Pomo summer: could there be anything more ridiculous than the idea of a Postmodern revival? It depends what you mean by Postmodernism, says Sam Jacob, in his column for Dezeen's summer season on the controversial movement.

A Postmodern revival, huh? Can you imagine a more absurd idea? Or anything that could characterise the sheer vacuous idiocy of contemporary architecture and design more than this?

Why? Well, because if there ever was such a thing as "Postmodernism" it was already about the pop-will-eat-itself nature of the modern world, about the emptiness of the stylistic gesture, about the collapse of history into an endlessly rearrangeable flatness, about the fluidity of meaning. Most of all, it wasn't a thing but an idea, a concept not a style.

Postmodernism's core was the floating signifier, the notion of the sign detached from the thing it once referred so that it no longer points to a clear, agreed upon meaning. Isn't reviving the sign of Postmodernism in such a literal, un-Postmodern way simply recasting its lighter-than-air essence with all the wit of a lead ballon?

A Postmodern revival of this sort is nothing less than a trap set by the past for designers of the future. And, if Dezeen is to be believed, we are walking into it with cartoon smiles drawn all over our dumb faces.

It's like Marx in reverse: First as farce, then as tragedy. Why? Because farce is a finely constructed theatre of the absurd that satirises an era's social mores. And tragedy? Because to reduce Postmodernism to a style is to fundamentally misunderstand its very essence.

But then, Postmodernism in architecture and design has constantly been misunderstood. Take those who regard it as an incarnation of Reagan-Thatcher politics. First, historically inaccurate – it was around much earlier than that. Second, that's just a convenient fit-up job, a circumstantial straw man built to protect fragile aesthetic sensibilities that masquerade as something more profound. And third, well it's just plain wrong.

Those who deny Postmodernism's intrinsically political project are those who don't really believe in architecture and design's inherent political capabilities, who dismiss the discipline to be capable of political agency in any other form than spelt with a capital P.

There are others who attempt to discredit Postmodernism as "inauthentic", who argue that it "dates" and that architecture should address a mythological "timelessness" that exists somewhere beyond the earthly qualities of fashion, culture and taste. But these are exactly the kinds of ideas that Postmodernism was gunning for, just the kinds of sacred cows that it swung for – and ironically, just the things that made it so very sincere and authentic. These were just the people that it sought to make uncomfortable through its disciplinary – rather than professional – idea of architecture. Bear in mind that these are the people who rely on an aesthetic veneer of serious authenticity to cloak their market-driven manoeuvres.

Postmodernism's suggestion that authenticity might be a more difficult idea, and that the designed world itself is an entirely synthetic "unnatural" thing remains a threat to these forms of practice. Its conceptual depth still provokes a defensive guard decades later – so it must have been doing something right.

Perhaps the biggest misunderstanding of all is that Postmodernism was an attack on Modernism itself.

Not at all: I'd argue that it was an attempt to understand Modernism in the context of the post-war era, in an age no longer dominated by the industrial machine but by the post-industrial age of global information. Postmodernism wasn't against Modernism but rather an attempt to stand Modernism's ground while new forms of modernity raged around it – a modernity Frederick Jameson called the "logic of late capitalism".

What Postmodernism did attack was the limp ghost of the International Style which cast Modernism as watered-down aesthetic, as a kind of neo-ism assuming the clothes of the Modern project while editing out the difficult parts.

In the 1950s, young architects felt that the original promise of Modernism has essentially been betrayed by the generation that preceded them. Groups like Team X and the Independent Group were attempts to re-boot the Modern project, to escape what they saw had become a lifeless doctrine And to do this they responded to the world as it was then, and to the way they imagined the future could be.

New Brutalism in Britain and Structuralism in the Netherlands both sought new forms of directness that reclaimed Modernism's rawness on the one hand while connecting it to the complexities of life-as-lived on the other.

Modernism, let me remind you, was a movement that included Dada, Surrealism, Joyce, Freud, and Futurism amongst much else. It was deeply strange, often antagonistic, mystic and visionary. Its architecture too should be seen as part of this world, not simply as the rational, logical, sincere and stylistically abstract, reductive thing that it has come to mean.

If we remember that Modernism itself was a volatile collection of the rational and the subconscious, that it was not only a social and technical revolution but also psychological and cultural one where surrealism and social reform went hand in hand. Understood in this way Postmodernism is not oppositional to the traditions of Modernism. Postmodernism is actually its last surviving relative. Or, conversely, one could argue that Modernism was all the things we more easily associate with Postmodernism avant la lettre.

From those post-war stirrings in CIAM and London's ICA came a new idea of what Modernism might be in a world increasingly dominated by media, popular culture and consumerism – how art, architecture and design might be relevant to this new world and what new kinds of lives it might be able to make within it. New Brutalism, Pop Art and Nouveau Futurism were a continuum of exploration that had begun at the start of the 20th century. And from the Smithsons, James Stirling, Reyner Banham, Richard Hamilton and Eduardo Paolozzi, we could draw a golden thread directly into the world that later became known as Postmodernism.

Postmodernism was – is – the continuing struggle to come to terms with and make sense of the modern world.

You might argue that Postmodernism was just a style, a discreet period in architectural history, something you can write nerdish listicles about if you can't bring any greater imagination to the project. In which case you never quite understood it in the first place (caveat: if you are an actual scholar it is, of course, totally legitimate to study a period – that's your job).

Or you can argue that Postmodernism is a continuing challenge. A challenge of how to conceive of architecture and design in our contemporary circumstance. In which case it is part of the long tradition of the avant garde that also includes Modernism.

Those who think Postmodernism means clinging on to things like loving Las Vegas or cartoons as if this was somehow interesting or anything radical are also, sadly, deluded. If Postmodernism had a cartoon quality, it was not about simplifying but about complicating, not about easiness but about difficulty. But then, those who don't know their history are condemned to repeat it as a farcical incarnation of the original.

Instead, and at its best, Postmodernism's real qualities are mean, sarcastic, blank, difficult, challenging, yet somehow simultaneously psychedelically positive.

So, to those of you contemplating a Postmodern revival, some advice. First, let's turn to the canon. What is really part of the Postmodern tradition that I'm advocating? And, more importantly, what isn't?

First: No historical jokes. Yes to projects about absence, loss, flatness, impossibility. But please, no bloody jokes for the sake of it. Yes too to pathos, rhetoric and provocation. Yes to reference but no to overblown self-reference. In other words, weed out all that historically inflected commercial schlock. Get rid of fun-for-fun's-sake. Bin the pseudo-academic references. But treasure those moments that make us break our stride, double-take and suddenly think about the nature of the world.

Remember too that Postmodernism's pluralism – once radical – has been co-opted as free market choice. The effects of fully fledged neoliberal capitalism on our physical, social and economic landscapes are profound and disorientating. In the wake of such pretzel logics as credit default swaps – the standard-bearing instrument of deregulated, dematerialised financial product – we might add confusion to Postmodernism's original complexity and contradiction.

Now, when everything is one click away from everything else, high Postmodernism's critical dialectic – the rhetoric of "double coding" that allowed Postmodernism to articulate its yes/no position – has exploded into multiple and provisional relationships. In our era of networked information, juxtapositions of high culture with popular, the historical with the contemporary or the academy with the everyday no longer operate in the same way. Rome and Las Vegas, the temple and the shed, the pediment and the billboard – once potent juxtapositions are now just more flotsam bobbing in the endlessly wide pool of culture.

And remember what Postmodernism was really about in the first place. It was, I would argue, a deep and profound investigation into late 20th-century conditions – conditions present in the world, and the condition of the designer within that world. It was an understanding of the ways in which cultural, economic and power structures were changing, how old structures were being dismantled and flattened.

It not only told us this would happen (why else would it have been so invested in flatness of two dimensions?), how it would happen (media, advertising, cars, and other consumerisms) and why it would happen (the ideology of late capitalism). It also knew that the mechanisms of culture would transform so radically that its own foundation would collapse, that its own critical position would too be flattened. Its ostentatious physical gestures were not waving but signalling a desperate truth at the moment before invisible torrents of neoliberal, free market capitalism washed over everything.

Postmodernism was about this world, about the tendencies that were just then beginning to surface. But now, well into the 21st century, this stuff is the world. We are now in the belly of the beast, devoured whole. If you are saying, as you embark on your Postmodern revival that, yes, we are all Postmodern now whether we accept it or not, and that the only real response is to fight fire with fire, then yes, I'll be behind you all the way.

In our flatlands of networked culture there is a pop-will-eat-itself perversity to Postmodernism's reappearance. But could its return, outside of its original historical moment, potentially allow it to come back steeled for battle and ready for revenge?

Released from the parochial arguments of grey and white, high and low, tradition and modernity that swirled around it and eventually drove it into the sand, could it not remerge as a truly transformative form of design practice? Could it help us escape fates of tragedy and farce? Could Postmodernism's ghost, in other words, fulfil its destiny more fully than it ever could in its original form?

Sam Jacob is principal of Sam Jacob Studio, professor of architecture at University of Illinois at Chicago and director of Night School at the Architectural Association, and edits Strange Harvest.