The celebrated historian Frank Dikotter, observing the passing show with a smile, exclaimed: 'I just love this, I really do.' I was walking through the Taipei streets with the specialist in Chinese history between the fall of the emperors and the coming to power of the communists. It was a Saturday evening and the fashionable young, so curiously unpretentious, thronged the pavements. Professor Dikotter is at Hong Kong University for a year, taking time out from London's School of African and Oriental Studies. He was over in Taipei for a week of lectures and seminars. He has recently caused something of a sensation in academic circles with his new book, Narcotic Culture. In this, he argues that opium, far from being a pernicious substance imported into China by the evil 19th century British, was in reality long known, tolerated and even venerated in the Celestial Empire. What is more, the British used it themselves, and in a stronger form. How could a nation like China, he asks, have been weakened by the use of something that was in every British medical cupboard at a time when the UK was successfully ruling one-third of the inhabited world? The book has the potential to cause dissension because the image of the opium trade as something disgraceful has, for a long time, been dear both to Chinese patriots and the overwhelming majority of western historians. The trade in opium has been equated with the slave trade, time and time again. But this is not true, says Professor Dikotter. The new argument carries added force because of his high reputation in academic circles. Taiwan is particularly interesting to Professor Dikotter because it is itself, in name at least - and in reality in much else besides - a continuation of the Republic of China (1911-1949) whose reputation he has done so much to enhance. By and large, he is full of admiration. He likes, for instance, Taiwan's endorsement of racial diversity, with its multilingual TV and radio stations, and recognised language rights for Hakka, native Taiwanese and Chinese. Professor Dikotter himself was born in the Dutch city of Maastricht, close to the French and German borders. Maastricht has its own dialect, he points out, which was - to his great delight - recently recognised by the European Union. There is no question of Professor Dikotter believing that drugs are, or even ought to be, tolerated in Taiwan. And he himself is a hard-working researcher. This was made clear when a friend of mine invited him to witness an all-night rave. He looked at his watch. 'Sorry - time for bed,' he said. It was 10pm.