Author argues that the conscience is a theme frequently flagged as a key aspect of Stoicism. Beyond mere consciousness, our self-awareness as agents, moral and otherwise, conscience specifies the ethical norms we honor in judging our experience and acting on it. Scholars have studied how the Stoics think we acquire these norms, how we apply them in concrete individual cases, and how we estimate this practice, prospectively or retrospectively, examining our conscience and steeling ourselves to the difficulties of acting in its light. Whether these processes depend on Ancient Stoic monopsychism – the notion that the soul has no subdivisions or infrarational faculties – has also drawn attention. In tracking its medieval fortunes, whether in Stoic or modified form, we will note as well some of the related ideas with which this doctrine traveled