CAMBRIDGE -- In ''Small Dances About Big Ideas," choreographer Liz Lerman has, in the space of an hour, pulled together the blood and tears and particulate matter that course through the genocide that has ravaged places from Nazi Germany to Rwanda, Darfur to Uganda. Yet her aim is not to tug at our heartstrings, or make us wring our hands.
The piece, commissioned for Harvard Law School's conference on the legacy of the Nuremberg trials, exists to address questions at once mundane and profound: How can a Western courtroom, or a tribunal in another culture, be an adequate response to mass violence? Then again, how can it not be? Indeed, what else do we, as a civilized society, have?
Lerman tackles those questions with vigor and grace, not literally, but with a kind of episodic abstraction. A young woman -- a victim of rape -- repeatedly hurls herself on a desk, then pulls a man's head through her legs, bent wide. A forensic anthropologist plants red flags -- marking the bones of the tortured -- along a circuitous path. Gesture, in the hands and bodies of Lerman's 12 eloquent, eclectic dancers, speaks volumes: Arms dart and rattle, torsos slump on one another, fingers splay over faces. Yet technique, remarkably, is never sacrificed, even among the older dancers in the group -- men and women who appear to be 60-plus.
The dance is peopled with characters, and a narrator -- Peter DiMuro, a former Boston dancer who is now artistic director of the Liz Lerman Dance Exchange -- who slips between the players, reading snippets of text by authors from Robert H. Jackson (statements before the Nuremberg tribunal, 1945) to Samantha Power (''A Problem From Hell: America in the Age of Genocide," 2002) that frame, and inspire, the movement. Running beneath and within the action are Darron West's rippling sound design and Lewis Folden's spare, movable set: a series of wooden benches and textured black panels that open up, toward the end of the piece, like a well-worn book to reveal a patchwork of muted color.
Among those characters are Raphael Lemkin, the lawyer/activist who coined the term ''genocide." A thorn in the side of complacency, he spins and crashes to the floor with increasing frenzy. And then there are the three Norns (source of the name ''Nuremberg) -- wise women from Norse mythology who help the gods understand the law. They bend and soothe the victims of mass violence.
One of the most wrenching sequences, surprisingly, is also the most spontaneous. Midway through the performance, DiMuro stops the show, and invites the audience, with the dancers onstage, to contemplate ''what we teach about retribution." One woman comments on obedience and disobedience. Another talks about frustration and blame. On the spot, DiMuro introduces gestures expressing their words that culminate in a dance phrase. Then, quietly, elegantly, toward the end of the piece the dancers reprise that phrase. The audience, spiritually, has entered the stage space.
It is an act of community that may perhaps be the answer we need after all.