There is a famous argument, drawn from a proof in economics, to the following effect: If it is infeasible to produce all of the elements that would together constitute an ideal social scenario (of some kind, such as efficiency or justice), it cannot be assumed that the second-best choice is to produce all of the feasible elements. The underlying point about the structure of value, which I call the Fallacy of Approximation, is much broader than is usually supposed. For example, it has nothing essentially to do with second, or best, or infeasibility. I unroll, unfold, and flip over the point’s initial scope, extending it also beyond the usual cases of causal interactions between contributing elements. (This leads to a comparison and contrast with G. E. Moore’s famous doctrine of organic unities.) Finally, I illustrate the point’s applicability in (surprisingly?) many contexts in moral and political philosophy. One aim is simply to become sensitized to the structural point and its ubiquity. A further aim is to see whether some active normative disputes can be advanced by proper attention to the tempting Fallacy.
Professor David Estlund, Lombardo Family Professor of Humanities in the Department of Philosophy at Brown University, is one of the world's foremost political philosophers. He is the author of the highly influential Democratic Authority: A Philosophical Framework (Princeton, 2008) and numerous important papers in political philosophy and democratic theory. Estlund is currently working on a book to be called Utopophobia, on questions of realism and idealization in political philosophy.