So the other night, I was hanging round the internet, looking for beef, as you do, when I spotted a tweet that made my blood pressure rise.

Matthew Goodwin, the politics professor who made his name predicting the rise of Ukip and then ate his own book live on television, had suggested that, so many months after Brexit and Trump, liberals were still struggling to get back in the game. The thing that got me was one of the responses: “Maybe liberalism is actually what got us into this pickle.”

17 months after the vote for Brexit, 12 months after Trump, I've not seen a single decent idea from liberals on how to get back in the game — Matthew Goodwin (@GoodwinMJ) November 4, 2017

First off, I was annoyed by this. The idea that an excess of rights for women and minorities and so on is what led to the Trump/Brexit backlash is one I've heard before, but it's still bloody offensive. Worse, even were it true, “your response to your oppression is the cause of your oppression” is the logic of the abuser.

Secondly I was confused, because wasn't the guy making this point meant to be on the left? What on earth was he doing peddling the “social liberalism brought about Brexit” line?

So I was just cracking my knuckles, readying myself to type a withering reply that would win him over, win the argument and definitely not be a complete waste of everyone's time, when I realised I was, in fact, wasting my time, even more than normal. Because I'd totally misunderstood what he'd meant. He hadn't, in all likelihood, been blaming liberal social values for the rise of the new nativist right: he'd been blaming economic liberalism, the nebulous Blair/Clinton/third way consensus that has made some people or places very rich while entirely leaving others to rot. So, I didn’t reply, which was probably for the best all round.

This thought process must have taken about three seconds, end to end, but it’s not the first time I’ve been through it, so you'd think I'd have got there rather quicker. Yet I still, every time, have to remind myself that there are two different types of liberalism, and so the point being made is not necessarily the one I instantly assume it is.

In fact, there are more than two. Off the top of my head:

“Liberal” – as in the values espoused by the yellow party in British politics;

“Liberal” – as spat out by gun-toting and grizzled Republicans on The West Wing, implying anyone half an inch left of Reagan;

"Liberal” – as used by Bernie Sanders and Jeremy Corbyn supporters, which generally means the bit of the left that isn't far left enough;

“Liberal” – as used by firmly right-wing men like Daniel Hannan, Toby Young et al to describe themselves, which best one can tell is a reference to the battle lines of Victorian politics and now just means they don't like the state very much;

“Liberal” – used by the left to describe that post-Thatcher economic consensus (low taxes, small state, etc), in what one assumes to be a contraction of neo-liberal;

“Liberal” – meaning a straightforward belief that other people's relationship status, skin colour, or sexuality is none of anyone else’s business, and the state/religion/literally everyone else should just butt the hell out;

"Liberal" – as in the values of the Economist, which combines both the previous two into the sort of package that Hillary Clinton can really get behind...

There are probably more I can't think of right now, but I'm starting to go cross-eyed here, so I'm going to stop. The point, I hope, is clear. “Liberal” and “liberalism” can mean a lot of different things, depending on who is speaking and what they think about gay rights/Brexit/the government of Alexander Kerensky which ran Russia for eight months between the two revolutions of 1917. Sometimes these definitions overlap. At other times, they definitely don't.

And sometimes they would be unrecognisable not just to the person being described, but to the version of the person speaking who walked the earth just a few years ago. Today, Blairites are sometimes described as liberals, but Tony Blair himself appointed a succession of home secretaries who actively sneered at those “woolly headed liberals” who thought that (oooh, another definition) locking people up without trial was kind of a bad idea. Why are Blairites liberal now when they very definitely weren’t back then?

What’s more, a key component of Blairism in office was a big, high-spending state. So how did Blairites end up in the same ideological box as George Osborne, the architect of austerity? Is the fact they oppose both Jeremy Corbyn and Brexit really enough to make both or either count as “liberals”?

I'm not sure what we do about any of this. I'd like to suggest we start using different terms which more precisely describe the flavour of liberalism being discussed, purely in the name of clarity – but I don't immediately know what they would be, and it's not like anyone listens to me anyway.

Yet I worry that the mess of different liberalisms might do real and lasting damage to the body politic. Right now, everyone and their dog seems to be at war with one liberalism or another, and a line you hear from nativist right and resurgent left alike is that liberals are the problem.

But which liberals? And which values? There’s one more definition of liberalism we should remember: the one that’s the opposite of authoritarianism. I rather like that form of liberalism, and at this point in history I’m rather terrified about its future. Before you go to war against liberalism, you should ensure you're aiming at the right target.