<P>In <I>Fratriarchy</I>, Juliet Mitchell expands her ground-breaking theories on the sibling trauma and the Law of the Mother. Writing as a psychoanalytic practitioner, she shows what happens from the ground up when we use feminist questions to probe the psycho-social world and its lateral relations.</P><P>In this pivotal text, Mitchell argues that the mother''s prohibition of her toddler attacking a new or expected sibling is a rite of passage from infancy to childhood: this is a foundational force structuring our later lateral relationships and social practices. Throughout the volume, Mitchell chooses the term ''Fratriarchy'' to show that, as well as the up-down axis of fathers and sons, there is also the side-to-side interaction of sisters and brothers and their social heirs. Making use both critically and affirmatively of Freud, Klein, Winnicott, Bion, Pontalis and others, <I>Fratriarchy</I> indicates how the collective social world matches the individual family world examined by