the nature of perception versus introspection. I also mention a possible alternative interpretation of the argument as a reductio of the very idea of the mind as an object of scientific study. This is an interesting proposal.