The fly is a bullet so black that for a second I think it's swooping right at my face. A blink and I realise it to be safely within the tank. I watch it flurry at the glass, then look beyond to the grizzled cow head, which lies on the floor crowned by a droning cloud of flies. This is a replica of A Thousand Years, which is being exhibited in the Tate Modern as part of its Damien Hirst retrospective. Despite the gruesome sight, it’s the alarming smell of rot that haunts me as I leave, and, upon reaching the Turbine Hall, I'm thankful for the clean air. The space currently rings with the rush of Tino Sehgal’s live commission, but were I walking here a year and a half ago my footsteps would be serenely crunching over what, at a first glance, might appear to be a pebble beach. In reality, this "pebble beach" was actually a carpet of 100 million individually-crafted porcelain sunflower seeds by Chinese artist Ai Weiwei, which acted as reminder of the value and idiosyncrasy of the individual amidst the homogeneity of China’s society of mass-production.

Hirst and Weiwei. Weiwei and Hirst. Despite their differences, there are many parallels to be drawn between the two artists. As well as exhibiting in the Tate within a year of each other, both are arguably the most internationally famous, and controversial, conceptual artists to have emerged from their respective countries. Both tend to have little involvement in the actualisation their ideas, instead preferring to employ workshops of artists. (Though it is worth noting that whilst Hirst infamously describes his own efforts as “shite”, Weiwei is known as an extremely capable craftsman.) Both facilitate ready-made objects (for Weiwei, pieces such as Table with Two Legs on the Wall, and for Hirst his Pharmacy series) and flirt with destruction (Hirst's The Natural History series, Weiwei's Dropping the Urn), perhaps as an off-shoot of their shared desire to shock. Most importantly, however, both are talented facilitators. Hirst is credited with bringing "BritArt" to the notice of the international art community and his rise to fame is largely attributable to his curation of degree shows such as Freeze in 1988. Weiwei, meanwhile, played a crucial role in establishing an underground Chinese art scene during the period of suppression that followed the Tiananmen Square protests and is currently lauded for his tireless activist social networking. Yet it is here that the two men part company, for the essence of their work is radically different, if not diametrically opposed.

I'm reminded of Hirst’s In and Out of Love in which butterflies hatch, feed and mate in a frenzy of life that is intended as a contrast to his paintings of collaged butterfly wings. In its replication for his retrospective I did indeed find hope as I stood in the humid room, willing colourful wings to chose me as a perch. But as soon as one did a steward plucked it away, it wings clamped between her index and middle fingers like she might a cigarette. At the table where she deposited it, three other stewards were bent over a bowl of fruit. “They’re looking a little insubstantial now.” One of them remarked. And she was right. At her words I saw that the browning flesh of a banana was studded with pieces of wing-shrapnel, which could have been jigsawed into the tatters of a butterfly that twitched atop an emaciated orange. Death even sharpens his scythe on Hirst’s Pharmacy installations. Of the pills that others would perceive as curative, Hirst says “you can only cure people for so long and then they’re going to die anyway.” Through these pieces and his unholy fusion of dichotomies (he claims that “in an artwork I always try to say something and deny it at the same time”) Hirst seems to beckon us into a nihilist descent. Indeed, by the time one exits past a taxidermied dove, it’s hard to shake the feeling that his main message is "why don’t you just lie down and die?"

Yet whilst it is true that the very maggot of our destruction is present at our conception, this cannot invalidate the curious and marvellous state that perseveres between birth and death. Weiwei knows this. In Study of Perspective he quite literally gives the finger to Tiananmen Square, and for Ai's Remembering, a monument to the thousands of school children killed by the Sichuan earthquake, thousands of backpacks spell out the words: "She lived happily for seven years in this world."  Life is invaluable to Weiwei, perhaps all the more so for its finitude, and he sees it as worth fighting for, even if to do so risks an early onset of Hirst’s fly-festered death. Faced with this comparison it’s easy to forget that it is Weiwei, not the death- obsessed Hirst, who faces the constant threat of silencing by a totalitarian regime.

A recent editorial in the Guardian contrasts the idea of "an artist with ‘the responsibility of a preacher’", to Hirst as “perhaps, the artist we deserve”, “purposeless, plutocratic, even pharmaceutical” like “the preoccupations of our age.” Yet the modus operandi works both ways, society shapes art and art shapes society. How else could an artist like Weiwei exist? In Britiain we are lucky enough to have the freedom of expression for which Weiwei risks his life, yet the use we make of our artistic liberties seems almost shameful. Weiwei’s work challenges his oppressive government, Hirst's follows the pack in seeking to dilute the meaning of the word "art". Weiwei hopes to shock the international community into signing petitions, Hirst the rich into signing cheques.

Hirst is, of course, an obvious straw man and there are many exceptions to the trend, yet I still struggle to think of a worthy example of a British practitioner who raises important political issues as succinctly, or has had such success in inspiring and motivating non-artists, as Weiwei. Though the Chinese undeniably face greater injustices, it would be laughable to call Britain a utopia. With the reputations of banking, media and politics sullied perhaps irretrievably, there are many scandals to be challenged by galvanising, inspiring art. For regardless of Hirst's missive, we’re not dead yet and some things are worth fighting for.