Modern autobiographers can be a strange brew: James called his ""the history of an imagination""; Miss Stein pretended hers was written by and about Miss Toklas. And so it goes. Sean O'Faolain's however, is more traditional, more reliable, more newsy, and, alas, not very intoxicating. There's a keen edge (""To every man his role; to every man his time"" seems to sum up the book's life-acceptance credo) and a number of plaintive truths. e.g., if the father hadn't been so upright the son ""might now admire him less and might then have loved him much more."" But O'Faolain's prose, superficially quite persuasive, floats away when you touch bottom. Amidst the details (sights, smells and feelings of his Cork childhood or the evocations of harvard-London-Dublin Literary life in the late 20's and 30's), one also gets marginalia -- philosophic/ theological reflections (mostly sentimental), or the Fate of Ireland (mostly self-indulgent) or his rank -and-file IRA days (mostly dull). The best parts are the robust portraits of Edward Garnett and Yeats, the charming sketches of married life, and the hard-won shrewdness about writing as a career. ""I have always been a romantic,"" says O'Faolain, ""with a hopeless longing for classic order,"" thus acknowledging his divided heart and thus accenting the importance of being able to say Vive Moi: A sweet book, and an eminently sane one; unfortunately these virtues have never run deep in Art.