Islamic and Christian societies held fundamentally different concepts of slavery

Evidence

There was, however, one element in Islamic civilization that had little or no effect on medieval Europe as the latter was being transformed into the center of a dominant world system. This was the Muslim concept of the slave. Great differences persisted between slavery in Western and Christian societies and slavery in Islam. — Cedric J. Robinson, Black Marxism_ The Making of the Black…, 495

Categorization

• XREF: Sets up the contrast the book will build on: Western Christian slavery as racial and closed versus Islamic slavery as mobile and open — relates to the reader’s broad question about what made Atlantic slavery distinct. — connects to: European observers took personal umbrage at Islamic defenses of slavery — Eve M. Troutt Powell, A Different Shade of Colonialism_…, 679