 This probability riddle is instructive and will be referenced throughout this entry. But the existence of quick, decisive solution shows that only a mild revision of our prior beliefs was needed. In contrast, when our deep beliefs conflict, proposed amendments reverberate unpredictably. Attempts to throw away a deep belief boomerang. For the malfunctions that ensue from distancing ourselves from the belief demonstrate its centrality. Often, the belief winds up even more entrenched. “Problems worthy of attack prove their worth by fighting back” (Hein 1966).