The one thing that a tolerant society must not tolerate is intolerance.
Hate speech is prohibited in the UK as a subsidiary of hate crime laws. So using known slurs, for example, is not technically legal here.
So, we have free speech — but free speech with an exclusion of hate speech.
Is that a contradiction in terms? Maybe. But life’s full of contradictions.
This one has an academic philosophical-ilaly name and everything — The Tolerance Paradox (aka The Paradox of Tolerance.)
(…Which sounds like an excellent title for an episode of Dr Who, tbh.)
Defined in a note to Chapter 7 of a book (The Open Society and Its Enemies) by some Austrian-British fella (Karl Popper, aka K. R. Popper,) The Tolerance Paradox is as follows:
‘Unlimited tolerance must lead to the disappearance of tolerance. If we extend unlimited tolerance even to those who are intolerant, if we are not prepared to defend a tolerant society against the onslaught of the intolerant, then the tolerant will be destroyed, and tolerance with them.’