On August 1, 1968, my 15th birthday, my parents gave me a single-lens reflex camera — a Practika, made in East Germany. There was a mystique about owning the product of a Communist state. The camera had the aura of forbidden fruit, not to mention Carl Zeiss optics.

It was curious that my parents bought me a German camera. They opposed buying anything from a country whose very name made my mother spit on the floor. But they excused the Practika, perhaps because it was the least expensive model on the market. Or was it because the German Democratic Republic was avowedly anti-fascist?

Three weeks later the Practika would be my faithful companion in combat at the Democratic convention.

I was there. Mom and Dad took me.

Twenty-eight years later, with children of my own, I still wonder what possessed my parents to shlep my brother, my sister and me on daily marches and into nightly melees in Grant Park, in front of the Hilton, while the whole world watched by klieg light.

Weren't they terrified for our safety, when we were charged by phalanxes of riot cops, their truncheons banging against shields and skulls, and by flying wedges of National Guard, hunkering down in jeeps?

What was Dad thinking when he calmly showed me the Guard's 50-caliber machine guns, where they squatted on tripods on the hot pavement, or when he introduced me to troops with bayonets fixed on their M16s? ("Don't worry," he mocked. "These soldiers are here to protect us.")

What was my mother thinking when, moments after a BBC-TV crew was shoved through the front window of the Hilton, she engaged a police commander in polite conversation about citizens' rights to protest and dissent?

I was too young and naive to be afraid. The experience was exhilarating. Adrenaline was new to me. Anyway, I had Yippies to photograph.

Why my parents took their children to riots when they could have left us safe at home with Bubbe says as much about the power of their conviction as it does about their judgment.

Less obvious, but perhaps most profound, was what our family forays said about my parents' Judaism. For them, the revelation at Sinai had not so much to do with God as with the liberation of humankind. Theirs was (and is) an ethical Judaism that distinguishes between right and wrong, between just and unjust wars, the virtue of emancipation and the evil of oppression. For them, divine service in the '60s meant the picket line, the freedom ride, the anti-war demonstration. And the binding of Isaac meant risking what's most important for the sake of beliefs.

So it was with my grandmother, the same bubbe who, frantic with worry, watched Chicago's streets explode on our black-and-white TV. She had grown feisty during World War I, when Russian and German troops swapped possession of her Lithuanian village as if it was a football. It was she who negotiated her family's safety, now speaking German, now Russian, now Polish, now Lithuanian. After the Russian Revolution, she was jailed by Bolsheviks for being a Zionist.

Talking now about Chicago '68, my parents still think demonstrating family-style was a good idea. As a thrilling civics lesson, it surpassed trips to Eugene McCarthy campaign rallies, polling stations and soup kitchens.

But more than civics, it was the Jewish obligation of tikkun olam, repair of the world, that my parents sought to teach their children that summer of '68. With due respect to those who served in the military, from the outset of America's involvement in Vietnam my parents felt it was their duty to oppose a war they saw as evil.

This August, I turned the same age my father was when he piled us into the car for our daily commute to the demonstrations. The Practika, the focus action of its Zeiss lens stiff from long disuse, now hangs in my son's closet. Occasionally I take it down, click the shutter and wonder: For what principles am I willing to stand on the line? And will I bring my children?