Phyletism or ethnophyletism (from Greek: ἔθνος, translit. ethnos, lit. "nation" and φυλετικός, phyletikos, 'tribal') is the principle of nationalities applied in the ecclesiastical domain: in other words, the conflation between church and nation. The term ethnophyletism designates the idea that a local autocephalous church should be based not on a local (ecclesial) criterion, but on an ethnophyletist, national or linguistic one. It was used at the local council held in Constantinople on 10 September 1872 to qualify "phyletist (religious) nationalism", which was condemned as a modern ecclesial heresy: the church should not be confused with the destiny of a single nation or a single race.