24.09 Minds and Machines spring an inconsistent tetrad. argument for (1) argument for (2) argument for (3) argument for (4)

Transcription

1 24.09 Minds and Machines spring 2006 more handouts shortly on website Stoljar, contd. evaluations, final exam questions an inconsistent tetrad 1) if physicalism is, a priori physicalism is 2) a priori physicalism is false 3) if physicalism is false, epiphenomenalism is 4) epiphenomenalism is false 1 2 argument for (1) argument for (2) out of type-a and type-b materialism, the former is much more plausible than the latter see Chalmers against type-b materialism hence: if physicalism (materialism) is, a priori physicalism (type-a materialism) is both the conceivability argument and the knowledge argument show that knowledge of every physical property a person has cannot by itself suffice to know which qualia, if any, his or her experiences instantiate hence a priori physicalism (type-a materialism) is false 3 4 argument for (3) argument for (4) type-e dualism is much more plausible than type-d dualism hence if physicalism is false (and so dualism is ), type-e dualism (and so epiphenomenalism) is obviously qualia are causally efficacious with respect to physical events, otherwise we wouldn t have any reason to think that there are any qualia hence epiphenomenalism is false 5 6 1

2 (1)-(4) are individually plausible, but at least one must be false 1) if physicalism is, a priori physicalism is 2) a priori physicalism is false 3) if physicalism is false, epiphenomenalism is 4) epiphenomenalism is false 7 t-physicalism and o-physicalism P is a t-physical property iff P is (i) the sort of property that a () physical theory tells us about or (ii) a property which metaphysically supervenes on properties that satisfy (i) so: having +ve charge and having mass are t- physical properties (by (i): the theories of electromagnetism/gravity) either having +ve charge or being green is a t- physical property (by (ii): necessarily, if x is positively charged, x is either positively charged or green) 8 P is an o-physical property iff P is (i) the sort of property required by a complete account of the nature of paradigmatic physical objects or (ii) a property which metaphysically supervenes on properties that satisfy (i) so: having +ve charge and having mass are o- physical properties (by (i): needed for a complete account of sticks and stones) either having +ve charge or being green is an o- physical property (by (ii): necessarily, if x is positively charged, x is either positively charged or green) a reminder from the philosophical toolkit: dispositions (powers, tendencies) a special kind of property examples: fragility, solubility, elasticity a fragile object is (to a first approximation) something that would break if it were struck a wine glass is fragile (has the property of fragility) even when it isn t manifesting the kind of behavior (breaking) distinctive of fragility 9 10 something new from the philosophical toolkit: categorical properties a special kind of property not a dispositional property the kind of property the possession of which explains the possession of a dispositional property in the case of a fragile vase, a property whose instantiation makes it the case that the vase is fragile thesis 1: physical theory tells us only about dispositional properties (roughly) to be positively charged is to be disposed to be attracted by electrons, repelled by protons, etc. (roughly) to have mass is to be disposed to warp space-time let s grant thesis 1 for the sake of the argument

3 thesis 2: if an object x has a dispositional property D, x has a categorical property C that explains why x has the dispositional property why would this vase break when struck (i.e. why is it fragile)? there must be an explanation, and if the explanation is in terms of more dispositional properties, we will need an explanation of why the vase has these dispositional properties so this chain of explanations must bottom out in an explanation in terms of categorical properties let s grant thesis 2 for the sake of the argument 13 conclusion from theses 1 and 2 paradigmatic physical objects have categorical properties (thesis 2) these categorical properties are not t- physical properties (thesis 1) but they are o-physical properties (by the definition of o-physical ) so, some o-physical properties are not t- physical properties 14 two kinds of physicalism t-physicalism: everything supervenes on t-physical properties o-physicalism: everything supervenes on o-physical properties t-physicalism implies o-physicalism, but not conversely 15 back to the knowledge argument 1 imprisoned Mary knows all the physical facts hence: 2 if physicalism is, Mary (before her release) knows all the facts 3 after her release, Mary learns something something she couldn t have known while imprisoned 4 if Mary learns something, she learns a fact hence (from 3, 4): 5 Mary learns a fact hence (from 2, 5): 6 physicalism is false all the t-physical facts, or all the o-physical facts? 16 all the t-physical facts both the conceivability argument and the knowledge argument show that knowledge of every t-physical property a person has cannot by itself suffice to know which qualia, if any, his or her experiences instantiate hence a priori t-physicalism is false the knowledge and conceivability arguments give us reason to believe: 2-t a priori t-physicalism is false but not: 2-o a priori o-physicalism is false

4 still an inconsistent tetrad 1-t if t-physicalism is, a priori t- physicalism is 2-t a priori t-physicalism is false 3-t if t-physicalism is false, epiphenomenalism is 4 epiphenomenalism is false 19 but: do we have reason to believe 3-t? 3-t if t-physicalism is false, epiphenomenalism is 3-o if o-physicalism is false, epiphenomenalism is no, because if t-physicalism is false, o- physicalism might yet be and if o-physicalism is, there s no obvious reason why the mental is epiphenomenal ophysical properties (even those that aren t t- pp s) are presumably causally efficacious 20 a consistent tetrad 1 if (t-/o-) physicalism is, a priori (t- /o-) physicalism is * 2-t a priori t-physicalism is false 3-o if o-physicalism is false, epiphenomenalism is 4 epiphenomenalism is false *i.e. if t-physicalism is, a priori t-physicalism is, and if o-physicalism is, a priori o-physicalism is the resulting position is type-f monism (panprotopsychism) consciousness is constituted by the [categorical] properties of fundamental physical entities...phenomenal or protophenomenal [i.e. o-physical] properties are located at the fundamental level of physical reality (Chalmers, C&IPIN) n.b. the nature of the protophenomenal [ophysical] properties is unknown, because physical theory does not tell us about them a taxonomy of theories type-a materialism/a priori physicalism (Lewis, Dennett [apparently]) type-b materialism/a posteriori physicalism (Tye, Levine) type-c materialism/a priori mysterianism (Nagel [maybe], McGinn [maybe]) type-d dualism/cartesian interactionism (Descartes) type-e dualism/epiphenomenalism (Jackson [when he wrote epiphenomenal qualia ]) type-f monism/panprotopsychism (Chalmers, Stoljar) 23 final exam sample quotation identification & explanation. Identity the authors of the following quotations. For each quotation, write a sentence or two explaining the main point. cut the pie any way you like, meanings just ain t in the head! sample answer: Putnam. Putnam is saying that two people who are intrinsically just alike (that is, who are molecule-for-molecule replicas) might mean different things by their words. 24 4

5 Such in outline is the official theory. I shall speak of it, with deliberate abusiveness, as the dogma of the Ghost in the Machine. It is one big mistake and a mistake of a special kind. It is, namely, a category-mistake. sample answer: Ryle. What Ryle calls the official theory is the dualism of Descartes. An example of a category mistake is this: thinking that MIT is just another building on campus, like the Stata Center, Kresge Auditorium, etc. sample multiple choice: 1. Is Ned Block's example of the Aunt Bubbles machine supposed to refute functionalism? 2. Does Searle think that strong AI is false? sample short answer (a paragraph): 1. What is behaviorism? Describe one objection to behaviorism that we discussed in class essay questions (answer 2 out of 3) 1. Nagel, Jackson, and McGinn all think that consciousness poses a problem for physicalism, on somewhat similar grounds. Critically compare and contrast their views. Is it that with consciousness, [the mind-body problem] seems hopeless? 2. In Consciousness and its place in nature, Chalmers distinguishes Type-A Materialism, Type- B Materialism, Type-C Materialism, Type-D Dualism, Type-E Dualism, and Type-F Monism. Pick one that you think is false. Explain what this theory is, and why you think it s false. Now take the theory that you think is (or, at any rate, is the least implausible of the lot). Explain what this theory is, and defend it against objections Could a suitably fancy robot think? More specifically, could a robot believe that it s raining in Cambridge? (Take the robot to be constructed from the usual materials: microprocessors, cables, servomotors, etc., with a variety of external sensors like cameras and microphones.) Could a suitably fancy robot have conscious experiences? More specifically, could a robot feel pain, or have a yellowyorange afterimage? Approach these questions by considering how they might be answered by various philosophers we have encountered, for instance Descartes, Smart, Block, Lewis, Putnam, Dennett, and Chalmers. Minds and Machines spring 2006 more on the final exam next time questions on web by wednesday read McGinn

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