In the early days of Hitler’s regime, Claude Ganz’s father marched in a parade along with his fellow World War I veterans — and was promptly arrested for violating a law forbidding Jews to bear arms.

Looking back with the wisdom of age to the war years, when his family lost 80 members to the Holocaust, Ganz quickly concluded that father didn’t know best.

“I asked my father, ‘How could you have not foreseen all these things that transpired? Why didn’t you get us out of Europe sooner?'” recalled Ganz, 74, a San Francisco investor, businessman and former appointee during the Clinton administration who aided the jump-start of the Bosnian economy.

“His answer was, ‘We considered ourselves to be German Jews, we had been in Germany for five generations and we never thought this madman Hitler could prevail.'”

In his adult years in San Francisco, Ganz was always uneasy about the highly assimilated nature of the city’s Jews — it reminded him too much of home. So when he was given the opportunity to bring a group of Jewish educators to the Bay Area five years ago, he jumped at the chance.

The Jewish Study Network has established a solid beachhead in the Peninsula in recent years, and now, much to the delight of San Franciscan Ganz, it has kicked off a weekly “crash course” in Judaism at the Jewish Community High School.

Ganz, JSN’s board president, is also one of about 40 adults of varying ages (he claims to be the oldest) showing up for classes on monotheism, the origins of the Torah and the inner workings of the Jewish calendar, taught from an inclusive, but Orthodox, point of view.

Held on Wednesday nights at 7:30, the weekly course is entitled “On One Foot” (a nod to Rabbi Hillel’s ability to sum up the entire Torah via the Golden Rule while awkwardly balancing on one foot) and taught, in turn, by the six rabbis and their families who make up JSN’s staff.

While the organization teaches nearly 20 courses on the Peninsula, this is the first (outside of small classes in private homes) in San Francisco proper.

Ganz, who is by no means an observant Jew, said that the beauty of the courses is that the goal isn’t to make participants more religious but, rather, more knowledgeable about their heritage.

“I’m not suggesting anybody should keep kosher, but they should understand what the laws of kashrut are all about. They should understand where they came from, what they’re all about. And that’s what these guys are doing. This is the stuff you didn’t get in Sunday school,” he said.

For more information about JSN’s “On One Foot” series, visit www.jsn.info or call (650) 961-4JSN.