The narrative structure of the Meditations, and the way in which its central character develops intellectually and morally within it, can give some insight into just what Descartes takes to be involved not only in being a thinking thing but also in continuing as the same thinking thing over time. While the Second Meditation establishes that the Cartesian self is a substance, the standard account of the Cartesian self maintains further that it is the self's substantial nature that both individuates it as a particular self and that accounts for its persistence as the same self over time. The meditator clearly makes intellectual progress over the course of the Meditations. The progress of the meditator towards epistemic virtue brings out that this process of shaping our awareness, our capacity of thinking, is not unconstrained but rather is guided by norms of rationality.