The myth of underdetermination

James Ladyman (Bristol University)

The idea that there is always underdetermination of theory by evidence that can only be resolved by epistemic or non-epistemic values is pervasive in philosophy of science, and informs epistemology and the methodology of metaphysics. Philosophical contrived scenarios aside, underdetermination is thought to be exemplified in science by examples such as geocentrism versus heliocentrism in the early scientific revolution, phlogiston versus oxygen in the chemical revolution, and Bohm versus Copenhagen quantum mechanics now. Relatedly, many philosophers are sceptical about crucial experiments and their role in theory-choice. This paper argues that underdetermination of theory-choice in these cases is a myth drawing on recent work on each of the putative examples above, and considering some crucial experiments in the Chemical Revolution. The way underdetermination is resolved in practice involves consilience or triangulation which is context-dependent and quantitative as well as qualitative.