What is the theme in A Canticle for Leibowitz by Walter M. Miller, Jr.?

Another theme in the book is "art". A Canticle for Leibowitz discusses art in several ways, primarily by following the creation and shifting fate over centuries of a wooden carving of St. Leibowitz, a widowed 20th-century weapons scientist who becomes a priest and founds an order dedicated to preserving human knowledge from the Flames Deluge and Simplification that claims his life. The 26th-century carving is interrupted when the abbot finds Brother Fingo's work too individualistic, but as Leibowitz's canonization nears, allows him to complete it, Fingo's image features crinkly eyes and a wry smile that Francis finds familiar but cannot place.