[hist-analytic] The "Analytic A Posteriori"

Bruce Aune aune at philos.umass.edu
Thu Sep 3 07:44:14 EDT 2009


OK, Danny, one more response on the color issue.  Again, I say that  
your alleged counterexamples are not inconsistent with what I say.   
The most they show is that we may be wrong in thinking that we are  
dealing with the very same color.  But I never doubted this or implied  
that it is any way doubtful.

1.  The spreading effect.  If we mask the adjoining colors of the red  
strip with a neutral color, we can see that the red strip is uniformly  
the same. We can discern no difference. (Of course, of course, we  
could make an error here; errors are always possible.) If we remove  
the masking material, the part of the strip adjoining the black line  
looks darker.  We know the color did not actually change.  We know we  
are dealing with an illusion.  (Who doubts this?)  The spreading  
effect is presented as an illusion.

Optimal conditions are conditions in which things (in this case  
colors) look the way they really are to people with optimal vision,  
i.e. who have the visual capacity to discern the colors things  
actually have in optimal conditions.  Don't tell me there is a  
circularity here.  Our conceptions of optimal perceptual conditions  
and optimal perceptual capacities are closely interrelated.  As time  
goes by we learn more and more about both kinds of optimality.  We  
learn to recognize more and more conditions (such as the spreading  
effect) that produce deceptive appearances.  We also learn more and  
more about optimal perceptual abilities.  We learn to devise tests by  
which to identify perceptual abnormalities.  None of this shows my  
principle to be false.

2. Transitivity/intransitivity.  Suppose we can discern no difference  
in color between a and b and b and c but we can discern a difference  
between a and c.  What do we conclude?  Assuming we are dealing with  
perceivers with keen vision, we will conclude that either (i) the  
three things are not being perceived in equally optimal conditions, or  
(b) there is some difference in the colors of a, b, and c that we are  
not discerning in these conditions.  So, if the matter is important,  
we continue to investigate the objects and the conditions.  Do we  
conclude the principle I gave is false?  NO.  We have indirectly  
discerned a difference that exists either in the relevant perceptual  
conditions or in one of the perceived colors.  We haven't located that  
difference, but we know it exists.

3.  Your third case:  "whatever conditions we specify as optimal, it  
is possible we can find other (even better) conditions under which we  
can distinguish between shades which were indiscernible under the  
(old) optimal conditions." Yes, this is possible.  Errors are always  
possible. But this doesn't mean the principle is false. You say "What  
we can discern depends upon our limited powers, so an enhancement of  
these powers would produce such a change of conditions.."  Yes, our  
powers can in principle be enhanced, and we can continue to learn  
about external conditions that can effect what we perceive.  But none  
of this shows that the principle is false.

Yes, yes, yes, mistakes are always possible.  But whoever doubted this?

I will comment on other things you say abut analyticity in another  
installment.  But please, no more about the color case.  I can imagine  
further things you might say, but let's leave the matter here.  Other  
readers can judge the matter on the basis of what we have already said.

Best, Bruce
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