IN November 1942, while Montgomery’s Eighth Army was fighting against Rommel’s Afrika Korps at Al-Alamein, the British Government published a report on Social Insurance and Allied Services. Popularly known as the Beveridge Report, it called for radical new policies to tackle the “five giants” of want, disease, ignorance, squalor and idleness.

If the democratic state could win a great war of survival against Nazi tyranny it could also marshal the resources necessary to win the peace – to improve the material condition and cradle-to-grave economic security not only of the very poorest, but of every family in the land.

The urgency of this moral mission must never be forgotten. The welfare state was never about sustaining a permanent underclass on the buroo; it was not intended to be merely a system of state-subsidised charity. The aim was more noble than that.

It sought to create a state dedicated not to the defence of inequality and privilege, but to the promotion of human flourishing and public well-being in every sphere. The whole legal-administrative apparatus of the state was to be orientated to the great vision of promoting a decent and dignified quality of life. This would apply across all policy areas, from taxes and benefits, through health care, housing and education, to industrial policy and infrastructure.

The period between 1945 and 1979 was not all “Peter and Jane” perfection. Much of the new social housing, for example, was cheaply built, brutally ugly and socially alienating. “Nae mair hooses ower piece-flinging height” was a fair comment on the shortcomings of post-war social democracy. Yet, on the whole, this audacious ambition to build a decent society was successful. The five evil giants were, if not entirely defeated, at least severely beaten back.

How far we’ve fallen. According to the meticulously researched UN report produced by Professor Philip Alston, one fifth of people in the UK live in poverty, with close to 40% of children predicted to be living in poverty by 2021. Every sentence of the report is a damning expose of the UK’s broken economy and of the UK Government’s wilful rejection of the common good. This gnawing, soul-crushing, hope-eroding poverty does not just affect a workless minority, but also large numbers of people in work – held back by low wages and precarious zero-hour contracts.

Austerity extends beyond punitive benefit sanctions to include the closure of facilities on which families depend – from libraries to swimming pools. The picture is one in which “compassion has been replaced by a punitive, mean-spirited and often callous approach apparently designed to impose a rigid order on the lives of those least capable of coping”.

It might be tempting to abandon constitutional preoccupations and concentrate instead on bread and butter issues. The Labour left have long held this view. Their failure of constitutional imagination is, nevertheless, a key part of the tragic story by which Beveridge’s dream gave way to Alston’s nightmare.

Constitutions defend rights and establish and regulate public institutions. They set over-arching public goals. They articulate and commit to values. The very act of constitution-writing symbolises the coming together of the nation around certain shared principles. None of this took place in 1945. Labour in office perpetuated the old structures of power (the electoral system, the House of Lords, geographical distribution of power, the vast shadowy prerogative of the Crown).

Tinkering since 1997 has mitigated this, but not corrected it. Despite devolution, power at the Whitehall core of the British state remains concentrated, secretive, minimally unaccountable and often in the pocket of rich special interests.

In short, we have an unregenerate state: it cannot consistently serve the public good, because it has not experienced that inner constitutional transformation – from dynastic empire to a state founded upon the common weal – without which all attempts at good works will sooner or later prove to be in vain.

The failure of the UK to undergo this inner transformation means that nothing is stable, solid or lasting. Everything is reduced to policy, expediency, immediacy.

A future Scottish constitution provides an opportunity to remake the state. On the one hand, it ought to enshrine institutional reforms like proportional representation, open government, strong independent oversight institutions and local democracy. On the other, it should enshrine social and economic rights, making the promotion of a dignified and decent quality of life for all a cornerstone of the whole political and constitutional order.

The draft constitution prepared for the SNP by Sir Neil MacCormick shows how this could be done. It commits the state to guaranteeing rights to education, housing and public health care, and the rights to decent working conditions and “reasonable means of subsistence” if unable to work.

Such constitutional commitments define a country. They raise a banner of decency and dignity. In the light of the Brexit omnishambles this task is more important than ever.