What central theme is reflected by the lessons Candide has learned? How does this theme help Voltaire achieve his purpose for writing?

's
aim in  is to disprove the philosopher Leibniz's optimism. This held that
our world is the best of all possible worlds and also suggests that any tragedies in this world
in some way work toward some greater good. Voltaire believed there was simply too much
corruption, hardship, andin the world around him to justify such a positive perspective.
In Candide, Voltaire has his title character travel across continents and
experience the foibles of multiple societies in order to prove that this "best of all
possible worlds" simply does not exist.

Pangloss, the young Candide's
tutor and thus his only source of education, is meant as a caricature of Leibniz. Throughout the
novel, Pangloss repeats his belief that we live in the best of all possible worlds, regardless
of circumstances that seem to show quite the opposite. Pangloss himself suffers tremendously and
sees others die and suffer needlessly, but he blindly repeats his philosophy independent of
those events. Candide, for a time, also repeats this philosophy, but he eventually matures a bit
through both what he witnesses firsthand and through his exposure to another philosopher,
Martin, who is a pessimist (but in the world of the novel, seems to have a much more reasonable
take on the world than does Pangloss). At the end of the novel, Pangloss is still spouting his
theory, but Candide has changed his tune: he now only wants to "tend the garden,"
believing that productive work in the only way to function in this nonsensically violent and
corrupt world. Candide learns that "the best of all possible worlds" does not exist,
so it may be best to avoid the outside world as much as possible.