was an Irish philosopher. His philosophical beliefs were centered on one main belief, the belief that perception is the basis for existence. In doing so, he rejected the notion of a material world in favor of an immaterial world. Berkeley felt that all we really know about an object we learn from our perception of that object. He recognized that in the materialist’s view the real object is independent of any perceiver’s perception. The pen on my desk would exist, whether or not I was in the room to see it or have a sensory exp ....