The Vanishing World and Köhler’s Inkwell
As cognition becomes more wary, it begins to separate mere appearances from objective existences. Some visual percepts turn out to be misleading, but they are considered exceptions in an otherwise reliable world. Such a worldview suffices for daily living, and it also suffices for psychologists who are untouched by the refinements of epistemology. They study, for example, optical illusions or dreams as curious deviations from a reality that otherwise is directly given.