Our ancient political system has lasted because it accepts that nobody is ever wholly right, and that nobody is ever right all the time. No Parliament can bind its successors. Every government knows that, in due time, it will lose office to its opponents who can overturn those changes they feel were wrongly forced on them.

This imposes an important rule on our national debates. We must be conscious that our common nationhood binds us together in these islands. We must be civil to those with whom we disagree, however hard we fight them in debate. We must listen to them if we expect them to listen to us. We must always keep in the back of our minds the possibility that we may be mistaken.

Forget this, even for a short time, and we begin to tread the unpleasant, slippery path that leads inexorably downwards, first to mutual spite and then to despotism.

Our ancient political system has lasted because it accepts that nobody is ever wholly right or right all the time

Now we are in the thick of a monumental contest about the future of our country in which both sides have deployed powerful, persuasive arguments.

Although they have fought their cause from the best of motives, sometimes, as in all such battles, they have let their standards slip: bent their figures, deployed personal attacks, exaggerated here and minimised there.

This weekend, the truly shocking murder of Labour MP Jo Cox has stilled some of the sound and fury of the campaign.

Jo was a strong believer in the British democratic process, and would have wanted voters to exercise their judgment on Thursday based not on emotions, but what is best for the future of this country.

Thankfully, our sophisticated electorate is capable of grieving for her loss without allowing the tragedy – and accompanying theories about her attacker’s motivations – to influence their decision.

As we near the end of this extraordinarily intense and volatile campaign, we are all about as well informed as it is possible to be about the rival cases.

So what do we know?

Firstly, those who yearn – as many do – for national independence, pure and simple, have learned that this is only on offer at a price.

By any calculation, a United Kingdom which left all the structures, markets, restrictions and protections and rules of the European Union would be bound to face higher tariffs, turmoil in the financial markets and a period of economic uncertainty.

Britain would be compelled to stand and fight alone for its existence in a hard, globalised world where those who cannot survive on their wits quickly fall behind.

The single-minded leaders of the Leave campaign contend that the issue is not, in the end, economic, but that they value independence so highly they are ready to pay any price for it.

So eager are they for a divorce that they are prepared to sacrifice a large chunk of our income, and trade down on living conditions, in order to walk out into a rose-tinted future of ‘freedom’.

Though it is interesting that they have been careful to make no such a declaration. Perhaps their reluctance to do so is they know that others – who do not share their passion for estrangement – may also have to pay the price, perhaps with their jobs.

It is not much of a vote-winner to say to the electorate: ‘You may have to suffer for my ideals.’

If their calculations are wrong, and leaving the EU does hurt others, will they be ready to face them and tell them it was worth it? This is why the great chorus of economists, businessmen, educators, historians, scientists and others who have urged that we remain in the EU cannot simply be brushed off as if their opinions are so much babble.

‘People have had enough of experts,’ sniped Michael Gove in the face of an alliance led by the Governor of the Bank of England, the CBI and the TUC – the most powerful stewards of the British economy, British business and British workers.

As we cannot know the future, it is at least reasonable to listen to those who can prove they have a good understanding of the present and have good knowledge of the past.

So, as we survey the much-pounded political battlefield, what do we see?

Many readers feel Remain has failed to deal with the question of border control and immigration

Many readers will think that the Remain camp have failed to deal with the question of mass immigration and control of our borders. The Prime Minister deserves some credit for toughening up the rules on EU migrants to Britain claiming in-work benefits.

But the overriding impression remains that the EU offered little of substance to Mr Cameron on this subject. It is a grave and continuing worry, not just for this country but for the whole of the EU. In the end it has been this one issue which has kept the Leave campaign united and above water. Without it, they would have sunk without trace.

If we remain in the EU after Thursday’s referendum – and Mr Cameron continues to lead the Government – he needs to heed that overwhelming message from the campaign.

If Brussels refuses to make further concessions over the principle of freedom of movement – granting us greater control over who is allowed to live on our sovereign soil – the issue of Europe will continue to contaminate British politics and cripple the essential functioning of the Conservative Party.

Andrew Green from Migration Watch claims an Australian points system would increase immigration

But as we vote, we must consider whether the immigration problem is enough on its own to decide the matter. The Brexiteers are themselves divided and inconsistent on it, even now. How would they handle it if they found themselves in charge in a post-referendum Britain?

Boris Johnson and Michael Gove, in their hearts, are not against large-scale migration as such, though they may have given the impression that they are. For all his protestations, Mr Johnson is not even consistently against the accession of Turkey to the EU that he now appears to oppose.

The enthusiasm of the Brexit leadership for the Australian points system for immigration is misplaced and poorly researched.

Even Lord Green of Migration Watch – an organisation dedicated to radically reducing net migration to this country – has written in this newspaper that adopting this policy would increase overall immigration to the UK. Mr Gove and Mr Johnson have no coherent idea of how they would actually do better if they obtained the control of our borders.

This nebulous promise, made by people who may not be wholly sincere about it, and who in any other circumstances would probably be at each other’s throats, is not enough to make us take the biggest national leap of faith in living memory. The human heart yearns for simple solutions and uncomplicated choices. The human head knows that, especially in the world we now inhabit, our deepest desires must somehow be moderated to suit the increasingly tough reality of a competitive world in which, though still a great nation, we no longer have the power or the wealth which once allowed us to live in splendid isolation.

Those who would have you believe in the plucky Little England of the past are selling a dangerous illusion.

Between 1950 and 1973, the year that Britain joined what we now call the EU, our economy was the slowest growing in Europe. Since 1973, the growth of national income per head has become the fastest, outstripping Germany, France and the US.

Mr Cameron, pictured, deserves credit for toughening up the rules over in-work benefit for migrants

We have attracted billions in foreign investment for companies looking for a gateway into Europe that enables our companies to export to the Continent free from tariffs and with freedom of movement. Block that gateway and we may stumble and fall.

It may well be that the nationalist ideals espoused by the charismatic leaders of the Leave campaign temporarily thrill the imagination.

But the sloganeering and rhetoric of the wider Brexit campaign – most notably Nigel Farage’s disgraceful ‘Breaking Point’ poster – has at times veered into deeply unsavoury territory.

As we highlighted earlier in the campaign, the Brexiteers have been embarrassed by the activities of far-Right fellow travellers, whose bigotry has polluted Leave’s authentic concerns about the effects of record levels of immigration. When deciding the future of nations, we require more reasonable men and women who are prepared to resist the clarion call of small-minded self-interest and face the hard slog of negotiation and compromise, and so retain for us those things which have been so skilfully won.

This newspaper believes that this is not the time to risk the peace and prosperity of our nation.

The economy will not implode if we leave, but it is naive to assume – as the Brexiteers do – that the Europe we reject but must continue to trade with will readily cut us a new deal, let alone one better than the one we have today.

We may be lured by the notion of being marginally freer, but we will be significantly poorer. For modern Great Britain to thrive and prosper we must work with, not against, our European partners; we must keep our seat at Europe’s top table and help shape its destiny; our strong, clear voice must be heard inside Europe, not be shouted from the sidelines.