Along with the belief that the whole is more than the sum or its parts, Gestalt psychologists also believed in the law of pragnanz, which roughly means the law of good figure. The law of pragnanz translates into the idea that people will perceive the best thing they can out of the stimuli that are presented to them. In some situations it is hard to obey the law of pragnanz, which is the case for impossible figures. Gestalt psychologists used the idea of figure and ground to help make their theory about the human perceptual system. Figure-ground perceptions are demonstrated in the perception of subjective contours.
People look for closure in the stiumli they see.
Gestalt psychologists also identified perceptual grouping principles.