Heidegger on Existsentialism

• The Sein und Zeit of Martin Heidegger (1889-1976) claimed that Phenomenology, up to this point, had been too half-hearted. 
• The first task of Phenomenology, Heidegger maintained, was to study the concept of being (Sein) which was prior to the cleavage between consciousness and reality. 
• The most important of Heidegger's coinages is Dasein. Dasein is the kind of being that is capable of asking philosophical questions.
• The primitive element of Dasein is 'being in the world'. 
• The activity of Dasein, for Heidegger, has three fundamental aspects. First, there is what he calls 'attunement': the situations into which we are thrown manifest themselves as attractive, or alarming, or boring, and so on, and respond to them with moods of various kinds. Second, Dasein is discursive: that is to say, it operates within a world of discourses, among entities that are articulated and interpreted for us by the language and culture that we share with others. Third, Dasein is 'understanding' in a special sense that is to say, its activities are directed towards some goal, some 'for-the-sake-of-it' which will make sense of a whole life within its cultural context. These three aspects of Dasein correspond to the past, present and future of time; the time that gives Sein und Zeit the second part of its title.
• The essence of Dasein, says Heidegger, is its existence. In saying this, he became the father of existentialism, the school of philosophy that emphasises that individuals are not mere members of a species and are not determined by universal laws. What I essentially am is what I freely take myself to be.
• The relationship between Heidegger and Husserl didn't end well, in 1929 Heidegger succeeded Husserl as Professor of Philosophy at Freiburg and in 1933 he became Rector of the University. In a notorious inaugural address in May of that year he welcomed Nazism as the vehicle through which German people would at last carry out its historic spiritual mission. One of his first acts as Rector was to exclude from the University Library all Jewish Faculty members, including Professor Husserl, who still had five years to live. After the war Heidegger had to do penance for the support of Hitler and was himself prevented from teaching in the University from 1945 to 1950. However, his thought remained influential up to and beyond his death in 1976.