Dr. Smith is one of those amiable, nondoctrinaire pediatricians who's willing to treat the baby (or play psychiatrist to the mother) for anything from diarrhea to bad eating habits to reluctant Sunday school attendance. But he does tell you up front that it drives him nuts to get those inane calls from hysterical mothers at 2:00 a.m. The mothers have been misinformed by Old Wives Tales and Dr. Smith has decided to prescribe some New Wives Tales as an antidote. He's got a pithy epigram for everything from teething, bed-wetting, colic and thumb-sucking to how to treat the growing child's experimentations with the family liquor cabinet: ""If you tell your child not to put a bean up his nose, you will have a child with a clogged nostril."" Unless an alarming symptom develops, Smith is inclined to be permissive. Time solves most problems: remember that a child must be motivated to clean his room, eat with a fork, or be polite and ""Learning waits on motivation which waits on maturation."" So Dr. Smith is against rigid schedules whether for infant feedings or the potty -- ""the trouble with this pressuring is that it sets the tone for the whole child-rearing process."" Without insulting the doting mother, he gets across the point that if she would only relax and enjoy the child haft her problems would solve themselves. A friendly, indulgent and reassuring guide.