The declaration by the WHO of tuberculosis as a 'global emergency' illustrates the paradox of tuberculosis. The treatment of this disease is a good example of 'evidence-based medicine', having been fine-tuned by numerous clinical trials. Modern short-course anti-tuberculosis therapy is among the most effective and cost-effective ways of saving and prolonging human life; yet, this disease is more prevalent today than in the days before the advent of effective therapy and is currently the cause of one in seven deaths and one in four preventable deaths among young adults. It would seem that something has gone seriously wrong and, to shed light on the cause, it is necessary to take a very broad historical look at the changing trends in the behaviour of the disease in communities worldwide and the attitudes of the various communities to the disease in their midst, not just to understand past mistakes, but to make sure we do not make the same mistakes now and in the future.