Economy: Which economic class(es) do you think contributed most to the Enlightenment? Why?

Answer 1

The upper middle classes.

Because the Enlightenment was primarily a movement among thinkers, the intelligentsia, e.g. Rousseau and John Stuart Mill. In those days, it was extremely rare for working and lower-middle class people to be able to get the education to join the intelligentsia, even if they had the IQ; and by and large the upper classes (royalty, aristocracy, gentry) didn't want to.