What use are theories that have no predictive power? That is a question many economists and political theorists should be asking themselves these days. Back in 1989 hardly anyone in the world of political science was able to predict the collapse of European Communism, the biggest event in world history since the end of World War II. In 2008 it was the turn of the economists. The vast majority of their number totally failed to see the collapse of international finance and the US housing market. Today it is once again the political scientists who failed to give us any warning of the impending revolutions now sweeping North Africa and the Middle East.
In the natural sciences the ultimate test of any theory is its ability to predict events. Economics is perhaps the social science that most aspires to the rigour of the natural sciences, but 2008 exposed its many failings. Political theory is not far behind on both counts.
Perhaps the problem is an even broader one. Maybe we are too enthusiastic about reaching consensus in social theories. The great debates within the social sciences tend to be sequential, and the various disciplines seem mostly to move from one consensus to another rather than coming to terms with the possible simultaneous existence of multiple consensual models. Debates between specialists too often seem set up to establish one valid theory. The co-existence of multiple theories seems like a weakness that embarrasses a discipline, largely because a theory in the natural sciences is universal and all-encompassing. In this sense the social sciences would do well to relax their burning desire to emulate the natural sciences. In the words of one group of political scientists: 'God Gave Physics the Easy Problems' so let's accept that neother economics nor politics is the same as physics.