 Hook’s defense of ethical naturalism against the anti-naturalist writings that were related to contemporaneous historical events also involved him in the rejection of Existentialist ethical theory. The empiricism and objectivity that were hallmarks of Dewey’s ethical theory were antithetical to the Heideggerian or Sartrean interpretation of normative ethical assertions as arbitrary commitments which represent the choices of persons who bear the burden of freedom and self-consciousness. Hook defended the pragmatic view that normative ethical judgments are evaluated and their truth or adequacy can be confirmed by an appeal to their consequences against the Existentialist thesis that the only criteria available for evaluation of a person’s moral commitments is one of their authenticity to the agent’s being engagée in the situation or accepting of the burden of responsibility for his personal commitments. The darkened canvass of moral phenomenology that emerged during the decade of the 1940s, with its scenes of total war, seemingly absurd resistance, and irrational genocide, did not alter Hook’s identification with the moral naturalism that had been developed as part of the moral canon of the earlier decades of the twentieth century.