Systematic reference to ICD-10 and to Good Practice Guidelines in diagnosis and therapy raises objections among numerous professionals of infant and child mental health services. They fear the limitation of the encounter and the sclerosis of inventiveness. This a priori antinomy should be questioned since between the so-called scientific conceptions and the theoretical and clinical practices of psychodynamic professionals, these new tools could be seen as the “creative mode of perception” that Winnicott defined. Far from drying up creativity, dealing with these new perspectives seems to encourage it by providing material to these clinicians, who have to link it to their experience and practice in order to adjust to the new clinical data.