In this thesis, the problem of human being’s alienation from its own Self, society, species-being, objects (products) and labour, which occurs in capitalist modernity through the formation of mass cultures, is analyzed in the conceptual context of Being and Time. In this respect, it is discussed that Heideggerian philosophy is not at odds with Marxism in contrast to Theodor W. Adorno’s arguments in The Jargon of Authenticity. Additionally, the claim of this study is that Heidegger’s ontologico-existential philosophy can be effective in the analysis and solution of the problem with regard to some socio-psychological causes and effects of alienation in which the method of political economy can remain inadequate. In particular, Dasein’s free a...