Declinism is in vogue. A number of books and articles have been written in recent years about the "Decline of the West." Perhaps most notable is Mark Steyn's bestselling book America Alone, which chronicles the fall of Europe, due in particular to declining birth rates and a resurgent Islam. Oriana Fallaci, Bat Ye'or, Bruce Bawer, and others have all written on this theme as well.
These are all books of nonfiction, and all of them, to varying degrees, raise alarms and offer lessons that urgently need to be heeded. Only a fool would ignore them; unfortunately, Europe and the West have far too many of those.
However, it is to the realm of fiction and poetry that one must go in order to find the pulse – indeed, the soul – of a culture and society. Think of Thomas Mann, W.B. Yeats, and T.S. Eliot.