Introduction
This introductory chapter sets out the themes of the book. Doctrines of judicial deference have begun to appear with growing regularity in the European Court of Justice’s free movement case law, especially in relation to Member State action. Their application has been controversial, which is unsurprising in light of the constitutional issues which deference raises: should judges intervene in the work of the legislators? How far can the EU restrict national autonomy? And what is the division of power between European and Member State courts? The chapter sketches the approach taken in the book and explains the empirical study on which the analysis is based. The idea of the ‘passive virtues’ is introduced and linked to the developments in EU free movement law.