 In an important proviso, Rawls adds that citizens may speak the language of their controversial comprehensive doctrines—even as public officials, and even on the most fundamental issues—so long as it can be shown that these assertions appeal to public values. So President Lincoln, for instance, could legitimately use Biblical imagery to condemn the evil of slavery, since his condemnations appealed to the public values of freedom and equality. Thus even within its limited range of application, Rawls’s doctrine of public reason is rather permissive concerning what citizens may say and do within the bounds of civility.