Describe symbolism in Art and Illusion: A Study in the Psychology of Pictorial Representation by Ernst Gombrich

In an important section of Part Three, Gombrich turns to "the perception of symbolic material," using his experience as a British Broadcasting Corporation monitor during World War II. He discusses how our knowledge and expectations contribute to what we actually see or hear. The greater the likelihood a given word will occur, the less likely we are to listen. In Gombrich's own words, "Where we can anticipate we need not listen. It is in this context that projection will do for perception." The beholder, in other words, closes the gaps through projection, the act of projecting the image he or she expects into "an empty or ill-defined area."

Likewise, incomplete visual images push the beholder into completing the image: artists provide the hints that the viewer must use to complete the image. Artists cannot represent every detail of reality, no matter how painstakingly they work. It is the creation of an illusion that allows the beholder to fill in the details. Gombrich asserts, "I believe that this illusion is assisted by what might be called the 'etc. principle,' the assumption we tend to make that to see a few members of a series is to see them all." Furthermore, the expectation of the viewer as well as the context of the image affect the meaning the viewer assigns to an image.