In Unto Others, philosopher Elliott Sober and biologist David Sloan Wilson team up to try to reconcile altruism with those scientific discoveries that seem to depict nature as "red in tooth and claw". In the first half, they deal with the prima facie evolutionary objection to altruism by arguing for the feasibility of group selection. In the second half, they carefully examine psychological evidence and philosophical arguments concerning altruism, ultimately concluding that although neither psychology nor philosophy is likely to decide whether altruism exists, there are evolutionary considerations that favor the emergence of unselfishness.