Group boundaries shift from blood to permeable culture, religion, and citizenship over time.

Evidence

In the earliest stage, definition is at once by blood, by place and by cult, the third being a natural concomitant of the first two. The three are usually indis­ tinguishable. In more sophisticated stages of development other attributes as­ sume greater importance. The two most articulate peoples of antiquity, those who have retained both their memories and their voices, that is to say, the Greeks and the Jews, devised special terms to define the outsider. Whoever was not Greek was a barbarian; whoever was not a Jew was a gentile. The one definition is cultural, the other, religious, and the two elements are closely inter-related. Both represent an important step forward in human evolution, in that the barriers they raise, though formidable, are permeable. One cannot change one’s blood, one’s race, one’s kin. One can, however, adopt a culture and embrace a religion; and as we know from antiquity and medieval history, this has happened many times. Already in antiquity, there were Hellenised barbarians and Judaised gen­ tiles, both directly and through Christianity. The Roman Empire added a new definition—citizenship, which was extended in stages until finally it included all the heterogeneous subjects of the Roman emperors. — Bernard Lewis, From Babel to Dragomans, 1015

Categorization

• XREF: Connects to Said-adjacent work on how civilizational self-definition proceeds by contrast with constructed outsiders (Greek barbarian vs. Jewish gentile as originary identity binaries). — connects to: The substance behind democratic homogeneity shifts historically, from religious conviction to national belonging. — Chantal Mouffe, The Democratic Paradox, 176