You searched for: “existentialist
existentialist (s) (noun), existentialists (pl)
An adherent of the belief that individuals create their own ethical values and are accountable for the consequences of their actions: The existentialists de Beauvoir and Sartre are believed to have influenced each other in their works, such as Sartre's "Being and Nothingness" and de Beauvoir's "She Came to Stay".