When Candide goes for a walk, he comes across a man with syphilis. The man turns out to be Pangloss, and the two have a tearful reunion. Pangloss informs Candide that Bulgarians invaded Thunder-ten-tronckh, raping Cunégonde, destroying the castle, and killing everyone. Candide begins to doubt that he lives in the “best of all possible worlds,” after all.
This is the first of many times in the novel that a character returns and is not immediately recognized, usually because unfortunate circumstances have changed them. The tragedy of what has happened in Thunder-ten-tronckh is made comic by irony and exaggeration: everything has gone suddenly and horribly wrong in the “best of all possible baronies.”
The conversation turns to Pangloss' syphilis. When Candide asks what the “sufficient cause,” of his illness was, Pangloss explains that he received the disease from Paquette. He then goes on to list all the people the disease passed through before reaching him, beginning with companions of Christopher Columbus. Pangloss explains that syphilis, which comes from America, was necessary so that luxury goods like chocolate and cochineal—an insect dye—could be brought to Europe.
Pangloss' long genealogy of his syphilis parodies the importance of genealogy to the aristocracy. Tracing the pedigree of your syphilis back to Christopher Columbus obviously proves nothing important, and the novel suggests that aristocratic pedigree is no different. This is also the first of many attempts to make the philosophy of optimism fit with the world's cruelty: Pangloss insists that his syphilis is somehow intrinsically connected to the many good things which come from the Americas.
Candide convinces Jacques the Anabaptist to pay for Pangloss' cure. Pangloss loses an eye and an ear to syphilis, but recovers. After two months, Jacques brings Pangloss and Candide to Lisbon. On the way there, they argue over whether or not everything in nature is good. Jacques argues that men have corrupted nature by creating such awful things as cannons, bayonets, and bankruptcy—which God did not place on Earth. Pangloss maintains that “private misfortunes make the general good.”
Pangloss' loss of an eye and an ear represents his detachment from the real world. Since nothing he hears, sees, or experiences can shake him from his doctrine of optimism, his senses come to seem unnecessary. Pangloss' argument with Jacques further emphasizes this detachment: while Jacques speaks about specific evils in the world, Pangloss responds by appealing to a “general good,” which he never defines.