In the schism between the popes of Rome and the Eastern
Orthodox Church, there were certain cultural and political factors which constributed to and fostered the schism. Certain
"theological matters joined with political and cultural factors to rend the fabric of Christian unity in two. For example,
a number of general practices differentiated Greek and Latin Christians and added to the growing sense of alienation. The
East allowed some clergy to marry; the West required celibacy. In the East the local parish priest could administer the sacrament
of confirmation; in the West only the bishop could. When celebrating the Eucharist, Catholics mixed the wine with water, while
the Orthodox did not. The West used unleavened bread, the East leavened. Differences over clerical beards, the tonsure, and
fasting also contributed to the deterioration of unity.
"Two controversies, however, were far and away the more important than all
the others combined. Together they drove the final wedge between the Catholic and Orthodox Christians: papal supremacy and
the "filioque" doctrine.