The universalism of Roman law finds its most meaningful expression in the ancient concept of “persona” used by the Roman jurists. “Persona”, in Roman law, was the principal juridical category which was able to include in itself all the “homines” without any discrimination (Omnes homines sunt personae). A “liber”, either a free- born (ingenuus) or a freedman (libertus), a slave (servus), a citizen (civis), a foreigner (peregrinus), a child, either unborn (nondum natus) or born (natus) etc. were the “species” of the “genus” “persona”. These “species” always could have changed -for example, a slave might become free through “manumission” (the release of a slave from the power of his master) or a “filius” subject to paternal power might become “sui iuris” (independent from paternal power) through the death of the “pater familias”, etc.- but not the “genus” “persona”. In fact the ancient jurists, different from the modern view, recognized only one category of “persona”: the humans. For the Roman “iurisprudentes” the concepts of “persona” and “homo” were reflecting the two different viewpoints of the same identity: the human being. Indeed, the technicality of the ancient “persona” consisted in its ability to refer to every possible part played by an individual and only by the individual in the “theater of law”. Nowadays, however, we seem to forget the real value of the concept of person. This paper aims to explain the concept of the “persona” in Roman law to reconstruct the historical memory of the modern jurists.