Boston — ''When I write, I pamper myself. I say to myself, 'Start anywhere, Sweetie. It's not in stone. You can rewrite it this afternoon. It's only a first draft.' ''
These unexpected sentiments come not from a new writer, but from one of America's most respected authors of books for children and young adults. Katherine Paterson has nine books to her credit, three of which have captured the highest awards in their field. Yet, in her case, success hasn't eclipsed a modesty that is rare among top writers.
An attractive, lean, energetic woman, Mrs. Paterson has intense brown eyes that flash in service of her ready wit and sharp intellect. She is keenly interested in people, ideas, her religion, and, above all, in writing. These interests surfaced repeatedly, as she talked before an auditorium full of teachers, librarians, colleagues, and fans here recently.
The topic on that occasion - and in nearly every serious discussion of contemporary children's literature - was the degree of ''realism'' it should contain.
Mrs. Paterson, a mother of four children in their teens and early 20s, feels that it's impractical to try to shield young readers from the pangs of divorce, death, war, and other topics that were far less common in children's literature a generation ago.
She takes issue with thinkers such as Marie Winn, whose recent book, ''Children Without Childhood,'' argues that parents should shelter the young from the harshness and ugliness of the adult world. Paterson says that's no longer possible. She believes the best alternative is to draw on honesty, sensitivity, and a sense of balance when dealing with touchy subjects - in literature or in life.
Mrs. Paterson claims that children today are frightened by forces beyond their parents' control and that silence only intensifies their terror. ''One 14 -year-old girl,'' she told her Boston audience, ''said that kids today know about the nuclear threat, but what terrifies them is not to talk about it, which makes the threat seem mysterious.
''I cannot write for these children and pretend that we live in another, more placid universe. It won't work,'' she explained.
Yet Mrs. Paterson feels her ''primary task is not to disturb . . . but to see through the disturbance to the unity so marvelously built into the creation, to somehow find my way through the cacophony . . . to the harmony of truth.'' She added, ''I feel I must write the best, the truest story I can write.''
In an interview after her talk (given during the Simmons College Institute on Children's Literature and titled ''Do I Dare Disturb the Universe?''), Katherine Paterson said there can be no doubt that books do have the potential of influencing young readers for good or for ill. Yet she cautions that parents ultimately can't control their children's reading and should not try to act as censors. Instead, she believes, they should attempt to give their children a healthy and well-rounded perspective from which to cope with life's challenges. ''The reader brings his own life to the book,'' she says. ''He takes from the book what he wants to take.''
Citing her own childhood, she says her parents, Protestant missionaries in Asia, were very conservative but that they never tried to censor her reading. Today she sees wisdom in the freedom they allowed her, even though a book can produce some jolts along the way. This wife of a Presbyterian minister recalls reading a disturbing book at age 15. ''I lost my faith when I read 'Wuthering Heights.' That was the book that said to me, 'There is no God.' . . . Well, I couldn't imagine that. . . . Yet, I had to learn that you have to lose your faith to find it.''
Reflecting on her roles as a parent and a writer, she adds, ''. . . What you hope for, pray for, and work for is to build the inner strength which helps (youngsters) cope with everything. And I think books do help them build that inner strength. I know they did in my life and know they have in my children's lives.''
As to the presence or absence of moral themes in contemporary children's literature, she observes that ''a book cannot be what the author is not. You write out of who you are, and it's not that you put it (a moral) there. But if you are a moral person it's going to be there. If you are writing at the deepest level of which you are capable . . . , then you will reveal things about yourself.'' She adds that when trying ''to write the best story you can write, a lot of your experience is going to come out in that book, whether you want it to or not.''
Writing is hardly a new experience for Mrs. Paterson. She began about 20 years ago, when she was expecting her first child. Among the laurels Katherine Paterson has won are the 1978 Newbery Award for ''Bridge to Terabithia,'' a 1979 Newbery Honor and a National Book Award for ''The Great Gilly Hopkins,'' and a 1981 Newbery Award for ''Jacob I Have Loved.''
Most of Mrs. Paterson's novels have revolved around historical themes. She explains, ''History is a powerful pair of eyeglasses with which to look at life. . . . Art is a means of seeing truth which cannot be observed directly.'' She is quick to add, however, ''A writer must write about what impinges on his or her life.''
In Mrs. Paterson's case, her birthplace supplies the locale for her newest book, ''Rebels of the Heavenly Kingdom,'' set in China during the 19th century. She was born in China and lived there with her missionary parents until she was 8. But ''Rebels of the Heavenly Kingdom'' isn't autobiographical. The story grew out of her reading about the Taiping rebellion of the 1850s. She was ''struck by what happens when people of high ideals take them into a holy crusade to save the world.''
While working on the book, Mrs. Paterson suddenly reached a point at which she couldn't write another page. ''I knew terrible things were going to happen, '' she explains. ''I am not a violent person. I hate for people to be hurt.'' She reasoned her way through the dilemma. ''A writer can't just say, isn't this awful,'' she recalls having thought. ''A writer must portray its awfulness.'' So , with an investment of two years' time, during which she made a trip to China, she completed the book.
Mrs. Paterson feels her role as a mother has complemented rather than jeopardized her career as a writer. She started writing just before the arrival of the first of her four children, John Jr., who is a sophomore at Dartmouth College. Her daughter Lin attends Earlham College in Indiana. Son David is a senior in high school in Norfolk, Va., where the Patersons live, and a second daughter, Mary, is a sophomore in high school.
Mrs. Paterson wrote all through the years when her children were small, even though she hardly ever had more than 10 minutes at a time to devote to her work. Nothing she wrote at that time was published. ''It wasn't very good,'' she says.
Yet, she wouldn't trade a pile of best sellers for the years she spent raising the children. ''There is no choice between those kids and the books I might have written . . . ,'' she says. ''I couldn't have written the books I wrote without children. They've given me so much. I was a career woman,'' she adds, referring to her four years of missionary work in China. ''You make a choice . . . I chose every one'' of those children.
Today Mrs. Paterson writes each day, from the time the last person leaves for work or school until her husband returns for lunch. When she is revising a manuscript she may put in longer hours.
In speaking of ''Jacob I Have Loved,'' which deals with twin sisters and their very different treatment and rivalry within their family while growing up, Mrs. Paterson says that many adults have complained about the ending. (The main character begins a career in rural nursing, then meets and marries a rough-hewn country man with three children.) Those unhappy readers say the book should have ended two chapters earlier. ''Yet no young person has ever questioned the ending of that book,'' she notes.
One young reader of ''The Great Gilly Hopkins'' wrote in a book report for school, ''This book is a miracle. Mrs. Paterson knows exactly how children feel.'' Mrs. Paterson adds, ''Of course, I don't know how children feel - no one knows. But I do know how I feel. And I try to stay true to those feelings. Anything else will fail the test.''
She says she makes it a point to try to give young readers hope and encouragement - to show them the value of not giving up.
To the question of what her next book will be, Mrs. Paterson answers, ''Don't ever tell anyone about what you're writing. If you do, you've already published it. I haven't even told my husband. . . . Or my editor.''
Katherine Paterson's fans will just have to wait and see. But one thing is sure: The wait promises to be worth it.