The word "mother" is one of the oldest in the English language, but the word "motherhood" dates only from the 16th century and even then referred merely to the fact of being a mother. Motherhood developed as a concept, particularly a moral concept, in the Victorian era and was part of the idealization of home and wife that is now widely regarded as being the result of the political and social pressures that kept women at home in the service of their menfolk. During this century the idealization of wives has gradually diminished, but that of motherhood has increased to the point where it is difficult to define what it really means. There is a tendency for social custom to dictate what is right, regardless of the realities of parents' and children's lives and their differing needs.

Books like the two at hand try to help mothers sort out the ambiguities in their roles and deal with their guilt. Many, including these two, are written by women who have professional knowledge of the subject and have also struggled with it in their personal lives. For instance, Sandra Scarr, a specialist in child development, has four children. Her book "Mother Care/Other Care," which deals mainly with working mothers and their problems, particularly with child care, is full of interesting information, common sense and thoughtful analysis based both on personal experience and on professional judgment.

Why, she asks, does contemporary western society stress the exclusive importance of mothers for children's normal development? No other culture has done so before. It has meant that each working woman has had to concoct an individual solution to the problem of child care during working hours, and for most this has only been done with difficulty and guilt.

Scarr takes us carefully through the steps involved in dealing with the basic dilemmas and in reconciling the needs of children with those of mothers. She emphasizes the strength and individuality of children and the variability of good child care, reviews the relevant literature and what public authorities have and have not done, and discusses how ideas about children and mothers have changed. She concludes with a valuable guide through the maze of day care history, legislation and myth.

Nancy Rubin, author of "The Mother Mirror," is a journalist who has specialized in home and family problems and has two daughters of her own. Rubin defines "the mother mirror" as the conflict between a woman's desire for independence and her wish to nurture, a conflict she analyzes through the experience of other mothers, childless career women and the findings of psychosocial experts. She makes a compelling case for her conclusion that for modern women living through a child's reflection is simply not enough.

As Scarr remarks, "The human species does not seem attuned to exclusive mothering at all, but to secure relationship with others." Most mothers know this, so how did all these restrictive and guilt-provoking theories come about? And why did women put up with them? Social historians have not yet worked through these questions.

Meanwhile, events have overtaken theories. The last 15 years have seen motherhood become increasingly a positive decision instead of an automatic stage in life. Any decision involves questioning and doubt. Personal need has begun to rival self-sacrifice in motherhood. The increasing independence of women has also led some men to demand a part in mothering, often right from the start. And there is a tendency today to later motherhood, increasing anxiety about infertility and also about genetic engineering and surrogate motherhood.

Nevertheless children continue to need love and security, mothers continue to long for babies, to love them dearly and to struggle with the problems of their generation.