Mark Twain said he would rather decline two drinks than one German verb. Reminded that verbs are conjugated, the redoubtable Mr. Twain replied he would still decline the drinks.

Here we have 60 notebooks in the German language, presumably written (forged) by a German, bought by a German magazine familiar with German verbs, adverbs, nouns, prepositions and the rest, and everyone went for the drinks to celebrate the discovery of what was huckstered as the "real Hitler," a compilation that promised to rewrite history. Now we know all of it is a fraud. It's enough, Mr. Twain would likely say today, to make you think twice about buying a German car.

It would all be laughable, if it weren't serious. This greedy and lamentable episode inflicts another scar on a profession already suffering self-inflicted wounds and makes it less credibly able to tell another institution --government, say--that its credibility is sinking.

"Serious journalism is a high-risk enterprise," propounded the London Sunday Times in apologizing to its readers for buying into the scam. If "serious" journalism is what Times editors believe they were engaged in, let us hope for more un-serious propagations.

Stern, the West German magazine and agent of the hoax, now says "our mistake was to rely on other people's evidence and to be governed by their demands for urgency." This sounds like a reference to reporter Gerd Heidemann, who brought the documents with the astonishing explanation that they had reposed in a village hayloft until two years ago. Can it be that no one questioned this improbable notion? Even when paying out a reported $3 million for possession? Since their exposure as forgeries, Mr. Heidemann has been sued by Stern's publisher for fraud and possibly enriching himself, and now, officially fired.

The Times is demanding return of the down payment ($200,000) it made for British and Commonwealth publication rights. Stern also negotiated rights in Europe with Paris Match and with Panorama in Italy for undisclosed sums.

How close Newsweek came to buying U.S. rights is not clear. It withdrew from negotiations when the price reportedly was $3 million. Nevertheless, the magazine devoted a 13-page cover story to the "diaries." Although it quoted some authoritative skeptics and a subheadline on the cover asked, "Are They Genuine?," the impression created with the aid of provocative newspaper and television advertising was that the entire story was authentic.

This week, the magazine's cover appears equally disingenuous. "Forgery: Uncovering the Hitler Hoax" suggests that Newsweek deserves the credit. Inside, credit is more clearly attributed to West German government officials, and rightly so. A first-person account by an American handwriting "consultant" claims to have identified Hitler's signature as forged. Nowhere, however, is there any acknowledgment that the weight of previous coverage could have misled readers nor, as the New York Times has noted, that the magazine touted the papers as having historical value, "genuine or not."

It may not be possible to separate avarice from the sheer stupidity of this enterprise. Now that it's been shown that the paper, ink and bindings were not available until 10 years after Hitler's death, it is astounding that Stern did not recognize this. Scholars can be excused from technical details, but not from what are now confirmed as substantive flaws. Similar papers have reportedly been shopped around Europe for some time. Two German scholars, one a biographer of Hitler, the other an expert on the Third Reich, say they were approached three years ago in Stuttgart by someone peddling what sounded like the same material. Of course, that was Clifford Irving.

In "Mein Kampf," about which there is no question of authorship, there is the line, ". . . the great masses of the people . . . will more easily fall victim to a great lie than to a small one." Not quite this time.