(August 18, 2013 at 2:42 am)Esquilax Wrote:(August 17, 2013 at 1:37 pm)Undeceived Wrote: What about optical illusions? Or how about this: does everything exist exactly as you see it? The sun looks perfectly spherical--are we justified in believing it is indeed a sphere? Can you confidently call a rock a rock without examining it to the last atom? Where do you draw the line between a rock and a boulder? Is that line verifiable... or do you the categories come from your head?
As for optical illusions, you might be seeing something that isn't there, but it won't have a physical presence that corresponds to any of your other senses, which should be your first hint that something is up.
So you do use reason in addition to or in opposition to your senses.
