Sanford Meisner

Sanford Meisner (August 31, 1905 – February 2, 1997) was an American actor and acting teacher who developed an approach to acting instruction that is now known as the Meisner technique. While Meisner was exposed to method acting at the Group Theatre, his approach differed markedly in that he completely abandoned the use of affective memory, a distinct characteristic of method acting.

Meisner maintained an emphasis on "the reality of doing", which was the foundation of his approach. Description above from the Wikipedia article Sanford Meisner, licensed under CC-BY-SA, full list of contributors on Wikipedia.