The Conservative Party cares an enormous amount about image, and has forgotten the importance of argument. It cannot bear looking bad, but does not worry to anything like the same extent about knowing how to beat Labour in debate.

Image is indeed enormously important. It was right yesterday to suspend the whip from Anne Marie Morris after she used the expression “nigger in the woodpile”. Anyone who has attempted in recent years to excuse those words will know such a defence simply adds insult to injury.

But ideas are enormously important too, and here Conservatives have yielded to the lazy belief that the battle has been won, so no further effort is required. In the recent general election campaign, Jeremy Corbyn was treated as such a feeble figure that no intellectual effort was needed in order to triumph over him.

This turned out to be a serious mistake. To those of us who can remember the 1970s, he may seem obsolete. But not everyone does remember the 1970s: there is always a new generation, which has been spared the lessons of history, is eager to reason things out from first principles, and may find in Corbyn a more generous moral outlook than appears to be offered by the worldly wise careerists and technocrats who shake their heads and assert that his policies would bankrupt us.

Corbyn also represents, in person, an elderly Labour generation which feels that ever since 1983, it has been written out of the script. He and his followers are taking their revenge on Tony Blair, and also on Neil Kinnock, more than on Theresa May.

But whatever the psychology of the Corbynistas, it is still necessary to meet them with argument, not just fob them off with contemptuous assertions which merely fortify their sense of moral superiority.

One reason why the Conservatives have since 2005 been discouraged from making robust arguments is that on the central issue of the present day – Europe – these arguments were bound to lead to civil war, pitting Tory against Tory.

This mortal danger has faced every party leader since Edward Heath. David Cameron tried to deal with it by urging his backbenchers not to “bang on about Europe”.

He concentrated instead on changing the party’s image. Thanks in part to him, the party is no longer so short of women and ethnic minority MPs.

When the issue of Europe nevertheless became unavoidable, he tried to finesse it by holding a referendum, which he expected to win.

But the standard of argument used by the two sides in that referendum was an insult to the electorate’s intelligence. Each side treated the other as if it was so contemptible that it did not deserve to be met with reasoned debate.

As Mervyn King, the former Governor of the Bank of England, afterwards observed, “there were good arguments on both sides, but to have a campaign where both sides thought the other were idiots – that was not very intelligent.”

Cameron lost a campaign in which he and his allies set out to terrify us rather than take us into their confidence.

In the pre-released text of the speech which she is to deliver this morning, May says that since the general election, it has become “even more important to make the case for our policies and our values, and to win the battle of ideas”. Yet she continues:

“So I say to the other parties in the House of Commons…come forward with your own views and ideas about how we can tackle these challenges as a country.

“We may not agree on everything, but through debate and discussion – the hallmarks of our Parliamentary democracy – ideas can be clarified and improved and a better way forward found.”

Here is plea to Labour to help her to get her version of Brexit through. As a parliamentary manoeuvre, of a kind of which Disraeli gave a bravura display in 1867, such a device may be unavoidable.

But to pass it off as “winning the battle of ideas” is another insult to our intelligence. Ideas are as nothing compared to the need to win the next vote.

Indeed, the Prime Minister indicates an underlying respect for Labour’s ideas, so long as these can be “clarified and improved”. Were she in a position of strength, as Stanley Baldwin was for most of the inter-war period, a policy of treating Labour with generosity, as a kind of junior partner to the Conservatives, might make sense.

But she is generally acknowledged to be weak, and this speech gives the impression that she is getting weaker.

Baldwin never treated socialist ideas with respect. He was highly alarmed by them. The Fabian Society had been founded as early as 1884, followed by the London School of Economics in 1895 and The New Statesman in 1913.

At at time when the franchise was widening in leaps and bounds, there was a clear danger that the socialists would win the battle of ideas and thereby the minds of the new voters. Conservative party workers had to be trained so that they could join this battle and win.

To this end, Ashridge College was set up in 1928, with the full support of Baldwin and of his closest collaborator, J.C.C.Davidson, who raised most of the money from a donor who was “deeply concerned at the danger of…Bolshevism”. Baldwin took this enterprise very seriously, and ensured that his colleagues did so too. After the 1935 general election, which resulted in a large majority for the National Government led by Baldwin and composed mainly of Conservatives, the Ashridge Journal proudly reported:

“The new Cabinet is almost entirely composed of Ashridge lecturers – Mr Baldwin, Mr Ernest Brown, Mr Neville Chamberlain, Mr Duff Cooper, Sir Philip Cunliffe-Lister, Mr Anthony Eden, Mr Walter Elliot, Sir Bolton Eyres-Monsell, Lord Hailsham, Lord Halifax, Sir Samuel Hoare, Mr Ormsby-Gore, Mr J.H.Thomas, and Lord Zetland. This is just as it should be. Indeed, association with Ashridge seems to be the surest stepping-stone to Cabinet rank.”

Is it conceivable that so many senior figures would today be found lecturing at a college devoted to the political education of Conservative party workers and others? Yet within living memory, this was the case. For although Ashridge (whose history is told by Clarisse Berthezène in Training minds for the war of ideas: Ashridge College, the Conservative Party and the cultural politics of Britain, 1929-54) was soon lost to the party and became a management college, it was replaced by Swinton Conservative College, at Masham in North Yorkshire.

Here between 1948 and 1975, 54,000 Conservative activists, agents and other students took courses. Lord Swinton, who provided his country house for this purpose, is the Sir Philip Cunliffe-Lister mentioned above, who was a minister in all Conservative and National governments between 1922 and 1955, except for the period 1938-43.

Swinton College was the brainchild of Rab Butler, and was intended to carry on the work of Ashridge. Harold Macmillan liked going there for the grouse shooting, Edward Heath held meetings of his shadow Cabinet there in the 1960s, and many distinguished lecturers would travel to this somewhat remote spot because they loved staying there, and could see the point of political education.

I am not trying to suggest that such an education is easily acquired, or renders Conservatives (or anyone else) invincible. But not even to attempt to impart the rudiments of Conservative thought to candidates, party workers, students and indeed voters is to leave the field open to others, some of whom will either be socialists or will in other respects be less than satisfactory, as my colleague Henry Hill has pointed out.

The great Tory journalist T.E.Utley (1921-88) warned, in a piece published in The Daily Telegraph on 20 October 1986, against the somewhat naive idea that the mixing, in lectures delivered by practising politicians, of high philosophy with practical politics is necessarily a good idea:

“After the war, a veritable factory of such lectures was set up in Lord Swinton’s house in Yorkshire, the exercise being supported lavishly out of Tory funds. As a penniless Tory journalist in the 1950s, I used to go there a lot, grateful for a fiver and even more for lunch on the Yorkshire Pullman. In return, I would deliver an extremely solemn piece on some such subject as the relationship between ‘liberty and law’. The formula was simple. There had to be a great display of academic obscurity, but there also had to be a political sting in the tail. I was not bad at it… But I was nowhere near so good as the great principal of Swinton, Sir Reginald Northam.

“He used to give a splendid piece called ‘The Tory Faith’. This consisted of a brief review of the history of the Tory party, pointing out that sometimes it had supported authority and sometimes freedom, but bringing out the essential theme of consistency in all these policies – i.e. that it had invariably been right. Then, he would suddenly descend from the clouds and convey some eternal and homely piece of Tory truth. He would say that when he was a lad he had to black his father’s boots every morning and that, if the job were not properly done, his father would beat him. After that, there was not a single dry eye or silent hand in the hall. The perennial essence of Toryism had been displayed.”

At Swinton, enjoyment and edification were happily combined. John O’Sullivan, who was a tutor there in the late 1960s, said that by the end of his four years, he had met everyone in the Conservative Party.

He observed that nowadays, all parties try to stifle debate, and turn their conferences into corporate events. O’Sullivan was not stifled: he fomented discussion of the liberal economic ideas which would later form part of Thatcherism.

Keith Simpson, now the MP for Broadland, remembers going to Swinton in the early 1970s as National Vice-Chairman of the Federation of Conservative Students, and recalls chairing a “very, very good debate” where Margaret Thatcher, Secretary of State for Education, “was savaged by everyone”.

Simpson mentioned David Davis, Eric Pickles and the broadcaster Andrew Neil as others who went to Swinton.

Part of the value of this exercise was the way in which very young people could mix with very senior figures, to the benefit of both.

If this happened more often in the Conservative Party of the present day, Corbyn’s success among young voters might have come as much less of a surprise, and the party might have more idea what to do about it.