After lecture ten I've pretty much burnt out on philosophy of the mind, but Prof McGinn keeps going so will I. This lecture is about the relationship of reality and one's perception of it. The goal (though I think it can never be attained) is to resolve the problem of appearance and reality.
Say with sight, I'm seeing a table. Am I seeing it as it is? Or, is it colored or altered by my mind. The question is not if the table exists, as the skeptic would ask. The question is how it appears to me in my senses. It is actually there but how do I perceive it? The first argument is from illusion.
In this argument, one person is actually seeing a black table, and a second person is seeing an illusion of a black table. The person "seeing" the illusory table is not really seeing a table he/she is seeing the sense datum of a table, and the assumption that the person seeing the actual table is actually seeing the table. The problem is, that the person that is actually looking at the table, is also only able to see via sense data. There are a couple attempts to answer this problem. One says that the person experiencing the illusion of the table, is seeing nothing. This cannot be the case, because to see nothing would mean that he/she isn't seeing a table, he/she is seeing nothing and nothing cannot be seen. The second (and better answer to my mind), is that the person experiencing an illusion is seeing an object that doesn't exist. One issue in this is just in terminology. The person isn't actually "seeing" a non-existent object, it could be said that the person is experiencing the illusion of seeing a non-existent object.
After talking about that argument, Prof McGinn moves on to a secondary argument within the concept of the relativity of sensation. He uses two specific examples, sugar being sweet/bitter, and the color being red/green. Is there a case such that sugar can be bitter to a specific person/sense-group? It seems plausible that scenario could exist. So, we have to revise how we say, such and such is sweet. We must say, such and such is sweet to me. Tastiness is a much easier issue. One person may say that a particular dish is tasty, and another may take the exact same dish and say it's disgusting. Obviously there is a relativism in the perception of taste.
Next, color. Take the color red. "This ball is red." Say a particular set of people (Prof McGinn uses martians for both of these arguments) see red as green. Again, it ends up saying, such and such looks red to me/us. They're relative to the observer. This isn't an attack on truth, it's not making truth relative, it's just pointing out that certain properties are relative to the perceiver. Prof McGinn sums colors are response-dependent properties.
NOT all properties are response-dependent. His example is shape. Round vs. square, that cannot be a subjective property. To accept this as a response-dependent property, we'd also have to give up on the notion that objects have particular properties. So, we have to divide different properties into categories of response-dependent and objective properties. Flavor and taste is obviously response dependent, as is attractiveness/sexiness, what about humor? These all seem obvious to me that they are completely response-dependent. Is beauty in the eye of the beholder?
This distinction is often called primary qualities as opposed to secondary qualities. Secondary qualities are like color, taste, sound, beauty, smell, etc. The primary qualities are in the realm of physics, shape, mass, size, number/quantity, etc. This is basically the same concept as what are manifest images or conceptions verses the scientific images or conceptions. The way we can think about this is to imagine what the universe looked like before anyone or anything was around to perceive the universe. IF color is a mind-dependent quality then the universe would be shades of gray or the abstract conception of the universe without a perceiver to give it the mind-dependent qualities.
Two polarizing views, realism-the universe is real as it is but it doesn't have perception-dependent qualities and idealism-objects are not these abstract images that we think they might be they are actually ideas within the mind of God and we receive them in our mind. All of these discussions concerning the mind and it's relationship with the universe and perception all lead up to the next lecture on what is the self. Because all of these issues with the mind revolve around the idea of there being a self to experience these things.
That's what Prof McGinn said (at least as I understand it), now for what I think about it...
First off, I want to clarify that I don't know for sure anything that I'm about to say, but it seems much more logical to me than how Prof McGinn describes the different types of perceptions and their categories. The biggest issue I have with Prof McGinn's delineation of senses (and I'm sure others would agree with him) is color. We might all perceive colors differently. We definitely name colors differently between different people.
Does that change the differences in light wavelength that makes different colors in the first place? Colors should not be put on the relative side of the perceived properties scale. Color is subjective in that it's a specific wavelength of light.
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| From Wikipedia, 1 Million colors |
One possible arrangement of some primary and secondary qualities:
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Primary Qualities
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Secondary Qualities
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Color
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Flavor
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Size
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Attractiveness
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Shape
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Smell
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Frequency/pitch
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Goodness of sound
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Mass
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Feel (smooth, rough, etc.)
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Atomic makeup
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Everything else…
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