Abstract

No-lose theorems state that---no matter what the result of an experiment will be---there will be a relevant epistemic gain if the experiment is performed. Here I provide an analysis of such theorems, looking at examples from particle physics. I argue that no-lose theorems indicate the pursuitworthiness of experiments by partially decoupling the expected epistemic gain of an experiment from the ex-ante probability that the primarily intended outcome is achieved. While an experiment's pursuitworthiness typically depends on the ex-ante probability that the intended outcome is realized, this is not the case if there is a no-lose theorem in place. I argue that this works only if (1) the theorem's win condition is attainable with reasonable effort, (2) the theorem's underlying assumptions are plausible, and (3) all potential experimental outcomes are epistemically relevant. I also explore the consequences of no-lose theorems for considerations of scientific pursuitworthiness. First, no-lose theorems can play an important role in assessing the risk associated with investing into a research project. Second, no-lose experiments can enhance scientists' agreement about the pursuitworthiness of experiments. My analysis also shows that no-lose theorems can face a number of limitations in these contexts.