The cultural aspects in this novel have to do with early 19th century England. In villages like the fictional Raveloe, people lived rural lives that were pretty much self-suffcient. As the Industrial Revolution continued, people began to move to the cities in droves for better work. The setting of the novel reflects the culture of rural England and the town and its inhabitants are described in great detail.
Also, if you are going to discuss culture, pay close attention to the subplot involving Godfrey Cass and the Cass family. English class structure figures into the plot because when Godfrey marries below his class, the conflict that develops between Godfrey and Dunsey has much to say about families and culture during the time period.
Finally, religion is part of the culture. The church was an important center of rural life. So much so that Silas is forced to leave town after being falsely accused by a church member. Everyone knew everyone else's business and Silas could not suffer the treatment of his fellow church members who would always look at him with suspicion.
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Some of the massive changes that were taking place at the time were the invention of various machines (particularly the power loom) that changed the relationship between producers and owners. The changes this wrought in the culture are important, particularly as they start to create a further gap between producers particularly because skilled labor could now be replaced by unskilled labor and machines.
In some ways, certain themes of the book run along with and counter to some of these developments. Silas himself goes through a period where he is focused only on making money, and it is only in the loss of much of it that he regains his passion for nature and some of the things that brought him great pleasure before. This can be linked to a society that in many ways became more concerned with money over almost anything else and some of the problems and changes that brought about.