The title of the fourth seminar does not refer to any theory of object relations. The main "object relationship" of the speaking being, as emphasized by Sigmund Freud, is the relationship with the lost object, that is, with the lack of object.In the fourth seminar, this lack is formed in three versions - deprivation, frustration, castration - depending on its real, imaginary, or symbolic reduction. A privileged "object" - the phallus - is elevated to the signifier of lack and signifies the Aufhebung of the imaginary, that is, the symbolization of enjoyment and thus the separation from it. This process of symbolization will be called by Jacques Lacan "paternal metaphor" because it will be connected with the intervention exercised by the symbolic father, the Name of the Father, in the insatiable and insatiable Desire of the Mother. We are literally in the workshop of processing paternal metaphor. 

Here, Lacan demonstrates in an unparalleled way that the phobic signifier - the horse that frightens the little patient - occupies the position of the Name of the Father to the extent that it allows it to be elevated to the symbolic order, to the order of castration, all the libidinal disturbance that it causes in little Hans, the libidinal game with the mother - especially when it is complicated by the arrival of a little sister and by the first pleasurable escapades of his real penis. Thus, as Jacques-Alain Miller notes, the genuine title of the fourth seminar would have been "The Function of Castration". Despite its patriarchal culmination, however, the essential, constantly creeping, aim of the fourth seminar concerns the mother.

Lacan deconstructs the alleged "simple" mother-child relationship and emphasizes that the mother functions as a carrier of symbolic donation, transforming the real object into a signifier of her desire. The latter remains insatiable and enigmatic, to the extent that a mother is also a woman, that is, a gendered being subject to phallic dialectic. The way in which the child will be inscribed as a phallic substitute opens up a wide field of clinical destinies, neurotic or perverse in character, which this book clarifies with timeless value analyses. The mother, the father, castration - thanks to this thematic triptych, the fourth seminar emerges as the most representative testimony of the first, "classical," period of Lacanian teaching.