I took the opportunity to remind my colleague that orthodoxy arose out of the African context.

Indeed, many of the shapers of Christian orthodoxy were African. Names like Augustine, Tertullian, Origen, Clement, Anthony, and Pachomius were familiar from my undergraduate church-history survey. But my professor had not presented them as Africans ministering and teaching in the context of an African culture.

The Congregation of the Doctrine of the Faith said yesterday: "These variations arise from so-called feminist theology and are an attempt to avoid using the words Father and Son, which are held to be chauvinistic."

Instead, it said that the traditional form of "Father, Son and Holy Ghost" had to be respected.

The alternative phrases originated in North America and started to become popular only in the past few years.

Christianity, a minority sect during much of the Roman Empire, became a world religion with a vast following after the Emperor Constantine converted to it, in the fourth century A.D. Then came Islam, in the seventh century: just a hundred years after Muhammad's death, in 632, the religion he founded reached beyond the Middle East to Africa, India, and significant parts of Spain and France.

In all civilizations, Zimmerman theorized, there are three basic family types. The "trustee" family is tribal and clannish, and predominates in agrarian societies. The "domestic" family model is a middle type centering on the nuclear family ensconced in fairly strong extended-family bonds; it's found in civilizations undergoing rapid development.