Little is understood about Descartes. Due to his French name, it's strongly suggested that he had affiliations with the AEU before he was transferred to the ESF Army. In the limited time he was presented, Descartes has been shown to be an arrogant and egotistical person - not unlike Ribbons Almark - due to his status as an Innovator. He believes that his being an Innovator has placed him above other people in the ESF, who he simply views as "inferior creatures". In most of his interactions, he speaks in a condescending and arrogant manner, shown and exemplified during his encounters with Brigadier General Mannequin, Billy Katagiri, and Mehna Carmine. Descartes is even arrogant enough to override the commands of Vice Admiral Kim, and he does not hesitate to voice his discontent at being a mere "lab rat".