A long tradition has produced a misleading interpretation of the categories of idiographic and nomothetic. Such an interpretation has hindered the development of psychology and more in general of social science. “Idiographic” has been treated as a matter of identity, an ideological approach that continues to be reproduced through the conflict with what-is-outside-it viii S. Salvatore, G. Marsico, and R. Andrisano-Ruggieri (i.e., nomothetic mainstream psychology). Far from such a militant ritualization of the concept, YIS aims at promoting a return to the origin of what Windelband (1904/1998) proposed, namely the idea of idiographic and nomothetic as categories depicting two complementary—rather than alternative - forms of knowledge building.