He's playing Elwood P. Dowd, the affable fellow who travels in the company of a six-foot-three-and-a-half white rabbit no one else sees, and Parsons makes the role of the enthusiastic bar-hopper -- made famous by Jimmy Stewart on film -- his own as he goes about bathing everyone one he meets with good humor no matter how they're intending to treat him for his supposedly abnormal behavior.
The complication that sets Harvey in motion, but never seems to register with sweet-natured Elwood, is that his sister, Veta Louise Simmons (Jessica Hecht), can no longer abide the shambles her social life has become and the effect that Elwood and Harvey are having on the prospects for marriageable daughter Myrtle Mae (Tracee Chimo).
At her wit's end, Veta thinks the solution to the problem is committing Elwood to Chumley Rest, a funny-farm presided over by tight-laced William R. Chumley (Charles Kimbrough, and hissecond-in-command, Dr. Lyman Sanderson (Morgan Spector).
As Chase's comedy alternates between the Dowd mansion's library and the sumptuous Chumley Rest reception area (David Rockwell designed the ingeniously turning set), several others are caught up in the ensuing ruckus, including womanizing orderly Duane Wilson (Rich Sommer), beguiled nurse Ruth Kelly (Holley Fain), Dr. Chumley's wife Betty (Carol Kane), baffled family friend Mrs. Ethel Chauvenet (Angela Paton), and befuddled Judge Omar Gaffney (Larry Bryggman).
The many incorrect assumptions and hilariously confusing results of Veta's botched plan keep the comic set-tos percolating enough to provide two hours of unmitigated fun. But for all the laughs, Chase even manages to suggest there's a method to Elwood's madness.
As one Harvey-induced incident evolves goofily into another and Elwood's apparent delusion begins to affect others, it becomes apparent that Chase is unmistakably implying that a little touch of lunatic behavior not only never hurt anybody, it undoubtedly helps one withstand life's otherwise daunting challenges.
No one appreciates this better that director Scott Ellis, who takes impressive command of a crackerjack ensemble, circulating in Jane Greenwood's impeccable period outfits. Indeed, every cast member embodies the spirit of the daffy goings-on, with special laurels due to Hecht for creating a break-out comedy characterization.
Oblivious to the danger into which Elwood has been placed, Parsons creates a magic spotlight for him and his unorthodox friend. Regularly exchanging knowing looks and comments with his tall chum, he reaches a performance peak when Elwood says, "I've wrestled with reality for 35 years, Doctor, and I'm happy to state I finally won out over it." Amen to that.