Among distinguished sociologists, Martin Heidegger was a German philosopher, critical in Being and Time of abstract theories of human existence because they neglected the concrete, actual, everyday world. He developed a view of this mundane social world which subsequently influenced the sociology of the life-world or everyday life. Heidegger formulated a philosophical methodology for the analysis of texts which contributed to the modern technique of deconstruction. His analysis of technological society was an important conservative criticism of capitalism, but his association with fascism has damaged his reputation. Heidegger is well known for his contributions to phenomenological sociology and existentialism, though as the Stanford Encyclopedia of Philosophy cautions, "his thinking should be identified as part of such philosophical movements only with extreme care and qualification".
Heidegger argues that human being is even more fundamentally structured by its Temporality, or its concern with, and relationship to time, existing as a structurally open "possibility-for-being". He emphasized the importance of Authenticity in human existence, involving a truthful relationship to our thrownness into a world which we are "always already" concerned with, and to our being-towards-death, the Finitude of the time and being we are given, and the closing down of our various possibilities for being through time. - John Richardson, Heidegger, Routledge, 2012.
Heidegger's later work includes criticisms of technology's instrumentalist understanding in the Western tradition as "enframing", treating all of Nature as a "standing reserve" on call for human purposes. Heidegger is controversial, mainly for his affiliation with Nazism, as Rector of the University of Freiburg, before his resignation in April 1934, for which he neither apologized nor publicly expressed regret.