In this essay I argue that one of the things that matters most to Descartes' account of mind is that we use our minds actively. This is because for him only an active mind is able to re-organize its passionate experiences in such a way that a genuinely human, self-governed life of virtue and true contentment becomes possible. To bring out this connection, I will read the Meditations against the backdrop of Descartes' correspondence with Elisabeth. This will reveal that in (...) Descartes' writings there is a crucial connection between the conception of ourselves as dreamers and the idea that we fail to realize our true potential as self-determined, active agents. Dreams, as Descartes conceives them, are passively received mental states that inhibit our freedom to use reason at will. To awaken here takes the form of activating our thoughts, which holds the key to freeing ourselves from the stimulus-response patterns that Descartes takes to be at work in animal conduct. Applied to the Meditations, these insights suggest that this work engages in questions far beyond the epistemological agenda. By activating the mind, the Meditations teach us how to realize our true human potential as virtuous thinkers and passionate agents. (shrink)