WE'VE ALL READ as much as we can stand lately about the century just ended, about the high points and about the dark moments that are likely to endure as bitter monuments to human perversity. But if those dark times are to remain real, frightening and cautionary to those who had the good fortune not to experience them, a significant part of the reason will be the stories told not just in history books but in public museums. And in this city in particular, a big measure of credit will belong to Jeshajahu Weinberg, founding director of this city's Holocaust Memorial Museum, who died Jan. 1 at age 81.

"Shaike" Weinberg, as he was widely known, was a shaper of public memory, not primarily as a historian or eyewitness but as a brilliant designer of museum exhibitions--here in Washington, where the museum that opened in 1993 has had a cathartic, nearly explosive effect, and also in Israel and more recently in Berlin and Warsaw, both now struggling to build museums that confront that same difficult past.

With the U.S. Holocaust Memorial Museum still drawing record crowds seven years after it opened, it's easy to forget how improbable the project once seemed to many, even the sympathetic. How would this narrative of European atrocity fit on America's Mall? Would the destruction of European Jewry hold out lessons for a wider public? In the end, the museum conveyed its message, not didactically but with unmissable clarity: Citizens everywhere have responsibilities to stand against evil and to bear witness.

For Mr. Weinberg, his colleagues say, everything came down to that clarity--the vivid, understandable telling of the tale in word and image. It may have been a legacy of his first career as a theater director; it may have been his legendary decisiveness, which meant these potentially touchiest of projects were not only launched but, against all odds, completed. It was surely those qualities--the clarity, the certainty--that drew museum planners in Germany and Poland to seek out his guidance, which he was still giving at his death.