simon blackburn think a compelling introduction to philosophy

Russell uses the example of a brown, shiny desk. The argument runs like this-1) We perceive something having some property F (e.g a crooked stick in water) 2)When we perceive something having some property F, then there has to be something that has this property 3)In an illusion, the physical object does not have the property F 4)Therefore what has the property F has to be something mental, a sense datum 5)Therefore in an illusion we see sense-data, and not the physical object immediately 6)Illusions can be subjectively indistinguishable from veridical perceptions 7)Therefore we see the same thing, namely sense-data, in both illusions and veridical perceptions 8)Therefore in all cases we see sense-data and not the physical object immediately 9)Therefore direct realism is false The argument from perceptual variation-A little reflection suggests that what we perceive isn't quite the same as what is out there. Illusions can be subjectively indistinguishable from veridical perceptions e.g a crooked stick in water, so this means we see sense data and not physical objects immediately.

Issues Argument from Illusion-Illusions are a distortion of the senses, which means what we perceive isn't how an existing object actually is. This claims that there are mind independent objects that exist independently of our minds and that the objects we perceive in our minds are directly correspondent to those objects. Direct realism-The immediate objects of perception are mind-independent objects and their properties.

Simon blackburn think a compelling introduction to philosophy