A few months ago, I fell on a column that Fairfax had left lying around. When Waleed Aly wrote, “Left and right have almost never been meaningful terms,” I took a little spill. Well, as you know, you just can’t be too careful at our age; even a mild injury can produce ongoing pain. Today, after a more serious public failure to define left and right, I am in traction.

This is not, entirely, a personal ache. It is more broadly social. You just can’t go about saying that historic and articulated political differences mean nothing, never have, and expect all future discussion to go on in good health. Whether you’re a friend of Marx, a member of the Mont Pelerin Society or just someone with a vigorous interest in policy, left and right must retain their meaning.

The description and basic classification of things in the world has a real world use. You don’t get to argue that birds are the descendants of dinosaurs without a taxonomy, and you only get to call Hillary Clinton a “socialist” if you’ve thrown all the history books away. And this definitional perversion was committed in The Guardian yesterday. Clinton is the choice of the “hard left”.

This doesn’t even really disturb me as a Marxist. It troubles me most as the owner of a first-year dictionary of political science; a reference manual whose terms Waleed Aly is professionally committed to uphold. Not to blame Aly entirely for the untidy co-mingling of categories that allows most everyone to squawk “left, right, what’s the difference?!” and then produce hybrid monsters like Tony Blair. But, come on, man! If we cannot depend on you, a chap whose first significant work as a public intellectual was to define the word “conservative” over 25,000 words, on whom can we depend?

Well, certainly not Van Badham, the Graun columnist who, like just about every other Graun columnist, is ardently committed to the delusion that “hard left” means a white power suit and the reckless invasion of Libya. Of course, these are both atrocities for which rational argument can be made. It’s not like there are no good and storied arguments for the policy and the pantsuits of Clinton. If you believe, as the next president does, that the US must continue its interventions, there are plenty of respected international relations experts to support your case. If you believe, as the next president does, that it is not a critical mistake for the masses to grow an elite investor class, you have 300 years of thinkers on your side.

As my colleague Bernard Keane points out in his candid essay on neoliberalism, a needless term which, as he points out, simply means “liberalism”, the genealogy of these ideas is easily traced. Although Bernard and I come to very different conclusions about the application of these ideas — he thinks that capitalism is ruined by bad apples, I think the whole crate is infected — we can agree on definitions, and therefore haven’t killed each other.

The political economist Mark Blyth takes a similarly taxonomic approach to terms like “left”, “right” and “liberal”. He, like Keane, has an impatience with the obfuscating word “neoliberal”, which columnists such as Badham throw around as a meaningless slur. In his very readable book Austerity: The History of a Dangerous Idea, Blyth traces “neoliberalism” back to its origins of the Scottish Enlightenment. “Hume’s claims do not echo today’s (neoliberalism) — today’s claims are direct replicas of Hume’s,” he writes. There is nothing “neo” about it.

I mean, shit. This stuff is written down, and there are not many people who bother to read it. Which would be fine, if they weren’t also in the business of writing about it. To say that Clinton aligns with your “hard left” and “economic” view should actually be impossible. Or, at least, a summary offence.

I do take Aly’s point that the Western world at large doesn’t seem to know the differences between left and right. This is a time wherein Breitbart, a radically right publication, throws its support behind WikiLeaks, a publisher that was, and remains, opposed to all coercive systems. This is a time wherein Tariq Ali, a plain old honest socialist, was urging for a Brexit vote, while Yanis Varoufakis, an avowed “erratic Marxist” argues to uphold the EU, an organisation he continues to loathe.

Trump takes on some of the language of revolutionary socialism, and, unfortunately, describes the Democratic nominee with far more precision than Badham does when he writes, “Bernie Sanders endorsing Crooked Hillary Clinton is like Occupy Wall Street endorsing Goldman Sachs.” And this tweet, in all likelihood, was authored by Stephen Bannon, the founder of Breitbart, an organisation that currently loves WikiLeaks, whose founder, very rightly, says that there is no point in leaking anything on Trump, because nothing could compete with the offensive shit the man himself currently says.

Former ALP voters turn to Pauline Hanson. Former Marxists turn to a nominee whose foreign policy created the conditions of the assassination of Berta Caceres, a Honduran indigenous environmental activist whom you’d think The Guardian would adore. And everyone is pretending very loudly that their confused voices are silenced — Badham, in a widely read news item, says that she is forced to discuss her passions in private on Facebook while Trump is in mainstream media saying that mainstream media ignores him. So we may be excused for asking: what the hell?

But, I don’t know if Aly himself, an intelligent and educated man, can be excused. It’s fine that he’s a centrist liberal, but he cannot claim, as others do, that this position is one that is neutral, and owes no debt to history. When a lecturer in politics quits the business of articulating historic political difference, we’re stuffed. Categories and their past are important. Without them, there can be no clear policy future.