Noah about to be baptised. In medieval Christianity, Noah's three sons were generally considered as the founders of the populations of the three known continents, Japheth/Europe, Shem/Asia, and Ham/Africa, although a rarer variation held that they represented the three classes of medieval society – the priests (Shem), the warriors (Japheth), and the peasants (Ham). In medieval Christian thought, Ham was considered to be the ancestor of the people of black Africa. So, in racialist arguments, the curse of Ham became a justification for the slavery of the black races. Isaac Newton, in his religious works on the development of religion, wrote
Japheth on his death (the descendants of Shem and Ham respectively correspond to the other two, those of the Ptolemies and Seleucids). As the point of the "blessing of Japheth" seems to be that Japheth (a Greek-descended people) and Shem (the Israelites) would rule jointly over Canaan (Palestine). From the 19th century until the late 20th century it was usual to see Japheth as a reference to the Philistines, who shared dominion over Canaan during the pre-monarchic and early monarchic period of Israel's history. This view accorded with earlier understanding of the origin of the Book of Genesis, which was seen