Filioque

===Linguistic issues===
{{See also|Perichoresis}}

Ware suggests that the problem is of semantics rather than of basic doctrinal differences.<ref name="LutheranOrthodox1998"/><ref>{{cite book|last=Zoghby|first=Elias|year=1992|title=A voice from the Byzantine East|others=Translated by R. Bernard|location=West Newton, MA|publisher=Educational Services, [Melkite] Diocese of Newton|isbn=9781561250189|page=43|quote=The Filioque controversy which has separated us for so many centuries is more than a mere technicality, but it is not insoluble. Qualifying the firm position taken when I wrote The Orthodox Church twenty years ago, I now believe, after further study, that the problem is more in the area of semantics than in any basic doctrinal differences. —Kallistos Ware}}</ref>{{Better source needed|reason=The work is a translation into English and there are already a few works by Ware that may contain the equivalent|date=November 2015}} The [[English Language Liturgical Consultation]] commented that "those who strongly favor retention of the ''Filioque'' are often thinking of the Trinity as revealed and active in human affairs, whereas the original Greek text is concerned about relationships within the Godhead itself. As with many historic disputes, the two parties may not be discussing the same thing."<ref>{{cite web|author=English Language Liturgical Consultation|date=May 2007|orig-year=1988|edition=electronic|title=Praying together|website=englishtexts.org|publisher=English Language Liturgical Consultation|url=http://www.englishtexts.org/praying.pdf|page=21|archive-url=https://web.archive.org/web/20070702021454/http://www.englishtexts.org/praying.pdf|archive-date=2 July 2007|url-status=dead}}</ref>

In 1995, the {{abbr|PCPCU|Pontifical Council for Promoting Christian Unity}} pointed out an important difference in meaning between the Greek verb {{lang|grc|ἐκπορεύεσθαι}} and the Latin verb ''{{lang|la|procedere}}'', both of which are commonly translated as "proceed". It stated that the Greek verb {{lang|grc|ἐκπορεύεσθαι}} indicates that the Spirit "takes his origin from the Father&nbsp;... in a principal, proper and immediate manner", while the Latin verb, which corresponds rather to the verb {{lang|grc|προϊέναι}} in Greek, can be applied to proceeding even from a mediate channel. Therefore, {{lang|grc|ἐκπορευόμενον}} ("who proceeds"), used in the [[Niceno-Constantinopolitan Creed]] to signify the proceeding of the Holy Spirit, cannot be appropriately used in the Greek language with regard to the Son, but only with regard to the Father, a difficulty that does not exist in Latin and other languages.{{sfn|PCPCU|1995}}

Metropolitan [[John Zizioulas]], while maintaining the explicit Orthodox position of the Father as the single origin and source of the Holy Spirit, declared that {{harvtxt|PCPCU|1995}} shows positive signs of reconciliation. Zizioulas states: "Closely related to the question of the single cause is the problem of the exact meaning of the Son's involvement in the procession of the Spirit. [[Gregory of Nyssa]] explicitly admits a 'mediating' role of the Son in the procession of the Spirit from the Father. Is this role to be expressed with the help of the preposition {{lang|grc|δία}} (through) the Son ({{lang|grc|εκ Πατρός δι'Υιού}}), as Maximus and other Patristic sources seem to suggest?" Zizioulas continues: "The Vatican statement notes that this is 'the basis that must serve for the continuation of the current theological dialogue between Catholic and Orthodox'. I would agree with this, adding that the discussion should take place in the light of the 'single cause' principle to which I have just referred." Zizioulas adds that this "constitutes an encouraging attempt to clarify the basic aspects of the 'Filioque' problem and show that a rapprochement between West and East on this matter is eventually possible".{{sfn|Zizioulas|1996}}