The sharp division between the ‘institutions view’ and the ‘disease view’ has been one of the distinctive features of the ‘root causes of economic progress’ literature. Based on evidence from cross-national data, the ‘institutions school’ claims that institutions are the only root cause of development, whereas the ‘disease school’ claims that diseases are also equally important. In this paper, I contribute to this literature by proposing a unified structure to marry the two conflicting views. I argue that overcoming diseases are of prime importance at an early stage of economic development, whereas institutions are more important at a later stage. I find support for this hypothesis in the development history literature on Africa, India, China and the Americas.