By Tim Allis and Maria Wilhelm
Updated September 19, 1988 12:00 PM

It was another rotten assignment, the kind I usually took to like lint to a cheap blue suit. But the fluorescent light of the classroom recalled too many all-night grading sessions and too many dead-end lectures. And the faces—bright, young and hopeful. Who were they kidding? Fingering a three-ring binder, I recognized the usual suspects: Heidegger, Kierkegaard, Nietzsche—guys who could find an existential dilemma looking down the barrel of a cocked .38. I wanted to spit. But I couldn’t. I was the prof. Sartre understood: No exit.

Sam Spade wasn’t a college guy—that wasn’t his game—but his spiritual protégé, Josiah “Tink” Thompson, spent the first 12 years of his career pounding the halls of academe. Then, in 1976, Thompson, 41 at the time, found an exit. He ditched his tenured job as a philosophy professor at Haverford College outside Philadelphia for a place in the gritty underworld of private investigation. Within months, Tink was on his bulky BMW R90S motorcycle, working as a $5-an-hour, low-level “operative” for supersleuth Hal Lipset, assigned to trail a labor activist during a violent cable workers’ strike in Oakland, Calif. A private dick ever since, Thompson has chronicled his one-of-a-kind career-change caper in his new book, Gumshoe: Reflections in a Private Eye.

“When we look at the professor, here’s what we see,” says Thompson today, the lecturer still. “He’s had a patrician education, he’s published three books and had a Guggenheim Fellowship, he has a lovely, loving wife, two terrific children, a cat and a Volvo. My very success had become a velvet trap. I felt a kind of deadness.” The son of a pottery-company sales manager in East Liverpool, Ohio, Thompson attended Phillips Academy at Andover, then Yale. In his senior year, he met his future wife, Nancy. He was a Navy frogman in the Middle East in the late ’50s before returning to Yale, where he got his Ph.D. in 1964. He was involved in the ’60s antiwar movement and toiled briefly as a special consultant for LIFE magazine’s investigation into the JFK assassination. His marriage also followed a familiar path of the era: Feeling he was “growing apart” from his wife, he had frequent affairs.

In 1976 Thompson embarked on a year’s sabbatical from Haverford and headed for Bolinas, just north of San Francisco, to finish a book he was writing on Nietzsche. But his work hit a snag, and his marriage continued to falter. The authority on existentialism plunged deep into his own dark night of the soul.

Then he met Lipset, the legendary San Francisco private eye credited as the inventor of the olive-in-the-martini microphone. Craving the “edge of experience,” Thompson asked for a job. A few days later, working on the labor dispute, he came to grips with the hazards of his new profession when he came across a bullet hole in a plate-glass door. “It was like a sudden glitch, stopping the Walter Mitty film in mid-sprocket hole, ” he writes in Gumshoe. “Whoever put that bullet hole in the door, I told myself, ‘isn’t going to care you’re some kind of college professor dicking around as a detective.” Hooked on what he calls the “voyeur’s rush,” he leaped into “the muck of human experience,” a world of messy divorces, child theft and murder.

His first days on the job were “pretty awful,” he admits. Yet, oddly, it turned out that such cold-coffee pursuits as sitting in a car for hours, watching for activity behind Venetian blinds, made him feel somehow “alive again.” Says Thompson: “What I loved about it was that you’d win or lose and see clearly whether you’d won or lost.”

Thompson worked for nearly three years before getting his private investigator’s license and starting his own firm in 1979. Since then, he has taken part in more than 80 homicide investigations and completed various other criminal defense cases. He charges $85 an hour for a local job—and a daily rate of $850 out of town.

Rumpled-looking in baggy cords, his craggy face a legacy of too many late nights, Thompson has confronted the demons of his new career and described them. “Gumshoe shows failure all over the place,” he says. “That’s what the job is like. The investigator isn’t a moral hero. Nobody told me that as a detective I was put on this planet to help determine who goes to jail. Someone can buy my loyalty.”

The paycheck, he has found, is no protection against feelings of guilt and moral confusion. He had bad dreams for some time after he helped kidnap a 6-year-old girl from her Indian father and return her to her American mother’s legal custody. The elaborate undertaking took Thompson to Bombay, where he hired an eccentric Indian detective and his group of Indian goondas, or “thugs.” “I never thought,” he says, “that I’d walk into a hotel room and look into the eyes of a father my age, who had sacrificed a lot for his child and who had been bound and gagged on my orders.”

No longer suspected of being a dilettante, Thompson has earned the respect of his professional colleagues. “He’s one of a handful of people who really care for their clients,” says Lip-set, who now considers Thompson a peer. “We’re cut from the same bolt.”

In the living room of the Thompsons’ rustic Bolinas home, Tink shows none of the stress of his calling. The couple’s personal troubles long ended, wife Nancy is grilling salmon steaks in the kitchen. Son Ev, 22, a college history major, is working on his car outside. (Daughter Lis, 24, works for American Express in New York.) Allegro the cat paws at the door.

Thompson’s published “work of self,” as he calls it, wasn’t easy on his family (Nancy says she still hasn’t read the parts dealing with his infidelities), but life with him has never been dull. “I don’t think I ever enjoyed being a faculty wife,” she admits. “Once we left Haverford, I never looked back.” The private eye sums it all up with a revelation that would bring an incredulous curl to Dashiell Hammett’s cynical lip. “The kicker to the story,” says Tink, “is I’m happy.”

—By Tim Allis, with Maria Wilhelm in San Francisco