Until the 1970s, writers on the history of medicine such as Charles Singer took a 'positivist' approach which saw the history of medicine as a vast sweep of steady progress from medieval times to the present.
For these writers, the Middle Ages were a time of dirt and superstition, the Early Modern age saw the development of the first scientific ideas, and the 19th century was an 'age of heroes' – such as Pasteur, Lister and Chadwick – who propelled medicine into our modern age where anything is possible.
After the 1970s, these views were challenged. Historians proved that treatment in the Middle Ages was often successful, and suggested that medieval towns were not as dirty as Early Modern towns. They showed that advances in public health occurred before Pasteur discovered germs and that doctors were doing adventurous surgery long before antiseptics and anaesthetics.
In 1976, Thomas McKeown even suggested that, apart from immunisation, medicine and public health played almost no part in the improving health of the nation, which he attributed to rising living standards and better food.