I’m working on a literature writing question and need an explanation and answer to help me learn.

Do a web search on “black humor.”  How does  Voltaire use black humor?  There are many examples, but use two or three  in your essay.  Does Voltaire’s black humor serve a socially useful  function?  Or is it, finally, just mean-spirited and cold?  Are there  places where Voltaire, in your opinion, goes over the line?  And how do  you draw that line?  Or do you think there is no line?  Explore.