Editor: In his Christmas Day column, ''Just Whose Tree Is It, Anyway?'', Professor Simon Schama makes the oft-repeated claim that the choice of the date Dec. 25 for the celebration of Christmas was an attempt by Christians to ''supersede'' the popular Roman festival of Saturnalia.
While there is some truth to this contention, your readers should know that this is not the whole story. In fact, there is good evidence that already in the third century Christians were celebrating the feast days of Dec. 25 (Christmas) and Jan. 6 (Epiphany). These two days are exactly nine-month intervals from two separate dates for the most ancient Christian feast day of Easter, March 25 in the Roman calendar and April 6 in the Asian calendar.
Since it is clear that the celebration of Easter included themes of passion, resurrection and incarnation (the impregnation of Mary by the Holy Spirit), then the commemoration of the birth of Christ nine months hence makes good sense. Therefore, despite Professor Schama's contention, the feasts of Christmas and Epiphany might well be original Christian celebrations.
Charles A. Bobertz.
The writer is assistant professor of theology at Loyola College.
Editor: Your Dec. 24 editorial, ''Fratricidal Georgia,'' made for interesting reading but omitted a number of pertinent facts:
Georgia is not a Yugoslavia, ''a time bomb ticking away.'' The Serbs and Croats are fighting a bitter and bloody ethnic war. Georgia is not engaged in a civil war or any kind of war. A handful of armed opposition rebels have stormed the government buildings with heavy artillery and sophisticated weapons. The rest of the country is quiet.
The violence in Georgia is occasioned by political, not ethnic, differences. Georgia was the first Soviet republic to declare independence, the first to hold multi-party elections and the first to elect a president in a free and open election with six candidates to choose from. Zviad Gamsakhurdia won this election last May with 87 percent of the vote.
President Gamsakhurdia has not refused a negotiated settlement of the current conflict. He has several times offered to negotiate but the opposition has not accepted the offer.
You put forward Eduard Shevardnadze as Mr. Gamsakhurdia's successor. You failed to mention that Mr. Shevardnadze was the much-hated head of the KGB in Georgia and ordered the execution of many young Georgians. There would be very strong opposition to Mr. Shevardnadze returning to Georgia in any official capacity.
The writer, a lobbyist, coordinates American Friends of Georgia.
Bush No Hoover
Editor: In his Dec. 23 letter, Albert Denny makes a comparison between George Bush and Herbert Hoover which -- though politically expedient -- seems unwarranted given his arguments.
He expresses agreement with the belief that Hoover's loss to FDR reflected the public's desire ''to use government as an agency for human welfare,'' and in doing so implies that George Bush faces a similar mandate this year.
Sure, that may have been the case back in 1932. But while most Americans are certainly dissatisfied with the way the president and Congress have handled the economy, this dissatisfaction clearly has not produced consensus that more costly social programs are the necessary solution.
Judging by the recent taxpaper revolts in Mississippi, New Jersey and even here in Maryland, it seems to me that promises of an ever-larger welfare state are the last thing voters will want to hear in 1992.
Richard J. Cross III.
Editor: I am writing in response to the Dec. 1 article by Richard Sia, ''Army's lean helicopter-leasing plan fattened up by congressional tinkering.''
Mr. Sia suggests that the congressionally directed change in acquisition strategy for the New Training Helicopter from lease to purchase came as a complete surprise to the Army. He also indicates that ''Army officials are privately expressing dismay over the abrupt congressional action.'' Neither of these contentions is true.
While the Army's initial strategy was to lease, we consistently made it known that we would prefer to buy the aircraft if we had adequate procurement funds. In fact, those were Secretary Michael Stone's words as quoted in Mr. Sia's article.
In anticipation of this possibility, the draft request for proposal that we issued in September included an option for direct purchase.
The congressional direction to procure was the result of cooperation between the Army and Capitol Hill on a procurement program that will provide a needed helicopter training capability at the lowest overall cost to the taxpayer.
The Army senior leadership is most satisfied with the congressional action and is dedicated to ensuring this well-conceived program succeeds.
Stephen K. Conver.
The writer is assistant secretary of the Army for research, development and acquisition.
What To Do about Salmonella and Eggs