"Halevi (12th century Jewish poet & "philosopher") meets the problem of conversion by arguing that converts are indeed not the equals of native Jews and that only after many generations, so it would seem, can their descendants be fully amalgamated into the Jewish people. To adopt a brilliant and amusing metaphor of Daniel J. Lasker's, just as IBM PC clones may run the same software as original IBM hardware, but are still not the real thing; so, too, converts may believe what native Jews believe, and act as they do (software), they are still not the same as native Jews (hardware)."
Maimonides on Judaism & the Jewish People (1991)
1. Priest (cohen)
3. Israel (ordinary Jews)
4. Impaired priest (descendent of a cohen who'd broken the marriage rules)
6. Freedman (former slave)
6. Natin (Gibeonite) (Jews forbidden to marry ordinary Jews)
7. Silent (of unknown fatherhood)
8. Foundling (abandoned as a child)"