Throughout the voyage, Candide and Martin debate philosophically. Martin explains that he has seen so many misfortunes that he has become a Manichean: he believes that God has abandoned the world, and left it in the hands of an evil being. Martin lists examples of evil and suffering throughout the world. Nevertheless, Candide maintains that there is such a thing as good in the world.
Candide's optimism, though it has returned, is clearly diminished: he no longer argues that the world is good, but rather that there is some good in the world. Candide's slightly darker outlook brings with it a new traveling companion: Martin is Pangloss' pessimistic opposite.
In the midst of their debates, the ship which Candide and Martin are traveling on passes close by two ships engaged in combat. The French ship sinks the Dutch ship, and dozens of men drown. Floating in the wreckage, Candide finds one of his Doradan red sheep. The Dutch ship turns out to have been the ship of the man who had swindled him in Suriname. Triumphant, Candide declares that sometimes crime is punished. Unfazed, Martin responds that “God punished the knave, and the devil has drowned the rest.” Even so, Candide takes the recovery of the red sheep as an omen that he will be reunited with Cunégonde.
Candide sees the battle as evidence that sin is punished, while Martin argues that you can’t see divine justice in a result that involved the loss of many innocent lives. Candide's recovery of the sheep goes along with his recovery of optimism. Sheep represent innocence and purity: traits that are associated with Candide from the narrator's description of him in the first chapter.