The Roman constitution recognised no right of public meeting; a gathering of the citizens by a citizen might be treated as a breach of the peace, or might be summarily visited by the _coercitio_ of a magistrate. But the increase of the magistrates, and the corresponding divergence of their views, supplied a partial substitute for this popular self-repression. It was open to any magistrate to introduce a citizen to the _contio_, and give him a right to speak (_producere in contionem_, _dare contionem_);[661] it was equally open to a colleague or superior to veto this permission;[662] but custom must have made such a use of the _intercessio_ very infrequent. The right of granting a _contio_ gave a limited power of debate on legislative matters to distinguished private individuals; but this was not its only use. It was the sole means by which political leaders, who might happen to be in a private station—as Pompeius after his return from the East, or Cicero after his recall from exile—could express their views;[663] it was also a convenient mode in which a magistrate might justify a line of conduct. We find a foreign king and a public informer thus produced to influence the popular mind. The _jus contionis dandae_ meant an increase in magisterial power, and was no true concession to democracy; the demagogue in opposition, who was not a magistrate or useful to a magistrate, had no opportunity of making his voice heard in Rome. The right of eliciting binding resolutions from the people when assembled in their _comitia_ (_jus cum populo agendi_) always remained an inherent attribute of the _imperium_; as such it belonged, under ordinary circumstances, to the consul and praetor; under exceptional conditions, to the dictator, interrex, and consular tribunes. It was also possessed by one at least of the occasional delegates of the highest magistrates, the master of the horse.[664] By these magistrates the _comitia_ might be assembled in any form—by curies, by centuries, or by tribes. None of the lower magistrates possessed in their own right the power to summon and preside over the assembly; but the extension of the _provocatio_ and the consequent growth of popular jurisdiction rendered it necessary that the lower magistrates with judicial powers should meet the people. Thus the curule aediles defended their sentences before the _comitia tributa_;[665] the delegates of the consular criminal jurisdiction, the _quaestores parricidii_, and _duumviri perduellionis_ brought their judgments before the _comitia_ of the centuries.[666] No plebeian magistrate had the _jus agendi cum populo_; hence when the tribune, in the exercise of his jurisdiction, wished to obey the command of the Twelve Tables, which confined the hearing of capital cases to the _comitia_ of the centuries, he had to ask a patrician magistrate—in this case the praetor—to call a meeting for him by a given day (_diem a praetore petere_).[667] When the praetor had named a day (_diem dixit_)