The question we want to address is what it takes for groups to constitute rational epistemic agents. The members of a group often hold disagreeing views. How can a group rationally move from such situations of internal disagreement to a unified group attitude? A possible answer is that group attitudes are rational if they result from the application of appropriate judgment aggregation methods. In Section 3.2 we discuss some problematic aspects of this answer, and then, in Section 3.3, we present an alternative proposal, according to which group (epistemic) attitudes are rational insofar as they are formed by responding competently or responsibly to the (epistemic) reasons available to the group as a group (this will require exercises of reasons-responding competences attributable to the group). In Section 3.4, we explore the idea that bare judgment aggregation methods have to be combined with collective deliberation in order for groups to be able to respond competently to reasons. In Section 3.5 we discuss the extent to which collective deliberation can be expected to solve internal group disagreements, paving the way for the adoption of coherent, reasons-responsive group attitudes. We suggest that conciliationist approaches to disagreement offer an optimistic picture of collective deliberation, as a method for bringing about internal group consensus. However, we will also explore possible limitations to the application of the conciliationist picture to realistic instances of group deliberation. Finally, in Section 3.6, we examine the role of dissensus and consensus in epistemically virtuous group deliberations.