What is the relevance of ideals for determining virtuous argumentative practices? According to Bailin and Battersby (2016), the telos of argumentation is to improve our cognitive systems, and adversariality plays no role in ideally virtuous argumentation. Stevens and Cohen (2019) grant that ideal argumentation is collaborative, but stress that imperfect agents like us should not aim at approximating the ideal of argumentation. Accordingly, it can be virtuous, for imperfect arguers like us, to act as adversaries. Many questions are left unanswered (...) by both camps. First, how do we conceptualize an ideal and its approximation? Second, how can we determine what is the ideal of argumentation? Third, can we extend Stevens and Cohen’s anti-approximation argument beyond virtue theory? In order to respond to these questions, this paper develops a second-best perspective on ideal argumentation. The Theory of the Second Best is a formal contribution to the field of utility (or welfare) optimization. Its main conclusion is that, in non-ideal circumstances, approximating ideals might be suboptimal. (shrink)