Waugh once said, ""There is no identifiable School of Sitwell. Three of them was enough."" Enough to create a legend in their own time as caustic catalysts provoking attention and promoting a modern spirit in the arts. Enough certainly to be almost endlessly self-perpetuating with a dazzling a fascination, not only through their own works but in such a one as this, carefully, gracefully presented as an ""interim"" assessment by their publisher, friend, curator. . . . Mr. Lehmann has divided the memoir-appraisal between the lives and works of each, carefully individuating them: (""We do not like to be treated as if we were an aggregate Indian god. . . ."" Edith). But it is Edith who dominates the trinity, the marmoreal presence with the face of a Modigliani (the Sitwells introduced the painter) and of Elizabeth the Virgin Queen (their forebears were Plantagenets). However, all three were to have a profound cultural impact, operating on their principle of attack and counter-attack, inveighing against philistinism (""Culchawed Cant""--Osbert), goading, glittering eccentrics who were as ""cosy as a nest of tigers on the Ganges""--Edith). . . . Their Noble Essences endure.