Mind If I Differ is a book that just happened. And a more felicitious one in the Catholic publishing field can scarcely be imagined. When Unitarian Betty Mills of North akots finished reading Lucile Hasley's Reproachfully Yours -- she wrote the author telling her that she enjoyed the book, but didn't quite ""buy"" the brand of Catholicism which convert-Hasley was selling. And she wondered if Mrs. Hasley might consider writing a book about the Church for non-Romans -- ""to inform -- not reform."" ucie Hasley answered the letter, and a Unitarian-Catholic dialogue began through the U.S. which was to last almost three years. The Hasley-Mills letters in book form are a captivating record of what two intelligent, witty, and ""believing"" women feel about their religions. Their sincerity and good will and the obvious respect each shows the other in trying to comprehend differing religious viewpoints could we be emulated by more learned theologians in loftier dialogues. When not discussing religion, the two ""sparring partners"" have some trenchant observations to make about husbands, reading, poetry, gardening, children, grandchildren and life today. These articulate women engage in a ""person-to-person dialogue"" on the level at which the ecumenical spirit of our times should descend if it is to be truly effective.