The value of conceptualizing the desirable dispositions of the teacher as virtues is illuminated through distinguishing such dispositions-as-virtues from other dispositions and from personality traits. Dispositions as virtues are qualities achieved by the individual's initiative, in the face of obstacles, and are intrinsically motivated. The complexity of any construct for student assessment is illustrated through distinguishing educational goals from teacher dispositions, specifically social justice; describing dispositions under the three categories of character, intellect, and care; and then indicating the complexity of each through self-knowledge, truthfulness, and compassion as exemplars of each category. Finally, using William Hare's work on open-mindedness, it is argued that transparent assessment is needed in which criteria are perspicuous to assessor and assessed. Student teachers can then create self-assessment protocols for each disposition-as-virtue to enhance understanding and professional growth.