We all know that the sky is blue, but fewer of us can say why it is so. Explanations intuitively provide more information than knowledge alone. Indeed, it seems that in order to practice medicine (and even science in general), we often don’t need to know why something happens. For instance, a number of studies have shown that frequent consumption of hot liquids such as green tea leads to increased risk of gastric cancer (e.g., see Mao et al., 2011). So, a physician might recommend to someone who is concerned about gastric cancer that she should avoid hot tea, even though researchers don’t quite know why consuming hot liquids leads to increased risks. Similarly, electroconvulsive therapy is an effective short-term treatment for depression. In fact, some studies, including one from The UK ECT Review Group (2003), show that it outperforms drug therapies. But researchers have limited knowledge of why sending electricity through the brains of patients with depression can improve their conditions. If all we care about is improving health outcomes of patients, then the search for answers to the “why” questions seems to be an epistemic cherry on top. 1