Final answer:
Benjamin Franklin had a major regret in his estranged relationship with his son, William, who remained loyal to the British during the American Revolution. Franklin's deist beliefs, emphasizing personal morality over church doctrines, may have also led to internal conflict regarding his life's decisions.
Step-by-step explanation:
Benjamin Franklin, an eminent inventor, writer, and statesman, experienced both the epitome of success and personal regrets. Despite his many accomplishments, Franklin harbored a notable regret regarding his relationship with his son, William Franklin.
William remained a loyalist to the British Crown during the American Revolution, which led to an irreparable rift between father and son, as they never reconciled. Additionally, Franklin's adherence to deism may have influenced his worldview, stressing moral responsibility over strict church doctrines, which could also have been a source of internal conflict, as it went against the more traditional religious beliefs of his era.