LIFE FORCE

LIFE FORCE Fay Weldon (Viking, $21) Leslie Beck's penis measures one-seventh of his total height. He has no other redeeming feature but, in this witty and cynical novel by Fay Weldon (The Life and Loves of a She-devil), he needs none. The six major (and one minor) female characters love him, and at least five of them bear him children. Life Force is wildly funny about sex, art, love, and, surely no mean feat these days, real estate. The novel is, in the least heavy-handed way imaginable, about the struggle between the principles and tastes of the British semi-intellectual class who grew up in the '60s, and the materialistic and instinctively destructive forces that characterize the greed of the '80s. In addition to a welcome attack on the contemporary mis-use of the verb ''to share,'' Weldon provides answers to some of the burning questions that Life Force raises, including how much women really care about the size of a man's extremities. B+ -AD-G