 Disagreement in belief occurs when two people have beliefs that cannot both be true and “neither is content to let the belief of the other remain unchallenged” (1948b, 1). If Smith believes that their and Jones’s anniversary is in June, while Jones believes their anniversary is in July, their respective beliefs are incompatible, since they cannot both be true; but Smith and Jones only disagree in the sense that Stevenson mostly focuses on when they desire, need, or attempt to coordinate their beliefs, perhaps because they would like to celebrate their anniversary as close to their wedding date as possible. Their disagreement is resolved when they modify their beliefs in ways that make them compatible, or when both cease to care about coordinating their incompatible beliefs.