From New Advent (
http://www.newadvent.org/cathen/05228a.htm)
Easter Controversy
SECOND PHASE
The second stage in the Easter controversy centres round the Council of Nicaea (A.D. 325). Granted that the great Easter festival was always to be held on a Sunday, and was not to coincide with a particular phase of the moon, which might occur on any day of the week, a new dispute arose as to the determination of the Sunday itself. The text of the decree of the Council of Nicaea which settled, or at least indicated a final settlement of, the difficulty has not been preserved to us, but we have an important document inserted in Eusebius's "Life of Constantine" (III, xviii sq.). The emperor himself, writing to the Churches after the Council of Nicaea, exhorts them to adopt its conclusions and says among other things: "At this meeting the question concerning the most holy day of Easter was discussed, and it was resolved by the united judgment of all present that this feast ought to be kept by all and in every place on one and the same day. . . And first of all it appeared an unworthy thing that in the celebration of the Jews, who have impiously defiled their hands with enormous sin. . . for we have received form our Saviour a different way. . . And I myself have undertaken that this decision should meet with the approval of your Sagacities in the hope that your Wisdoms will gladly admit that practice which is observed at once in the city of Rome and in Africa, throughout Italy and in Egypt. . . with entire unity of judgment." From this and other indications which cannot be specified here (see, e.g. Eusebius, "De Paschate" in Schmid, "Osterfestfrage", pp. 58-59) we learn that the dispute now lay between the Christians of Syria and Mesopotamia and the rest of the world. The important Church of Antioch was still dependent upon the Jewish calendar for its Easter. The Syrian Christians always held their Easter festival on the Sunday after the Jews kept their Pasch. On the other hand at Alexandria, and seemingly throughout the rest of the Roman Empire, the Christians calculated the time of Easter for themselves, paying no attention to the Jews. In this way the date of Easter as kept at Alexandria and Antioch did not always agree; for the Jews, upon whom Antioch depended, adopted very arbitrary methods of intercalating embolismic months (see CALENDAR, Bol. II, p. 158) before they celebrated Nisan, the first spring month, on the fourteenth day of which the paschal lamb was killed. In particular we learn that they had become neglectful (or at least the Christians of Rome and Alexandria declared they were neglectful) of the law that the fourteenth of Nisan must never precede the equinox (see Schwartz, Christliche und judische Ostertafeln, pp. 138 sqq.). Thus Constantine in the letter quoted above protests with horror that the Jews sometimes kept two Paschs in one year, meaning that two Paschs sometimes fell between one equinox and the next.
The Alexandrians, on the other hand, accepted it as a first principle that the Sunday to be kept as Easter Day must necessarily occur after the vernal equinox, then identified with 21 March of the Julian year. This was the main difficulty which was decided by the Council of Nicaea. Even among the Christians who calculated Easter for themselves there had been considerable variations (partly due to a divergent reckoning of the date of the equinox), and as recently as 314, in the Council of Arles, it had been laid down that in future Easter should be kept uno die et uno tempore per ommnem orbem, and that to secure this uniformity the pope should send out letters to all the Churches. The Council of Nicaea seems to have extended further the principle here laid down. As already stated, we have not its exact words, but we may safely infer from scattered notices that the council ruled:
that Easter must be celebrated by all throughout the world on the same Sunday;
that this Sunday must follow the fourteenth day of the paschal moon;
that that moon was to be accounted the paschal moon whose fourteenth day followed the spring equinox;
that some provision should be made, probably by the Church of Alexandria as best skilled in astronomical calculations, for determining the proper date of Easter and communicating it to the rest of the world (see St. Leo to the Emperor Marcian in Migne, P.L., LIV, 1055).
This ruling of the Council of Nicaea did not remove all difficulties nor at once win universal acceptance among the Syrians. But to judge from the strongly worded canon i of the Council of Antioch (A.D. 341; see Hefele-Leclereq, "Conciles", I, 714), as also from the language of the Apostolic Constitutions and Canons (see Schmid, Osterfestfrage, p. 63), the Syrian bishops loyally co-operated in carrying into effect the decision of the Council of Nicaea. In Rome and Alexandria the lunar cycles by which the occurrence of Easter was determined was not uniform. Rome, after the hundred-and-twelve year cycle of Hippolytus, adopted an eighty-four year cycle, but neither gave satisfactory results. Alexandria adhered to the more accurate nineteen-year cycle of Meton. But it seems to be clearly established by the most recent researches (see Schwartz, op. cit., pp. 28-29) that the lunar cycles were never understood to be more than aids towards ascertaining the correct date of Easter, also that where the calculations of Rome and Alexandria led to divergent results, compromises were made upon both sides and that the final decision always lay with accepted ecclesiastical authority.
From the THE LETTER OF THE SYNOD IN NICAEA TO THE EGYPTIANS (
http://www.piar.hu/councils/ecum01.htm)
The following is not found in the latin text, but is found in the greek text :
We also send you the good news of the settlement concerning the holy pasch, namely that in answer to your prayers this question also has been resolved. All the brethren in the East who have hitherto followed the Jewish practice will henceforth observe the custom of the Romans and of yourselves and of all of us who from ancient times have kept Easter together with you. Rejoicing then in these successes and in the common peace and harmony and in the cutting off of all heresy, welcome our fellow minister, your bishop Alexander, with all the greater honour and love. He has made us happy by his presence, and despite his advanced age has undertaken such great labour in order that you too may enjoy peace.
Both the dates of Easter of the Egyptians and of the Romans and of "all those from ancient times have kept Easter together with them" are considered canonical by the Synod althought the way of claculating the date of Easter in Rome and Alexandria were very different...so we can not assure that the First Council of Nicea (AD 325) stipulated that the Alaxandrian Paschalion was to be used by the entire Church.
