Oxford is a place that is just alluded to in North and South. It's where Mr. Hale went to school and where his old friend from school, Mr. Bell, lives. This place sort of represents Mr. Bell, who is the one who suggests to Mr. Hale that he and his family should move to Milton in the first place. 

In the early to mid 1800s, people were starting to question the practicality of studying at Oxford, while Oxford pushed back against this idea that the focus of study needed to be moved away from more philosophical study. In North and South, the question of whether or not educational study is worthwhile, especially in a place like Milton, gets brought up a lot. Mrs. Thornton doesn't understand why Mr. Thornton cares to take tutoring lessons, and people vary on their opinions toward Mr. Hale as a tutor because that job doesn't mean much in Milton. People respect him, but at the same time know there isn't a place for philosophy to thrive there. Oxford at this time was also disconnecting from any relationship with the Church, so this helps to see why Gaskell chose to have Mr. Bell represent this place, since he encourages Mr. Hale to leave his parsonage when he doubts. 

The cultural clash between we see through the Industrial Revolution and education symbolizes that, where progress used to be found in education, progress is now found in industrialization. People are starting to ask, where does education fit into this world if it does at all? What happens to people like Mr. Hale? Even through characters like Nicholas Higgins who represents Milton's working class struggles with knowing education isn't necessarily valuable in Milton, he can't be equal with the people who run the manufactures because he isn't educated. Even the spiritual doubts that come up often in this novel have to do with literacy and comprehending intangible ideas; someone like Higgins can't trust someone else's interpretation of the Bible. He would rather read it himself and make his own decisions about it.