Nostalgia is the pang we feel upon realising the impossibility of returning to an idealised past. Coined in the 17th century to describe a pathological homesickness, it’s now understood as a sentimental fondness for the cultures and values of bygone eras — often of one’s own childhood.

But in politics especially, a wistful nostalgia can slip into a more malignant refusal to engage with today’s pressing questions, or anticipate those of the future.

Lurking behind many appeals to things “retro” is an ethical dilemma: how can we cherry-pick what we like about the past without somehow excusing its failings? The notion of “retrogression” implies an overarching teleology of progress — and why would you long for a past that’s politically “worse” than the present?

Perhaps I’m just being nostalgic myself, but I believe nostalgia doesn’t have to be either an indulgent fantasy or shorthand for philistinism and conservatism. Clearly, the comfort nostalgia bestows is what makes it so politically powerful — and it’s politic to consider how to draw on this power ethically, rather than in the service of our worst instincts.

Nor does looking backward preclude Julia Gillard’s obsessive impulse to “move forward”. Nostalgia can express ambivalence at the swift pace of social and economic change; it lets us weigh what’s gained against what was lost. And it seems wise to seek lessons from the past, rather than assume that all we leave behind are mistakes.

Every few years, magazine trend pieces tell us that “retro is back”. Of course, for some people it never went away — antiques dealers, for example, and those involved in heritage subcultures (rockabilly, mod, steampunk) or historical role-playing scenes.

This is commodity nostalgia — the sort that manifests in buying, collecting and studying consumer goods from the past. It’s expressed in an aesthetic of “quaintness” — finding anachronistic texts, ideas and objects desirable precisely because they are now considered outmoded.

Commodity nostalgia uses consumer goods as sensory bridges between a present defined as crass or uninspiring and a magical, glamorous past. Through the distinctive looks, scents, tastes and textures of longstanding brands — Brylcreem, Pears, Barney Banana, Fred Perry, Chanel No. 5, Glomesh — consumers can revisit their remembered pasts and imagine how it might have felt to live in whatever period these brands were at their peak.

Manufacturers who realise the value of commodity nostalgia can become folk heroes by resuscitating once-loved, discontinued brands. They can also inject their workhorse brands with retro glamour by re-imagining them as “classics”.

For retro fans, the past feels authentic. People were more civil then; things were better made. Some, like the women profiled in a British documentary, Time Warp Wives, even want to stage a dramatic retreat from the grimmer realities of modern life by crafting meticulously period-perfect retro lifestyles.

“It may sound silly, but living like this really does make me happier — as though I’m existing in one of those old-fashioned TV shows where everything is always wonderful,” says ’50s-styled housewife Joanne Massey.

People such as Joanne are often presented as deluded, imprisoning themselves in a sterile fiction. In her 1984 book On Longing, Susan Stewart calls nostalgia “a sadness without an object”, because it’s fuelled by the longing to return to an imaginary point that’s always behind and before our lived experience. Indeed, we wax nostalgic precisely because we realise the impossibility of ever reaching this idealised past.

Imagining history as a linear narrative, though, enables a powerful public discourse of “progress” that seeks to puncture nostalgia’s utopianism; to reveal with the gimlet eye of hindsight how bad things really were. We see it in TV’s Supersizers team attempting to subsist on the revolting cuisines of the past, and in the deliberately abject griminess of period cinema. We see it in compendiums of old-fashioned advertisements, whose shameless racism and s-xism is intended to shock or amuse.

The obvious flipside of Joanne Massey’s desire to live in the 1950s is the 1998 film Pleasantville. Two cynical 1990s teenagers find themselves magically transported into the black-and-white world of their favourite fifties TV serial, which they literally bring into colour as they introduce their “liberated” values to the hermetic town of Pleasantville.

The fifties are often publicly invoked as a totem of all that is small-minded, conservative and repressive. When governments refuse to engage with socially progressive ideals such as abortion and gay marriage, they’re routinely accused of nostalgic impulses: wanting to turn back the clock on social policy.

But demonising the past always serves the ideologies of the present. From juvie-hall B-movies to novels about junkies, fifties culture displayed a strongly nihilistic streak. Norman Mailer’s 1957 essay The White Negro located this discontent in the still-recent horrors of WWII. People’s trust in traditional morality and authority was shaken, along with their faith that their lives mattered.

Ironically, the mid-century cultural touchstones that are now celebrated nostalgically were intended to critique and confront. Grace Metalious’s Peyton Place (1956) unmasked small-town hypocrisy; Christopher Isherwood’s A Single Man (1964) mined the loneliness of the closet; in Portnoy’s Complaint (1969), Philip Roth turned an excoriatingly hilarious eye on Jewish self-loathing. Frank O’Hara’s poetry and John Cheever’s fiction captured, in Natasha Vargas-Cooper’s lovely phrase, “the sensation of an atomised heart pounding furiously in a dissolving world”.

Before the fifties came that other anti-nostalgic bogeyman, the Victorian era. The still commonsensical belief that 19th-century British culture was hypocritically repressive was almost single-handedly kick-started by Lytton Strachey’s 1918 book Eminent Victorians, an iconoclastic biography of four key personages of the era. Simon Joyce notes in his 2007 book The Victorians in the Rearview Mirror — one of many recent re-evaluations of the period’s legacy — that the Bloomsbury group, of which Strachey was a key member, “preferred to define the past as one-dimensional and the present as marked by complex ambiguities”.

However, nostalgia need not assume a linear narrative. The truism that history repeats itself implies a cyclical notion of time in which we can revisit the past temporarily, playfully, not situating authenticity permanently in either the present or the past, but weighing them against one another.

As Mad Men’s Don Draper says in his extraordinary campaign pitch for Kodak’s new slide projector: “It’s called the Carousel. It lets us travel the way a child travels: round and around, and back home again, to a place where we know we are loved.”

I’ve just finished Chocolate Wars by Deborah Cadbury, a terrific history of the entrepreneurs who shaped the chocolate industry. The Cadburys, Rowntrees and Frys ran their companies according to their Quaker principles of social equity over profit, and responsible corporate stewardship over ruthless competition.

It’s a conspicuously nostalgic book. The author, a distant relative of the chocolatier family, begins sweetly by reminiscing about her childhood visits to the Bournville factory, and ends on a dark, bitter note: Kraft’s hostile takeover of Cadbury in February 2010, trampling the firm’s 180 years of benevolent corporate governance.

However, Quaker capitalists’ utopian ideals don’t seem quaint and outmoded. Rather, they quite strikingly anticipate the “corporate responsibility” turn of the past 20 or so years. Quaker chocolatiers agitated against cocoa slavery, provided excellent workplace conditions, encouraged unionism and created model villages with state-of-the-art factories at their centre.

Even the Swiss firms that lurked on the edges of the English chocolate industry, and the ambitious Americans Milton Hershey and Forrest Mars, have marvellously energetic backstories. These entrepreneurs recall the inventiveness, tenacity and sheer personal magnetism of the fast-food pioneers — Ray Kroc, Clarence Birdseye, Harland Sanders — chronicled in Eric Schlosser’s Fast Food Nation.

First published in 2000 at the height of anti-globalisation sentiment, Schlosser’s book is widely considered an exposé of ethically bankrupt fast-food industry practices. But only by waxing nostalgic about the industry’s founding figures can we realise that the real ethical problem with today’s fast-moving consumer goods megacorporates is their remoteness. Unlike Forrest Mars, who once fell to his knees in a board meeting and prayed to Snickers, these leviathans have no intimate stake in any of their brands. They see them merely as cash cows to be acquired and demerged, as wedges to stymie competing brands.

Cultural critic Linda Hutcheon writes that “nostalgia is not something you ‘perceive’ in an object; it is what you ‘feel’ when two different temporal moments, past and present, come together for you and, often, carry considerable emotional weight”.

For Hutcheon, this element of feeling, of active participation, creates nostalgia’s power. So, perhaps the way towards an ethical nostalgia is not to feel guilty and helpless about our longing for the past, but rather to actively negotiate with it now, and in the future.

This essay is part of Crikey’s Big Ideas series. We’ve had enough of sound bites set on repeat, glib slogans and half-baked committees  —  we’re looking for the vision thing. One Crikey subscriber will also get the chance to share their Big Idea with our readers: send us a three-line pitch, on an issue of national importance that gets you fired up, to boss@crikey.com.au with “Big Ideas” in the subject line.