Sartre’s argument that anguish has nothing to do with inaction is meant to respond to the Communist objection that existentialism prevents people from taking moral action because existentialists believe there are no definite values in the world. In fact, Sartre argues, believing in predetermined values is lying to oneself about the true source of values: our actions. The version of the Abraham story Sartre is referencing comes from Kierkegaard, who in his book
Fear and Trembling imagined how Abraham could take the “leap of faith” required to sacrifice Isaac. Sartre reveals his suspicion of such faith when he argues that he could not have known whether it was truly the “voice of an angel” and not a hallucination.