Lack or Loss of something is required to set the symbolic in motion.
The Phallus is the signifier of lack
A woman’s sexual identity can, in fact, involve many different possible combinations, for unlike masculine and feminine structure, which in Lacan’s view constitute an either/or, there being no middle ground between them, ego identification can include elements from many different persons, both male and female. In other words, the imaginary level of sexual identity can, in and of itself, be extremely self-contradictory.
The very existence of sexual identity (sexuation, to use Lacan’s term) at a level other than that of the ego, at the level of subjectivity, should dispel the mistaken notion so prevalent in the English-speaking world that a woman is not considered to be a subject at all in Lacanian theory. Feminine structure means feminine subjectivity. Insofar as a woman forms a relationship with a man, she is likely to be reduced to an object —object (a)— in his fantasy; and insofar as she is viewed from the perspective of masculine culture, she is likely to be reduced to nothing more than a collection of male fantasy object dressed up in culturally stereotypical clothes: i(a), that is, an image contains yet disguises object (a). That may very well imply a loss of subjectivity in the common, everyday sense of the word —”being in control of one’s life,” “being an agent to be reckoned with,” and so on— but it in no way implies a loss of subjectivity in the Lacanian sense of the term. The very adoption of a position or stance with respect to (an experience of) jouissance involves and implies subjectivity. Once adopted, a feminine subject will have come into being. The extent to which that particular subject subjectivizes her or his world is another question.