Many proponents of deliberative democracy expect reasonable citizens to engage in rational argumentation. However, this expectation runs up against findings by behavioral economists and social psychologists revealing the extent to which normal cognitive functions are influenced by bounded rationality. Individuals regularly utilize an array of biases in the process of making decisions, which inhibits our argumentative capacities by adversely affecting our ability and willingness to be self-critical and to give due consideration to others’ interests. Although these biases cannot be overcome, I draw on scientifically corroborated insights offered by Adam Smith to show that they can be kept in check if certain affective and cognitive capacities are cultivated. Smith provides a compelling account of how to foster sympathetic, impartial, and projective role-taking in the process of interacting with others, which can greatly enhance our capacity and willingness to critically assess our own interests and fairly consider those of others.