From everything I can see here, he lived in and described medieval society in England. Was it corrupt? Did it work well for most of the people? Did it work well for only the upper levels of the society? You'd need to read the work to know what he was thinking.
John of Salisbury: http://en.wikipedia.org/wiki/John_of_Salisbury
Middle Ages (aka Medieval times): http://en.wikipedia.org/wiki/Middle_ages
In John of Salisbury's 12th century "The Body Social," John rehearses the well-known conceit in which various members of society are compared to the parts of the human body. The prince is the head, the Senate the heart, judges the eyes. And those who are in charge of business? "Financial officers and keepers ... may be compared with the stomach and the intestines."
You would have to read the work to be able to write the paper well; it's apparently available in an anthology called The Portable Medieval Reader.
The problem is that the instructor makes it seem as if all that we need to know with regards to describing the society can come from "The Body Social" alone.
So, I guess a reasonable question thereafter might be: what types of society were/are there? This is the first time that I've heard such a question posed.
If you read this one
(which is 7th in the Google results above), you'll see part of an essay written that uses "The Body Social" to describe the situation in Leningrad in 1941. So yes, John of Salisbury's work can be used to help describe just about any society you care to apply it to -- with different results for each society.
If the question is asking which society HE is describing, however, he can only be describing the one in which he lived. Then you'd need to research English society in Salisbury in the time when the author was an adult (when he wrote this).