THE UPI DISPATCH appeared in this paper last week, and we were transfixed by a single line in it. Idi Amin, it said, had established "one of the most brutal regimes ever witnessed . . ." So far so good, but then: "on a continent already noted for past cases of savagery." A continent already noted for past cases of savagery? By whom? We wondered. Surely not by anyone who had contemplated, let us say, European or Asian history - or even one or two things known to have gone on in the Americas in the past few hundred years.

We would not, of course, wish to dismiss the claim of any continent to this particular distinction - with the possible exception of Antarctica. But fair is fair, and it seems to us to be rankly unfair for UPI or anyone else to bestow savagery ratings on entire continents that they do not deserve. What, after all, does Africa have to put up against the ravages of the Crusades or the Thirty Years War or the Holocaust? To the best of our knowledged and belief, neither Attila nor Genghis Khan nor Joseph Stalin was an African, any more than Auschwitz or Gulag Archipelago was an African invention.

That black Africans have been known to be vicious to each other on a grand scale is not open to dispute. What is open to dispute is whether their depredations have somehow been distinctive in the sorry march of history. We think they have not come anywhere near such distinction, and that that that is the point to be kept in mind about the ineffable Idi Amin. He is dishonoring his continent, rather than honoring its traditions, in his attempt to win the savagery championship for this decade