Isn't it strange how eastern "Orthodox" blame the Pope for the schism, when it is their hurt pride that caused them to break from true orthodoxy and make their own Patriarch their head. The Greek "Orthodox" Church still calls the Pope "first among equals", yet they treat him like last among un-equals, even refusing to send a high "Orthodox" Church official to greet him during his visit to Greece.
History clearly shows, without argument, that the eastern Church recognized Rome and the Pope as the central authority of the entire Church. Even the writings of the early eastern Saints proves this; writings by Athanasius, Chrysostom, Cyprian of Carthage, St. Ephram the Syrian; all recognized Rome as the seat of Church authority.
That the Pope added the "filioque" to the Creed was certainly within his authority, especially since the Bible itself makes it abundently clear that the Holy Spirit does proceed from the Son as well as from the Father.
The Greek Church claims that Jesus somehow does not have the authority to "send" the Holy Spirit on His own, that the Holy Spirit proceeds only from the Father, thereby making Jesus less than God the Father. But hear what Jesus Himself says on this matter: "And Jesus came and said to them, "All authority in heaven and on earth has been given to me." (Mathew 28:18).
The Holy Spirit can proceed directly from the Son, because the Holy Spirit is the Spirit of the Son: "If you have not the Spirit of Christ, you have not the Spirit of God", (Romans 8:9).
The schizmatic Greek "Orthodox" Church wants to separate the divide the authority of the Holy Trinity, (just as they separated and divided the authority of the Catholic Church) - but Jesus Christ chatises this schizmatic theology when He says:"The Father and I are one." (John 10:30)
Now we see Jesus Personally sending the Holy Spirit on the Apostles, on His own authority: "And when he had said this, he breathed on them, and said to them, "Receive the Holy Spirit." (John 20:22)
But perhaps the greatest evidence of all that the Greek "Orthodox" schism was a horrendous error on their own part, was the Council of Florence in 1439, where the Greek Church admitted their grevious error and put it in writing. At this Council the Greek Church signed a written proclamation of their belief in the "filioque", (that the Holy Spirit does proceed from the Father and the Son), and thereby reconciled with the Pope and Holy See of Rome. That they have pulled away from Rome again after signing this proclamation at the Council of Florence shows their own fickleness and self will in action.
Saint Athanasius, the great Eastern Saint who fought so courageously against a similar error called 'Arianism', (which claimed that Jesus was the Son of God, but not equal to God), must be turning in his grave at this arrogant Greek schism.