Max Wertheimer (1880-1943) was a co-founder of Gestalt psychology, one of the most influential schools of thought in the history of psychology. His 1912 paper on apparent motion (the phi phenomenon) — the perception of movement when stationary lights flash in sequence — demonstrated that perceptual experience cannot be reduced to individual sensory elements. The perceived motion was a genuine perceptual experience that existed nowhere in the individual stimuli, establishing the Gestalt principle that the whole is different from the sum of its parts.
Gestalt Principles
Wertheimer and his colleagues (Wolfgang Köhler and Kurt Koffka) formulated the laws of perceptual organization: proximity (elements close together are grouped), similarity (similar elements are grouped), good continuation (elements forming smooth lines are grouped), closure (incomplete figures are perceived as complete), common fate (elements moving together are grouped), and the overarching law of Prägnanz (perceptual organization tends toward the simplest, most regular, most symmetric interpretation). These principles describe how the brain organizes sensory input into meaningful perceptual structures.
Wertheimer's last work, Productive Thinking (published posthumously in 1945), applied Gestalt principles to problem solving and education. He argued that genuine understanding involves grasping the structural relationships within a problem (insight), not merely memorizing procedures. He contrasted productive thinking (reorganizing the problem to reveal its underlying structure) with blind, mechanical application of learned rules — anticipating modern emphasis on conceptual understanding over rote learning in education.