Intellectual vices are defects of intellectual character, such as intellectual laziness, intellectual cowardice, narrow-mindedness, closed-mindedness, and dogmatism. This chapter focuses on the structure of intellectual vices. It considers whether intellectual vices exhibit a symmetrical structure. This consideration leads to an assessment of “motivationalism” concerning intellectual vice. Intellectual vices make a negative contribution to personal worth. They reflect negatively on their possessor qua person. The structure of intellectual vices mirrors that of intellectual virtues. However, it is important to ask whether the kind of closed-mindedness, gullibility, and intellectual recklessness just alluded to necessarily would be genuine intellectual vices. The structure of intellectual vices is not symmetrical with that of intellectual virtues in the sense that, to possess an intellectual vice, a person need not be defective across all four dimensions of an intellectual virtue. To better understand whether the proposed model of intellectual vice is compatible with motivationalism, one must return to the relevant notion of responsibility.