The principle of subsidiarity was adopted as part of the law of the European Union as a response to perceptions of excessive centralisation and bureaucratisation within the European system of government. If subsidiarity is a solution to these problems in Europe, it might be asked: could it also be a solution to similar problems that arise in other federal systems, such as those of the United States and Australia? However, posing the question in this way is misleading because it is not at all clear that subsidiarity has been a solution in Europe, and in any case it cannot be assumed that a solution in one context will necessarily operate effectively in another. This article closely examines the nature and operation of the principle of subsidiarity in Europe and asks what lessons might be learned from it. To do this, the article begins by identifying the carefully defined operation of the principle in EU law, and then closely examining the application of the principle, firstly as a political decision-making procedure that involves the Member State parliaments in the European policy-making process, and secondly as a juridical principle enforceable by the European Court of Justice. The possible adoption of the principle in other federations is then discussed, but limitations on its effectiveness in Europe, as well as the different institutional and political circumstances of the Australian federal system, are shown to undermine its likely usefulness, unless other more fundamental issues about the way in which the federal system is understood, organised and operated are addressed. The final part of the article suggests that these more fundamental issues are best understood and addressed in the light of a broader, more substantial, ‘social’ conception of subsidiarity: a conception not unrelated to the Roman Catholic social theory from which the idea of subsidiarity originally derived. A more substantial, social conception of subsidiarity, it is argued, can help us to understand why the application of the principle in Europe has had only limited effect and also why its application in other federal systems is unlikely to remedy problems of centralisation and bureaucratisation. This is because the European version of subsidiarity is focused on the question of how the functionalist objectives of the EU can most appropriately be achieved, with only tangential consideration being given to the proper functions, purposes and responsibilities of the constituent Member States themselves. Focusing simply on the scope and reach of the competences of the central organs of government is not enough. Nor is it sufficient, as in Australia, to focus only upon the immunities that the constituent States ought to enjoy as self-governing political communities. Rather, the key task is to identify the proper functions and purposes (munera) of the various political (and social) communities and associations that make up the wider political community of which they are an integral part. The proper immunities that a particular community should enjoy cannot be identified apart from and identification of the appropriate munus of that community. Although an admittedly difficult and highly controversial task, unless the issue of the munera is addressed, ‘subsidiarity’ as a principle is not going to have much effect, for its fundamental lesson about the nature and integrity of the munus of each community – social and political – will not have been learned
