Final answer:
The individual born into an affluent English family and graduating from Cambridge in 1831 is not identified in the provided excerpts, which mention figures like W. E. B. Du Bois, Henry James, and T. S. Eliot, but with different educational timelines that do not match the specifics of the question.
Step-by-step explanation:
The individual described as born into an affluent English family and graduating from Cambridge University in 1831 is not explicitly named in the provided reference material. The references provided discuss various historical figures and their education, affiliations, and contributions, but none match the precise details of the question. Historical figures such as W. E. B. Du Bois, Henry James, and T. S. Eliot are mentioned as having received an education and coming from affluent backgrounds. Still, their timelines and university associations do not align with the specifics provided for the 1831 Cambridge University graduate. Without a precise name or more specific contextual clues, it is impossible to accurately identify the individual referred to in the question.