These words conclude the foreword to 1961’s “Lanterns and Lances,” the last essay collection author James Thurber published during his prolific career. Although the writer and cartoonist’s work inspired the annual Thurber Prize for American Humor, here he expresses a sincere desire for his readers: Don’t let past disappointments color how you see the world. When entering any situation, assuming the worst suspends our ability to access authentic emotions, and, as a result, to make clear-eyed, open-hearted decisions. By contrast, Thurber asserted that his creative life was guided by “a basic and indestructible thread of hope.”