For the last 2,500 years, philosophers have struggled to define the connection between perception and reality. The idea that our perceptions of the world might not resemble the actual world with any great degree of accuracy was a critical force in the development of philosophy and science. As philosophers have puzzled over this question throughout the ages, dreams always seem to have eluded them. Dreams introduce perceptions that the "common sense" thinker will insist do not form a part of the actual world, but how is it that these perceptions differ from those of waking life? When the 18th century Anglican Bishop George Berkeley revolutionized modern thought by constructing a beautifully simple yet wholly counterintuitive metaphysics in which reality is defined by perception and not the other way around, he too was faced with the problem of dreams, and it is a problem that his writings alone may not adequately solve. If, as Berkeley asserted, "to be is to be perceived," does it follow that dreams are real?