Scott Alexander argues for the use of probabilities in decision-making even without well-defined models, using examples to show why this approach is necessary and beneficial in real-world situations. Longer summary

Scott Alexander argues against the idea that probabilities should not be used without well-defined models. He presents scenarios where probability judgments are necessary even in novel situations, such as alien contact or evaluating research proposals. The post discusses the importance of making probability estimates in real-world decisions, even when precise models are unavailable. Scott acknowledges some valid criticisms but ultimately argues that using probabilities allows for better decision-making, accuracy checking, and challenging overconfidence. He suggests that alternatives to probabilistic thinking fall short when faced with real-world choices. Shorter summary