I propose to consider the question, "Can machines think?" This should begin with definitions of the meaning of the terms "machine" and "think." The definitions might be framed so as to reflect so far as possible the normal use of the words, but this attitude is dangerous, If the meaning of the words "machine" and "think" are to be found by examining how they are commonly used it is difficult to escape the conclusion that the meaning and the answer to (...) the question, "Can machines think?" is to be sought in a statistical survey such as a Gallup poll. But this is absurd. Instead of attempting such a definition I shall replace the question by another, which is closely related to it and is expressed in relatively unambiguous words. The new form of the problem can be described in terms of a game which we call the 'imitation game." It is played with three people, a man (A), a woman (B), and an interrogator (C) who may be of either sex. The interrogator stays in a room apart front the other two. The object of the game for the interrogator is to determine which of the other two is the man and which is the woman. He knows them by labels X and Y, and at the end of the game he says either "X is A and Y is B" or "X is B and Y is A." The interrogator is allowed to put questions to A and B. We now ask the question, "What will happen when a machine takes the part of A in this game?" Will the interrogator decide wrongly as often when the game is played like this as he does when the game is played between a man and a woman? These questions replace our original, "Can machines think?". (shrink)

Where does the mind stop and the rest of the world begin? The question invites two standard replies. Some accept the demarcations of skin and skull, and say that what is outside the body is outside the mind. Others are impressed by arguments suggesting that the meaning of our words "just ain't in the head", and hold that this externalism about meaning carries over into an externalism about mind. We propose to pursue a third position. We advocate a very different (...) sort of externalism: an _active externalism_, based on the active role of the environment in driving cognitive processes. (shrink)

Adams and Aizawa, in a series of recent and forthcoming papers ((2001), (In Press), (This Volume)) seek to refute, or perhaps merely to terminally embarrass, the friends of the extended mind. One such paper begins with the following illustration: "Question: Why did the pencil think that 2+2=4? Clark's Answer: Because it was coupled to the mathematician" Adams and Aizawa (this volume) ms p.1 "That" the authors continue "about sums up what is wrong with Clark's extended mind hypothesis". The example of (...) the pencil, they suggest, is just an especially egregious version of a fallacy said to pervade the literature on the extended mind. This fallacy, which they usefully dub the "coupling-constitution fallacy", is attributed , in varying degrees and manners, to Van Gelder and Port (1995), Clark and Chalmers (1998), Haugeland (1998), Dennett (2000), Clark (2001), Gibbs (2001), and Wilson (2004). The fallacy, of course, is to move from the causal coupling of some object or process to some cognitive agent, to the conclusion that the object or process is part of the cognitive agent , or part of the agent's cognitive processing (see e.g. Adams and Aizawa (This volume) ms p.2). Proponents of the extended mind and related theses, Adams and Aizawa repeatedly assert, are prone to this fallacy in part because they either ignore or fail to properly appreciate the importance of " the mark of the cognitive" viz the importance of an account of "what makes something a cognitive agent" (op cit ms p.3). The positive part of Adams and Aizawa's critique then emerges as a combination of the assertion that this "mark of the cognitive" involves the idea that "cognition is constituted by certain sorts of causal process that involve non-derived contents" (e.g. op cit ms p.3) and that these processes look to be characterized by psychological laws that turn out to apply to many internal goings-on but not currently (as a matter of contingent empirical fact) to any processes that take place in non-biological tools and artifacts. In what follows, I shall try to show why these arguments display nothing so much as mutual failures of communication: crossed wires concealing a couple of real, important, but much more subterranean, disagreements. In particular, I try to show why the negative considerations advanced by Adams and Aizawa fail to successfully undermine the argument for the extended mind, and why their more radical positive story, unless supplemented by implausible additional claims, fails to cast doubt on the claim that minds like ours can (without the need for any radically new techniques, technologies or interventions) extend into the world. (shrink)