Abstract

What are the conceptually necessary and sufficient conditions for a person, or organism, to perceive a given object? More precisely, what is the nature of our ordinary thought about perception that gives rise to our willingness or unwillingness to say that S perceives O? Some form of causal theory of perception is now, I think, widely accepted. Such a theory maintains that it is part of our concept of perception that S perceives O only if O causes a percept, or perceptual state, of S. I accept this causal requirement, though with some qualification. The crucial problem for the theory of perception is what must be added to the causal requirement. Not all causes of a percept are said to be perceived. Smith looks at a tree illuminated by the sun, when the sun is not itself in view. His visual percept is caused by the tree, but not only the tree. The percept's causal ancestry includes the sun and the array of light two inches from Smith's eyes. Why do we say that he sees the tree, but not the sun or the array of light? What principles underlie this invidious choice among causes? Similarly, we think of a bat as perceiving objects in his path, but not as perceiving himself. Yet, since he emits the sonar signals these objects reflect, he is himself a cause of his percepts. Why don't we say he perceives himself?