The Latin brocard ''aut simul stabunt aut simul cadent'' (or ''simul simul'' for short), meaning ''they will either stand together, or fall together'', is used in

law Law is a set of rules that are created and are enforceable by social or governmental institutions to regulate behavior,Robertson, ''Crimes against humanity'', 90. with its precise definition a matter of longstanding debate. It has been vari ...

to express those cases in which the end of a certain situation automatically brings upon the end of another one, and vice versa. The first use of this expression in the mass media, which made it known to the non-specialists, was in occasion of one of the first crises between

fascist Italy Fascism is a far-right, authoritarian, ultra-nationalist political ideology and movement,: "extreme militaristic nationalism, contempt for electoral democracy and political and cultural liberalism, a belief in natural social hierarchy and the ...

and the

Vatican Vatican may refer to: Vatican City, the city-state ruled by the pope in Rome, including St. Peter's Basilica, Sistine Chapel, Vatican Museum The Holy See * The Holy See, the governing body of the Catholic Church and sovereign entity recognized ...

concerning the

Concordat A concordat is a convention between the Holy See and a sovereign state that defines the relationship between the Catholic Church and the state in matters that concern both,René Metz, ''What is Canon Law?'' (New York: Hawthorn Books, 1960 st Edi ...

Pope Pius XI Pope Pius XI ( it, Pio XI), born Ambrogio Damiano Achille Ratti (; 31 May 1857 – 10 February 1939), was head of the Catholic Church from 6 February 1922 to his death in February 1939. He was the first sovereign of Vatican City fr ...

is believed to have pronounced the sentence to express the fact that challenging the Concordat would have swept away the whole

Lateran treaty The Lateran Treaty ( it, Patti Lateranensi; la, Pacta Lateranensia) was one component of the Lateran Pacts of 1929, agreements between the Kingdom of Italy under King Victor Emmanuel III of Italy and the Holy See under Pope Pius XI to settle ...

, reopening the Roman question.

Constitutional law

In contemporary constitutional law, especially in the

regions In geography, regions, otherwise referred to as zones, lands or territories, are areas that are broadly divided by physical characteristics (physical geography), human impact characteristics (human geography), and the interaction of humanity and t ...

and

municipalities of Italy The (; plural: ) is a local administrative division of Italy, roughly equivalent to a township or municipality. It is the third-level administrative division of Italy, after regions ('' regioni'') and provinces (''province''). The can also ...

, this expression is often used to refer to a mechanism where the resignation or the death of the head of government causes the dissolution of the legislature. This includes the case of the approval of a

motion of no confidence A motion of no confidence, also variously called a vote of no confidence, no-confidence motion, motion of confidence, or vote of confidence, is a statement or vote about whether a person in a position of responsibility like in government or mana ...

, whereby the legislature can only dismiss the head of government at the price of its own dissolution. The ''simul-simul'' provision is typical of

semi-parliamentary system Semi-parliamentary system can refer to either a prime-ministerial system, in which voters simultaneously vote for both members of legislature and the prime minister, or to a system of government in which the legislature is split into two pa ...

s and contrasts with the

cohabitation Cohabitation is an arrangement where people who are not married, usually couples, live together. They are often involved in a Romance (love), romantic or Human sexuality, sexually intimate relationship on a long-term or permanent basis. Such a ...

al mechanism of

semi-presidential republic A semi-presidential republic, is a republic in which a president exists alongside a prime minister and a cabinet, with the latter two being responsible to the legislature of the state. It differs from a parliamentary republic in that it has ...

Variants and abbreviations

*''simul stabunt aut simul cadent'' *''simul stabunt vel simul cadent'' *''simul stabunt, simul cadent'' *''simul simul'' Politics of Italy {{government-stub