Practicable Ideals

Political theorists are divided over how realistic normative ideals need to be to guide policy. The literature has now spawned a bewildering number of positions on idealism, realism, fact-sensitivity, and practice-dependence. This paper adds to the pile with the constraint of ‘practicability’. Impracticable ideals will fail to guide rational agents committed to justice. I suggest the terminology of practicability is helpful in order to distinguish these ideals from merely unrealistic ideals. Appeals to unrealistic possibilities are often efficacious, I argue, just so long as we do not make empirical mistakes about the objects and kinds stipulated in those possibilities. Such empirical mistakes are what trigger the guidance critique. John Rawls’ ideal of international justice, for example, is largely considered a poor guide because it “idealises the subject of justice” (Valentini, 2009). It idealises all states as liberal regimes, which obscures the perverse incentives the ideal generates for dealings with less-than-liberal regimes. Rawls’ proposed principles for toleration fail to guide us given the non-negligible probability they will incentivise corrupt elites in illiberal regimes to seize power and destabilise incumbent governments. Yet in its current guise the guidance critique leaves an important puzzle unaddressed: insofar as any principle of justice is action-guiding it will need to idealise the subject of justice to some extent. An appeal to justice is not an appeal to state or individual behaviour as it is, it is an appeal to state or individual behaviour as it might be. We need to idealise the subject of justice in some sense and so we need to distinguish in what sense it is acceptable (i.e. practicable) and in what sense it is not (i.e. impracticable). The guidance critique will otherwise risk being either too restrictive or not restrictive enough. I suggest that we can acceptably idealise the subject of justice so long as we do not make a mistake about the nature of that subject. Rawls, for one, overlooks human nature with his account of international justice. This is to be distinguished from simply idealising away from non-actual circumstances. While talk of human nature is often shrugged off as outdated metaphysics in political philosophy, this is not in keeping with other fields of philosophy (e.g. Barcan Marcus, 1961; Kripke, 1974; Putnam, 1975; Soames, 2003; 2010). If an ideal is no longer normatively desirable once we factor in empirically-discovered patterns of human nature (pace Estlund, 2011), it is impracticable and we should look for an alternative. Appeals to impracticable ideals have, I argue, lead to a wide range of applied mistakes in political theory.