<P> Heidegger's philosophy is founded on the attempt to conjoin what he considers two fundamental insights: the first is his observation that, in the course of over 2,000 years of history, philosophy has attended to all the beings that can be found in the world (including the world itself), but has forgotten to ask what Being itself is . Heidegger thought the presence of things for us is not their being, but merely them interpreted as equipment according to a particular system of meaning and purpose . For instance, when a hammer is efficiently used to knock in nails, we cease to be aware of it . This is termed "ready to hand", and Heidegger considers it an authentic mode, saying that the given ("past") has presence in an oversimplified way when reduced to possible future usefulness to us . </P> <P> Heidegger claimed philosophy and science since ancient Greece had reduced things to their presence, which was a superficial way of understanding them . One crucial source of this insight was Heidegger's reading of Franz Brentano's treatise on Aristotle's manifold uses of the word "being", a work which provoked Heidegger to ask what kind of unity underlies this multiplicity of uses . Heidegger opens his magnum opus, Being and Time, with a citation from Plato's Sophist indicating that Western philosophy has neglected Being because it was considered obvious, rather than as worthy of question . Heidegger's intuition about the question of Being is thus a historical argument, which in his later work becomes his concern with the "history of Being", that is, the history of the forgetting of Being, which according to Heidegger requires that philosophy retrace its footsteps through a productive destruction of the history of philosophy . </P> <P> The second intuition animating Heidegger's philosophy derives from the influence of Edmund Husserl, a philosopher largely uninterested in questions of philosophical history . Rather, Husserl argued that all that philosophy could and should be is a description of experience (hence the phenomenological slogan, "to the things themselves"). But for Heidegger, this meant understanding that experience is always already situated in a world and in ways of being . Thus Husserl's understanding that all consciousness is "intentional" (in the sense that it is always intended toward something, and is always "about" something) is transformed in Heidegger's philosophy, becoming the thought that all experience is grounded in "care". This is the basis of Heidegger's "existential analytic", as he develops it in Being and Time . Heidegger argues that describing experience properly entails finding the being for whom such a description might matter . Heidegger thus conducts his description of experience with reference to "Dasein", the being for whom Being is a question . </P> <P> In Being and Time, Heidegger criticized the abstract and metaphysical character of traditional ways of grasping human existence as rational animal, person, man, soul, spirit, or subject . Dasein, then, is not intended as a way of conducting a philosophical anthropology, but is rather understood by Heidegger to be the condition of possibility for anything like a philosophical anthropology . Dasein, according to Heidegger, is care . In the course of his existential analytic, Heidegger argues that Dasein, who finds itself thrown into the world (Geworfenheit) amidst things and with others, is thrown into its possibilities, including the possibility and inevitability of one's own mortality . The need for Dasein to assume these possibilities, that is, the need to be responsible for one's own existence, is the basis of Heidegger's notions of authenticity and resoluteness--that is, of those specific possibilities for Dasein which depend on escaping the "vulgar" temporality of calculation and of public life . </P>

One interpretation of the basic phenomenological philosophy is that