"Seminar" is a bulls-eye comedy about the power of words and the fragility of the writers who use them -- and as an added bonus, it's also an odd take on what it means to be a mentor.

Is the fabled editor named Leonard -- an acrimonious megalomaniac with a butcher's knife for a tongue – a good mentor or a bad one? From the glimpses we get in Theresa Rebeck's fast-moving play, he's horrible. It's doubtful that four young-adult fiction-writer wannabes can get anything but contempt in return for the $5,000 each paid for a weekly writing workshop with this guy.

Not so fast, though. Leonard must have good editing judgment. Otherwise, how could he have the reputation that led these writers to him? And how can we trust judgment expressed with constant bombastic nastiness? After all, the permission Leonard gives himself to couple his ideas with the meanest of words is itself a form of judgment.

"Seminar," in a fiery production by Philadelphia Theatre Company, looks perceptively at a character who is supposed to be a coach and a safety net, and has a reckless way of being both. Rebeck writes revealing, funny plays ("Mauritius," "The Understudy," "Bad Dates") about people who live or work on the edge of their egos, and none is more forceful than "Seminar," which played last year on Broadway. (She also created NBC's "Smash.")

The Philadelphia Theatre Company version is directed by Scott Schwartz ("Golda's Balcony" on Broadway), without an ounce of fat; the swift beat of the intermissionless 90 minutes nicely reveals the tensions among the four writers who ally to face their hostile mentor.

He's played by Rufus Collins, with an intriguing touch of suspense – we're not sure what this guy will say next or how he'll say it, but we know we want to hear it. Geneviève Perrier, Luigi Sottile, Teresa Avia Lim and Matt Harrington are the seminar students, and their portrayals display a deep understanding of the unique peccadilloes of their characters.

It all plays out on Kevin Rigdon's evocative sets – the stylish living room of one of the students, where everyone comes to the seminars, and the mentor's more wood-built, work-a-day living space. You'll never want to be in an actual seminar like "Seminar," but as a fly on the wall, you get a great seminar's worth of impressions.
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SEMINAR runs through April 14 in the Philadelphia theatre Company production at the Suzanne Roberts Theatre, Broad and Lombard Streets. Tickets: $46-$59. www.philadelphiatheatrecompany.org or 215-985-0420.