Why are you here? I’m not asking in a professional capacity. I don’t mean: why do you exist? (My day-job is philosophy.) I mean: why are you at a university? What are universities for?

Well, it is clear enough what this one is for. According to its mission statement, Cambridge exists “to contribute to society through the pursuit of education, learning and research at the highest international levels of excellence.” Education, learning and research – nothing else. Not (or not directly) other desirable things like economic growth, or social justice, or equality of opportunity. As the University of Chicago puts it: “[A university’s] prestige and influence are based on integrity and intellectual competence… It should not, therefore, permit itself to be diverted from its mission into playing the role of a second-rate political force or influence.”

How it pursues that mission may be different from how schools do it. Consider my own subject. I do care that they can (a) think for themselves; (b) defend their views against criticism; or (c) if they can’t do (b), change their mind.

Supervisions can help achieve this. Every week you write an essay: on democracy, or the mind, or religion. Your supervisor discusses it with you. The discussion will challenge you; and you must respond. This goes on for an hour. Then you do it again the following week. One student – now a successful advertising executive – remarked to me that after three years of that she knew she’d never be intellectually intimidated by anything ever again.

But the process only works if student and teacher are completely free to air any views. Suppose a student writes an essay arguing for the benefits of immigration. The teacher should feel free to draw a vivid picture of its costs. (What the teacher really thinks is immaterial.) Or suppose a teacher argues that trans women should have access to certain single-sex facilities. The student should feel free to argue that they shouldn’t. She might be about that. But unless she can freely defend that view, she’ll never understand why it is wrong.

And of course lecturers should be free to teach as they like. Unfortunately none of this seems to be happening.

There are several causes of this situation. One of them is a well-meaning but misplaced idea that we should respect everyone else’s beliefs, identities and values.

For instance, in 2019 Jordan Peterson accepted an academic invitation to visit Cambridge. But the Divinity Faculty cancelled it. The ostensible reason was that he had been photographed next to a man wearing a T-shirt that was rude about Islam. Endorsing the cancellation, the Vice-Chancellor wrote that ‘robust debate can scarcely occur… when some members of the community are made to feel personally attacked, not for their ideas but for their very identity’. Then the senior leadership tried to impose a ‘free speech’ policy demanding respect for all identities and opinions.

But a university education must question your most basic beliefs. These include beliefs, for instance religious beliefs, that may belong to your ‘identity’. For that reason, academic inquiry cannot be a respecter of persons, or dogmas, or institutions, especially not those that our society most venerates. It can only respect truth.

Don’t agree with something just because everyone else finds it obvious. Truth is not a social but an individual possession: each of us must find it for herself. Don’t join in bullying anyone who contradicts an ideology, as happened in 2020 when students mobbed a Clare College porter who stuck by his principles. If someone that you otherwise respect says something that fashion or ideology calls bigoted or offensive – whether on trans or race or Israel, or just being rude about the monarchy – don’t reflexively disengage, but stop and think: maybe there are principled reasons for disagreement.

And above all, listen to that voice at the back of your head, the one saying that what you are being told, so vehemently, so often and by everybody, doesn’t quite make sense: maybe it isn’t true; maybe you need to think it through for yourself. That voice has been nagging us since we came down from the trees; it has driven the moral and scientific progress of our species; it is our most precious possession. You must never let anyone silence it.

Arif Ahmed is a Philosophy lecturer at Gonville & Caius College