Karl Bühler

Karl Ludwig Bühler (27 May 1879 – 24 October 1963) was a German psychologist and linguist. In psychology he is known for his work in gestalt psychology, and he was one of the founders of the Würzburg School of psychology. In linguistics he is known for his organon model of communication and his treatment of deixis as a linguistic phenomenon.

He was the dissertation advisor of Karl Popper. Provided by Wikipedia