Kronfeldner M. Commentary: How norms make causes. International Journal of Epidemiology. 2014;43(2):1707-1713.There are always many causes involved in the coming into being of something. If, for instance, there are many factors that are causally involved in the etiology of a disease, even if each only has a small influence, then, in principle, they all have to be taken into account to get a complete causal explanation of the phenomenon at issue. But, as a matter of fact, complete causal explanations are rather hard to get (or too expensive) if not impossible, i.e., completely beyond our scientific abilities. In practice, we usually select even among those causes which are ontologically on a par, e.g., among genetic and environmental factors...