Marguerite Heber Bowen is 42 years old as this novel opens; she has been battered by life a bit more than the average person, and for some time she has been enjoying perversely the latest role thrust upon her by circumstance: "the crazy lady from down by the sea." She has been living alone in an isolated farmhouse on an island somewhere in Canada's Maritime Provinces, supported and confined there by the terms of divorce from her husband, a rising young politician in Ontario who has found someone younger and more helpful to his career.

On the island, Marguerite has spent her time watching crabs skitter through the tidal pools, visiting a place down the road where wild roses grow, reading Penguin classics and old New Yorkers and thinking about the tangled path that brought her to this beautiful, lonely place. The results of that meditation, embodied in a long letter to a friend and adviser, are the substance of "The Glassy Sea," which is a brief but very eventful novel, an agenda for a women's movement, an exploration of the basic problems in our society and frequently poetry of a very high order.

In her attempt to put her experience into focus, Marguerite Bowen uses all the resources of a splendidly cluttered and agile mind. The ingredients of her meditation, as of her life, are miscellaneous in the extreme and would look a bit silly spread out in a cold summary. But the concrete details are important only because Marian Engel has used them so beautifully, working them together in a prose collage of biographical fact, symbolism, fragments of philosophy and theology and acute social observation. The ideas that chase one another through Marguerite's mind are all the more fresh and memorable for being embodied in the sharp, physical images of poetry. The people one encounters in her memory are all the more human for being symbols as well.

The most symbolic, the most absurd and the most human element in the book is the Eglantine Sisters, a pre-Raphaelite sort of Anglican religious community with which Marguerite spent 10 years -- a sort of recess from the hard business of living -- before going to marriage, a variety of emotional disasters, divorce and exile.

From one viewpoint, the Eglantines, housed in an enormous Victorian mansion and supported by a variety of endowments, were a misguided venture into medievalism, of no real use to anyone but the handful of women they sheltered from reality. Marguerite gives full justice to that attitude, but there is another that finally prevails. In a generation devoted to "the search for alternative life styles," this world of women, bound together by a simple set of rules and dedication to a common dream, can easily assume another meaning, and set in the context of Marguerite's life, that meaning becomes more and more persuasive.

She is gently led out of the Eglantines after 10 years because she is the youngest member by more than a generation. The others are dying off or drifting into senility, and the mother superior does not wish to leave her alone, at the end, with nothing to do but bury and mourn for her sisters. "It was too good to be true, of course," she reflects, "but I cannot condemn an institution that cost nobody anything and made nine women happy."

Later, in the solitude of her divorce-exile, Marguerite slowly modifies her view of the society she has fled. The view is clearly tinged with the blood from her marriage-inflicted wounds, but it is one with many adherents today, and she expresses it eloquently: "The fall-out from the battle of the sexes is getting worse every day and will continue to do so. The men are running scared . . . there is a ghastly woman-hate in the air and they are acting it out; and women are responding with either aggression or fear. Men, forced by politics and literature and the facts in front of their eyes to see women as they are, are frightened . . . Marriage is changing, people are afraid of change, war has broken out."

And so, at the novel's end, even though she is not sure whether she believes in God, let alone the Anglican Church, Marguerite agrees to re-establish Eglantine House. And as the community's second founder, she knows exactly what she wants: "a core of women helping other women to put their lives . . . in order. The casualties are coming in greater and greater numbers, and though I would like to take the men, too, and bang all their heads together, and cry, 'Off with the old, on with the new,' and 'You must love one another or die!' it is women I am committed to working with and I shall do that."

It sounds terribly apocalyptic, taken out of the novel's context. Easier to accept, perhaps is another judgment justifying the existence of the Eglantines: "To lead a harmless existence in the twentieth century is a great accomplishment." But underneath the variations in rhetoric, both statements say substantially the same thing. It is a thing worth saying, and its worth is compounded in this book by the quirky elegance with which it is said.