Pirate Parties are suggesting a solution to citizens’ dissatisfaction with representative democracy that seeks to remedy the system from within. By combining direct democratic participation with a highly flexible model of representation, liquid democracy promises the best of both worlds: Citizens can freely choose to either vote directly on individual policyissues, or to delegate their votes to competent representatives who vote on their behalf. This delegation is policy-area specific and can be retracted instantly. So far, democratic theory has neglected this model of democratic decision-making. This article fills this gap. We first define the basic model of liquid democracy. We then defend two theses: First, liquid democracy mobilizes more political expertise than purely representative democracy; second, liquid democracy is more egalitarian than the latter. We draw on social epistemology, arguments from collective intelligence, and empirical research on voter competence to argue that we can expect ordinary citizens to master their tasks in a liquid democracy. Finally, we discuss two problems affecting the basic model of liquid democracy: a problem of unequal voting power, and a problem of policy-inconsistency. They can be addressed by combining liquid democracy with a trustee model of representation, requiring decision-makers to adhere to deliberative norms, and balancing liquid decision-making in legislatures with an executive that reviews the formal feasibility of policies and moderates package deals between proposals from different policy areas. Acknowledgments The original ideas for this paper were developed during a workshop on liquid democracy that was organized by the authors at the University of Cologne in spring 2012. We are indebted to all participants of the workshop, but in particular to Saskia Ruth, Holger Reinermann, and Gregor Zons for their contributions during the inspiring discussions we had. We would further like to thank Rene Roderstein for giving us the opportunity to present insights from the workshop to members of the Cologne Pirate Party and receive their feedback. Previous versions of this paper have been presented at the PDD Specialist Group Conference, 9-11 July 2014, Newcastle, England and at the 4th Global International Studies Conference, 6-9 August 2014, Frankfurt am Main, Germany. We wish to thank Sergiu Gherghina, Bob Goodin and three anonymous referees of the Journal of Political Philosophy for their excellent comments that have helped us improve this article. Both authors wish to acknowledge financial support received from the Fritz Thyssen Foundation while drafting the manuscript.