Judith Wax's tragic death in last week's Chicago plane crash makes her book title, "Starting in the Middle," an ironic epitaph to a promising beginning. The gift of laughter is hard to find lately. Judith Wax had a rich supply and should be remembered for it. She and Judith Viorst both marched to a different tune in the recent Muzak of women's books (i.e., their books do not portray all men as rats, nor life on one passage after another), though their steps diverged when they got to humor. Where Wax's book is a belly laugh, Viorst's is only a grin.

"Love & Guilt & the Meaning of Life, Etc." by Viorst is a collection of random thoughts which might drop like pearls in ordinary con tion. When assembled in book form, like interchangeable plastic beads popped together to make a necklace, they are colorless and lacking in lustre. With statements like, "Growing Old: I'd rather grow azaleas." or, "being in love is better than being in jail, a dentist's chair, or a holding pattern over Philadelphia, but not if he doesn't love you back," you don't have much to grab on to.

This is not to say that Viorst isn't funny or clever. She is both, but not in this book. You can pass a pleasant 15 or 20 minutes polishing off all three courses of her book and a couple of hours later you're hungry again. Worse yet, you cannot remember a single morsel.

I feel terrible about not liking "Love & Guilt & the Meaning of Life, Etc." After all, Viorst and I have passed two decades together. In her previous books, "It's Hard to be Hip Over Thirty" and "How Did I Get to be Forty and Other Atrocities," she made me laugh when crying seemed more appropriate. Now, much as I love her work, she is making me feel guilty because I think she has missed the meaning of life and fallen into etc.

Judith Wax's book "Starting in the Middle" shows that one can begin at 40 if: 1) you've kept your sense of humor; 2) you have friends who have had affairs and tell about them; 3) you have a loving and supportive husband; and 4) your reentry writing is printed in three prestigious national magazines.

For those with none of the above, Wax would be hard to take if she didn't write with warmth and wit tempered by glimpses of her own dark nights of the soul. Her book describes the pain of watching death move in old friends and the shock of hearing that the perfect couple has split. In telling the story of her son who shaved his head, donned a saffron robe and joined the Hare Krishans, she used wry humor as frosting for her despair. You have to admire a woman who could laugh while her son chanted. As she put is, "One of the worst shocks of middle age is finding out no one is really in charge."

Wax wrote of her friend Maggie whose husband of 25 years came to breakfast one morning and 'asked to have his eggs over easy and his marriage over period." She told of women coping with nests emptied by death, divorce and other natural causes and of wives who find "the challenge hasn't been learning new tricks, but juggling them within old marriages."

Judith Wax was at her best when describing the "guilt-edged insecurities" of our generation. She saw the canapes of compunction being passed around life's living room by both parents and progeny. She may have sampled one now and then but knew the heartburn for what it was - excess gastric acid.