Although international in scope, the social concerns in Celebration are more or less incidental to the novel's main theme. These social concerns center on the encroachment of the modern world on traditional ways of life in Turkey and Africa, as when the isolated village of the Yezidi, a Kurdish tribe in eastern Turkey, is razed to make room for a highway. Similar depredations occur or can be observed as a group of gun-running mercenaries travel through eastern Africa on their way to deliver a load of goods to Sudanese rebels. To an alarming degree, the favored means of introducing traditional peoples to "civilization" seems to be modern warfare.

The novel's main characters are sophisticated refugees of these cultural clashes, people who have lived through awful events, who have experienced the death of loved ones or other terrible losses. They themselves have had close brushes with death; although scarred by their experiences, they are far from lost souls, and one theme of the novel is that such people have developed a heightened awareness and sensitivity to life. They have, as the novel's epigraph states it, crossed over the river Styx and their eyes have been opened. Hence they celebrate life even amid its shambles.