This chapter explores each of the questions raised by the structure and actions of ministries, starting with the political context(s) they create and operate within. Since ministries tend to be given the administrative and usually also legislative initiative in their own policy sphere, a major consequence of the match between party/faction and ministry means that ensuing discussion and debate is focused on one policy field at a time. The chapter clarifies the effects of policy differentiation by seeing how and why parties want to control particular ministries in coalition governments – and how such behaviour can be generalized to factions within single-party governments. The existence of the slow-moving and change-resistant ‘policy regimes’ contributes to slowing down the implementation of new government targets. Policymaking will best be represented as a series of different one-dimensional single line spaces, each representing issues which have to be considered but separately from the others.