Max Wertheimer
Max Wertheimer (Austrian German: [ˈvɛrthaɪ̯mɐ]; April 15, 1880 – October 12, 1943) was a psychologist who was one of the three founders of Gestalt psychology, along with Kurt Koffka and Wolfgang Köhler. He is known for his book Productive Thinking and for conceiving the phi phenomenon as part of his work in Gestalt psychology.