On the 27th of May, 2019, the Freudian Institute of Rome, together with the Library of the Freudian Field and the Secretariat of SLP Rome organized the presentation of the book Seminar XVI “From an Other to the other” by Jacques Lacan. In this seminar, Lacan compares the signifier and jouissance and explores the antinomy between an Other of knowledge and the other of jouissance to indicate how, from the relationship that is established between jouissance and the signifier, an additional function is released that Lacan calls with a term coined from Marx's surplus value: surplus jouissance.