REFERENDUM. - The r. is one of the institutions of direct democracy. These have in common the personal participation, rather than participation through representatives (so-called "indirect or representative democracy"), of those entitled to vote, for the formation of a legally relevant resolution. Its political foundation is found in contractualist doctrines, by virtue of which, strictly speaking, the direct manifestation of the popular will ought to be the rule, and the representative one the exception. If instead the opposite comes about, this is due to insurmountable practical necessities. The institutions of direct democracy are in reality rarely adopted, except, and in limited ways, in certain countries where they have a certain tradition, such as Switzerland and the United States of America, or if they exist in the abstract, they nevertheless prove not to be applied, as in the U.S.S.R.
There are nevertheless events and cases for which it appears right and appropriate that there be an explicit manifestation of the will of the people; whether this is then an organ of the State or not is a debated and controversial question, in correlation with the other question of whether or not it is an organ in the exercise of the electoral function.
In an excessively broad sense, all the institutions of direct democracy could be included under the r., but within these one usually distinguishes, besides the disputed direct election of the head of State, the plebiscite, the veto, the revocation of the mandate (individual or through the early dissolution of the Chambers), the legislative initiative, and the r. in the strict sense (for the adoption or non-adoption of a law or of a measure). The distinctions do not always prove clear-cut, especially between plebiscite and r.; in fact, the changing and complex legislative provisions do not always find an exact place within the categories delineated in the abstract. In general it may be said that the plebiscite is brought about from time to time in extraordinary circumstances, whereas the r. can be arranged and regulated in an ordinary manner; the former may have application in international law, as well as in internal (constitutional) law, the latter only in internal law (constitutional and administrative); the former (according to at least one authoritative opinion) concerns the approval or disapproval of a fact or event with effects on the formation or structure of the State or of its government, the latter concerns a normative or otherwise juridical act.
In Italy there were plebiscites for the annexation of various territories to the Kingdom of Sardinia first and then to the Italian one, and a r. was held on 2 June 1946 for the choice of the institutional form (monarchical or republican).
Some provisions of the new Constitution provide for the r. in several cases, with a very broad adoption of it in comparison with the charters of other countries, thus accentuating the character of a mixed democracy, that is, both direct and representative. It is, moreover, premature to establish what effective application it will have, in the absence still of the laws that would make its application possible.