In “Human Nature and the Limits (If Any) of Political Philosophy,” (2011) David Estlund defends what are sometimes called “ideal” or utopian political theories against the charge of being incompatible with human nature. For example, a utopian socialist or egalitarian political theory might require a degree of selflessness from the citizenry that it is entirely unrealistic to expect flesh and blood humans to possess. Therefore, it is said, the political theory is defective and false. To this familiar objection, the familiar reply from defenders of utopian political theory is to claim that human nature is indeed up to the demands of their theory, or at least it will be once the dog-eat-dog pressures imposed by capitalism have been swept away and we enter the New Jerusalem.

But Estlund does not take this tack. What distinguishes his defense of utopian political theory is a willingness to agree for the sake of argument that we can know in advance that people will never bring themselves to act as the theory requires—which means he acknowledges that the theory should never be implemented, since to do so would bring catastrophic social dysfunction. Nevertheless, this does not invalidate the theory! Such a utopian political theory would remain the normative ideal: we ought to rebuild society on the model it prescribes and comply with its moral demands on our personal actions. Only, since we will never so comply, we ought not to rebuild society in the way it prescribes. But that does not mean there is anything wrong with the theory.

In what follows, I will elaborate and critique Estlund’s argument. TL;DR: The main thrust of his argument makes a valid and interesting point, but not one that saves ideal theory’s bacon.