Summary — The introduction of pay for members of parliament represents an important stage in the history of Italian political institutions, marking the passage from one kind of political class to another. Law no. 665, of 1912, established the conditions for an acceleration in the decline of the political class of the nineteenth century, which was composed of cadres elected on the basis of their economic and social position. These carried out their roles as members of parliament without remuneration, in line with the Statuto albertino, according to which "the functions of senator and deputy do not give rise to any recompense or indemnity" (article 50). The overcoming of this constitutional prohibition was to lead progressively to the introduction of a new political class: that of professional politicians who, according to Weber’s definition, live for politics and live on politics.