Kościuszko did not give up on improving his military knowledge. He audited lectures for five years and frequented the libraries of the Paris military academies. His exposure to the French Enlightenment, along with the religious tolerance practiced in the Polish–Lithuanian Commonwealth, strongly influenced his later career. The French economic theory of physiocracy made a particularly strong impression on his thinking. He also developed his artistic skills, and while his career would take him in a different direction, all his life he continued drawing and painting.