Voltaire's story is largely an indictment of claims that there are forces that presume a power higher than human intellect or reason. As one of the Enlightenment philosophies, this makes sense.

Multiple such forces lead to sorrow and chaos. First is, perhaps, human biology. Candide is drawn to Cunegonde, whose name may be a sexual pun. From this early desire—the acting on of which leads to Candide's first fall and expulsion from the garden of Westphalia—sexual impulses (Candide's as well as other's) lead to human disease and violence.

More damaging, though, are the impulses to religion. Voltaire was especially contemptuous of religions that said they alone were the "chosen" or "only" inheritors of God's blessings. We see this in the ridicule of Jews and Catholics, whose claims for superiority cause them to harm others. Only the Anabaptist Jacques, who risks himself for others regardless of their religion, is presented as honorable in his religion.

The Thirty Years' War, linked to Ferdinand II's imposition of Catholicism on the Holy Roman Empire's inhabitants, illustrates a nightmarish view of religious zeal that spreads into other areas of public life and fosters increased nationalistic zeal as well.

Such absolute and passionate commitments to abstract ideals impedes a rational consideration of how one is meant to live and how one can best pursue one's happiness. "Cultivating one's garden" becomes both a tangible and a metaphorical message on how to avoid the irrational and how to dedicate oneself to concrete good for oneself and ultimately others around oneself. In this way, free will can exert itself on a meaningful object without harm to others equally seeking to cultivate their garden.

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.