It was in thorough consistency with constitutional principles that the burgesses, just as being the sovereign power, should not on ordinary occasions take part in the course of public business.  So long as public action was confined to the carrying into execution of the existing legal arrangements, the power which was, properly speaking, sovereign in the state could not and might not interfere:  the laws governed, not the lawgiver.  But it was different where a change of the existing legal arrangements or even a mere deviation from them in a particular case was necessary; and here accordingly, under the Roman constitution, the burgesses emerge without exception as actors; so that each act of the sovereign authority is accomplished by the co-operation of the burgesses and the king or -interrex-.  As the legal relation between ruler and ruled was itself sanctioned after the manner of a contract by oral question and answer, so every sovereign act of the community was accomplished by means of a question (-rogatio-), which the king addressed to the burgesses, and to which the majority of the curies gave an affirmative answer.  In this case their consent might undoubtedly be refused.  Among the Romans, therefore, law was not primarily, as we conceive it, a command addressed by the sovereign to the whole members of the community, but primarily a contract concluded between the constitutive powers of the state by address and counter-address.(14) Such a legislative contract was -de jure- requisite in all cases which involved a deviation from the ordinary consistency of the legal system.  In the ordinary course of law any one might without restriction give away his property to whom he would, but only upon condition of its immediate transfer:  that the property should continue for the time being with the owner, and at his death pass over to another, was a legal impossibility—­unless the community should allow it; a permission which in this case the burgesses could grant not only when assembled in their curies, but also when drawn up for battle.  This was the origin of testaments.  In the ordinary course of law the freeman could not lose or surrender the inalienable blessing of freedom, and therefore one who was subject to no housemaster could not subject himself to another in the place of a son—­unless the community should grant him leave to do so.  This was the -abrogatio-.  In the ordinary course of law burgess-rights could only be acquired by birth and could never be lost—­unless the community should confer the patriciate or allow its surrender; neither of which acts, doubtless, could be validly done originally without a decree of the curies.  In the ordinary course of law the criminal whose crime deserved death, when once the king or his deputy had pronounced sentence according to judgment and justice, was inexorably executed; for the king could only judge, not pardon—­unless the condemned burgess appealed to the mercy of the community and the judge