KEYWORDS: behaviorism, Chinese Room Argument, cognition, consciousness, finite automata, free will, functionalism, introspection, mind, story generation, Turing machines, Turing Test.
2. My position accords well with the decline of behaviorism, and specifically the apparent decline of the behavioristic Turing Test (see Rey, 1986) and any number of the Turing-like Tests proposed in the literature [NOTE #1]. Readers familiar only with Turing's original test (Turing, 1964), and not with the variations that have been derived from it, should imagine now an ever more stringent sequence of Turing-like tests T1, T2, T3,..., the first member of which is the original imitation game. How does the sequence arise? In T2 we might allow the judge to observe the physical appearance of the contestants; in T3 we might allow the judge to make requests concerning the sensorimotor behavior of the contestants; in T4 we might allow the judge to take skin samples; in T5 we might allow the judge to run brain scans, then surgical probing, and so on. The point is that we can pretty much rest assured that AI will gradually climb up the sequence; that soon we'll have T.75, eventually T1 (though probably not by 2000 as Turing had predicted), etc. I hold that robots will pass, if not all, then at least a goodly number of tests in the Turing Test sequence, but they will always lack some of the properties claimed, in "What Robots Can and Can't Be" (henceforth, ROBOTS), to be necessary for personhood. I defend this position with precise deductive arguments which (in my opinion) sometimes border on proofs.
4. Let us call the AI/Cog-Sci project to build a person the "Person Building Project." PBP will denote the proposition that the Person Building Project will succeed. This project has flesh-and-blood proponents, optimistic ones. For example, according to Charniak and McDermott (1985, p. 7), "The ultimate goal of AI research (which we are very far from achieving) is to build a person, or more humbly, an animal." Some of the arguments in ROBOTS, if sound, could, with minor modification, refute Charniak and McDermott's thesis that AI can succeed in building a sophisticated animal. But what I wish to attack directly is the heart of the Person Building Project: the proposition that persons are automata.
5. Here, in a nutshell, is why I think the Person Building Project will fail. (The symbol -> stands for material implication; ~ stands for truth-functional negation):
(1) PBP -> Persons are automata. (2) ~ Persons are automata. Therefore: (3) ~ PBP.6. This is a formally valid argument: simple modus tollens. Premise (2) is repeatedly established in ROBOTS through instantiations of a simple schema, viz,
(4) Persons have F. (5) Automata can't have F. Therefore: (6) Persons can't be automata.In the book, F stands for such things as free will, the ability to infallibly introspect (over a narrow range of properties), an inner "what it's like to be" experience, etc.
7. Why is (1) true? Those engaged in the Person Building Project are committed to certain well-defined algorithmic techniques which, though hard to enumerate precisely, are used when you construct and program a high-speed computer with sensors and effectors. If someone managed to build a person by stirring up some fertile biological soup in the right way, or by somehow compressing all of evolution into a second of development that could be magically applied to a single-cell creature, this would not spell success for the person builders I have in mind. To affirm PBP is to hold that certain computer techniques will produce people. Nor is the idea that by using these techniques you'll get lucky and bring a person into existence through a side-effect of what you've done. There are those whose ultimate aim is this side-effect -- thinkers who hope to build a computational device whose structure is appropriate for "ensoulment," a device alongside which a person, an immaterial entity, will pop into existence and connect up with the device in some way (e.g., see Turkle, 1984). These thinkers aren't my concern herein. I'm concerned with those who think AI techniques are near the essence of personhood, or mindedness (or mentality, mentation, cognition) itself.
8. For such cognitive engineers, the success of their techniques won't show that people are, essentially and in general, the particular computers they are working on. If a team of cognitive engineers succeeded beyond their wildest dreams and happened to do so by programming a Cray 4, they would not be entitled to hold that persons are Cray 4s. There is no reason to think that the specific physical material (the particular computer and peripheral components) constituting the robots produced by the Person Building Project will be essential. Human persons happen to be made of flesh, not silicon; AI (unlike, say, neurophysiology) does not work with flesh. So behind PBP is "AI-Functionalism," according to which people are idealized computers. This intuition is, as Haugeland (1986) has suggested, captured elegantly by "Persons are automata," or at least by something very close to it.
11. Cole summarizes his argument as follows:
I suppose that many like myself who believe that persons are automata suppose this because we see that neurons appear to be finite probabilistic automata, that is to say they have computable transfer functions. From there we note that brains are composed merely of neurons (neural nets), along with some supporting structures, glial cells, etc., and that brains produce mentality. (ROBOTS, P. 126)12. I show that this argument, tempting though it is, is ultimately untenable. If one assumes agent materialism and jumps beyond what we know to be the case (that brains, with supporting structures, produce mentality), to what many suspect is the case (that brains, with supporting structures, are persons), then Cole's argument does work -- but such a strategy would need independent defense (Pollock 1989).
13. Overall, Cole seems to vote "yes" on all six components of the Contemporary Cognitive Sextet:
(C1) Token Physicalism, (C2) Agent Materialism, (C3) Functionalism, (C4) Persons are Automata, (C5) Person Building will succeed, (C6) Robot Building will succeed.My own vote on each, supported by the arguments in the book, would be:
(C1) Maybe (C2) Maybe (C3) No (C4) No (C5) No (C6) Yes
17. It should be obvious how Jonah gives rise to a Chinese Room-like situation. Suppose it's 2040, and that person-builders have produced robots which they herald as persons. Since one of the hallmarks of persons is that they can converse in and understand natural languages, the person-builders will claim that their robots can do the same. If these robots converse in and understand some natural language L, it should be a trivial matter to get them to speak and understand Chinese. So, here we are in 2040: some no doubt super-long computer program P enables robots to speak and understand Chinese. And here is how Jonah enters the picture. We simply give him P, ask him to reduce P to a Register program P', and then ask him to run P' on his visualized Register machines in such a way that input we give him on index cards (strings in Chinese) goes into register R0; and the output, after processing, comes back into R0, whereupon Jonah spits back this output, writing it down for us on an index card. Jonah does not himself speak a word of Chinese.
18. The argument then runs as follows. It appears that Person-Building AI/Cog Sci is committed to
(7) If the Person Building Project will succeed, then there is a computer program P such that when P runs on a computer M there is a person s associated with M who understands Chinese.And
(8) If there is a computer program P such that when P runs on a computer M there is a person s associated with M who understands Chinese, then if Jonah reduces P to P' and runs P' Jonah understands Chinese.But
(9) It's not the case that if Jonah runs P' Jonah understands Chinese.19. Hence, by hypothetical syllogism and modus tollens it follows from these three propositions that the Person Building Project won't succeed. Proposition (9) is not to be viewed as a premise, but rather as an intermediate conclusion following (by elementary logic) from the following three propositions.
(L*) If an agent s understands two natural languages L0 and L1, then s can (perhaps only after considerable effort that produces a long-winded translation) translate between L0 and L1. (10) Jonah (by hypothesis) understands English. (11) Jonah CAN'T translate between English and Chinese.20. Three objections to Searlean arguments appear to be the most up-to- date and promising, one from Churchland & Churchland (1990; cf. Searle 1990), and two rather more subtle ones, one from Cole, and one from Rapaport (personal communication). I rebut all three.
If the Person Building Project will succeed, then AI- Functionalism is true.Now, assume that person-builders will manage to build robotic persons. By modus ponens, then, we of course have AI-Functionalism, the "flow chart" version (Dennett, 1978) of which is
(AI-F) For every two "brains" x and y, possibly constituted by radically different physical stuff, if the overall flow of information in x and y, represented as a pair of flow charts (or a pair of Turing machines, or a pair of Turing machine diagrams,...), is the same, then if "associated" with x there is an agent s in mental state S, there is an agent s' associated with or constituted by y which is also in S.22. Now let 'B' denote the brain of some person s and let s be in the mental state FEARING PURPLE UNICORNS. Now imagine that a Turing machine M, representing exactly the same flow chart as that which governs B, is built out of 4 billion Norwegians all working on railroad tracks in boxcars with chalk and erasers (etc.) across the state of Texas. From this hypothesis and (AI-F), it follows that there is some agent m constituted by M which also fears purple unicorns. But it seems intuitively obvious that
There is no agent m constituted by M that fears purple unicorns.We've reached a contradiction. Hence our original assumption, that the Person Building Project will succeed, is wrong. I consider and rebut the best objections I know of to this reasoning.
24. The book ends with two arguments without precedent in the literature, one concerning free will and the other concerning introspection.
(12) If determinism, the view that all events are causally necessitated, is true, then no one ever has power over any state of affairs. (13) If indeterminism, the view that determinism is false, is true, then, unless people enjoy iterative agent causation, no one ever has power over any state of affairs. (14) Either determinism or indeterminism is true (a tautology). Therefore: (15) Unless iterative agent causation is true, no one ever has power over any state of affairs. [from (12)-(14)] (16) If no one ever has power over any state of affairs, then no one is ever morally responsible for anything that happens. (17) Someone is morally responsible for something that happens. Therefore: (18) It's not the case that no one ever has power over any state of affairs. [from (16), (17)] Therefore: (19) Iterative agent causation is true. [from (18), (15)] (20) If iterative agent causation is true, then people aren't automata. Therefore: (21) People aren't automata. [from (8), (9)]The chapter includes a defense of all the premises in this argument.
(22) If there is some significant mental property that persons have, these robots must also have this property; (23) The objects of these robots' "beliefs" (hopes, fears, etc.) -- the objects of their propositional attitudes -- are represented by formulas of some symbol system, and these formulas will be present in these robots' knowledge bases; (24) These robots will be physical instantiations of automata (the physical substrate of which will be something like current silicon hardware, but may be something as extravagant as optically based parallel hardware).27. It follows from the doctrine of hyper-weak incorrigibilism and (22) that the powerful robot (call it 'r') eventually to be produced by Strong AI/Cog Sci will be able to introspect infallibly with respect to a certain privileged set of mental properties C'. That is, it follows that the relevant instantiation of hyper-weak incorrigibilism is the case, viz,
(25) For every property F, if it's a member of C', then it is necessarily true that: if r believes r has F, r does indeed have F.But now in light of (23) it follows that (25) implies that
(26) For every property F, if it is a member of C', then, necessarily: if the formula corresponding to r's belief that r has F is an element of r's knowledge base, then r does indeed have F.28. Let's suppose, then, that we have in the picture, along with our robot r, a certain particular property from C', say the property SEEMING TO BE IN PAIN, a property we'll designate 'F*'. It follows that
(27) It is logically necessary that: if the formula corresponding to r's belief that r has F* is in r's knowledge base, then r does indeed have F*.29. Now, having arrived at this point, let's turn to a simple and well- known fact about hardware (ANY hardware), namely, that it is physically possible (that is, not contrary to the laws of physics) that hardware fails. Accordingly, it is physically possible that the substrate of r fails, and since, in turn, it is physically possible that this failure is the cause of the fact that the formula in question (the formula corresponding to r's belief that r has F*) is in r's knowledge base:
(28) It is logically possible that the formula in question is in r's knowledge base while r does NOT have F*.30. But (27) and (28), by an elementary law of modal logic (in a word: if it's logically necessary that if P then Q, then it's not logically possible that P while not-Q) form a contradiction. Hence, by indirect proof, our original assumption, that symbolicist Person Building will succeed, is wrong. I go on to consider and refute a number of objections to this line of reasoning, including one that is likely to come from connectionists.
2 For a fascinating account of a real-life idiot savant reminiscent of Jonah, see the case of Christopher, in Blakelee (1991).
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