Freedom of speech is one of the core principles of America’s First Amendment. It is often defined as a person’s right to say whatever they like, as long as such speech does not endanger someone else’s personal safety. This goes to the heart of a crucial idea, which is that speech — even speech that we find repugnant — is different from conduct.

The boundaries of that idea have been tested in recent years in many ways. They were tested again last week when three presidents of elite US universities — the University of Pennsylvania, Harvard, and MIT — appeared before a House committee examining antisemitism on campuses in the wake of the Israeli war in Gaza. A wave of pro-Palestinian protests have hit campuses all over the US, where university politics lean heavily to the left.

Such schools have in recent years tended to err on the side of condemning those who champion impolitic views, often conservative ones, or criticise leftwing ideas such as critical race theory. Now, that tendency has left them straddling an uncomfortable line between protecting individuals and protecting free speech.