This in-depth analysis of Heidegger's major works finds a fundamental thematic unity in the philosopher's effort to overcome the subjectivism of modern philosophy and to account for the ontological hierarchy that it alone constitutes a foundation for everything else. The author sees this challenge to the Cartesian tradition as the key to understanding Heidegger's views on human beings and language, as well as their influence in the issues of identity and representation in contemporary philosophy.