Mary Jacobus writes 'In Lacan's seminars of the late 1950s and early 1960s, the evolving concept of the objet (petit) a is viewed in the matheme of phantasy as the object of desire sought in the other...a deliberate departure from British Object Relations psychoanalysis'.

In 1957, in his Seminar Les formations de l'inconscient, Lacan introduces the concept of objet petit a as the (Kleinian) imaginary part-object, an element which is imagined