Candide hires Martin, a downtrodden scholar, to accompany him on his journey from Buenos Aires to France precisely because of Martin’s misfortune and pessimism. Martin embodies the polar opposite philosophical standpoint of Pangloss and Candide’s. Martin believes that the world is inherently evil, that any semblance of good is fleeting and that even what appears happy is undoubtedly not.
So what is Martin’s philosophy, exactly? Martin reveals that he is a Manichaeist. Basically, Martin believes that God has abandoned the world, which is now consumed by evil and suffering. He has great contempt for the Optimist viewpoint that evil is only an illusion, merely shadows in a beautiful picture.
Although Martin’s philosophy is as extreme as Pangloss’s and is sometimes flawed, his worldview has a much stronger empirical basis in the context of the novel. This is a fancy way of saying that, given all the awful things that happen in the book, Martin’s argument is a lot stronger than Candide’s.
Martin is also much less absorbed in philosophy than Pangloss and Candide, perhaps because of the hopelessness dictated by his worldview. He comments willingly in response to Candide’s probes, but does not pause to philosophize in the midst of crisis. Basically, he’s a reality check to Candide’s philosophical daydreaming.