were present in the planning phase, were excluded from the final composition of the painting and obscured by the brown background. In the figure on the far right, there is remorse in the eye and in the slipping of the cheek. Originally this face was positioned more than three-quarters of the way up; in the final version it is in profile. Diagnostic examinations of the Trieste version have also revealed several other "pentimento" that rule out the possibility that it could be a contemporary replica. They testify to the hesitations and changes made to the composition by the artist Caravaggio during the painting process and therefore reveal that it is an original work from Caravaggio's hand. The pentimenti are numerous and visible to the naked eye and with UV rays, IR rays or X-rays and are an essential source for the working process of this painting, which now allows us to disprove all theories that this painting is a copy. Current condition of the painting of the Trieste version In 2022, the painting "Doubting Thomas" was subjected to a necessary cleaning and elaborate examinations in Florence. The result: the pentimenti discovered during the cleaning carried out on the present painting confirm that it is probably even the first version of Caravaggio's interpretation of this theme. The technical and radiographic analyses and X-ray examination have revealed pentimenti (not simple corrections) to such an extent that even the hypothesis that it is a copy seems unthinkable. The proof that it is an original by Caravaggio is also quite clear from the transparency profile. The diagnostic examinations of the painting revealed very interesting aspects regarding the painting technique. And in this sense, the process of the painter appears clearly legible, able to develop the drawing and adapt it to the creative impulse that manifests itself free from the constraints of a predefined design, while the composition gradually adapts to the limits of the canvas to better convey the emotions of the story to the viewer. We are therefore not dealing with simple pentimenti, but with a genuine plastic and poetic redefinition of the entire painting. This therefore completely rules out the possibility of a copy. In short, according to some leading Caravaggio scholars such as Mina Gregori, Denis Mahon, Maurizio Marini, documentary research, diagnostic studies, i.e. a stylistic and formal analysis without prejudice, and looking at the painting itself, not an often poor