Now more than ever, the question of what is appropriate subject matter for comedy is an endless debate. Ferne Pearlstein’s delightful new documentary ‘The Last Laugh’ explores when humor is appropriate in the face of tragedy, starting with the Holocaust.

Shock comedy makes big money and tends to launch careers when it works, but no one ever seems to be in agreement about where the line in comedy lies or when that changes. Admirably, Pearlstein doesn’t attempt to provide definitive answers. She makes it clear that the debate is endless and difficult to pinpoint. The only real test is whether or not people laugh, and even that can be questionable. Thankfully, not landing on any particular conclusion hardly hampers the documentary. It just encourages further debate after she delivers quite a bit of her own.

The closest thing to a star in this expertly edited parade of talking heads and stock footage is Renee Firestone, a 91-year-old Auschwitz survivor who lost her entire family to the mass tragedy. Now she speaks about that dark patch of history professionally, and despite that somber career path is filled with a joyous love of life. She encourages laughter as a crucial means of escape from tragedy. Along with other historians, she discusses the secret cabaret shows that often went on in concentration camps as an attempt to distract through entertainment in the harshest of times. Throughout the movie, Firestone is shown reacting to jokes about the Holocaust and rarely cracks a smile. However, she’s not against the jokes. She’s just the film’s barometer for how those who are too close to any subject will never be able to share in the humor.

The film also includes a smorgasbord of brilliant comedic voices including Mel Brooks, Sarah Silverman, Jeff Ross, Harry Shearer, Larry Charles and Susie Essman sharing their own experiences and thoughts on the matter. They of course discuss ‘The Producers’ and the intensely controversial nature it had at the time, which may be hard to understand now. Some contemporary examples like Silverman and clips of ‘Borat’ prove to be more divisive (though sadly Sacha Baron Cohen is not on hand to defend, and ‘Borat’ director Larry Charles only vaguely discusses the value of causing offense and breaking taboos). Jerry Lewis’ infamous unreleased Holocaust comedy ‘The Day the Clown Cried’ gets its usual lampooning, while ‘Life Is Beautiful’ is equally attacked and praised. (Most of the criticisms are more to do with sentimentality than the humor.) Some discussion questions whether or not the popularization of the term “The Soup Nazi” on ‘Seinfeld’ devalued the discomfort with the word “Nazi.” And eventually, September 11th is discussed as a new taboo subject that many feel still shouldn’t be touched.

Every issue covered has its defenders and attackers. Even ‘All in the Family’ is put through the ringer. It’s rare that anything made after the 1970s comes out completely devoid of criticism, which brings into question whether or not time is really the great comedic equalizer (and sadly that’s not discussed). While no concrete conclusions are made about any of the controversial issues discussed, the mere exploration of the topics proves fascinating enough.

The conversation eventually comes back to Renee Firestone and her assertion that comedy is an immensely important aspect of life regardless of the topic. That some folks will be offended by some jokes and others won’t almost seems irrelevant. The documentary is an ode to that cultural value as well as the particular resilience of the Jewish people and their use of comedy as a weapon. It will intrigue and satisfy those who are interested in the subject matter. Those who love discussions about the value and edges of comedy will find plenty food for thought and quite a few giggles woven within the tightly packed and briskly paced doc. Although the big questions of ‘The Last Laugh’ aren’t really answered, sometimes merely hearing a question asked and discussed is enough, especially if that questioning comes with a laugh or three.