Provides a detailed and authoritative analysis of the infamous filioque ('and the Son') clause added to the Nicene Creed and how four major medieval theologians defended it.

The original Nicene Creed (381 AD) said
that the Holy Spirit 'proceeds from the
Father' and the Eastern Orthodox
churches follow that wording to this day.
However, in the West the growing tradition
was to think of the Spirit as 'proceeding
from the Father and the Son'
(Latin: filioque) and eventually in 589
AD the ecumenical creed of Nicea was
modified by the Catholic Church to
include the word 'filioque' ('and the
Son'). This controversial move was the
sole doctrinal cause of the Great Schism that divided the Orthodox and
Catholic Churches (1054 AD) and it remains a dividing issue with the Christian
Church to this day.
This study examines the defence of the filioque clause in four of the leading medieval
theologians in the Catholic Church seeking to show why it mattered so much to them.