Being and Time raises the problem of "authenticity," that is, the potentiality or otherwise for mortal "Dasein" to exist "fully" enough that it might actually understand being. Heidegger is clear throughout the book that nothing makes certain that "Dasein" is capable of this understanding. Finally, this question of the authenticity of individual "Dasein" cannot be separated from the "historicality" of "Dasein". On the one hand, "Dasein", as mortal, is "stretched along" between birth and death, and thrown into its world, that is, thrown into its "possibilities", possibilities which "Dasein" is charged with the task of assuming. On the other hand, "Dasein's" access to
Being work of such influential theorists as W. V. O. Quine, to name one of many. One of the most fundamental questions that continues to exercise philosophers is posed by William James: "How comes the world to be here at all instead of the nonentity which might be imagined in its place? ... from nothing to being there is no logical bridge." The deficit of such a bridge was first encountered in history by the Pre-Socratic philosophers during the process of evolving a classification of all beings (noun). Aristotle, who wrote after the Pre-Socratics, applies the term category (perhaps not originally)