What ideas did this Italian philosopher, poet, essayist, and philologist, who wrote the poem L'infinito, come in touch with while living in a secluded town in the conservative Papal States?
Giacomo Leopardi:  Although he lived in a secluded town in the conservative Papal States, he came in touch with the main ideas of the Enlightenment, and through his own literary evolution, created a remarkable and renowned poetic work, related to the Romantic era.
i don't know