From chalmers@paradox.soc-sci.arizona.edu Wed Sep 8 13:20:52 1999 Return-Path: Received: from Arizona.EDU (Penny.Telcom.arizona.edu [128.196.128.217]) by paradox.soc-sci.arizona.edu (8.9.3/8.9.3) with ESMTP id NAA06773 for ; Wed, 8 Sep 1999 13:20:52 -0700 Received: from DIRECTORY-DAEMON by Telcom.Arizona.EDU (PMDF V5.1-12 #24137) id <01JFQ9CC7OYOB8TCN4@Telcom.Arizona.EDU> for chalmers@paradox.soc-sci.arizona.edu; Wed, 8 Sep 1999 13:20:55 MST Received: from paradox.soc-sci.arizona.edu by Telcom.Arizona.EDU (PMDF V5.1-12 #24137) with ESMTP id <01JFQ9CAO2M8B8T9S4@Telcom.Arizona.EDU> for chalmers@Arizona.EDU; Wed, 08 Sep 1999 13:20:53 -0700 (MST) Received: (from chalmers@localhost) by paradox.soc-sci.arizona.edu (8.9.3/8.9.3) id NAA06767 for scicon; Wed, 08 Sep 1999 13:20:47 -0700 Date: Wed, 08 Sep 1999 13:20:47 -0700 From: David Chalmers Subject: Qualia and Knowledge (from Matt) To: scicon@paradox.soc-sci.arizona.edu Message-id: <199909082020.NAA06767@paradox.soc-sci.arizona.edu> MIME-version: 1.0 Content-type: TEXT/PLAIN; CHARSET=US-ASCII Status: R >From landsurveyor@hotmail.com Wed Sep 8 10:27:34 1999 Date: Wed, 08 Sep 1999 10:25:43 -0700 (PDT) From: Matt Herbert Subject: Qualia and Knowledge To: chalmers@u.arizona.edu X-Originating-IP: [128.196.23.108] Dave, Sorry to bother you again, but I can't get this sent to the listserv. I copied the address from your homepage; not sure what the problem is. Feel free to post to listserv if possible. Thanks Matt Jackson's distinction between the physical facts about sensing and the sensory experience itself is similar in some important ways to Russell's distinction between knowledge by description and knowledge by acquaintance. (In turn, Russell and other philosophers probably owe a debt to Aristotle for suggesting this distinction in _Posterior Analytics_, but I'm happy to let the scholars handle that issue.) I'm not sure if Russell's analysis will comfort the qualia freaks or the reductionists, but it will be worth a look. First some background is in order (Cf _The Problems of Philosophy_, chapts. 4,5). Russell is out to give an exhaustive taxonomy of knowledge, and his first cut is between knowledge of facts and knowledge of things. This distinction expresses the difference betweeen knolwedge that p and familiarity with x. The acquaintance/description distinction is a refinement of the familiarity-with-x concept. I won't attempt to improve on Russell's clarity regarding this distinction: "In the preceding chapter we saw that there are two sorts of knowledge: knowledge of things, and knowledge of truths. In this chapter we shall be concerned exclusively with knowledge of things, of which in turn we shall have to distinguish two kinds. Knowledge of things, when it is of the kind we call knowledge by _acquaintance_, is essentially simpler than any knowledge of truths, and is logically independent of knowledge of truths, though it would be rash to assume that human beings ever, in fact, have acquaintance with things without at the same time knowing some truth about them. Knowledge of things by _description_, on the contrary, always involves . . . some knowledge of truths as its source and ground" (p. 46). It may be helpful to think of Mary as lacking acquaintance with a certain quale (say, redness), despite having maximal descriptive knowledge of it. Russell's characterization of acquaintance as logically independent of description matches up with this intuition: one may possess all the descriptions of x and yet not be able to infer what the experience of x is like. It seems that both Russell and Jackson are making an implicit appeal to the operation of distinct faculties. There are inference modules, whose input can only be facts and whose output can only provide furhter, extrinsic facts about x's (how they relate to y's, what they do under condition c, etc.), and there are sensory modules, whose input is experience of x and whose output, strictly speaking, is non-propositional, intrinsic information about x's which nonetheless can give rise to propositions to be fed into the inference module. A faculty of description and a faculty of acquaintance, if you will. I apologize for not drawing a moral from these bits; it's only a clarifying illustration. I might as well admit my allegiance, however. I think there are good arguments and intuitions in favor of the Russell/Jackson view about qualia. The arguments (that I know) are epistemological and have to do with the need to anchor propositional knowledge in non-propositional experience; the intuitions are those of first-person phenomenology that Dave alludes to in _The Conscious Mind_. Matt Herbert 8 Sep 99 ______________________________________________________ Get Your Private, Free Email at http://www.hotmail.com From chalmers@paradox.soc-sci.arizona.edu Wed Sep 8 13:22:34 1999 Return-Path: Received: from Arizona.EDU (Penny.Telcom.arizona.edu [128.196.128.217]) by paradox.soc-sci.arizona.edu (8.9.3/8.9.3) with ESMTP id NAA06785 for ; Wed, 8 Sep 1999 13:22:33 -0700 Received: from DIRECTORY-DAEMON by Telcom.Arizona.EDU (PMDF V5.1-12 #24137) id <01JFQ9EFPXXCB8T0WF@Telcom.Arizona.EDU> for chalmers@paradox.soc-sci.arizona.edu; Wed, 8 Sep 1999 13:22:36 MST Received: from paradox.soc-sci.arizona.edu by Telcom.Arizona.EDU (PMDF V5.1-12 #24137) with ESMTP id <01JFQ9EEQKK0B8TJGY@Telcom.Arizona.EDU> for chalmers@Arizona.EDU; Wed, 08 Sep 1999 13:22:35 -0700 (MST) Received: (from chalmers@localhost) by paradox.soc-sci.arizona.edu (8.9.3/8.9.3) id NAA06779 for scicon; Wed, 08 Sep 1999 13:22:28 -0700 Date: Wed, 08 Sep 1999 13:22:28 -0700 From: David Chalmers Subject: Epiphenomenalism (from Juraj) To: scicon@paradox.soc-sci.arizona.edu Message-id: <199909082022.NAA06779@paradox.soc-sci.arizona.edu> MIME-version: 1.0 Content-type: TEXT/PLAIN; CHARSET=US-ASCII Status: R >From jurosan@usa.net Wed Sep 8 11:35:48 1999 Date: Wed, 08 Sep 1999 20:36:11 +0100 (MET) From: JURAJ HVORECKY Subject: Epiphenomenalism To: David Chalmers X-MIME-Autoconverted: from quoted-printable to 8bit by paradox.soc-sci.arizona.edu id LAA06549 Ok, we have been talking a lot about Jacskon yesterday, but we didn't really touch the issue of epiphenomenalism. And ther are couple this I want to know about it. First, I pretty much understand the statement that qualia are epiphenomenal. I suppose my intentional zombie twin riding her car would stop on the red color the very same way I would. And maybe that is what we do - we stop because we process the information about the light and then the thing is somehow ACCOMPANIED by an experience. So ther is a slight intuition about it. But epiphenomenalism (E) seems to come in two forms - (E) of mental states and (E) of qualia. Now I do not know much about the first one, but I trust Fodor in his Making minds matter more that is is compatible with physicalism to say the mental events produces causes on the physical. What I am more interested into is how (E) of qualia is possible. There are two ways to procede - qualia are inefficacious on the physical and qualia and inefficacious on the mental. It seems like Jackson is switching between the two views. Can qualia be absolutely inefficacious, that is can they have no influence on mental? Well, if that is the case, then they would not be stored in the memory, they would be just passing by. But then the knowldge argument does not work, because they would be NEW at every single moment. In fact, how would one even talk about knowledge, if there is no connection between a quale and the mental event (knowing of x)? But if they are not epiphenomal toward other mental states, they might as well have role in a causal chain toward a physical. If I take for granted that my experiencing of a red light does not cause me to stop (via zombie example), then it still might have a role of comparision this particular red mental image with those previously stored and therefore possibly influence my next zombie-like stop at the redlight. To put it in a different way, my qualia might not influence my physical behavior at the moment they are experienced, but leave their guiding trace for later unconscious processing. So I am quite unsure where exactly (E) comes into the picture. Juraj ____________________________________________________________________ Get free email and a permanent address at http://www.netaddress.com/?N=1 From chalmers@paradox.soc-sci.arizona.edu Wed Sep 8 18:24:43 1999 Return-Path: Received: from Arizona.EDU (Penny.Telcom.arizona.edu [128.196.128.217]) by paradox.soc-sci.arizona.edu (8.9.3/8.9.3) with ESMTP id SAA07459 for ; Wed, 8 Sep 1999 18:24:43 -0700 Received: from DIRECTORY-DAEMON by Telcom.Arizona.EDU (PMDF V5.1-12 #24137) id <01JFQJY22KQ8B8T6JL@Telcom.Arizona.EDU> for chalmers@paradox.soc-sci.arizona.edu; Wed, 8 Sep 1999 18:24:45 MST Received: from paradox.soc-sci.arizona.edu by Telcom.Arizona.EDU (PMDF V5.1-12 #24137) with ESMTP id <01JFQJY0QKJKB8T8Y8@Telcom.Arizona.EDU> for chalmers@Arizona.EDU; Wed, 08 Sep 1999 18:24:44 -0700 (MST) Received: (from chalmers@localhost) by paradox.soc-sci.arizona.edu (8.9.3/8.9.3) id SAA07453 for scicon; Wed, 08 Sep 1999 18:24:38 -0700 Date: Wed, 08 Sep 1999 18:24:38 -0700 From: David Chalmers Subject: Re: Qualia and Knowledge To: scicon@paradox.soc-sci.arizona.edu Message-id: <199909090124.SAA07453@paradox.soc-sci.arizona.edu> MIME-version: 1.0 Content-type: TEXT/PLAIN; CHARSET=US-ASCII Status: R On Matt's comments re qualia and knowledge: I think it is right that the difference between knowledge of qualia and knowledge of the external world is closely related to Russell's distinction between knowledge by acquaintance and knowledge by description. Certainly Russell believed that the only true cases of knowledge by acquaintance are cases of direct knowledge of phenomenal states, and he believed that knowledge of the external world was knowlwedge by description. A lot of contemporary philsoophers have disagreed with him about this (e.g. holding that we have perceptual knowledge by acquaintance with external objects), but my own view is that there is something right about his view. It's certainly true that a "qualia freak" has to pay special attention to the first-person epistemology of qualia, which may well end up being different in interesting ways from the epistemology of the external world. For example, there may be something special to say about the justification of our beliefs about qualia. My own view is that justification of our beliefs in qualia stems at least in part from our acquaintance with the qualia themselves, in a way that doesn't apply to knowledge of external knowledge. Unlike Russell, I'm not sure that I'd call acquaintance a form of knowledge, though; I'd prefer to reserve the latter term for knowledge of truths. Of course like Russell I think that we also have knowledge of truths about qualia that is in some ways grounded in acquaintance. I talk about this a bit in Chapter 5 of my book, and Tim Bayne has an interesting paper taking issue with some aspects of the view coming out in Philosophy and Phenomenological Research. I've been working on a more developed view in the vicinity of this in a paper called "The Content and Epistemology of Phenomenal Belief", whic is online in outline form at http://ling.ucsc.edu/~chalmers/papers/belief.html I'll probably also give a colloquium in the philosophy dept on this topic in the spring. I don't think Jackson needs to assume these somewhat controversial views about acquaintance in order for his argument to go through. He needn't make any such theoretical claims about acquaintance, modules, etc, in order to make it plausible that Mary gains new knowledge. Nevertheless, one might well argue that the special character of knowledge of qualia that his thought-experiment exploits stems from the special underlying epistemology. --Dave. From chalmers@paradox.soc-sci.arizona.edu Wed Sep 8 18:29:12 1999 Return-Path: Received: from Arizona.EDU (Penny.Telcom.arizona.edu [128.196.128.217]) by paradox.soc-sci.arizona.edu (8.9.3/8.9.3) with ESMTP id SAA07468 for ; Wed, 8 Sep 1999 18:29:11 -0700 Received: from DIRECTORY-DAEMON by Telcom.Arizona.EDU (PMDF V5.1-12 #24137) id <01JFQK4LDRB4B8T2C6@Telcom.Arizona.EDU> for chalmers@paradox.soc-sci.arizona.edu; Wed, 8 Sep 1999 18:29:15 MST Received: from paradox.soc-sci.arizona.edu by Telcom.Arizona.EDU (PMDF V5.1-12 #24137) with ESMTP id <01JFQK4K81XCB8T6LD@Telcom.Arizona.EDU> for chalmers@Arizona.EDU; Wed, 08 Sep 1999 18:29:13 -0700 (MST) Received: (from chalmers@localhost) by paradox.soc-sci.arizona.edu (8.9.3/8.9.3) id SAA07463 for scicon; Wed, 08 Sep 1999 18:29:07 -0700 Date: Wed, 08 Sep 1999 18:29:07 -0700 From: David Chalmers Subject: Re: Epiphenomenalism To: scicon@paradox.soc-sci.arizona.edu Message-id: <199909090129.SAA07463@paradox.soc-sci.arizona.edu> MIME-version: 1.0 Content-type: TEXT/PLAIN; CHARSET=US-ASCII Status: R Juraj raises the issue of epiphenomenalism. I'd prefer not to distinguish qualia from mental states, as qualia are examples of mental states; maybe it's clearer here to distinguish qualia from intentional states such as beliefs. The question Juraj raises is then whether, according to the epiphenomenalist, qualia have causal effects on beliefs. There seem to be at least two possibilities, depending on the status of beliefs: (1) Qualia cause beliefs, but beliefs don't cause behavior. (2) Beliefs cause behavior, but qualia don't cause beliefs. (One might also hold that there is no causal connection between either pair, but I'll set that position aside.) As far as I recall, Jackson isn't explicit about the causal status of beliefs in his paper, but it's clear from elsewhere that he thinks beliefs are not epiphenomenal and that he is a materialist about beliefs. That seems to commit him to option (2). Some other epiphenomenalists might hold e.g. that beliefs themselves are essentially tied to the phenomenal and so are non-physical, and so would embrace option (1). Both of these are somewhat counterintuitive, especially when it comes to beliefs about qualia. I talk about this issue a fair bit in my book (Chapter 5 again), as I think it's the most serious problem for the epiphenomenalist. Position (2) seems to raise questions about how we could ever know about qualia, and about how we could ever remember qualia, as Juraj said. In the book I try to defend position (2), or at least to argue that it isn't fatally flawed, partly by arguing that our knowledge of qualia is grounded in our acquaintance with them rather than through any causal connection between qualia and beliefs. In effect the suggestion is that the causal theory of knowledge is inappropriate for knowledge of qualia, for reasons partly to do with those discussed above. One can say something similar about memories. On this view, one would still have the beliefs about the qualia, and the memories; it's just that they wouldn't be directly caused by the qualia. Of course the view is still somewhat counterintuitive in the way it separates our qualia and our beliefs. I now hold a slightly different view (in the paper mentioned in my reply to Matt; it's also in the book but less emphasized there) on which beliefs about qualia are partly *constituted* by qualia. In effect a quale is a component of a belief about that quale. If that's the case, the relation between qualia and beliefs about qualia is tighter than a mere causal connection; it's a constitutive connection (in effect one is "part" of the other). I think there is strong, independently motivated reasons for believing this in any case. And it gets around the problem about the disconnection between the belief and the quale. Of course it will turn out that now, on the epiphenomenalist view, beliefs (or at least beliefs about qualia) will be at least partly nonphysical too, because of the part that is grounded in qualia. Note that one needn't say that they are entirely nonphysical or epiphenomenal. It may be that beliefs are partly constituted by physical/functional states and partly by phenomenal states; if so, their phenomenal part won't have an effect on behavior, but the other part will. I guess something similar *could* apply as a way of making sense of another view Juraj mentions, on which qualia causally affect beliefs which later causally affect behavior. If the aspect of the belief that a quale affects is not the same aspect that causes behavior, then maybe these two things could be reconciled even for an epiphenomenalist. There are still some awkwardnesses about this position, and all in all I have some preference for the panprotopsychist view over the epiphenomenalist view partly because of the awkwardnesses, but I do think that epiphenomenalism can at least avoid any fatal flaws here. --Dave. From bradt@u.arizona.edu Fri Sep 10 00:01:14 1999 Return-Path: Received: from Arizona.EDU (Penny.Telcom.arizona.edu [128.196.128.217]) by paradox.soc-sci.arizona.edu (8.9.3/8.9.3) with ESMTP id AAA11625 for ; Fri, 10 Sep 1999 00:01:14 -0700 Received: from DIRECTORY-DAEMON by Telcom.Arizona.EDU (PMDF V5.1-12 #24137) id <01JFSA0NA0UOB8T2V0@Telcom.Arizona.EDU> for chalmers@paradox.soc-sci.arizona.edu; Fri, 10 Sep 1999 00:01:19 MST Received: from paradox.soc-sci.arizona.edu by Telcom.Arizona.EDU (PMDF V5.1-12 #24137) with ESMTP id <01JFSA0LSHUOB8T96J@Telcom.Arizona.EDU> for chalmers@Arizona.EDU; Fri, 10 Sep 1999 00:01:17 -0700 (MST) Received: from snipe.prod.itd.earthlink.net (snipe.prod.itd.earthlink.net [207.217.120.62]) by paradox.soc-sci.arizona.edu (8.9.3/8.9.3) with ESMTP id AAA11620 for ; Fri, 10 Sep 1999 00:01:07 -0700 Received: from mrector.shiva.com (ip232.tucson6.az.pub-ip.psi.net [38.29.66.232]) by snipe.prod.itd.earthlink.net (8.9.3/8.9.3) with SMTP id AAA04544 for ; Fri, 10 Sep 1999 00:01:11 -0700 (PDT) Date: Fri, 10 Sep 1999 00:05:01 -0700 From: Brad Thompson Subject: RE: Qualia and Knowledge In-reply-to: <199909082020.NAA06767@paradox.soc-sci.arizona.edu> To: scicon@paradox.soc-sci.arizona.edu Reply-to: bradt@u.arizona.edu Message-id: <000001befb5a$cd5e72a0$e8421d26@mrector.shiva.com> MIME-version: 1.0 X-Mailer: Microsoft Outlook 8.5, Build 4.71.2173.0 Content-type: text/plain; charset=iso-8859-1 Content-transfer-encoding: 7bit Importance: Normal X-MSMail-Priority: Normal X-MimeOLE: Produced By Microsoft MimeOLE V4.72.3110.3 X-Priority: 3 (Normal) Status: RO I think that this was an interesting remark that Matt made regarding the knowledge argument and its relationship to Russell's distinction between knowledge by acquaintance and kn. by description: > It seems that both Russell and Jackson are making an implicit > appeal to the > operation of distinct faculties. There are inference modules, > whose input > can only be facts and whose output can only provide furhter, > extrinsic facts > about x's (how they relate to y's, what they do under condition c, etc.), > and there are sensory modules, whose input is experience of x and whose > output, strictly speaking, is non-propositional, intrinsic > information about > x's which nonetheless can give rise to propositions to be fed into the > inference module. > A faculty of description and a faculty of acquaintance, if you will. I don't agree that Jackson needs to make such an appeal (though it is certainly not incompatible with his argument and it has an independent plausibility). What I find interesting about the suggestion, though, is that it really points toward one of the stronger materialist defenses against the knowledge argument. Jackson's argument requires that there can be no inference (logically or semantically speaking) from the physical facts to the phenomenal facts. But I think that the Mary thought experiment *by itself* really only demonstrates something weaker--that one cannot make an inference from the physical facts to the phenomenal facts in what one might call a "psychological sense" of inference. And the above psychological story explains why: our representations of sensory states are in a different "format" or a different module (or psychologically encapsulated in some other way) than our so-called descriptive representations of theoretical knowledge. This is essentially one of Churchland's points in the article we read. But by itself I don't think it fully succeeds against the knowledge argument, since one is still struck by the strong intuition that Mary does in fact learn a new *fact* rather than just acquire a new representation of an old fact. But once again, the above psychological story suggests a materialist solution--one of "explaining away" the apparent distinctness of the two types of facts. It's basically the same point about inferences mentioned above, except now we're not concerned with Mary's psychology but rather with our own psychology (when we are considering the thought experiment). I try to imagine being Mary in the black-and-white room , and so I activate a set of my own descriptive, theoretical representations. This doesn't put me in a state in which my sensory representations of redness are activated (since, according to the present hypothesis, these two types of representations reside in different modules or the like). I then imagine being Mary and seeing a ripe tomatoe--and this *does* activate the relevant sensory representations. This explains why it *seems* to us that Mary learns something new. It would seem that way even if Mary *didn't* learn something new. So the seeming as such can't be taken as evidence for either hypothesis. (This strategy is similar to one given by Christopher Hill in the paper that Dave mentioned before). We're left now with the question of whether or not we have good reason for thinking that our sensory concept of red is co-referential with some descriptive term in the language of neuroscience (or other science). The above materialist response to the knowledge argument doesn't answer *that* question, but it does suggest that it *could* be for all the knowledge argument shows. Brad From chalmers@paradox.soc-sci.arizona.edu Sun Sep 12 22:54:52 1999 Return-Path: Received: from Arizona.EDU (Penny.Telcom.arizona.edu [128.196.128.217]) by paradox.soc-sci.arizona.edu (8.9.3/8.9.3) with ESMTP id WAA06004 for ; Sun, 12 Sep 1999 22:54:52 -0700 Received: from DIRECTORY-DAEMON by Telcom.Arizona.EDU (PMDF V5.1-12 #24137) id <01JFWEKCNDCWA60B12@Telcom.Arizona.EDU> for chalmers@paradox.soc-sci.arizona.edu; Sun, 12 Sep 1999 22:54:55 MST Received: from paradox.soc-sci.arizona.edu by Telcom.Arizona.EDU (PMDF V5.1-12 #24137) with ESMTP id <01JFWEKAKYK0B8TD18@Telcom.Arizona.EDU> for chalmers@Arizona.EDU; Sun, 12 Sep 1999 22:54:52 -0700 (MST) Received: (from chalmers@localhost) by paradox.soc-sci.arizona.edu (8.9.3/8.9.3) id WAA05998 for scicon; Sun, 12 Sep 1999 22:54:42 -0700 Date: Sun, 12 Sep 1999 22:54:42 -0700 From: David Chalmers Subject: What experience teaches (from Joel M.) To: scicon@paradox.soc-sci.arizona.edu Message-id: <199909130554.WAA05998@paradox.soc-sci.arizona.edu> MIME-version: 1.0 Content-type: TEXT/PLAIN; CHARSET=US-ASCII Status: R >From jmartine@U.Arizona.EDU Sun Sep 12 21:33:21 1999 Date: Sun, 12 Sep 1999 21:32:54 -0700 (MST) From: Joel A Martinez Subject: What experience teaches To: chalmers@U.Arizona.EDU In what follows I present some of David Lewis' objections (in "What Experience Teaches") concerning Jackson's Knowledge argument. I also include a brief explanation of the ability hypothesis, as he presents it, along with some of my own comments. (Since I was not sure how many people have read Lewis' paper I included more summary. this made my e-mail longer. I apologize for the length.) Lewis denies what he calls "The Hypothesis of Phenomenal Information" (HPI) on the grounds that it commits us to a much more "peculiar" view of the world (his words, not mine) than does materialism. But first, let me be clear about what the Hypothesis is; it is familiar to all of us, maybe just not under this name. It is the claim that besides physical information there is an irreducibly different kind of information to be had: *phenomenal information*. So, it is possible for there to be two cases that do not differ physically but do, however, differ, phenomenally. According to Lewis, the characterization of information according to the HPI, is in terms of excluding possibilities. That is, when we get physical information we narrow down the possibilities, sometimes even to one, but there is a range of phenomenal possibilities which we leave open. He uses an analogy of a location of a point on an x-y plane. We may be able to pinpoint the x coordinate exactly, but no amount of x-coordinate info. is going to help us figure out where the y-coordinate lies. "Any amount of x-information leaves open all the y-possibilities." (pg. 583) When we finally do make our y-measurement we acquire a new kind of information, which allows us to eliminate possibilities which were previously open. Similarly, when Mary finally sees red, she is able to eliminate possibilities that were previously left open to her. Now, invoking the HPI (as a reason why no amount of physical information suffices to teach us what a new experience is like) allows Jackson to construct the knowledge argument. Lewis cannot formulate a version of Materialism (even a very limited version in terms of a small class of possible worlds) which holds given the HPI. He show us that the two are incompatible. As mentioned above, Lewis opts to reject the HPI. He rejects is for two reasons: 1) It is more "peculiar", 'and therefore less tempting than it may at first seem.' (pg. 586-587) 2) we are not *forced* to accept it. B/c an alternative hypothesis (the ability hypothesis) allows us to explain how experience can best teach us what it is like. That is, we can hold (a) that experience, and nothing else (at least in the actual world) can teach us "what it is like", while still (b) rejecting the HPI and (c) accepting Materialism. 1): Why the HPI is so "peculiar": First, b/c it is actually opposed to more than just Materialism, according to Lewis. He shows this with the following argument: "Let parapsychology be the science of all the non-physical things, properties, causal processes, laws of nature, and so forth that may be required to explain the things we do. Let us suppose that we learn ever so much parapsychology. It will make no difference. Black-and -white mary may study all the parapsychology as well as all the psychophysics of color vision, but she still won't know what it is like...our intuitive starting point wasn't just that *physics* lessons could not help the inexperienced to know what it is like. It was that *lessons* couldn't help. If there is such a thing as phenomenal information it isn't just independent of physical information. It's independent of *every sort of information that could be served up in lessons for the inexperienced*. For it is supposed to eliminate possibilities that any amount of lessons leave open. Therefore phenomenal information is not just parapsychological information, if such there be. It's something very much stronger." (I think there is quite a lot to say about this argument, but I want to comment on the ability hypothesis and, since this is already getting long I will save commentary on this for someone else or for some other time.) (2) The second reason why HPI is so "peculiar" is that, according to Lewis, the possible alternatives, in the case of something the likes of which we have never experienced (like the alternatives concerning what it would be like to be a bat), is completely unthinkable. Lewis admits that a range of unthinkable alternatives is not impossible; but it is, he says, "peculiar" and is "enough to suggest that we may somehow have gone astray. (I think that the Thompson paper actually suggests something counter to this. It may be possible to get an idea of what some completely foreign experience may be like (e.g. we can plot a novel color by changing the geometry of our color space), and hence generate some range of possibilities. So, the HPI may not be so peculiar, in this respect, after all.) (3) The third peculiarity is how "isolated" phenomenal information is from all other kinds of info. (I take Lewis here to mean by "isolated", seemingly not making any difference in the physical world.) Mary's behavior would presumably change when she saw green for the first time. to quote Lewis "..her jaw drops and she says "At last! So this is what it's like to see colors!" But, if the HPi is right, she could not be doing any of this as a result of seeing colors for the first time. In order for Mary to do or say anything different her particles must move differently. But how can acquiring phenomenal information make a difference as to the motion of her particles? Lewis makes this point in a somewhat dramatic fashion. "If something non-physical sometimes makes a difference to the motions of physical particles, then physics as we know it is wrong. Not just silent, not just incomplete--wrong." (pg. 590). The Ability Hypothesis- (Since we discussed this in class, I will say only what is relevant to the comments I make.) So, Lewis sees better reason for rejecting the HPI than materialism. He then (following Nemirow) wants to replace talk of learning a new fact with learning a new ability. Learning what it is like to see a new color is then, like learning to wiggle your ears or eat with chopsticks. No amount of information will suffice for you to acquire the ability. Information might help, but until you do it, you will not know what it is like. Once you know what it is like you have the ability to recall memories of wiggling your ears, imagine wiggling your ears, etc.. So, the ability hypothesis can be formulated as follows "knowing what an experience is like just *is* the possession of these abilities to remember,imagine, and recognize". Lewis' point is that, what enables one to do all this new stuff is not the possession of a new kind of *information*; for Lewis, there are no "phenomenal facts". It is simply *knowing how* to do something. Commentary: I think that it would be interesting to look at empirical research that is being done concerning recognition of colors, tastes, etc. in children. I say this b/c when I consider my experience of red or the taste of broccoli, it does not seem to me that I am engaging in the performance of some kind of skill. Red, the experience of it, seems to me to be a given in my subjective experience in the world. But, if it is an acquired ability, then I would have had to develop it, like I developed my ability to use chopsticks. I definitely don't remember developing the ability to see red, but I very well may have when I was very young. I don't know, that is why I think it would be interesting to look at such studies (I am sure there are some out there.). For, if the Ability Hypothesis is right, shouldn't we be able to see this ability develop in children? That is, they would get better at *recognizing* colors; not *naming colors* b/c that could very well concern language acquisition and not sensory experience. Of course, a defender of the ability hypothesis could then say that not all abilities are acquired. Some are natural abilities. This seems plausible to me. So, the materialist has a response to the question of whether this ability is acquired. But, there remains something unsatisfying about the ability hypothesis. That is, I might be able to see red (and other people cannot) but, explaining *how* I do it still does not seem to me to get around the fact that *I am seeing it*. They still seem to be two different phenomena; the seeing and the ability to see seem distinct to me. As I have tried to comment above, I also do not think that Lewis has succeeded in making the HPI sound incredibly peculiar. Thompson's paper helps make sense of how we may be able to develop a range of possibilities. I hope that some find Lewis' arguments interesting. Again, I apologize about the length. Joel Joel A. Martinez Social Science Bldg. Rm. 213 Dept. of Philosophy University of Arizona P.O. Box 210027 Tucson, AZ 85721-0027 USA Office #138 Phone 520-621-7098 From anhabib@U.Arizona.EDU Mon Sep 13 00:18:44 1999 Return-Path: Received: from Arizona.EDU (Penny.Telcom.arizona.edu [128.196.128.217]) by paradox.soc-sci.arizona.edu (8.9.3/8.9.3) with ESMTP id AAA06132 for ; Mon, 13 Sep 1999 00:18:44 -0700 Received: from DIRECTORY-DAEMON by Telcom.Arizona.EDU (PMDF V5.1-12 #24137) id <01JFWHHCYZ3KA60633@Telcom.Arizona.EDU> for chalmers@paradox.soc-sci.arizona.edu; Mon, 13 Sep 1999 00:18:48 MST Received: from paradox.soc-sci.arizona.edu by Telcom.Arizona.EDU (PMDF V5.1-12 #24137) with ESMTP id <01JFWHH9BUQOB8U7KL@Telcom.Arizona.EDU> for chalmers@Arizona.EDU; Mon, 13 Sep 1999 00:18:42 -0700 (MST) Received: from pavo.U.Arizona.EDU (pavo-2.U.Arizona.EDU [128.196.137.196]) by paradox.soc-sci.arizona.edu (8.9.3/8.9.3) with ESMTP id AAA06127 for ; Mon, 13 Sep 1999 00:18:28 -0700 Received: from localhost (anhabib@localhost) by pavo.U.Arizona.EDU (8.8.6 (PHNE_17190)/8.8.6) with ESMTP id AAA29879 for ; Mon, 13 Sep 1999 00:18:34 -0700 (MST) Date: Mon, 13 Sep 1999 00:18:34 -0700 (MST) From: Allen N Habib Subject: More on the knowledge argument... To: scicon@paradox.soc-sci.arizona.edu Message-id: MIME-version: 1.0 Content-type: TEXT/PLAIN; charset=US-ASCII Status: RO To all, I know I'm jumping into the fray a little late, and you might all be heartily sick of hearing about Jackson's knowledge argument, but here are some (few) thoughts about it and the postings concerning it so far. Just to quickly recap Jackson's initial argument, I think it might be schematised like so: Premis 1. If materialism is true, then in principle, all mental facts are reducible to physical facts. Premis 2. If this is the case, then Mary can't learn anything new when she (finally) sees a red tomato, since ex hypothesi Mary already knew all there was to know about the physical facts that might underlay such an experience, i.e. a whole bunch of scientific facts about the workings of the brain. Premis 3. But Mary certainly seems to learn something new when she sees the tomato. She has a new experience, and all her prior knowledge about the neurology that might underpin such an event is not sufficient to give her this new knowledge without the experience. Conclusion 1. Not all mental facts are exhausted by physical facts Conclusion 2. Materialism is false As Churchland points out, the argument is subject to attack at the second premis, and the charge is one of equivocation. Specifically, two senses of the word 'learn' (or alternatley, the word 'know' if the argument is phrased in those terms) are employed. As Matt pointed out in his Sept. 8 posting, these two senses might be understood by using Russell's distinction between 'knowledge that' and 'knowledge of' or knowledge of truths and knowledge of things. Matt opines that these terms might correspond to different faculties of the mind: a descriptive faculty and a faculty of acquaintance, respectfully. This would help explain why Mary learns something new, because she receives input to her faculty of acquaintance upon viewing the red tomato, where previously she only had information concerning red in her descriptive faculty. Dave's reply to Matt (also on Sept 8th) seems to endorse this reading, although Dave is quick to point out that Jackson need not tie himself down to this story of things mental for his argument to go through. All he needs, says Dave, is for Premis three to sound plausible, that is for it to seem to us that Mary does learn something new upon seeing the tomato, regardless of the possible mental ontology underlying it. But, as Brad points out in his Sept 10th posting, this distinction in types of knowledge can be used against Jackson, especially if something like Matt's 'faculties of the mind' story is adopted. As he (Brad) says ". . .our respresentaions of sensory states are in a different 'format' or a different module (or psychologically encapsulated in some other way) than our so-called descriptive representations of theoretical knowledge.". Brad goes on to say that in fact Mary doesn't learn anything new, but that she is simply put into a state where her sensory representaions of red are activated when she sees the tomato. And, since until she sees the tomato, all she has are the representaions of red to be found in her descriptive faculty, and since those two faculties are insulated from one another, it seems as if she does learn something new. But this intuition (that she does learn something new) is explained by the fact that we can put ourselves into representational states by an effort of the will, whereas it seems that Mary cannot, consequently it seems to us that these latter representations are new or extra information, when in fact they are but different representations of the same information, stored in different formats in the different modules of our mind. (this last bit is just my feeble attempt at a recounting of Brad's argument, and may well be completely incorrect. I would welcome comments and corrections if this is the case, from Brad or anyone) Here I part ways with Brad, and I think that a materialist might better reply to Jackson that it is becauses of the equivocation on knowledge or learning in his argument that it seems that Mary 'knows' or 'learns' something new. My argument would go like this: Mary has a neural event(s) that she had never had before upon seeing the red tomato, and insofar as that neural event had causal reprecussions on the rest of her brain (i.e. leaving traces in memory, or altering or adding to those parts of the brain that are responsible for what we have here been calling the descriptive faculty) then, if this is what we mean by learning something, Mary has definitely learned something. But this is as it should be, since Mary's brain underwent changes that it had never undergone before. This is at least a necessary condition for learning something new, on a materialists analysis of that term, so it is not surprising that Mary has learned something new when it occurs. The problem is that, in premise two, we are told that Mary already 'knows' everything there is to know about the physical facts that underlay colour-vision, and this is disingenuous. By 'knows' here do we mean that Mary has had the neural events that correlate with every pertinent bit of information about colour-vision? or do we just mean that Mary has studied and memorised (and believes) all the propositions that correspond to facts about the neural correlate(s) of colour-vision. If the latter, then a different sense of knowledge is being employed than the one in the above explanation of how Mary comes to learn something new, since it artificially limits the range of neural events that are to count as learning to those involved with reading and understanding sentences. If the former sense is in use, then what reasons do we have for excluding those neural events that underwrite normal colour-vision as pertinent? How can we say truly of Mary that she has all the knowledge about colour-vision there is to have if her brain has never undergone these paradigm transformations? I don't think we can. It is only if we invoke the restricted sense of knowledge, that of sentence appreciation, that this exclusion makes sense, but then of course Jackson's argument has no sting, since all it seems to be saying is that Mary didn't have a certain type of neural event before she saw the tomato, and she did after she saw the tomato, and that the differences in her brain between the two stages qualifies her as having learned something after having seen it. In other words (if anybody is still with me) I don't think materialists need to deny that Mary learns anything new, they can simply say that in the broad, materialistic sense of knowledge, Mary does learn something new, since her brain acts in ways it never did before, but in this sense of learning, new physical facts are appealed to, namely the events in the brain that underwrite colour-vision, and if we deny 'knowledge' of these, meaning of course that we deny her the actual neural events, and not just sentences describing the neural events, then we can't say that she knows everything that there is to know about colour-vision. Pheeeew. Sory that took so long, and I also apologise for the inelegant writing, but the material forces some very laboured constructions. Also I'm a terrible writer. Please help me on this or any other score with your comments. Thanx to all Allen "Time flies like an arrow. Fruit flies like a banana." Groucho Marx From rachaelp@U.Arizona.EDU Mon Sep 13 13:42:04 1999 Return-Path: Received: from Arizona.EDU (Penny.Telcom.arizona.edu [128.196.128.217]) by paradox.soc-sci.arizona.edu (8.9.3/8.9.3) with ESMTP id NAA07149 for ; Mon, 13 Sep 1999 13:42:03 -0700 Received: from DIRECTORY-DAEMON by Telcom.Arizona.EDU (PMDF V5.1-12 #24137) id <01JFX9JD3GXSB8U2IV@Telcom.Arizona.EDU> for chalmers@paradox.soc-sci.arizona.edu; Mon, 13 Sep 1999 13:42:08 MST Received: from orion.U.Arizona.EDU by Telcom.Arizona.EDU (PMDF V5.1-12 #24137) with ESMTP id <01JFX9JASRS0B8U29V@Telcom.Arizona.EDU> for chalmers@Arizona.EDU; Mon, 13 Sep 1999 13:42:05 -0700 (MST) Received: from localhost (rachaelp@localhost) by orion.U.Arizona.EDU (8.8.6 (PHNE_17190)/8.8.6) with ESMTP id NAA05424; Mon, 13 Sep 1999 13:42:03 -0700 (MST) Date: Mon, 13 Sep 1999 13:42:02 -0700 (MST) From: Rachael J Parkinson Subject: Re: Experience as a Kind (from Sarah) In-reply-to: <199909131855.LAA06899@paradox.soc-sci.arizona.edu> To: David Chalmers Cc: scicon@paradox.soc-sci.arizona.edu Message-id: MIME-version: 1.0 Content-type: TEXT/PLAIN; charset=US-ASCII Status: RO I have some concerns regarding reduction, particularly as it is laid out by Churchland in "Reduction, Qualia, and the Direct Introspection of Brain States." In this article, Churchland seems to be arguing for a weaker type of reduction, one in which not even indirect deducibility is a requirement. On the D-N model of reduction we see that thermodynamics is reducible: molecule dynamics plus dynamic/thermodynamic bridge laws entail thermodynamics. Churchland weakens this view by arguing that there does not necessarily have to be a smooth reduction. My first question is- how is this view of reduction so different from an epiphenominalist view that brain facts plus pyschophysical bridge laws entail phenomenal facts? In class, Dave argued that the epiphenomenalist view is not really a *reduction* of experience to brain states. This is because psychophysical laws are not necessary but contingent. Dave further argued that for a strong sense of reduction you need the micro facts to entail the macro facts without an irreducible appeal to laws. This is a view in which P (micro facts) necessarily implies Q (macro facts). Or in other words,in all possible worlds which P holds, Q holds. But what are the micro facts? They are a combination of microphysical entities and microphysical laws. If you take away the laws, the reduction can not hold. (We can imagine a world where the microphysical entities are the same but the microphysical laws have changed. This world would be very different from our own.) My second question is this: if we throw psychophysical laws into the pot, then couldn't we say that the micro facts (which include various bridge laws, particularly psychophysical bridge laws) necessarily entail the macro facts (including concsiousness). So it would be impossible to conceive of a world that had the same micro facts/laws as ours that did not also have the same macro facts,(again, including concsiousness.) I guess my concern can be traced back to Dave's contention that psychophysical laws are not necessary but contingent. It seems to me that most physical laws are not necessary across all possible worlds. The view that brain facts plus psychophysical bridge laws entail phenomenal facts does not seem that different from other scientific reductions, especially given Churchland's weaker requirements for reduction. If someone could please elucidate on the difference between scientific reduction in the realm of physics, for example, and Dave's non-reductive view of consiousness I would appreciate it. Cheers, Rachael From chalmers@paradox.soc-sci.arizona.edu Tue Sep 14 00:16:33 1999 Return-Path: Received: from Arizona.EDU (Penny.Telcom.arizona.edu [128.196.128.217]) by paradox.soc-sci.arizona.edu (8.9.3/8.9.3) with ESMTP id AAA08249 for ; Tue, 14 Sep 1999 00:16:33 -0700 Received: from DIRECTORY-DAEMON by Telcom.Arizona.EDU (PMDF V5.1-12 #24137) id <01JFXVP1PB0GB8UIJA@Telcom.Arizona.EDU> for chalmers@paradox.soc-sci.arizona.edu; Tue, 14 Sep 1999 00:16:38 MST Received: from paradox.soc-sci.arizona.edu by Telcom.Arizona.EDU (PMDF V5.1-12 #24137) with ESMTP id <01JFXVOZ1VUOB8U53R@Telcom.Arizona.EDU> for chalmers@Arizona.EDU; Tue, 14 Sep 1999 00:16:35 -0700 (MST) Received: (from chalmers@localhost) by paradox.soc-sci.arizona.edu (8.9.3/8.9.3) id AAA08243 for scicon; Tue, 14 Sep 1999 00:16:24 -0700 Date: Tue, 14 Sep 1999 00:16:24 -0700 From: David Chalmers Subject: Comments To: scicon@paradox.soc-sci.arizona.edu Message-id: <199909140716.AAA08243@paradox.soc-sci.arizona.edu> MIME-version: 1.0 Content-type: TEXT/PLAIN; CHARSET=US-ASCII Status: R Hi, here are some very brief comments on people's postings: (1) Re Sarah's comments: The idea that consciousness might not be a natural kind is interesting. Personally I think it is, if anything is; but I'm not sure whether any of these issues really turn on the matter. Even when a property is a very unnatural kind (e.g. "in my desk"), maybe we won't be able to give a unified explanation of its instances, but that won't stop one from giving a fine explanation of any single instance of the property. Here we're not concerned so much with historical explanation (which can be tricky) as reductive explanation -- just giving an account of the micro facts which will necessitate and explain the fact that e.g. a particular pen is in my desk. And that doesn't seem too hard in principle. But for consciousness, even explaining a single instance seems tricky. So I'm not sure the issues are entirely analogous. (2) Re Allen's comments: I think what really matters is not sentence-knowledge but what we might call factual knowledge, i.e. knowledge of the way the world is. Even if knowing what red is like isn't sentence knowledge, it seems to be factual knowledge. I take it that Allen's central response is to deny that Mary has complete physical knowledge before seeing red, because she hasn't experienced red yet. If that is to apply to factual knowledge (which is what's relevant here), then I suppose it implies that knowing all the truths of physics doesn't give one complete factual knowledge. In a certain sense that might be enough for Jackson already -- if there are facts that go beyond physical facts, he might say he's home. Perhaps he might concede the point that to know those facts, one has to go into a certain neural state. That would imply there is a close connection between the neural state and the new fact; maybe one could even construe it as a fact about the state (e.g. what it's like to be in that state). But there's nothing here that suggests or implies that it's a *physical* fact about that state, and Jackson would presumably argue that the situation dictates the opposite. So I think the materialist may need to appeal to something more than the mere fact that being in the neural state is required for knowledge here. (3) Re Rachael's comments: On the entailment model of reductive explanation, the claim will be that the micro facts entail the macro facts. The micro facts here may include the micro laws, but they may not include any special bridge laws. E.g. for chemistry to be reductively explained in terms of physics, on this view, is for the chemical facts to be entailed by the physical facts (including physical laws). But in the case of consciousness, the anti-reductionist's claim is that the physical facts and physical laws don't entail the existence or character of consciousness. If we throw the bridge laws into the base, then we might get an entailment, but that's just what we're not allowed to do where reductive explanation is concerned. The relevant difference here is that ordinary scientific reductions will have an entailment from micro facts and laws without bridge laws, whereas on the nonreductive view of consciousness, one needs to include bridge laws to get an entailment. The very different status of micro laws and bridge laws is what makes the difference here. (4) Re Simon's and Joel M.'s comments: Some good points, to which I don't have much to add here. I think Crick and Koch managed to get a bit confused in the logic of their reasoning about essential features of consciousness, in just the way that Simon nicely points out. Re the psychophysical principles that I give, these are certainly very far from complete, and they certainly don't give sufficient conditions for consciousness. A final theory of consciousness will need principles that are much more detailed and specific. --Dave. From press@U.Arizona.EDU Tue Sep 14 01:09:42 1999 Return-Path: Received: from Arizona.EDU (Penny.Telcom.arizona.edu [128.196.128.217]) by paradox.soc-sci.arizona.edu (8.9.3/8.9.3) with ESMTP id BAA08363 for ; Tue, 14 Sep 1999 01:09:41 -0700 Received: from DIRECTORY-DAEMON by Telcom.Arizona.EDU (PMDF V5.1-12 #24137) id <01JFXXJY25XCB8TZ2D@Telcom.Arizona.EDU> for chalmers@paradox.soc-sci.arizona.edu; Tue, 14 Sep 1999 01:09:47 MST Received: from paradox.soc-sci.arizona.edu by Telcom.Arizona.EDU (PMDF V5.1-12 #24137) with ESMTP id <01JFXXJWTNV4B8U1Y7@Telcom.Arizona.EDU> for chalmers@Arizona.EDU; Tue, 14 Sep 1999 01:09:46 -0700 (MST) Received: from f1n3.u.arizona.edu (IDENT:press@f1n3.U.Arizona.EDU [128.196.137.103]) by paradox.soc-sci.arizona.edu (8.9.3/8.9.3) with ESMTP id BAA08358 for ; Tue, 14 Sep 1999 01:09:36 -0700 Received: from localhost (press@localhost) by f1n3.u.arizona.edu (8.8.8/8.8.8) with ESMTP id BAA41554 for ; Tue, 14 Sep 1999 01:09:42 -0700 Date: Tue, 14 Sep 1999 01:09:42 -0700 (MST) From: Joel K Press Subject: Allen's solution to Mary Arg To: scicon@paradox.soc-sci.arizona.edu Message-id: MIME-version: 1.0 Content-type: TEXT/PLAIN; charset=US-ASCII Status: RO All- Allens solution to Jacksons knowledge argument is similar to one that Ive been mulling over for several days now. Actually, it is probably the very same argument. I dont think I can greatly improve on Allens statement of it, so Ill just re-post it before talking about an anticipated objection. >My argument would go like this: Mary has a neural >event(s) that she had never had before upon seeing the red tomato, and >insofar as that neural event had causal reprecussions on the rest of her >brain (i.e. leaving traces in memory, or altering or adding to those >parts >of the brain that are responsible for what we have here been calling the >descriptive faculty) then, if this is what we mean by learning something, >Mary has definitely learned something. But this is as it should be, since >Mary's brain underwent changes that it had never undergone before. This >is >at least a necessary condition for learning something new, on a >materialists analysis of that term, so it is not surprising that Mary has >learned something new when it occurs. The problem is that, in premise two, >we are told that Mary already 'knows' everything there is to know about >the physical facts that underlay colour-vision, and this is disingenuous. >By 'knows' here do we mean that Mary has had the neural events that >correlate with every pertinent bit of information about colour-vision? or >do we just mean that Mary has studied and memorised (and believes) all >the >propositions that correspond to facts about the neural correlate(s) of >colour-vision. If the latter, then a different sense of knowledge is being >employed than the one in the above explanation of how Mary comes to learn >something new, since it artificially limits the range of neural events >that are to count as learning to those involved with reading and >understanding sentences. > If the former sense is in use, then what reasons do we have for >excluding those neural events that underwrite normal colour-vision as >pertinent? How can we say truly of Mary that she has all the knowledge >about colour-vision there is to have if her brain has never undergone >these paradigm transformations? I don't think we can. It is only if we >invoke the restricted sense of knowledge, that of sentence appreciation, >that this exclusion makes sense, but then of course Jackson's argument >has >no sting, since all it seems to be saying is that Mary didn't have a >certain type of neural event before she saw the tomato, and she did after >she saw the tomato, and that the differences in her brain between the two >stages qualifies her as having learned something after having seen it. > In other words (if anybody is still with me) I don't think >materialists need to deny that Mary learns anything new, Just to ensure that we are indeed thinking the same thing, the idea is that learning (coming to know) on the materialist account (and on some dualist accounts too really) just comes down to having a brain state that somehow represents the fact known. If we suppose that materialism is true, Marys experience when she first sees a ripe tomato also comes down to having a particular sort of brain state. So the materialist can claim that though Mary does indeed learn something when she has her first experience of red, he can also claim that she learns a materialistic fact, i.e. what happens when that brain state occurs in her brain. The objection to this argument that I see looming, and that (I think) Dave alluded to when we were discussing Churchland, is that Allen and I have missed the point - namely that Mary can gain this knowledge ONLY through experiencing it. She can know everything else about color vision through other means, so the experience fact (what it is like) cannot be reduced to these other facts. It seems, the objector might say, that if the experience fact were just one more physical fact, Mary ought to be able to deduce it from the rest of the physical facts she knows. After all, Mary even knows everything there is to know about the very particular brain state that produces red sensations, but she cannot know what it is like to have that brain state in her brain without experiencing it. I suppose Allen and I can still claim that the experience fact is still a physical fact of some sort, but it is apparently a weird sort of non-reductive physical fact, which is about as bad as a non-reductive non-physical fact from a reductivists point of view. At least with non-physical facts there would be an explanation of why the reduction fails. I think the way around this objection is to show that, while there is a difference between the way Mary knows "what it is like to experience red," and the way that she knows about other physical facts (like which brain state causes subjects to experience red), this difference is not a fundamental difference between two different ways of knowing (a la Matts reference to Russell). The claim is that all learning just comes down to finding ways of appropriately modifying ones brain, and that all functionally equivalent means of achieving this end count as learning the same thing. Consider the various ways that Mary can learn about "what it is like to experience red." 1) Mary looks at a ripe tomato (or other red object). Light bounces off the tomato, interacts with her retinae, causing neurons to fire, and a particular brain state arises. So long as Mary remembers the salient features of this experience, she knows what it is like to experience redness. 2) While still in her black and white room, Mary uses her extensive knowledge of brain physiology and the other sciences to directly stimulate her brain in such a way that it enters the state that she knows should cause her to have an experience of redness. 3) While still in her black and white room, Mary uses her extensive knowledge of brain physiology and the other sciences to develop monitoring devices with which she can observe the various processes going on in her brain (like an EEG only much much better). Using the real-time information provided by these devices as biofeedback, she trains herself to manipulate her brain into any state she desires. (I think I read somewhere that some people can manipulate a computer mouse pointer by learning to manipulate certain brain waves. The ability Im attributing to Mary is like that, but much more complex. Mary, of course, has a complete knowledge of her own brain, so she can achieve a higher level of control.) Once she has mastered the control of her brain, (and no longer needs the crutch of the monitoring devices) she decides she wants to experience redness, so she manipulates herself into the appropriate state and learns about this experience. The point is not that Mary experiences red in 1) but learns about red in 3), but rather that she both learns and experiences in all the cases. The implementation of learning varies greatly, but in each case she comes to know the same fact. 1) is the way most of us learn about redness. In 2) Mary learns about redness without ever seeing a red object. In 3) she learns about red without any external manipulation. All she needs are lots of facts about her brain and practice with controlling it. Once she has really mastered these techniques, when color-deprived Mary thinks, "What is red like?," the answer is just a thought away. But 1), 2), and 3) all produce the same knowledge. These imagined cases are obviously pretty far-fetched, but then so is Jacksons claim that Mary knows "all the physical facts." But I can make the same point about learning with a more down to earth example. When we learn basic mathematics, like multiplication say, we use different techniques as we go. When I first learned multiplication we were given worksheets with grids on them. For 4x5 there would be a 4 by 5 grid, and we were supposed to count the 20 squares formed by the grid to get the answer. I thought this was cool, so I used it for quite a while. However, as the numbers got bigger the grids got clumsier and I grudgingly learned to multiply multi-digit numbers on paper, then in my head. Though they differed in implementation, all of these exercises counted as learning the product of two numbers. Theres probably much more that could be said about this. But not tonight. Let me know what you think. Joel PS - I see that Dave has already replied to Allen by the time I've written and posted this. (Do you never sleep?) I only looked at that post briefly, but I think my comments are relevant to Dave's reply. However, since I do sleep, I will let these comments stand as is for now. From lachter@u.arizona.edu Tue Sep 14 10:09:42 1999 Return-Path: Received: from Arizona.EDU (Penny.Telcom.arizona.edu [128.196.128.217]) by paradox.soc-sci.arizona.edu (8.9.3/8.9.3) with ESMTP id KAA08815 for ; Tue, 14 Sep 1999 10:09:42 -0700 Received: from DIRECTORY-DAEMON by Telcom.Arizona.EDU (PMDF V5.1-12 #24137) id <01JFYGFGM1EOB8U7N1@Telcom.Arizona.EDU> for chalmers@paradox.soc-sci.arizona.edu; Tue, 14 Sep 1999 10:09:49 MST Received: from paradox.soc-sci.arizona.edu by Telcom.Arizona.EDU (PMDF V5.1-12 #24137) with ESMTP id <01JFYGFFHVLCB8UAM8@Telcom.Arizona.EDU> for chalmers@Arizona.EDU; Tue, 14 Sep 1999 10:09:47 -0700 (MST) Received: from trifid.u.arizona.edu (IDENT:root@trifid.U.Arizona.EDU [128.196.137.197]) by paradox.soc-sci.arizona.edu (8.9.3/8.9.3) with ESMTP id KAA08810 for ; Tue, 14 Sep 1999 10:09:36 -0700 Received: from [128.196.99.98] ([128.196.99.98]) by trifid.u.arizona.edu (8.8.8/8.8.8) with ESMTP id KAA20726; Tue, 14 Sep 1999 10:09:43 -0700 Date: Tue, 14 Sep 1999 10:08:30 -0700 From: Joel Lachter Subject: Re: Allen's solution to Mary Arg In-reply-to: X-Sender: lachter@pop.u.arizona.edu To: Joel K Press Cc: scicon@paradox.soc-sci.arizona.edu Message-id: MIME-version: 1.0 Content-type: text/plain; charset=us-ascii Status: RO Joel Press asks us to "onsider the various ways that Mary can learn about 'what it is like to experience red.'" But all three of the ways he mentions involve actually experiencing red. It is not clear to me that this is necessary. Suppose Mary knows enough about what her reactions would be to seeing red that she could actually recognize red. This could be fairly automatic given Mary's advanced state of knowledge. Further suppose that she COULD induce the experience of red in herself. Again, this could be fairly automatic since she knows a lot about how the brain works and presumably understands the mental gymnastics involved in biofeedback kind of activities better than anyone currently does. Here is the question, if Mary can recognize red experiences and can induce red experiences in herself in what sense is she missing "facts" about what red is like? Joel (Lachter) At 1:09 AM -0700 9/14/99, Joel K Press wrote: >All- > >Allens solution to Jacksons knowledge argument is similar to one that Ive >been mulling over for several days now. Actually, it is probably the very >same argument. I dont think I can greatly improve on Allens statement of >it, so Ill just re-post it before talking about an anticipated objection. > >>My argument would go like this: Mary has a neural >>event(s) that she had never had before upon seeing the red tomato, and >>insofar as that neural event had causal reprecussions on the rest of her >>brain (i.e. leaving traces in memory, or altering or adding to those >>parts >>of the brain that are responsible for what we have here been calling the >>descriptive faculty) then, if this is what we mean by learning something, >>Mary has definitely learned something. But this is as it should be, since >>Mary's brain underwent changes that it had never undergone before. This >>is >>at least a necessary condition for learning something new, on a >>materialists analysis of that term, so it is not surprising that Mary has >>learned something new when it occurs. The problem is that, in premise >two, >>we are told that Mary already 'knows' everything there is to know about >>the physical facts that underlay colour-vision, and this is disingenuous. >>By 'knows' here do we mean that Mary has had the neural events that >>correlate with every pertinent bit of information about colour-vision? or >>do we just mean that Mary has studied and memorised (and believes) all >>the >>propositions that correspond to facts about the neural correlate(s) of >>colour-vision. If the latter, then a different sense of knowledge is >being >>employed than the one in the above explanation of how Mary comes to learn >>something new, since it artificially limits the range of neural events >>that are to count as learning to those involved with reading and >>understanding sentences. >> If the former sense is in use, then what reasons do we have for >>excluding those neural events that underwrite normal colour-vision as >>pertinent? How can we say truly of Mary that she has all the knowledge >>about colour-vision there is to have if her brain has never undergone >>these paradigm transformations? I don't think we can. It is only if we >>invoke the restricted sense of knowledge, that of sentence appreciation, >>that this exclusion makes sense, but then of course Jackson's argument >>has >>no sting, since all it seems to be saying is that Mary didn't have a >>certain type of neural event before she saw the tomato, and she did after >>she saw the tomato, and that the differences in her brain between the two >>stages qualifies her as having learned something after having seen it. >> In other words (if anybody is still with me) I don't think >>materialists need to deny that Mary learns anything new, > >Just to ensure that we are indeed thinking the same thing, the idea is >that learning (coming to know) on the materialist account (and on some >dualist accounts too really) just comes down to having a brain state that >somehow represents the fact known. If we suppose that materialism is >true, Marys experience when she first sees a ripe tomato also comes down >to having a particular sort of brain state. So the materialist can claim >that though Mary does indeed learn something when she has her first >experience of red, he can also claim that she learns a materialistic fact, >i.e. what happens when that brain state occurs in her brain. > >The objection to this argument that I see looming, and that (I think) Dave >alluded to when we were discussing Churchland, is that Allen and I have >missed the point - namely that Mary can gain this knowledge ONLY through >experiencing it. She can know everything else about color vision through >other means, so the experience fact (what it is like) cannot be reduced to >these other facts. It seems, the objector might say, that if the >experience fact were just one more physical fact, Mary ought to be able to >deduce it from the rest of the physical facts she knows. After all, Mary >even knows everything there is to know about the very particular brain >state that produces red sensations, but she cannot know what it is like to >have that brain state in her brain without experiencing it. I suppose >Allen and I can still claim that the experience fact is still a physical >fact of some sort, but it is apparently a weird sort of non-reductive >physical fact, which is about as bad as a non-reductive non-physical fact >from a reductivists point of view. At least with non-physical facts there >would be an explanation of why the reduction fails. > >I think the way around this objection is to show that, while there is a >difference between the way Mary knows "what it is like to experience red," >and the way that she knows about other physical facts (like which brain >state causes subjects to experience red), this difference is not a >fundamental difference between two different ways of knowing (a la Matts >reference to Russell). The claim is that all learning just comes down to >finding ways of appropriately modifying ones brain, and that all >functionally equivalent means of achieving this end count as learning the >same thing. > >Consider the various ways that Mary can learn about "what it is like to >experience red." > >1) Mary looks at a ripe tomato (or other red object). Light bounces off >the tomato, interacts with her retinae, causing neurons to fire, and a >particular brain state arises. So long as Mary remembers the salient >features of this experience, she knows what it is like to experience >redness. > >2) While still in her black and white room, Mary uses her extensive >knowledge of brain physiology and the other sciences to directly stimulate >her brain in such a way that it enters the state that she knows should >cause her to have an experience of redness. > >3) While still in her black and white room, Mary uses her extensive >knowledge of brain physiology and the other sciences to develop monitoring >devices with which she can observe the various processes going on in her >brain (like an EEG only much much better). Using the real-time >information provided by these devices as biofeedback, she trains herself >to manipulate her brain into any state she desires. (I think I read >somewhere that some people can manipulate a computer mouse pointer by >learning to manipulate certain brain waves. The ability Im attributing to >Mary is like that, but much more complex. Mary, of course, has a complete >knowledge of her own brain, so she can achieve a higher level of control.) >Once she has mastered the control of her brain, (and no longer needs the >crutch of the monitoring devices) she decides she wants to experience >redness, so she manipulates herself into the appropriate state and learns >about this experience. > >The point is not that Mary experiences red in 1) but learns about red in >3), but rather that she both learns and experiences in all the cases. The >implementation of learning varies greatly, but in each case she comes to >know the same fact. 1) is the way most of us learn about redness. In 2) >Mary learns about redness without ever seeing a red object. In 3) she >learns about red without any external manipulation. All she needs are >lots of facts about her brain and practice with controlling it. Once she >has really mastered these techniques, when color-deprived Mary thinks, >"What is red like?," the answer is just a thought away. But 1), 2), and >3) all produce the same knowledge. > >These imagined cases are obviously pretty far-fetched, but then so is >Jacksons claim that Mary knows "all the physical facts." But I can make >the same point about learning with a more down to earth example. > >When we learn basic mathematics, like multiplication say, we use different >techniques as we go. When I first learned multiplication we were given >worksheets with grids on them. For 4x5 there would be a 4 by 5 grid, and >we were supposed to count the 20 squares formed by the grid to get the >answer. I thought this was cool, so I used it for quite a while. >However, as the numbers got bigger the grids got clumsier and I grudgingly >learned to multiply multi-digit numbers on paper, then in my head. Though >they differed in implementation, all of these exercises counted as >learning the product of two numbers. > >Theres probably much more that could be said about this. But not tonight. >Let me know what you think. > >Joel > >PS - I see that Dave has already replied to Allen by the time I've written >and posted this. (Do you never sleep?) I only looked at that post >briefly, but I think my comments are relevant to Dave's reply. However, >since I do sleep, I will let these comments stand as is for now. From press@U.Arizona.EDU Tue Sep 14 21:37:00 1999 Return-Path: Received: from Arizona.EDU (Penny.Telcom.arizona.edu [128.196.128.217]) by paradox.soc-sci.arizona.edu (8.9.3/8.9.3) with ESMTP id VAA09819 for ; Tue, 14 Sep 1999 21:36:59 -0700 Received: from DIRECTORY-DAEMON by Telcom.Arizona.EDU (PMDF V5.1-12 #24137) id <01JFZ4FLSJ1SB8Q3ZS@Telcom.Arizona.EDU> for chalmers@paradox.soc-sci.arizona.edu; Tue, 14 Sep 1999 21:37:07 MST Received: from paradox.soc-sci.arizona.edu by Telcom.Arizona.EDU (PMDF V5.1-12 #24137) with ESMTP id <01JFZ4FKSUDSB8UCHZ@Telcom.Arizona.EDU> for chalmers@Arizona.EDU; Tue, 14 Sep 1999 21:37:06 -0700 (MST) Received: from f1n7.u.arizona.edu (IDENT:press@f1n7.U.Arizona.EDU [128.196.137.107]) by paradox.soc-sci.arizona.edu (8.9.3/8.9.3) with ESMTP id VAA09814 for ; Tue, 14 Sep 1999 21:36:51 -0700 Received: from localhost (press@localhost) by f1n7.u.arizona.edu (8.8.8/8.8.8) with ESMTP id VAA38934; Tue, 14 Sep 1999 21:36:59 -0700 Date: Tue, 14 Sep 1999 21:36:59 -0700 (MST) From: Joel K Press Subject: More Mary To: lachter@U.Arizona.EDU Cc: scicon@paradox.soc-sci.arizona.edu Message-id: MIME-version: 1.0 Content-type: TEXT/PLAIN; charset=US-ASCII Status: RO All, Joel Lachter's comments about my comments about Allen's solution to the Mary Argument are, I think, in the same spirit. >Joel Press asks us to "onsider the various ways that Mary can learn about >'what it is like to experience red.'" But all three of the ways he >mentions >involve actually experiencing red. It is not clear to me that this is >necessary. Suppose Mary knows enough about what her reactions would be to >seeing red that she could actually recognize red. This could be fairly >automatic given Mary's advanced state of knowledge. Further suppose that >she COULD induce the experience of red in herself. Again, this could be >fairly automatic since she knows a lot about how the brain works and >presumably understands the mental gymnastics involved in biofeedback kind >of activities better than anyone currently does. Here is the question, if >Mary can recognize red experiences and can induce red experiences in >herself in what sense is she missing "facts" about what red is like? Both of these additional ways of learning about red seem plausible to me if we assume Jackson's stipulation that Mary knows everything about brains, science and so on. We could add these to the list I started as numbers 4) and 5). However, the reason that all my examples contained an experiencing of red is that those who share Jackson's intuitions probably won't accept Joel L.'s cases as real possibilities. My cases were designed to show that experiencing red and other ways of coming to know about red blend into each other, leaving Jackson no reasonable place to draw the line between the two. Joel L.'s cases nicely extend the spectrum of cases. Thanks for the input. Joel (Press) From chalmers@paradox.soc-sci.arizona.edu Wed Sep 15 00:03:22 1999 Return-Path: Received: from Arizona.EDU (Penny.Telcom.arizona.edu [128.196.128.217]) by paradox.soc-sci.arizona.edu (8.9.3/8.9.3) with ESMTP id AAA10200 for ; Wed, 15 Sep 1999 00:03:21 -0700 Received: from DIRECTORY-DAEMON by Telcom.Arizona.EDU (PMDF V5.1-12 #24137) id <01JFZ9J2YR34B8U0J3@Telcom.Arizona.EDU> for chalmers@paradox.soc-sci.arizona.edu; Wed, 15 Sep 1999 00:03:29 MST Received: from paradox.soc-sci.arizona.edu by Telcom.Arizona.EDU (PMDF V5.1-12 #24137) with ESMTP id <01JFZ9J0UWOWB8UCDP@Telcom.Arizona.EDU> for chalmers@Arizona.EDU; Wed, 15 Sep 1999 00:03:26 -0700 (MST) Received: (from chalmers@localhost) by paradox.soc-sci.arizona.edu (8.9.3/8.9.3) id AAA10194; Wed, 15 Sep 1999 00:03:13 -0700 Date: Wed, 15 Sep 1999 00:03:13 -0700 From: David Chalmers Subject: Re: Allen's solution to Mary Arg To: lachter@u.arizona.edu, press@u.arizona.edu Cc: scicon@paradox.soc-sci.arizona.edu Message-id: <199909150703.AAA10194@paradox.soc-sci.arizona.edu> MIME-version: 1.0 Content-type: TEXT/PLAIN; CHARSET=US-ASCII Status: R Quick comments on messages from Joel and Joel (inc.): (1) Re Joel P: I think Jackson might say the same thing I said to Allen. In a certain sense it might be a "materialistic fact" in that it's a fact about what it's like to be in a given brain state, but on the face of it this still involves different properties of the state in quesion, properties distinct from the physical properties she knows about already. It may be true that to know the fact in question one has to be in the brain state, but it's not clear that that suffices to make the fact a physical fact. Compare: I may have to be in a certain physical state to know that Paris is in France, but that doesn't mean the Paris fact is a fact about my brain state. (2) Re Joel L.: Joel suggests that on the basis of her physical knowledge, Mary could learn to indirectly recognize red experiences (by noticing her reactions) and could learn to induce the experiences in herself. The question then, in what sense is she missing "facts" about what red is like? This is complex, but on the face of it there are lots of cases where a capacity for indirectly recognizing X and constructing X's leaves us mostly ignorant about Xs. Just say we know that fire always cause smoke, and that matches always cause fire, and that's all we know about fire (we've never even seen it). Then we might be in a position where we could recognize the presence of fire (by observing smoke) and where we could bring about the presence of fire (by lighting matches), while knowing hardly anything about the character of fire. We'd just know about one or two associated causal relations. So indirect recognition and construction seem to be fairly weak criteria for knowledge. --Dave. From lachter@u.arizona.edu Wed Sep 15 16:41:07 1999 Return-Path: Received: from Arizona.EDU (Aurora.Telcom.arizona.edu [128.196.128.236]) by paradox.soc-sci.arizona.edu (8.9.3/8.9.3) with ESMTP id QAA11677 for ; Wed, 15 Sep 1999 16:41:06 -0700 Received: from DIRECTORY-DAEMON by Telcom.Arizona.EDU (PMDF V5.1-12 #24137) id <01JG08DN443KA5ZQKS@Telcom.Arizona.EDU> for chalmers@paradox.soc-sci.arizona.edu; Wed, 15 Sep 1999 16:41:09 MST Received: from paradox.soc-sci.arizona.edu by Telcom.Arizona.EDU (PMDF V5.1-12 #24137) with ESMTP id <01JG08DHF368B8UJ46@Telcom.Arizona.EDU> for chalmers@Arizona.EDU; Wed, 15 Sep 1999 16:40:45 -0700 (MST) Received: from trifid.u.arizona.edu (IDENT:root@trifid.U.Arizona.EDU [128.196.137.197]) by paradox.soc-sci.arizona.edu (8.9.3/8.9.3) with ESMTP id QAA11672 for ; Wed, 15 Sep 1999 16:40:27 -0700 Received: from [128.196.99.98] ([128.196.99.98]) by trifid.u.arizona.edu (8.8.8/8.8.8) with ESMTP id QAA17080; Wed, 15 Sep 1999 16:40:36 -0700 Date: Wed, 15 Sep 1999 16:39:48 -0700 From: Joel Lachter Subject: Re: Allen's solution to Mary Arg In-reply-to: <199909150703.AAA10194@paradox.soc-sci.arizona.edu> X-Sender: lachter@pop.u.arizona.edu To: David Chalmers Cc: press@u.arizona.edu, scicon@paradox.soc-sci.arizona.edu Message-id: MIME-version: 1.0 Content-type: text/plain; charset=us-ascii Status: RO Dave, I don't think I was clear enough about how this example is supposed to work. I think you can automatically and instantaneously recognize something you have never seen before. That was definitely the experience I had when I heard that bat in my bedroom. On a fairly regular basis I recognize things that I have never seen before without doing any "conscious" (nonautomatic) reasoning. I bet when you were first introduced to your girlfriend's parents (assuming such an even has occurred), you recognized her father/mother/brother/dog without having to think "Hmmm, this person is male and about 25 yrs older than her, while this other person it about her age so this must be the father..." It is just automatic when you have enough background information. There are lots of things that people recognize instantly without having seen them. Similarly for imagining things. Now it seems to me quite plausible that Mary can recognize red automatically. That is, it is not clear to me that it would be necessary for Mary to do any conscious reasoning to see red. Further it is pretty clear that you and I go through unconscious reasoning in recognizing color so any distinction is going to have to lie with the conscious reasoning. In essence I think that it is quite plausible to think that Mary is just like you and me except that she is not having a red experience and she has no memories of having had such an experience. I don't see how either of those is going to buy you an absence of knowledge. I also don't like your fire example. It seems to me that in the fire example I know almost nothing about fire, while Mary knows everything (or nearly everything) about red. Similarly, the average person knows much more about fire than that it produces smoke, while the average person knows almost nothing about red except that it causes red sensations. It seems to me that a better analogy might be to compare someone who has only seen flames (say he has seen candles burn), but otherwise knows nothing about fire, to someone who has read extensively about fires but has never actually seen a flame. Who will more quickly identify a forest fire? Joel At 12:03 AM -0700 9/15/99, David Chalmers wrote: >Quick comments on messages from Joel and Joel (inc.): >(2) Re Joel L.: Joel suggests that on the basis of her physical >knowledge, Mary could learn to indirectly recognize red experiences >(by noticing her reactions) and could learn to induce the experiences >in herself. The question then, in what sense is she missing "facts" >about what red is like? This is complex, but on the face of it there >are lots of cases where a capacity for indirectly recognizing X and >constructing X's leaves us mostly ignorant about Xs. Just say we know >that fire always cause smoke, and that matches always cause fire, and >that's all we know about fire (we've never even seen it). Then we >might be in a position where we could recognize the presence of fire >(by observing smoke) and where we could bring about the presence of >fire (by lighting matches), while knowing hardly anything about the >character of fire. We'd just know about one or two associated causal >relations. So indirect recognition and construction seem to be fairly >weak criteria for knowledge. > >--Dave. From lan@U.Arizona.EDU Sat Sep 18 15:03:16 1999 Return-Path: Received: from Arizona.EDU (Penny.Telcom.arizona.edu [128.196.128.217]) by paradox.soc-sci.arizona.edu (8.9.3/8.9.3) with ESMTP id PAA00777 for ; Sat, 18 Sep 1999 15:03:16 -0700 Received: from DIRECTORY-DAEMON by Telcom.Arizona.EDU (PMDF V5.1-12 #24137) id <01JG4QJKBSRKB8UOTK@Telcom.Arizona.EDU> for chalmers@paradox.soc-sci.arizona.edu; Sat, 18 Sep 1999 22:04:12 MST Received: from orion.U.Arizona.EDU by Telcom.Arizona.EDU (PMDF V5.1-12 #24137) with ESMTP id <01JG4QJIA2O0B8U1LW@Telcom.Arizona.EDU> for chalmers@Arizona.EDU; Sat, 18 Sep 1999 22:04:10 -0700 (MST) Received: from localhost (lan@localhost) by orion.U.Arizona.EDU (8.8.6 (PHNE_17190)/8.8.6) with ESMTP id WAA17291; Sat, 18 Sep 1999 22:04:08 -0700 (MST) Date: Sat, 18 Sep 1999 22:04:08 -0700 (MST) From: Lonnie A Nelson Subject: Re: Allen's solution to Mary Arg In-reply-to: To: Joel Lachter Cc: David Chalmers , press@U.Arizona.EDU, scicon@paradox.soc-sci.arizona.edu Message-id: MIME-version: 1.0 Content-type: TEXT/PLAIN; charset=US-ASCII Status: R Regarding all of the previous... A somewhat annoying trait that I have is that I like to know what I am referring to before I refer to it, therefore, I was wondering, Would someone (anyone) mind defining exactly what is meant by "knowledge", specifically that which mary does or does not have. It seems to me that a person can mean various things when they use the word knowledge. If it is being used in the "knowledge about the things in the world" sense, I would like a definition (operational, of course) of the word "things" in this sense. It seems to me that an experience is a "thing". Unless you are talking about "things composed of known forms of matter". So, how is "Knowledge" meant? --Lonnie ___________________ It is a common fate of all knowledge to begin as heresy and end as orthodoxy. -Thomas Huxley Lonnie A Nelson Department of Psychology Human Energy Systems Laboratory University of Arizona lan@u.arizona.edu