“The majority of European Constitutions enshrine the principle of separation between Church and State” says a 2013 report from the Directorate-General for Internal Policies, but the degree to which this is implemented differs enormously. With some European nations committing deeply to separation of powers, others enshrining their commitment to the separation of church and state implicitly, and others having only a notional commitment and a de facto partnership between church and state, how should European governments act in a world where religious diversity (including atheism) are at an all-time high?