Can accidental federalism do it?

European integration is yet again at a major crossroad. In the political debate of the last five years or so, there have been several references to a light federation – sometimes combined with a re-discovery of the Ventotene manifesto of 1941-193 – to overcome the current political and economic problems. There are two problems with this political vision. First, can a resurrection of the Ventotene manifesto materialise without visionary leaders or at least a deep re-orientation of preferences among the European political and bureaucratic elites? How do we get to a light federation from the status quo? Second, where is the trust (or, in the language of the Ventotene manifesto, the ‘lava of popular passions’) needed to provide social support to a non-incremental shift towards a light federation? In this paper we  argue that the causal effects of learning on change can be reversed: it is change that, under certain conditions, generates the pre-conditions for non-incremental learning via adaptation. Adaptive policy-makers who might turn out to be the accidental federal heroes of the EU. We illustrate this argument by using findings from experimental and behavioural economics on learning. We then run the same argument on trust, showing how trust is learned via socialisation and interaction – hence it is a product of integration rather than a precondition for it.