Piattoli developed contacts with notable figures on the Polish political scene, initially from the group opposed to the royal faction. By the end of his stay in Paris, he likely became a supporter of reforms in France and Poland, and begun taking his first serious steps in political activism, through the involvement in the Quattuowirat, a group of magnates planning a (never realized) confederacy. He became a foreign member of the Société des Amis des Noirs.
