Brexiteers argue for ‘sovereignty’, i.e. that Brexit should release us entirely from the grip of Europe, leaving us free to make our own way in the world. But it is our democratically elected parliament that is sovereign, and if it decides to hand over some of that decision-making power to external bodies, so be it. Romans would have seen larger issues here.
The Latin for ‘sovereignty’ was maiestas (our ‘majesty’) which meant at root ‘superiority’. Cicero said of it that ‘maiestas lies in the esteem accorded to the authority and name of the Roman people’.
This maiestas manifested itself in various ways. There were the law-making people’s assemblies, with the power to appoint its leaders; the authority of the senate and of the consuls; the military might of Rome; the libertas of Rome, bowing to no one else’s will, and of its citizens and their families, with legal protection to live their lives freely, as they chose, in accordance with the law and the famous mores — customs, values — of their ancestors; even the power of the senate to suspend law in emergencies; and behind it all lay the (to Romans) manifest will of the gods, which had made Rome what it was.
This republican ‘sovereignty’, then, could not be located in any one person or institution. It emerged collectively through Rome’s laws, assemblies, offices, institutions, customs, personal ties and obligations, and social and religious practices. But throughout ran a single thread: in the absence of a single source of final power, Rome’s maiestas was communal and indivisible.
That notion of sovereignty maps rather well on to our bolshy British sense of it. It covers everything about being British. And that is why parliament is not at liberty to outsource our sovereignty to an alien power such as the EU. If parliament cannot say ‘no’ when it so chooses (to the EU or anyone else), it is not sovereign; and because the tentacles of the EU reach so wide and deep into our national life, a parliament in hock to it ultimately puts our whole way of life at risk.