The first thing Suzanne Gordon will tell you is that ""this is not an upbeat book."" To be lonely in America is to be ashamed for it carries a stigma; in a society which has extended the competitive ethic of capitalism to sex and friendship, being lonely is an admission of failure. Paradoxically, after examining the multitude of ""businesses"" which have sprung up to exploit the commercial potential of loneliness (encounter groups and contact seminars, singles bars and apartment complexes, the gurus who promise spiritual bliss and salvation, Werner Erhard's Esters. the computer dating services), the author concludes that this multi-million dollar industry seems only to accentuate feelings of alienation and anomie. Gordon has amassed overwhelming and pathetic evidence that social and human isolation, and the feelings of lovelessness that go with it, are not confined to marginal groups--are not, for instance, the temporary affliction of the recently divorced or those who, because of age or infirmity, have been shunted into goldenage ""retirement communities."" Toughest is her conclusion that our loneliness is a byproduct of the qualities of life we have been taught to value most--social mobility and the ethic of personal growth and fulfillment. Both have tended to erode the ties of community and kinship. One consequence of this dissolution of the social nexus, Ms. Gordon believes, is the frantic, desperate overvaluation of romantic love--if only we can find the one all-purpose soulmate and bed-partner ""we believe we really don't need anyone else."" This delusion is more likely to destroy a marriage by demanding that it bear the weight of all the other, discarded alliances of friendship, work and community. Gordon has made her way through the psychological literature which touches on this condition--Harry Stack Sullivan, Fritz Peals, Rollo May, R. D. Laing--and found it to be scant, sometimes platitudinous. The bulk of her material comes from the men and women of all ages whom she interviewed--it's their daily search for a remission of their isolation which gives the bock its impact. Somewhere in that crowd of faces you may get an unwelcome sense of recognition. . . .