Perception is so continually present, close to us, and diverse in its forms that it is one of the most challenging themes for psychological reflection. We are so captivated by what we perceive that the hows and whys remain in the background. In the wilderness of everyday life, perception can easily embarrass the investigator who ceases to take it for granted, for attempts at conceptualization seem alien, in one way too crude and in another too sophisticated in their complexity. Perception, therefore, tends to elude the grasp of knowledge and to remain à great mystery.