Ehrenfels, Christian von (1859-1933)
Austrian philosopher and psychologist. In his paper Über Gestalt Qualitäten/On Gestalt Qualities 1891, he first introduced the notion of gestalt to explain observations of wholeness and object-constancy in perception.
For example, a circle is still seen as a circle even after its size or colour has changed. A whole that retains its specific character when changes occur that affect all its parts he termed a Gestalt and its special property a Gestalt quality. His ideas were important in the early history of Gestalt psychology.