Clement XIII's pontificate will be repeatedly disturbed by disputes respecting the pressures to suppress the Jesuits coming from the progressive Enlightenment circles of the philosophes in France.

Clement XIII places the Encyclopédie of D'Alembert and Diderot on the Index Librorum Prohibitorum, but this index is not as effective as it had been in the previous century.

More unexpected resistance comes from the less progressive courts of Spain, the Two Sicilies, and Portugal.

The reforming minister of Joseph I of Portugal, the future Marquis of Pombal, expels the Jesuits from Portugal in 1759 and transports them all to Civitavecchia, as a "gift for the Pope."