the object of its lack, for desire, because desire is lack, is in our experience identical to the very instrument of desire, the phallus.
Lacan asserts the structural identity of desire and lack, arguing that the phallus, raised to the function of signifier, occupies the symbolic place of what desire, as constitutive absence, can never possess.
, The Seminar of Jacques Lacan, Book VIII: Transference, 2015thesis