''A happy vicar I might have been Two hundred years ago,'' George Orwell wrote in 1947. But instead he lived a life of political engagement in what he called a ''tumultuous, revolutionary age.'' The British were reminded last month just how engaged he was, when excerpts from his diaries were published there. Though Orwell's disputes with fellow leftists were legendary, there was some surprise at new evidence that the creator of Big Brother had informed for the British Government in the late 1940's.

In his crabbed scrawl, and with characteristic acidity, Orwell secretly wrote down the names of prominent figures who he felt were so enamored of the Soviet Union that they had lost their political independence. He sent some names to a propaganda unit of the British Foreign Office, suggesting they were not fit for writing assignments. ''It isn't a bad idea,'' he said, ''to have the people who are probably unreliable listed.''

He was wrong-headed in a number of his listings. Stephen Spender, whom Orwell labeled a ''sentimental sympathizer'' in 1949, contributed an essay the next year to ''The God That Failed,'' an indictment of Communism. And some comments are simply appalling. The anti-Semitic and anti-homosexual overtones of his notes are clear.

Nevertheless, we should resist the temptation to condemn all of these secret scribblings as Orwellian double-think. The author of ''1984'' maintained that he ''named names'' not because of any private vendetta or opposition to dissent, but because totalitarianism posed a greater threat to liberty than providing information on those with a history of supporting the Soviet Union. This was a hard-won conviction, born of his experience with Stalinism in the Spanish Civil War. ''The conscious enemies of liberty,'' he wrote, ''are those to whom liberty ought to mean most.''