More than any other institution, slavery placed its stamp on male homosexual relations in ancient Rome. While the pervasive Hellenization of Roman society in the second and first centuries B.C. mitigated the traditional hostility towards homosexuality and homosexual relations and even, in cultured circles, fostered and idealizing acceptance of male pederastic relations patterned after the model of classical Greece, this transformation of attitudes would have produced less concrete effects had Rome not concurrently become a slave-owning society on a large scale, due to overseas conquests. The strictures of Roman law and tradition applied only to sexual relations among free men and women; sexual relations between freemen and female or male slaves were unlikely to incur much social stigma. Although there is evidence that some Romans did indeed exploit their slaves, fortunately the great lacuna within the law and tradition, together with the emergence of more humane values regarding slavery and sexual relations, allowed genuine love-relationships (both heterosexual and homosexual) to receive a large measure of social action as a form of concubinage. Roman culture, however, unlike classical Greek civilization, made little contribution to an informed acceptance of homosexual relation grounded in an understanding of human ethics and psychology.