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Unformatted text preview: Announcements and Such • Genesis : “Watcher of the Skies” from Foxtrot • Sections meet this week in their permanent location • Permanent section locations are posted on web • You should have received 2 emails re sections • The Thursday 3-4 section meets in 235 Dwinelle • Final course roster will be set this week (everyone?) • First Chunk of Audi is online < 122/audi_1.pdf > • No Lecture on Tuesday! • Today: Perception III (of III) • Brief review, then the final perception readings… Review from Last Time I • The Naive, direct realist has no way to handle cases of illusion & hallucination • Sense-Datum (SD) theory is an alternative, indirect form of realism • SD : objects cause mental representations , (sense-data) which we directly perceive • These sense-data can misrepresent the external physical objects that cause them • When such misrepresentation happens, we suffer from perceptual illusion • SD : in hallucination, there are still sense- data present, but no object causing them Digression on Misrepresentation I • How is misrepresentation even possible , from a causal/realist point of view? • Fred Dretske has a nice paper on this issue (it’s called “ Misrepresentation ”) • He discusses magnetosomes — tiny organisms that live in the ocean. • In their “normal” environment/niche, the amount of oxygen in the water tends to increase as one goes due north • They evolved magnetic-field detectors to help them move toward oxygen-rich • A sudden change in their environment caused these systems to misrepresent Digression on Misrepresentation II • One could tell a similar story about the perceptual systems of human beings • Plausibly, they are designed to produce representations (with a certain degree of accuracy) in certain environments • When subjected to a radically abnormal or unusual environment/scene, one’s perceptual system may misrepresent • Last time, we saw various compelling and persistent visual illusions. • Perhaps we’re like magnetosomes… • Our normal environments/niches haven’t presented us with such “weird” scenes Review from Last Time II • The argument from hallucination (AFH) is used to motivate SD-theory. • AFH: genuine & hallucinatory experience are intrinsically indistinguishable . 㱤 they must have the same objects (SD) • The AFH is unsound : • There need not be any object of Halluc. • Even if there is, why should they be the same type as in genuine perception? • And, why should both be mental / internal ? • AFH does have intuitive appeal — G&H experiences do “ feel ” like the same types Adverbial Theories I • So, the SD-story faces serious problems....
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- Spring '07
- Philosophy of perception, hallucinations, visual experience, adverbial theories