Causal Generalizations and Good Advice

In this essay, I focus on the convergence of two problems. The first is our nemesis, the reference-class problem. The second is the problem of causal generalizations such as 'smoking causes lung cancer'. problem has been with us since the time of Hume. Within the of the probabilistic theory of causation (which I have been since the early '90s), this problem takes on a very precise . All parties to the dispute agree that the truth of such a generalization upon certain conditional probabilities; they disagree the configuration of these probabilities that must obtain in for the claim to be true. The key to solving this second problem in the observation that causal generalizations can serve as guides life: if I know that smoking causes lung cancer, that gives me a good not to smoke. Here is where the two problems converge. One way formulate the reference-class problem is as follows: which objective, probabilities should guide my decisions? I answer that one be (partly) guided by the conditional probabilities that figure the probabilistic theory of causation. This, in turn, helps us to solve second problem. 'Smoking causes lung cancer' describes a configuration objective, conditional probabilities, such that if the agent guided by those probabilities, it would be rational for her to from smoking. Like Hume, I conclude that the truth of a generalization is partly a subjective matter.