Katherine Dunn is swearing at us from beyond the grave.

When Portland lost the beloved author nearly three years ago, we also had to give up on her long-in-the-works follow-up to her 1989 classic, Geek Love. While The Cut Man is unfinished, and unlikely to make it to any kind of mass printing, Tin House Books offers something of a consolation in the form of On Cussing (Tin House, $12.95, 64 pages), the result of a collaborative effort to bring Dunn's popular lecture, delivered to Pacific University's MFA in writing program, to a wider audience.

Perhaps no one was more qualified than Dunn to argue the art of obscenity, and she delivers her satisfying crash course on its history and proper usage with Strunk-and-White precision. She argues first that there is a creative etiquette to it. Overuse in life and narrative robs a curse word of its power: "A writer's aim should be to give genuine thought to the use of this limited but significant vocabulary," Dunn says, "and above all to avoid cliché and tedium."

Not only do bad words "carry emotional TNT," research bears out that judicious use of colorful language confers added credibility on the speaker—at least, Dunn states, when we're talking about how juries regard witnesses. An f-bomb can function as nearly any part of speech, so there is no excuse for laziness in vulgarity. To prove her point, Dunn riffs exhaustively on the various flavors of cussing, illustrating how alliteration and biblical allusions pair especially well. Fittingly, Gus Van Sant intros the book by describing Dunn's use of expletives as like "a velvet glove with a strong fist enclosed that can pack a punch."

At 64 pages, On Cussing is a quick read that's also grounded in robust academic curiosity, with Dunn offering a quick linguistic history of the dirtier side of the English language. Earlier waves of obscenity were all about sacrilege, but blasphemy has given way to body-shaming and racial and ethnic slurs, which really got going with the rise of the British Empire. More recently, she adds, we've added gender epithets to the mix.

Beyond serving as a bonus round for Dunn's career, On Cussing refutes the idea—commonly thrown around as an excuse for mediocrity in entertainment and politics—that the world has gotten too PC. Dunn argues that you can absolutely work blue. It just takes some skill.

SEE IT: A Celebration of Katherine Dunn is at the Urban Studio, 935 NW Davis St., urbanstudiopdx.com, on Friday, March 29. 6 pm. $10.