The philosopher Jean Wahl criticized Sartre's arguments about the topic of "nothing". The philosopher Frederick Copleston 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. He also expressed sympathy for Marcel's criticism of Sartre, and described Sartre's view of freedom as both "nihilistic" and possibly inconsistent with some of Sartre's other views. The philosopher A. J. Ayer wrote that, apart from some psychological insights, the book was "a pretentious metaphysical thesis" and "principally an exercise in misusing the verb 'to be'."