The tale is basically a downer -- Morton was reviled as a moral thug attempting to profit from his discovery, while others attempted to deny him the honor of it by claiming to have made it themselves. Morton died in poverty, a broken man.
Not surprisingly, no one could figure out how to make an "entertaining" adaptation. The book kicked around Paramount for several years until it was assigned to Preston Sturges, who'd written and directed a string of films that were wildly successful with both the public and critics.
Sturges resolved the book's "problems" by telling the story in flashback, so that all the unhappy stuff was at the beginning, and by treating the material as -- a comedy!!! The resulting film makes abrupt shifts between seriousness and farce. This -- along with Paramount's attempt to market it as a straight comedy -- probably explains why it was such a flop.
Although the film was shortened and re-edited by the studio, it remains (contrary to some reviewers' opinions) completely coherent, with most of the story told in an ordinary linear fashion. There were some unresolved plot points -- why was the US Government willing to give Morton [$$$] -- but they don't affect one's comprehension of the story line.
There has never been a better screenwriter than Preston Sturges, and in "The Great Moment" he shows a marvelous ability to puncture serious scenes with wisecracks. Joel McCrea -- a generally stiff and uninteresting actor -- is at his comic best, brilliantly trading barbs with the other performers.
The best part of the film is the last scene. With the ever-unimaginative Victor Fleming providing an underscore of the "Ave Maria," Sturges ends the film with a truly nasty send-up of "inspirational" movie making.
If you're a Sturges fan, don't let "The Great Moment" pass by.
This review is based on the out-of-print MGM LaserDisk edition. I have not seen the tape, and cannot comment on its technical quality.
