As we have seen throughout this unit theorising the European Union (and its predecessors) is a worthwhile and fruitful task. A full appreciation of theory is essential for a complete understanding of the EU.
We have noted many different ways of conceptualising and theorising about the EU. The main distinction in conceptualisation, as you will have undoubtedly noticed, concerns the question of the state’s role in EU affairs. The divergence between supranationalism and intergovernmentalism is inherent in nearly all theories of the EU and they all tackle this question in one way or another.
As we have seen there are many theories that have sprung from these theoretical conceptualisations. Some of the theories are prescriptive in nature, such as federalism, functionalism and transactionalism. It is important to remember that these theories do have explanatory power, but their use is often (but not always) linked with a prescription of how the EU should be. Most other theories such as neo functionalism and LI have more of an explanatory edge and remain popular despite having been around in academic circles for quite some time. As you will have noticed these theories still continue to be invoked in the supranationalism/intergovernmentalism debate and have influenced many of the thinkers who have come after them to this day.
You will have also noticed that these theories explain EU/EC integration rather than the continued workings of the EU. Theories such as the new institutionalisms and constructivism have gone beyond explaining EU integration per se, and have the capacity to explain the contemporary functioning and policy making of the EU. It is important to bear in mind the historical setting of theory. Federalism and functionalism are old theories that predate the even European Coal and Steel Community and therefore it is apparent that they will involve a degree of prediction when talking about the EU. The new institutionalisms, MLG and constructivism are all much more recent and appeared at a time when the EU institutional structure was considerably more developed. Therefore it is only natural that they contain more of an explanation for the functioning of the EU than some previous theories derived at the time of a simpler institutional context.