In this paper, the authors argue for two main claims: first, that the epistemic results of group deliberation can be superior to those of individual inquiry; and, second, that successful deliberative groups depend on individuals exhibiting deliberative virtues. The development of these group-deliberative virtues, the authors argue, is important not only for epistemic purposes but political purposes, as democracies require the virtuous deliberation of their citizens. Deliberative virtues contribute to the deliberative synergy of the group, not only in terms of improving the quality of the group's present decisions, but also improving the background conditions for continued group deliberation. The authors sketch a preliminary schedule of these group-deliberative virtues modelled on Aristotle's conception of virtue as the mean between two extreme vices. The virtues discussed in this article include deliberative wit, friendliness, empathy, charity, temperance, courage, sincerity, and humility.