When the wind is blowing in a certain direction, it can be hard to avoid the bad smell. First we have Christopher Heaton-Harris MP’s extraordinarily inept and potentially sinister letter to all vice-chancellors, demanding to know what was being taught about Brexit and the names of those teaching it. Then this was followed by the Daily Mail’s front page denunciation of universities for their allegedly biased anti-Brexit teaching, together with a full page naming and shaming 14 heads of Oxbridge colleges who are identified as “lefties”. These are not passing breezes: the bad smell is going to get worse.

Presumably, it will now fall to some other minor Tory to write to the heads of the CBI, the Institute of Directors, and other similar hotbeds of loony leftism demanding information about those members who have dared to wonder whether after a hard Brexit everything really will be tickety-boo. Business leaders, professors, judges … they’re all “enemies of the people”. But that’s the thing about witch-hunts: they never run out of witches.

One aspect of the Heaton-Harris affair that has attracted relatively little comment is the sheer breathtaking presumptuousness of his letter. He seems to have thought he needed only to snap his fingers to make VCs jump to his bidding, assembling information, some of which is in the public domain anyway. This is significant: it’s a small indication of political triumphalism and of the condescension bordering on disdain towards universities manifested by those who think they hold the purse strings.

We shall be told, of course, that all of this is an overreaction, a loss of a sense of proportion. So what if a dull-witted Tory MP does something thoughtless while the Daily Mail indulges in a spot of gutter journalism – this you call news? But the conjunction of these two items is significant – and anyway, it is hardly as though the Mail’s foaming was distinguished by its sense of proportion. Its “Wanted!” poster of the 14 college heads included such clearly incriminating details as “friends include Ed Miliband”, “has written in the New Statesman”, and is “nicknamed Beardie”. It is not as though we are dealing with a closely argued case here.

But there is, nonetheless, a more fundamental issue at stake. Academics, like other human beings, may have convictions on a range of issues, from the meaning of life to the likely winner of the next race. But the idea that their teaching and writing must therefore be little more than a disguised way of promoting such convictions reveals an inability to understand how the disciplines of science and scholarship operate. It reveals the self-defeating reductionism of such paranoid thinking, since it presumes that all we have are prejudices, the only difference being that my prejudice is right and yours is wrong.

Similarly, these attacks betray a patronising attitude towards students, who, it is implied, will passively imbibe whatever is put before them. University students are, in my experience, a lot more intelligent, individual, and counter-suggestible than that. In fact, the pro-Brexit witch-hunters are missing a trick: they ought to welcome attempts at indoctrination by anti-Brexit academics, since there could be no better way to provoke students to think Brexit must have a lot going for it.

And provoking students to think, really think, is one of the reasons we have universities in the first place. Part of what is so depressing about the recent attacks and others like them is the demonstration, yet again, that the attackers don’t value, or perhaps don’t even believe in inquiry, evidence, and argument. Because if you do believe in those things, you have to accept that society needs to provide a partly protected space where such disciplined inquiry has priority over all more proximate purposes – and that it may mean lots of people coming up with conclusions you don’t like.

Defences of freedom of thought only have bite when the thoughts being safeguarded include ones you fundamentally disagree with. The University of Chicago has put its name to an excellent statement about the importance of freedom of speech on its campus, part of which says: “For members of the university community, as for the university itself, the proper response to ideas they find offensive, unwarranted and dangerous is not interference, obstruction, or suppression. It is, instead, to engage in robust counter-speech that challenges the merits of those ideas and exposes them for what they are. To this end, the university has a solemn responsibility not only to promote a lively and fearless freedom of debate and deliberation, but also to protect that freedom when others attempt to restrict it.”

Just so – and let’s not forget that this applies to ideas some students might prefer not to encounter or speech they might prefer not to hear. Let’s also not forget the more indirect, and perhaps more insidious, ways in which “others” may attempt to restrict that freedom.

Meanwhile, having shown himself so intensely concerned with the teaching of European politics in British universities, I’m sure Mr Heaton-Harris will be delighted to know that his letter to vice-chancellors is on the way to becoming a set text. After all, it has several merits for that purpose: it’s short, representative, revealing, and already exists in multiple copies.