Being and Nothingness was "a pretentious metaphysical thesis" and "principally an exercise in misusing the verb 'to be'." The philosopher William Barrett, writing in "Irrational Man" (1958), described "Being and Nothingness" as "a great, uneven, brilliant and verbose tome". He noted Sartre's debts to Heidegger, but nevertheless credited him with originality. He criticized Sartre for neglecting Heidegger's "notion of the truth of Being", his understanding of what it means for a subject or object to be. In his view, Sartre failed to "deal with the problem of truth in a radical and existential way", instead viewing truth in "the ordinary intellectualistic sense that
Being and Time of what a hammer "is" is not determined by a theoretical understanding of its presence, but by the fact that it is something we need at the moment we wish to do hammering. Only a "later" understanding might come to contemplate a hammer "as" an object. The total understanding of being results from an explication of the implicit knowledge of being that inheres in "Dasein". Philosophy thus becomes a form of interpretation, but since there is no external reference point outside being from which to begin this interpretation, the question becomes to know in which way to proceed with this