Influenced by the writings of Jean-Jacques Rousseau and the American Revolution, Xavier joined a number of like-minded citizens in the Inconfidência Mineira, a revolutionary movement. They envisioned an independent Brazilian republic, with São João del Rei as its capital and the conversion of Vila Rica to an university town. The proposed flag for the new republic had a green triangle over a white background, surrounded by the Latin motto "Libertas Quae Sera Tamen" ("Freedom, Even If It Be Late").