and Event (1988). and also separately, the enactivist approach to cognition theory. Bertrand Russell dismissed Being and Time ("One cannot help suspecting that language is here running riot"). The analytic philosopher A. J. Ayer called Heidegger a charlatan. But the American philosopher Richard Rorty ranked Heidegger among the important philosophers of the twentieth century, including John Dewey and Wittgenstein. The conservative British writer Roger Scruton called (2002) Being and Time a "description of a private spiritual journey" rather than genuine philosophy. But Stephen Houlgate (1999) compares Heidegger's achievements in Being and Time to those of Kant and Hegel. Simon Critchley writes (2009) that it is impossible to understand developments in continental philosophy after Heidegger without understanding Being and Time. Related work Being and Time is the major achievement of Heidegger's early career, but he produced other important works during this period: The publication in 1992 of the early lecture course, Platon: Sophistes (Plato's Sophist, 1924), made clear the way in which Heidegger's reading of Aristotle's Nicomachean Ethics was crucial to the formulation of the thought expressed in Being and Time. The lecture course, Prolegomena zur Geschichte des Zeitbegriffs (History of the Concept of Time: Prolegomena, 1925), was something like an early version of Being and Time. The lecture courses immediately following the publication of Being and Time, such as Die Grundprobleme der Phänomenologie (The Basic Problems of Phenomenology, 1927), and Kant und das Problem der Metaphysik (Kant and the Problem of Metaphysics, 1929), elaborated some elements of the destruction of metaphysics which Heidegger intended to pursue in the unwritten second part of Being and Time. Although Heidegger did not complete the project outlined in Being and Time, later works explicitly addressed the themes and concepts of Being and Time. Most important among the works which do so are the following: Heidegger's inaugural lecture upon his return to Freiburg, "Was ist Metaphysik?" (What Is Metaphysics?, 1929), was an important and influential clarification of what Heidegger meant by being, non-being, and nothingness. Einführung in die Metaphysik (An Introduction to Metaphysics), a lecture course delivered in 1935, is identified by Heidegger, in his preface to the seventh German edition of Being and Time, as relevant to the concerns which the second half of the book would have addressed. Beiträge zur Philosophie (Vom Ereignis) (Contributions to Philosophy [From Enowning], composed 1936–38, published 1989), a sustained attempt at reckoning with the legacy of Being and