This is a funny little collection of articles in which Chesterton defends all sorts of things, like detective stories, nonsense, baby-worship, slang, patriotism, etc.
This is him defending popular literature:
One of the strangest examples of the degree to which ordinary life is undervalued is the example of popular literature, the vast mass of which we contentedly describe as vulgar. The boy's novelette may be ignorant in a literary sense, which is only like saying that a modern novel is ignorant in the chemical sense, or the economic sense, or the astronomical sense; but it is not vulgar intrinsicallyŚit is the actual centre of a million flaming imaginations.
The simple need for some kind of ideal world in which fictitious persons play an unhampered part is infinitely deeper and older than the rules of good art, and much more important. Every one of us in childhood has constructed such an invisible dramatis personŠ, but it never occurred to our nurses to correct the composition by careful comparison with Balzac.
Literature is a luxury; fiction is a necessity. A work of art can hardly be too short, for its climax is its merit. A story can never be too long, for its conclusion is merely to be deplored, like the last halfpenny or the last pipelight.
His explanation of the psychological and even moral need ordinary people have of stories is one of the best arguments I've ever read on the great debate between high and low literature, even though I'm one of the elitist snobs he frowns upon