Pondering the meaning of life and the existence of God isn’t exactly unprecedented fodder for a play. Nor, for that matter, is it always very easily sold as theatrical entertainment.

You’ve probably heard most of the philosophical pros and cons before, especially if you saw last year’s “The Sunset Limited” at Theatrical Outfit, where artistic director Tom Key has shown a penchant for producing spiritually relevant, if potentially sermonizing, dialogues on the subject.

In the case of that drama, the debate ultimately felt somewhat heavy and pretentious. It wasn’t that the opposing arguments weren’t well-balanced or well-reasoned, but they were slightly harder to buy coming from two characters who spoke a bit too eloquently and profoundly to be fully believed as downtrodden common-man types.

The Outfit’s latest think piece, “Freud’s Last Session,” asks many of the same age-old questions. But playwright Mark St. Germain provides an intriguing and invigorating twist by imagining a meeting between two men for whom such weighty conversation makes perfectly logical sense: famed psychoanalyst and atheist Sigmund Freud and noted author and theologian C.S. Lewis.

Not surprisingly, the results are smart and thought-provoking. More unexpectedly, under the smooth and brisk direction of Jessica Phelps West, they’re also genuinely witty and enjoyable.

David de Vries’ tour-de-force performance alone is not to be missed. As the aged, dying Freud, he’s virtually unrecognizable in his white hair and beard, but the actor isn’t merely hiding behind the makeup. In his deliberately paced movements and gestures, in his occasionally staggered speech pattern and wavering vocal quality, he brings an utterly convincing physicality to the role of this 83-year-old man who’s fighting a losing battle with oral cancer.

The play unfolds in 1939 London, where the Jewish Freud fled to escape the Nazi invasion of his native Austria at the outset of World War II. At the time, Lewis was an Oxford professor most widely known as a satirical essayist (he wouldn’t write the first of his “Narnia” books for another 10 years).

His religious conversion as a younger man is particularly fascinating to Freud, who’s contemplating suicide and invites Lewis to his home for afternoon tea and one final exchange of impassioned ideas about science and religion, body and soul, reality and fantasy, life and death and afterlife – and, naturally, sex.

For the most part, “Freud’s Last Session” does a highly respectable job of looking at all sides of the issues without necessarily taking sides, thus encouraging us to think for ourselves and draw our own conclusions.

Andrew Benator’s subdued portrayal of Lewis offers an effective contrast to de Vries’ animated Freud. Based on the opening-night performance, however, the Outfit show gradually tips the scales in his favor. Whether it’s an acting choice by Benator or a directorial decision by West, Lewis aims a lot of his observations to the audience as much as to the other character in the room (a stately study designed by Isabel and Moriah Curley-Clay).

Subconsciously, at least, it suggests that we’re intended to identify more strongly with Lewis and his views, because he’s literally speaking to us. And it feels a bit like cheating in more ways than one.

Theater review

“Freud’s Last Session”

Grade: B+

Through Nov. 13. 7:30 p.m. Wednesdays-Saturdays; 2:30 p.m. Saturdays-Sundays; 2:30 p.m. Wednesday (Oct. 26). $15-$30. Theatrical Outfit (Balzer Theater at Herren's), 84 Luckie St., Atlanta. 678-528-1500. www.theatricaloutfit.org.

Bottom line: The show might lean against him, but the marvelous David de Vries rules.