After Helen Gahagan Douglas was elected as a Democratic representative in 1944, news outlets spread rumors of a vicious rivalry between her and Republican congresswoman Clare Boothe Luce; one headline read helen vs. clare: torch vs. icicle. “For reporters short of real news,” Douglas complained, “it was a simple day’s work to speculate that we would claw at one another.” The women resolved to avoid giving fodder to such baseless stories by never discussing the same subject on the same day.

“Mine is a peaceable disposition,” Heinrich Heine writes in his journals, declaring simple wishes: a humble cottage, some fine trees out front. But “if God wants to make my happiness complete,” he adds, “he will grant me the joy of seeing some six or seven of my enemies hanging from those trees. Before their death I shall, moved in my heart, forgive them all the wrong they did me in their lifetime. One must, it is true, forgive one’s enemies—but not before they have been hanged.”

Carl Jung attributed his split with his mentor Sigmund Freud around 1910 in part to a generational divide. “Our descendants are our most dangerous enemies,” Jung argued, “for they will outlive us, and, therefore, without fail, will take the power from our enfeebled hands.”

The eponymous temptress of Dolly Parton’s 1973 hit “Jolene” was based, according to the country singer, on a bank teller who flirted with her husband, Carl Dean. “Every time I look at him sleeping over there in his La-Z-Boy, snoring, that hair turning gray at the temples,” Parton said in a 2014 interview, “I wonder if Jolene is still around. I’ll call her up and say, ‘You come and get him now!’ ”