In "Candide," the forces of evil in the world deter the exercise of one's free will. Dr. Pangloss, a follower of Gottfried Leibnitz, who attempts to use logic to explain evil, feels that certain laws of "sufficient reason" restrain even God's ability to create a perfect reality. However, even though there is evil, it is still the "best of all possible worlds," Pangloss believes.
It is his character, Martin, who reflects Voltaire's dark wit and pessimism. Rather than believing in "the best of all possible worlds" in which everything that happens is "right," Martin feels that the devil essentially rules the world. Yet Voltaire satirizes the person who can only reject. Yet, although evil does exist to prevent man from exercising his free will at times, he must "cultivate his own garden," essaying to seek some safety within which he can exercise his own choice.