NOT AS A STRANGER (948 pp.)Morton ThompsonScibner ($4.75).
At an age when his contemporaries dreamed of becoming cowboys or firemen, seven-year-old Lucas Marsh already knew his life work: he would be a doctor. He was handicapped from the first. Mamma, a neurotic and mystic who believed that only the spirit could heal, hated the very idea of medicine and hysterically begged Luke to forget it. Daddy Marsh, the crude, unscrupulous owner of a string of harness shops, insisted that Luke shift his sights to business and the big money. Luke obediently said yes, mother, yes, dad; but what his parents never...