The Fall 2018 issue of Lapham’s Quarterly is dedicated to strife. We live in contentious times, and we often lament the lack of comity and cooperation in our social realm. Yet—as the Rivalry & Feud issue shows—not all opposition is bad, and not all feuds are destructive. Contributors to the Rivalry & Feud issue—including Sigmund Freud on sibling rivalry, Mary McCarthy on the nature of cultural rivalry, Andrew Carnegie on the virtues of business rivalry, and Joanne B. Freeman on the caning of Senator Charles Sumner on the floor of the U.S. Senate—show not all opposition is bad, and not all feuds are destructive. “To outwit an enemy,” writes Plutarch, “is not only just and glorious but profitable and sweet.” Rivalry & Feud shows us how humans can rise to challenges and make the best of their myriad disagreements.