Elwood P. Dowd is a lovely fellow. He greets everyone with a smile, is kindhearted, generous, mannerly, and, by most standards, quite mad. It’s obviously not his personality that makes Elwood so puzzling and irritating to his family and friends — and to the Freudian charlatans at a nearby sanitarium. In fact, most everyone finds Elwood rather charming. It’s Elwood’s invisible friend, Harvey, a 6-foot white rabbit with ESP, that has everyone in a tizzy.

In our era of complex routines and lifestyles, Mary Chase’s 1953 play “Harvey,” running through Aug. 25 at Acadia Repertory Theatre, is an endearing reminder of how vital simple pleasures can be. Elwood, who “wrestled with reality for 40 years … and finally won out over it,” becomes a hero for our times. With elegant concern, sincerity and delight, Elwood outshines the ’90s kind of wildmen by getting in touch with some essential human truths without ever really leaving his own backyard. There’ll be no screaming in the woods for Elwood and his pal Harvey. They prefer to warm themselves in the golden moments of life: picking flowers in the garden, holding a woman’s soft hand, carousing with bartenders, and listening to the hopes, regrets, loves and hates of others. Existing in such a reality isn’t practical for most of us in the normal, workaday world, but isn’t it pretty to think that life can be so easily enjoyed?

Acadia Rep does a fine job capturing the spirit and comedy of this play, and much of the credit goes to Eugene J. Tierney, whose entertaining characterization of Elwood is genuinely sweet and unadorned. The friendly honesty of Tierney’s gentle expression is warmly inviting.

The most unexpectedly impressive moment of the evening, however, is an incredibly smooth and confidently executed set change in which a parlor is converted to a doctor’s office. The slick choreography won a round of applause opening night.

Theatrically, the actors, in general, offer the season’s strongest performance with this show. Julie Sheehan, as Elwood’s skittish niece, begins the show with terrific comic expressions, which unfortunately dwindle as the evening progresses. John Erickson, as the stodgy Dr. Chumley, jumps in with a great start and loses a bit of that initial energy, but manages to maintain his usual onstage finesse. And Kathleen McInerney, as Nurse Kelly, is bright and crisp.

Less compelling are the overdone performances of Susan Horner (Veta), Darren Campbell (Dr. Sanderson), and Christian Brandjes (Wilson), all of whom are in lead roles. Cartoonish though Veta is, Horner would do well to tone down her frenzy, and Campbell his emoting. Brandjes might be a bit clearer if, when delivering lines, he took the full-length cigar from his mouth. Bit parts played by Christine Erickson, Glenda Whitney, Matthew Hochman, Lydia Frances Maier, and Alan Gallant were enjoyable.

“Harvey” will be performed 8:15 p.m. Tuesday-Sunday and 2 p.m. Sunday through Aug. 25, at Acadia Repertory Theatre in Somesville. For tickets, call 244-7260.