Fri, 02/19/2010 - 17:17
Secondary qualities are qualities manufactured in the brain as a result of sensory input. For example, electromagnetic radiation of the right frequency entering the eye produces a sensation of green, which is manufatured in the brain out of neural signals sent from the eye. So if secondary qualities are manufactured in the brain, how do they get out there into the external world? How does the green get into the grass?
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Sun, 02/28/2010 - 11:58
#2
Perception
But when you see green grass, the green is outside your head; it is also public and material, while the supposed sensation of green is inside your head, private, and mental.
Sat, 03/06/2010 - 12:35
#3
So what's the problem?
The "green" outside your head that is public and material is simply a wavelength of light. The private sensation of green inside your head is a mentally interpreted sensation. There is no way to know if two people’s perceptions of green are the same — my "green" could be your "orange" but because we have spent our whole lives building similar associations with our personal perception of green, we treat it the same way.
Isn’t the answer contained in the question? There is no green in the grass, because it’s a quality manufactured in our minds. The only quality the grass has is to be able to reflect a certain wavelength of electromagnetic radiation which, after entering our eyes, our minds interpret as "green".