The observational perspective common to the various papers framed the diagnostic process by identifying the variables of juxtaposition between the clinical research of group analysis and the clinical-empirical research of McWilliams and Lingiardi. From a group-analytic perspective, the diagnosis can be conceptualised as an encounter between several territorialities, those of the clinician and the patient, and between their internal and extemal groupalities. Complexity has a multidimensional character, crossing the various layers of the psychic: intrapsychic, intersubjective, and group. In the diagnostic understanding, the authors emphasise the centrality of the construction of the co-transferential field, the therapeutic project and the therapist’s subjective experience. The labyrinthine dimension of Venice becomes a metaphor for the diagnostic procedure as co-construction together with the patient ofhis inner city.