Being and Time Heidegger's "description of the world of phenomena" to be "fascinating, but maddeningly abstract". He suggests that much of "Being and Time" is a "description of a private spiritual journey" rather than genuine philosophy, and notes that Heidegger's assertions are unsupported by argument. Stephen Houlgate compares Heidegger's achievements in "Being and Time" to those of Kant in the "Critique of Pure Reason" (1781) and Hegel in "The Phenomenology of Spirit" (1807) and "Science of Logic" (1812-1816). Simon Critchley calls the work Heidegger's "magnum opus", and writes that it is impossible to understand developments in continental philosophy after Heidegger without understanding it.
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)