Homework: How do the following three examples express the Enlightenment ideal of man as a rational being? There are several aspects to consider including formality and patterns and balance, light versus darkness, lightness vs heaviness, optimism vs pessimism, and the relationship of reason & emotion. Emphasize your points by comparison to contrasting musical examples we have heard in class before. (If you wish, you might also comment on the similarity or difference of these three pieces from the point of view of national style.)
I highly recommend the film "Amadeus" as an introduction to the Classical period and to Mozart and his rival Salieri. With regard to the dramatization of music and the explanation of music in its full meaning and context, it is the best film ever made. I also recommend the book "The Enlightenment" by Peter Gay.
The chart below is from Google NGram, which measures the usage of words in books over time. An interesting way to show the varying priority and attention given to the concept of reason over time! (Of course this measures the usage of the word in all its senses, not especially the concept of man's ability to form abstractions. But the other usages are of "reason", as in "He didn't have a good reason for doing that," are closely related.)