Complex sentence: "L'art pour l'art" (translated as "art for art's sake") is credited to Théophile Gautier (1811--1872), who was the first to adopt the phrase as a slogan.
Split into simpler sentences: L'art pour l'art (translated as "art for art's sake") is credited to Théophile Gautier (1811--1872). Gautier, however, was the first to adopt the phrase as a slogan.