Playwright Mark St. Germain struck a chord with “Freud’s Last Session.” The play, which imagines a meeting between the famed psychoanalyst and theological author C.S. Lewis, played an unusually long run off-Broadway and has been popular out in the regions.

The Guthrie Theater asked Rob Melrose to direct the show in its Dowling Studio, with actors Robert Dorfman (Freud) and Peter Christian Hansen (Lewis). The production, handsomely designed on the featureless black and white lines of a scientific lab/afterlife by Michael Locher, opened last weekend.

Ostensibly, St. Germain brings the men together to inquire of each other’s world view, balanced on the question of a divine entity. Dorfman’s Freud puts it more bluntly. He wants to know why Lewis, a former atheist and a man whose intellect Freud regards on a par with his own, “could suddenly abandon truth and embrace an insidious lie.”

Hansen’s Lewis, courteous and sharp in riposte, argues that the ancient presence of societal codes suggests a moral conscience that is a product of God. He challenges the sterile righteousness of science and contends that passion and joy testify to God’s existence.

For a play based on deep ideas, “Freud’s Last Session” stays frustratingly near the surface. On occasion, St. Germain pursues an angle — such as Freud’s suggestion that Moses was an Egyptian who led the Hebrews into the wilderness and then was killed in a rebellion. Viewed through the prism of psychoanalysis, this incident (taken from Freud’s “Moses and Monotheism”) suggests that guilt over the rebellion caused the Hebrews to invent a religion.

The play is set in the wake of Germany’s 1939 invasion of Poland, which allows for numerous distractions — planes flying overhead, radio broadcasts, details of war. World War II has provoked decades of debate over God’s existence but here it proves to be a distraction from more trenchant depth.

To his credit, St. Germain is less interested in choosing a winner than he is in producing a reaction of two intellects diametrically opposed who are nonetheless breathing the same air.

Dorfman’s Freud is feisty, full of one liners, even as he suffers with the agony of oral cancer. Hansen’s Lewis is terribly eloquent, perhaps a bit too handsome and fashionably dressed for the Oxford don. Director Melrose emphasizes the dialectic of debate by putting audience members on each side of the long, rectangular stage and then letting his actors criss-cross each other as they pace.

I wanted to like this play very much. Dorfman and Hansen bring as much sinew to the project as we could hope for and Melrose has overseen a fine production. The wish is for more meat, something substantial that would keep us up long into the night.