As for the popularity and its meaning, there need be no quarrel over that term. Let us rule out such accidents as when a weak book becomes widely known because it is supposed to be indecent, or because it is the first to embody popular propaganda, or because its hero is identified with an important figure of real life, or for any other casual reason. If a novel, because of the intrinsic interest of its story, or on account of the contagion of the idea it contains, is widely read by many kinds of readers, and if these readers on their own initiative recommend the book they have read to others, that is popularity, and a sufficient definition. Perfection of form is not enough to make a book popular. A story has to move or few will read it, but it is doubtful whether a greater technical achievement than this is required for popularity. "Samson Agonistes" is technically perfect, but was never popular, while, to pass from the sublime to its opposite, "This Side of Paradise" was most crudely put together, and yet was popular. The best-built short stories of the past decade have not been the most popular, have not even been the best. No popular writer but could have been (so I profoundly believe) more popular if he had written better. But good writing is not a specific for unpopularity. The excellent writing of Howells could not give him Mark Twain's audience. The weak and tedious construction of Shakespeare's "Antony and Cleopatra," the flat style of Harold Bell Wright's narratives, has not prevented them from being liked. Form is only a first step toward popularity. Far more important is an appeal to the emotions, which good technique can only make more strong. But what is an appeal to the emotions? "Uncle Tom's Cabin" appealed to the emotions, and so does "Get-Rich-Quick Wallingford." To what emotions does the popular book appeal? What makes "Treasure Island" popular? Why did "Main Street" have such an unexpected and still reverberating success?