Slaves, Tolkien, Tuchman, art; Originals: Women in Art, by Eleanor Munro. New York: Touchstone Books/Simon & Schuster. 528 pp. $12.95.

A compilation of biographies and a critical analysis of the work of nearly 50 women artists of three generations - among them Mary Cassatt, Georgia O'Keeffe, Lee Krasner, and Nell Blaine.

Munro, a former art critic, tells how her dissatisfaction with formal criticism led to developing a method, called ''psychoesthetics,'' of circular biography through which she and the artists unearthed connections between their vivid childhood memories and their artistic imagery.

A shared common denominator among the artists in the book is a ''turning point . . . a technical breakthrough that liberated the artist to rejoin her imagination with the primal sources that illuminated it as a child and from which she had been alienated during her academic period.''