Assigned Weekly Questions
May 12th
NOTE: These questions require more background knowledge and general thought than what will be typical of our "reading questions". This is an attempt to get everyone up to speed on some standard issues in the philosophy of mind. Don't worry if you cannot give a definitive answer; just say what you do know and say what you don't understand.
1. "Eliminativism" usually refers to "Eliminativist Materialism" a thesis in the philosophy of mind, that states that some or all of our ordinary folk theory of the mind is false. (See The Stanford Enclyclopedia entry for a 'refresher" or idf you have not taken a philosophy of mind course.) What is the thesis of Eliminativism about colour properties as described by Byrne & HIlbert? How does it differ from eliminativist theses about the nature of mental states? Note that Byrne and Hilbert state explicitly that the Problem of Realism is NOT a problem about the meaning of colour words or colour concepts.
2. What is "Berkeley's Challenge" to Dispositionalism? When dispostionalists speak of "standard viewing conditons" (for colours), what sorts of conditions do most dispositionalists have in mind?
3.Byne and HIlbert have little use for Thompson's "ecological relationalism". What is the theory of "ecological relationalism" supposed to be? Do you think it differs from standard dispositionalism? For the curious, click HERE for 1 page Nature article on how spiders (which prey on bees) make flowers more inviting to foraging bees, in virtue of the spider colouring.
Tuesday, May 17th
Causes of Color
1. Frankly, even at this stage, I find it difficult to understand the explanations given by Hardin in this section on why various kinds of objects/media are seen as being blue, because in these explanations he leaves out what is common to all these cases. So let's concentrate on one question: why is the sky blue? (Hint: If you type in "why is the sky blue" in Google, you will find any number of answers, of different levels of sophistication).
2. What DO all blue things have in common (apart from being perceived, typically, by human observers)? (Hardin tells you at the end of the explanations.)
3. Hardin explains briefly why this common property does not provide a good answer to the question "what is colour (or the colour blue)?". Do you have any idea of the general point he is trying to make? He gives us many details, but what do these details have in common? (Do the best you can here; this passage is quite turgid.)
Thursday, May 19th
Physiology of Vision and Colour Physiology
Please note: These readings are very detailed and you will not need to know understand all of it (these readings were chosen because they are up-to-date, and the story about colour vision is changing very quickly). We will cover the relevant information in class. However, please read the the Hardin for general background on visual processing, and read the Solomon & Lennie for colour physiology, up until the section on cortical processing.
1. What is a center-surround cell? How does it work? Recall that at the beginning of the section (The Camera and The Eye), Hardin says: "Unlike a passive camera, the eye begins from the moment its receptors
absorb light to transform and reorganize the optical information that comes to it from the world. The retina is, in fact, a bit of extruded brain, and by examining those first steps of visual processing which
it executes we may hope to gain an inkling of how the brain constructs those chromatic experiences which constitute a portion of its sensory representation of the world." In what way does a center/surround cell transform visual imformation as opposed to simply record it?
2. What is the principle of univariance? (Solomon and Lennie) Although the three cones are often called the Red, Green and Blue cones, why does it follow from the principle of univariance that each cone could not be responsible for the perception of a single colour (i.e. red, green or blue)?
3. Are there equal numbers of all the three cone types—S, M & L? How does an M-On cell work? An L-On cell work? (There are center-surround cells that are chromatically — wavelength— selective.)
Tuesday, May 31st
Additional Questions on Colour Physiology
1. How did Hering's proposal (for the physiological basis of colour vision) differ from Helmholtz's? Why on Hering's view can there not be a reddish-green? (See Hardin p. 28)
2. In figure I-14 in Hardin, what does this figure illustrate? More pointedly, how was this figure generated, from what kind of data? Why is the "whiteness" or achromatic value always positive?
3. What is the chromatic cancellation procedure?
Thursday, June 2nd
Colour Phenomenology (Hardin & Clark)
1. Harding gives three empirical examples (based on infant perception, colour naming in the Dani, and adult English speakers "guesses" about the make-up of binary hues) to support the thesis that colour opponency serves to organize our phenomenology of colour, independently of afge, language, and psychological knowledge. Do you find any of these examples convincing? Why or why not.
2. What is the difference between 'phenomenal properties' and 'qualitative' properties? (This distinction serves to organize the entire paper.
3. From Clark. Why does Clark say that a quality space is NOT a stimulus space? P. 5 Why, in psychophysics, is a stimulus a "class of stimulus occasions"?
4. On Page 15, Clark writes: "A simple conclusion follows: if we are to define a term for a qualitative property (a 'qualitative' term), we cannot mention any stimuli. We can mention only the structural properties that give the qualie its place in the quality space. "Orange' cannot be defined as 'the colour of ripe oranges' or in any similar way, no matter how sophisticated. It can be onluy be defined as something like 'the colour midway between red and yellow, and more similar to either than turquoise'." Why does Clark claim this?
Tuesday, June 6th (Thompson, Palacios, Varela)
1. What is a "ternary" colour? (No, not a colour as experienced by the River Tern, Greater or Lesser Tern or Terns in general!) See page 382.
2. In the authors' argument against "objectivism", they start with the two following premises: (1) For something to be a chromatic color, it must be a hue. (2) For something to be a hue, it must be either unique or binary (or ternary).
What kind of premises do you take these to be? That is, are they supposed to be a conceptual truths? Or is it supposed to be a scientific or empirical truth? (The answers here are important because the argument, in the following paragraphs depends upon the "non-expendibility" of these two premises.) It is true that colour systems—actual colour systems—have opponent processes, and this, plus the exact form our human opponent processes, explains why our colours are binary. Is opponency a necessary property—either empirically or conceptually—of colour properties?
3. On pages 386 & 387, the authors argue that the property "being a surface" is not an objective property. They give 4 different arguments in the following four paragraphs (beginning "First..", "Second..."). Try to reconstruct ONE of those arguments. What do you make of it?
Tuesday, June 21, Harman, Cohen
Question on Harman reading: What is Harman's understanding of the concept of a colour, say red? What does he mean by a "primitive perceptual concept"? And how does this avoid circularity in his final dispositionalist account of colour properties (e.g. redness)?
Question on Jonathan Cohen's "Relationalist Manifesto": Choose one of Cohen's responses to criticisms from (1) colour constancy (2) reduction tubes (3) Perceptual variation. State the objection to Cohen and Cohen's response (2 short paragraphs); provide your own assessment of Cohen's response. Due Friday, June 24th, by email, as a WORD attachment.
Thursday, June 23, Hardin
Question on Hardin's "The Virtues of Illusion". Both Hardin and Cohen conclude, on the basis of the variation in colour experience between individuals and species, that colour cannot be an objective property of the world, However, Hardin wishes to go one step further: because there is not theoretically acceptable way to designate some property of the environment as the property of colour, therefore colour must be an illusion. But if colour is an illusion, some story is needed about why it would be that we have this large and computationally complex capacity for seeing "the colours". Without some story or other, it simply doesn't make sense. Hardin has a story in terms of informational capacties of the human visual system. What is that story (in 1 page of succint writing)? Due Monday, June 27th,, by email, as a WORD attachment.