This week's offering of the Brattle Theater Company is, for the most part, a finished and sometimes brilliant production. The play itself has received the distinction in some quarters of being among the best of modern drama. Although I cannot rank it so highly, the play remains a very delightful, if vaguely formulated piece, and it contains one very masterful characterization.

"Shadow and Substance" gives a spiritual picture of Ireland by confronting several variations of Roman Catholicism with modern unorthodoxy. The story concerns the reactions of several members of a small Irish town to the scandalous book of a local schoolmaster. The action centers about the local Canon, who, with classical dignity, decides the provincial efforts of the townspeople to burn the txe publically with malicious ceremony--but he dismisses the teacher. The balancing force in this conflict is Brigid, the Canon's maid, who is in communication with her namesake, St. Brigid, and who has a longing to become a nun. Although the play admits of no explicit and patent interpretation, I would venture the theory that Brigid, in her simple piety, open love and semi-martyrdom at the end represents the core of Christianity, which is, in some respects, perverted in the other characters.

But, to my mind, author Vincent Carroll's major achievement in this play is the character of Canon Skerritt. After a too leisurely opening scene, his entrance is a refreshing one; the play seems to change its caliber immediately. In him, the play wright's command of limpid, precise prose is very powerful. And more, the Canon is a rounded character whose pomposity and reverence of classicism are explored in skillful detail. This character receives full understanding and appreciation in the hands of Thayer David. David gives a performance which is remarkable for its restraint and technical perfection. And Julie Haydon, the guest star, brings to her role of Brigid not only her appropriately chaste beauty, but a quiet and winning style.

The production is further enhanced by some of the minor comic characters who are given colorful interpretation by other members of the Brattle company. Miles Morgan, Mary Manning and Jeanne Tufts were ingenious and very very funny. Will West, however, through lack of subtlety did not fulfill the promise of his excellent, catoon-like make-up. Jerry Kilty and Robert Rockman were adequate as the two young priests.

Jan Farrand was, as usual, charming and energetic, and although Robert Fletcher's performance as the schoolmaster was quite acceptable, I felt he lacked assurance, and his mugging and on-and-off brogue detracted from his characterization. But my reaction is to be pitted against the applause he won from members of the audience after his final exit.