I HAVE never been slacking in advancing the case for a proper written constitution. There are many advantages to be derived from agreeing the basic ground-rules of the state, writing them down in an authoritative Fundamental Law, and enforcing them.

Constitutions can do many things. They can protect human rights and civil liberties. They can regulate the institutions of the state, so that those in power cannot play fast-and-loose with the rules. They can set out how parliament is elected, when and under what conditions it can be dissolved, how its speaker or presiding ­officer is to be chosen, when it must sit, and how it ­enacts legislation.

Constitutions can prescribe the composition of the government and the rules for choosing and removing a prime minister. They can ­separate the government’s active, executive, policy-making functions from the primarily ceremonial, figurehead position of the head of state. They can define the mechanisms of ­political accountability, establish parliamentary committee structures, and recognise the role and duties of the leader of the opposition.

Constitutions can protect the independence of the judiciary, regulating the appointment, tenure and removal of judges. They can ­establish and protect the “neutral guardians” that uphold the financial, electoral and administrative integrity of the state, such as the auditor general, electoral commission, boundaries commission, and civil service commission.

They can divide powers, responsibilities and resources between national government and ­local authorities. They can proclaim the identity of the state – its flag, anthem, territorial claims and citizenship. Very often, constitutions seek to settle, in various complex and nuanced ways, the relationship between the state, as a universal community of all citizens, and the various ­religious communities to which some of its members might belong.

Many constitutions commit the state – by means of socio-economic rights or “directive principles” – to pursue certain policy objectives, from the provision of public services to the protection of the environment.

A constitution can even enshrine certain ­ethical values or principles of good governance. For example, a constitution can require members’ interests to be declared, or can set out meritocratic principles to be applied in public appointments or protect the committee on standards in public life from being undermined by the prime minister’s personal cronies.

Constitutions also set out the manner and form according to which they can be amended, balancing adaptability to emerging future needs with resilience against momentary shocks and political pressures.

Many of the deep structural problems of the United Kingdom arise from, or are exacerbated by, the lack of a sure constitutional foundation. These problems could easily be avoided in an independent Scotland, if we get off on the right constitutional footing.

It is just as important, however, to keep in mind the things that a constitution cannot do.

A constitution cannot create a utopia. Those that are make grandiose promises – as some of the Soviet-inspired constitutions did – rarely deliver. Working democratic constitutions are prosaic, even boring, documents: heart-stirring rhetorical flourishes, if present at all, should be confined to the preamble.

Besides, mere words on a page cannot ­transform society or control the state; they are worth only the public commitment to them that sustains their legitimacy. The people of a well-constituted democracy respect, obey and ­uphold their constitution not merely because it is called a ‘constitution’, but because it is theirs: the people, in accepting the constitution and ­living in accordance with it, have invested it with an ­enduring moral, as well as legal, ­authority.

CONSTITUTIONS are not party manifestos. They cannot settle every aspect of policy. At best, a constitution is a framework and foundation for democratic politics – not a substitute for it.

More fundamentally, we return to the distinction between letter and spirit, between the law of the constitution and the ethics of the constitution. The constitution sets the stage, but the actors are ministers, parliamentarians, civil servants, judges and citizens, who must bring the set to life. If they are rotten, even the best constitution will not save the show.

If we are to build a healthy democracy, we need not only a new constitution, but an accompanying renewal of “civic virtue”. This includes basic civility, a sense of fair play, reasoned disagreement, a presumption that ­opponents are acting in good faith (unless they show otherwise), respect for the truth, ­moderation, willingness to compromise, probity and integrity, seriousness, the acceptance of ­responsibility for one’s actions, a sense of public duty, and dedication to public service.

We have had our fill of careless, devil-may-care government. We need leaders inspired by ­caritas rei publicae (loving care towards ­democratic institutions) and caritas civium (loving care ­towards fellow citizens), who care about the rules and institutions, care about truth and honour, and care about the people and country they are supposed to serve. A ­constitution can encourage and anchor all these things, but it cannot replace them.

Wendy Barrie of the Scottish Food show is this week’s guest on the TNT show. Join us on IndyLive at 7pm on Wednesday