During his studies, he was influenced by the ideas of Enlightenment and then the French Revolution. Francia was disgusted by Paraguay's "casta system", which was imposed by Spain, and as a lawyer, he would defend the less fortunate against the affluent. A devotee of the Enlightenment and the French Revolution, a keen reader of Voltaire, Jean-Jacques Rousseau, and the French Encyclopedists, Francia had the largest library in Asunción. His interest in astronomy, combined with his knowledge of French and other subjects considered arcane in Asunción, caused some superstitious Paraguayans to regard him as a wizard who could predict the future.