“There is no more dangerous mistake than the mistake of supposing that we cannot have too much of a good thing.” Thus spake George Bernard Shaw. Excess is as damaging as shortage in most things that are considered good. More is better but only up to a point of satiation. Beyond the satiation point, the marginal utility of a good is negative, as an economist may put it. Particular instances of that generalization are not hard to find.
Food, for instance, is a good that in excessive quantities is a …