Many liberals believe that individuals have a right to autonomy and self-determination, and that, consequently, strong group rights, which compromise individual rights, are unjustified.  This position implicitly relies on a controversial endurantist metaphysics of personal identity. Some contemporary metaphysicians, however, accept a different, four-dimensionalist account of personal identity. From this perspective, exercises of individual autonomy and exercises of group authority are metaphysically on a par: each involves relations of domination among numerically distinct person-stages, justified by a unity relation. This raises a challenge for liberals. Supposing for the sake of argument that four-dimensionalism is true, what—if anything—justifies attributing a right to autonomy to individuals, while denying it to groups? I explore possible answers, none of which succeed fully in vindicating the orthodox liberal position.