THERE is a slight but possibly significant difference in the way in which Western and Eastern Christians understand the Trinity. The version of the Nicene Creed familiar to most of us in the West says that the Holy Spirit “proceeds from the Father and the Son”, while the Orthodox version insists that the Holy Spirit “proceeds from the Father” alone.

The disputed clause, the filioque, as it is commonly known, crept into the Western Church from the end of the seventh century, and was formally incorporated into the Creed in 1014. The addition was always condemned in the East, becoming one of the causes of the Great Schism in 1054.

It may be hard for us to see where the real problem lay, but it began with early Christian writers’ describing the Father as the “fountainhead” of Godhead. In the Greek-speaking East, this could be pressed to emphasise the fatherhood of God to the point at which both the Son and the Spirit might be thought of as in some way inferior. The equal divinity of the Son was resolved up to a point at Nicaea, but there was still speculation about the Spirit.

In the West, one argument for the Spirit’s equal divinity was that the resurrected Son breathed the Spirit on the disciples, and so it was fitting to speak of the Spirit’s coming from the Son as well as the Father. The equality of the Spirit was also affirmed by liturgical formulations that spoke of Father, Son, and Holy Spirit as equals.

Western Christians suspected that a faint shadow of the Arian heresy hovered in the East — an accusation that Eastern Christians have always vigorously denied. In his great work on the Trinity, St Augustine argued that what defined the members of the Trinity were the relationships between them. For Augustine, the Spirit simply was the divine Person who constituted the relationship between Father and Son: “Love of the Father, love of God the Son,” as a later Latin hymn would put it.

In the East, Augustine was criticised for reducing the Spirit to a less than fully personal being. The Eastern critique also suggests that a mistaken view of the Trinity lies behind a certain theological restlessness in the West, an obsession with the Spirit as a divine disturber rather than as the bearer of tradition.

The Trinity is political as well as theological. The “social Trinity” has often been rather clumsily invoked as the basis of Socialism. I have even heard the Trinity referred to in relation to diversity, equality, and inclusion.

In contrast, President Putin’s Tsar-like rule could, perhaps, be traced to the Monarchian tendency in Orthodoxy: the Father as fountainhead of divinity being mirrored by the rule of one Great Man. Perhaps some of our political tensions go back to the Great Schism and our competing versions of the Nicene Creed.