It matters, however, comparatively little, for the appreciation of Rousseau’s political theory in general, that he failed to become the theorist of the modern State. By taking the State, which must have, in essentials, everywhere the same basis, at its simplest, he was able, far better than his predecessors, to bring out the real nature of the “social tie,” an alternative name which he often uses for the Social Contract. His doctrine of the underlying principle of political obligation is that of all great modern writers, from Kant to Mr. Bosanquet. This fundamental unity has been obscured only because critics have failed to put the Social Contract theory in its proper place in Rousseau’s system.