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 and Nothingness of metaphysics which denies or refuses grace inevitably ends by setting up in front of us the image of an atrophied and contradictory world where the better part of ourselves is finally unable to recognise itself." The philosopher Jean Wahl criticized Sartre's arguments about the topic of "nothing". The philosopher Frederick Copleston, writing in "A History of Philosophy" (1946–1986), described Sartre's view that all human actions are the result of free choice as "highly implausible", though he noted that Sartre had ways of defending his position. The British philosopher A.J. Ayer said that, apart from some psychological insights, the book