Anti-Enlightenment?

Candide, Martin, Pangloss, and other chacters spend the entirety of the narrative arguing about philosophy and never really getting anywhere.  Martin's pessimism is never shaken, Candide never seems to be certain of Pangloss's philosophy, and Pangloss, even though he realizes he is wrong, maintains his position simply out of stubborness.  Voltaire repeatedly mocks the philosophers of his time directly and indirectly, particularly Leibniz.  In the last chapter Martin says, "Let's work without speculation, it's the only way of rendering life bearable."  In this, Voltaire seems to be satirizing human nature and, by consequence, the Enlightenment.  The fact that the characters are stagnant and never truely change their opinions and that the reclussive Turk they meet in the last chapter seems to be the only content character in the entire story seems to imply that the idea that there is no limit on human progress or human understanding is intrinsically false.