Full Idea
In the course of the argument the first person has acquired a character; he is not merely conscious, but self-conscious.
Clarification
The 'Cogito' is Descartes' famous "I think therefore I am"
Gist of Idea
In the Cogito argument consciousness develops into self-consciousness
Source
Roger Scruton (Modern Philosophy:introduction and survey [1994], 4)
Book Reference
Scruton,Roger: 'Modern Philosophy: introduction and survey' [Sinclair-Stevenson 1994], p.41