There have been rave reviews for the Aztecs show at the Royal Academy, but this art was produced by one of the most bloodthirsty ‘civilisations’ that has ever existed.

Included in the show are sacrificial knives and a pot used for storing flayed human skins. Other exhibits are frightful idols before which fiendish rites were committed on the top of pyramidal temples. One Aztec sculpture is dressed in a wooden cloak - but this turns out to be a substitute for the human skin which draped it in real life. We may have been shocked by Dr Gunter van Hagens recently-televised autopsy on Channel 4, but that was performed on a dead man for the scientific purpose of establishing cause of death. The Aztec artefacts were used on living, screaming people for obscurantist religious reasons - reasons that might be described today as ‘cultural’. Indeed, bejewelled as they are with jade and gold, they all look exceedingly beautiful. For that reason alone, it is worth forking out the £10 entrance fee.

Nowadays we tend to judge civilisations by the diversity of their cultural legacy. Given the reasons Aztec art was produced, perhaps we should adopt other criteria. Their diverse culture happens to have been a gory amalgam of other people’s art and other people’s hearts. Believing that they had to sacrifice human blood to persuade the Sun to rise each morning, Aztec monarchs like Montezuma conducted wars to gather prisoners for sacrifice.

Today’s dominant multicultural ideology in the West tends to turn a blind eye to the dubious ethics of ancient civilisations - especially when they were subsequently conquered by a European power, as the Aztecs were by the Spaniard Hernando Cortez in 1521. The reason Cortez and his 600 warriors found it relatively easy to invade Mexico was that, apart from neighbouring tribes welcoming Cortez as a saviour, the temple priesthood had begun to sacrifice Aztec children too.

Maybe it would be more consistent of those of us who despise the equally sanguinary record of Western imperialism if, when confronted by the brilliance of the Aztec culture, we were to contemplate changing our definition of civilisation altogether. Hopefully the Aztecs exhibition will lead us to question prevalent childish notions of civilisation. Is it really acceptable to believe that materialism is wicked while the road to civilisation lies through cultural accomplishment alone?

Western romantics see modernity as the root of all evil, and patronise primitive communities as sweetness and light. Yet most human societies have had a blood-soaked past, even the nomadic aborigines and bushmen. The more civilised Aztec empire and the subsequent Spanish Inquisition may have produced buckets of blood and epidemics of disease, but both also created wonderful art. Material progress since then has brought a better life for all. One reason for this has been the enlightened disconnection of irrational religion, culture and art from any responsibility for running modern society. Perhaps that is a new yardstick by which we can measure civilisation.

Multiculturalists tend to disregard the atrocities committed by non-European regimes in the name of culture because they hope to thrust art into the political prominence it formerly enjoyed in the days of the Renaissance and before. Another sanctimonious example of politicised art has been going on at Hoxton’s White Cube Gallery, where Jake and Dinos Chapman have erected numerous tribal idols, which they have adorned with the celebrated iconography of the McDonalds burger company. If the Aztec artefacts at the Royal Academy fill us with chilly admiration, we can also see tribal imagery on display at the other end of London, this time paraded with detached irony.

In this work, the Chapman brothers criticise the hypnotic appeal generated by the famous brands owned by global corporations. These icons allegedly compel us to buy merchandise as if we were Aztec subjects charmed into submission by a tribal fetish. To counter this insidious influence, the savage logos of the Chapmans coolly savage mass consumption. But this is precisely what many adverts do already. The trickster Chapmans are trying to convert us to their sustainability agenda by using the same techniques fat cats like advertising mogul Charles Saatchi have been using for years. How long will it be before the Chapmans’ ethnic artefacts appear in a new Ronald McDonald advert?

Aztecs is at the Royal Academy, Piccadilly, London till 11 April 2003
Jake and Dinos Chapman: Works from the Chapman Family Collection is at the White Cube Gallery, Hoxton Square, London till 7 December 2002