This study analyses how the link between politics and conscience was articulated and shaped by confessors as counsellors to monarchs throughout the seventeenth century. Against the backdrop of the momentous intellectual, theological, and political shifts during this period, it examines comparatively how ethical challenges of political action were confronted in Spain and France and how questions of conscience became a major argument in the hegemonic struggle between these competing Catholic powers. Counsel of conscience was not a peripheral feature of early modern political culture but fundamental for the definition of politics and conscience. Tracing the rise and fall of confessors as counsellors reveals the parallel transformation of both, getting closer to a historical understanding of the modernization of politics with the idea of an individual conscience at its heart. Placed at the junction of norms and practices, royal confessors shaped the ways in which the royal conscience was identified and scrutinized. By the same token, their expertise and activities remained a source of anxiety and conflict that triggered wide debate on the relationship between State and Church and religion and politics. The notion of counsel of conscience, of which this book provides the first in-depth analysis, challenges fundamental historical paradigms such as the emergence of absolutism, individualization, and the division of public and private. Putting theological concepts and religious dimensions back into political theory and practice sheds new light not only on the importance of counselling for early modern statecraft but also on the reconfiguration of normative frameworks underlying it.