"It is a truth universally acknowledged," is the famous opening line from Jane Austen's novel "Pride and Prejudice." The full sentence completes the thought:

"It is a truth universally acknowledged, that a single man in possession of a good fortune, must be in want of a wife."

This opening line sets up the context of societal expectations and matrimonial concerns in 19th-century England, introducing themes that the novel will explore throughout its narrative.