[The letters preserved by Vittorio Benussi 'Fund Sante de Sanctis'].

Through the publication of a previously unpublished exchange of letters, this paper examines the relations between the Italian psychologists Sante De Sanctis and Vittorio Benussi. The collaboration between the two scholars, which emerges from the 23 letters presented here, was solid and long-lasting both on the scientific plane and on the personal one. It began in 1905 on the occasion of the Fifth International Congress of Psychology held in Rome, and it terminated more than 20 years later, in 1927, with the death of Benussi, who took his own life. The Benussi-De Sanctis correspondence (1905-1927) is part of a archive, denominated the "Sante De Sanctis (1893-1935) Archive," which has been recently constituted on the basis of commonly shared archival criteria. In order to facilitate a better understanding of the general context of Sante De Sanctis's scientific relations, the Appendix contains an analytical list, divided into 170 files, of all those who sent letters to him between 1893 and 1935.