Josh Radnor, who plays Aaron in The Babylon Line, is known by most people from his memorable role on the hit television comedy “How I Met Your Mother.” Yet when I asked him to name the pivotal moment in his career, he replied, “Every job is my big break.” He explained: “When I was at NYU” – where he finished an MFA in acting in 1999 – “I simply wanted to work in the professional theater. Once I got my Equity card, I wanted to work at one of the major professional theaters in New York. Then I wanted television. Each of these moments has been important for me.”

Radnor, who grew up in Columbus, Ohio, keeps returning to the stage. “Theater helps me reconnect to something elemental,” he said. He has done several stints at New York Stage and Film’s Powerhouse season at Vassar, in part because its summer productions fit in with his schedule on “How I Met Your Mother.” That long-running comedy, Radnor said, “had a very particular voice – slightly weird, spiky, and intelligent.”

Would Babylon’s Aaron, who eventually becomes a television writer, have written for “Mother”? “I’m not sure,” Radnor responded. “I asked Rich” – the Babylon playwright, Richard Greenberg – “what kind of TV writer Aaron would have been. He said Aaron was good at that job. He brought a literary sensibility to network programming.” Radnor himself has applied his intelligence as a writer and director to two feature films: Happythankyoumoreplease, which won the Sundance Film Festival Audience Award in 2010, and Liberal Arts, which played at Sundance two years later.

As for Aaron’s self-image as a writer, Radnor said that “It’s 1967, and he’s under the sway of very male authors like Mailer, Updike, and Roth. But he’s aware that he’s not quite as tough as they are. As Aaron says, ‘I didn’t have a war.’ He had asthma, so he didn’t serve in Korea.”

With his literary ambitions, Aaron would rather not teach. “He thinks it’s beneath him to be in a classroom,” Radnor said, “much less a classroom on Long Island, much less as a teacher of adult education.” He continued: “Aaron is not prepared for the level of engagement he encounters in his students. Joan and Frieda, in particular” – he’s referring to the characters portrayed by Elizabeth Reaser and Randy Graff – “wake him up. Aaron’s students are all deeply talented, even if only at self-expression.” Radnor said that it was easier for Joan to re-invent herself than it was for Aaron. “In 1967, we are on the edge of a profound shift for so many groups in society. As a woman, Joan could be swept along by that shift, and switch categories with more facility than Aaron could.”

The drama of social dislocation also forms part of Disgraced, the Ayad Akhtar play that was produced at LCT3 in 2012 and subsequently went to Broadway, where Radnor was part of its cast. “Disgraced was a different challenge than The Babylon Line,” Radnor said. “There, I wasn’t on stage as much as I am this time. Babylon requires a great deal of physical and mental energy. It’s a workout.”

Brendan Lemon is the editor of