In a critique of the theory of the "Clash of Civilizations," Bulliet proposes a new reading of history that bridges the gap between Islam and the West, arguing that both sides can be better understood within the framework of a unified Islamic-Christian civilization.

Beyond their common textual roots and shared cultural background, the twin societies have charted parallel trajectories in geographically neighboring regions, passed through similar stages of evolution, and faced comparable internal problems, to which they responded in not incompatible ways.

Since 1500, through the accumulation of divergences and under the pressure of random historical events, their paths diverged - yet the idea of a common heritage, always present, allows us to envision the prospect of reconciliation.

(. . .) [Excerpt from the text on the back cover of the edition]