entities necessarily presupposes, namely, our understanding of that in virtue of which entities are entities", Carman writes. This line of inquiry is based on the "ontological difference"—central to Heidegger's philosophy. In 1937's "Contributions to Philosophy" Heidegger calls the ontological difference "the essence of Dasein". He accuses the Western philosophical tradition of incorrectly focusing on the "ontic"—and thus forgetful of this distinction. This has led to the mistake of understanding being as such as a kind of ultimate entity, for example as idea, energeia, substantia, actualitas or will to power. According to Richard Rorty, Heidegger envisioned no "hidden power of Being" as an ultimate entity. Heidegger tries to rectify ontic philosophy by focusing instead on the meaning of being—or what he called "fundamental ontology". This "ontological inquiry" is required to understand the basis of the sciences, according to "Being and Time" (1927). This inquiry is engaged by studying the human being, or Dasein, according to Heidegger. This method works because of Dasein's pre-ontological understanding of being that shapes experience. This implicit understanding can be made explicit through phenomenology and its methods, but these must be employed using hermeneutics in order to avoid distortions by the forgetfulness of being, according to interpretations of Heidegger. Fundamental Ontology, regarded as a project, is akin to contemporary meta-ontology. Later works: The Turn Heidegger's Kehre, or "the turn" (die Kehre) refers to a change in his work as early as 1930 that became clearly established by the 1940s, according to various commentators. Heidegger rarely used the term. Recurring themes include poetry and technology. Commentators such as William J. Richardson (1963) describe, variously, a shift of focus, or a major change in outlook. The 1935 Introduction to Metaphysics "clearly shows the shift" to an emphasis on language from a previous emphasis on Dasein in Being and Time eight years earlier, according to Brian Bard's 1993 essay titled "Heidegger's Reading of Heraclitus". In a 1950 lecture Heidegger formulated the famous saying "Language speaks", later published in the 1959 essays collection Unterwegs zur Sprache, and collected in the 1971 English book Poetry, Language, Thought. This supposed shift—applied here to cover about thirty years of Heidegger's 40-year writing career—has been described by commentators from widely varied viewpoints; including as a shift in priority from Being and Time to Time and Being—namely, from dwelling (being) in the world to doing (time) in the world. (This aspect, in particular the 1951 essay