Abstract Many veterans of the 1991 Gulf War have developed unexplained somatic and psychological symptoms and are more likely to suffer chronic ill health than matched control samples. The association between these symptoms and possible causal environmental exposures has been extremely controversial and remains unresolved. Controversy surrounding aetiology has rehearsed the ‘mind–body’ debate arising from Cartesian dualism and has demonstrated how scientific data may be subject to a broad interpretation, influenced by the prejudices and attitudes of the commentator.