Why? Because. The most terrible of motives, the most unanswerable of retorts — Because.
[Pourquoi ? Parce que. Le plus terrible des motifs et la plus indiscutable des réponses: Parce que.]
Victor Hugo (1802-1885) French writer
Les Misérables, Part 4 “St. Denis,” Book 6 “Little Gavroche,” ch. 1 (4.6.1) (1862) [tr. Hapgood (1887)]
Sourcing, notes, alternate translations: wist.info/hugo-victor/76086/