Question: What does Thaïs and Thaïs have in common?

Context paragraphs:
Thaïs (novel): Thaïs is a novel by French writer Anatole France, published in 1890.  It is based on events in the life of Saint Thaïs of Egypt, a legendary convert to Christianity who is said to have lived in the 4th century.  It was the inspiration for the opera of the same name by Jules Massenet.

Thaïs (opera): Thaïs (] ) is an opera, a "comédie lyrique" in three acts and seven tableaux, by Jules Massenet to a French libretto by Louis Gallet, based on the novel "Thaïs" by Anatole France.  It was first performed at the Opéra Garnier in Paris on 16 March 1894, starring the American soprano Sibyl Sanderson, for whom Massenet had written the title role.  The original production was directed by Alexandre Lapissida, with costumes designed by Charles Bianchini and sets by Marcel Jambon (act 1, scene 1; act 3) and Eugène Carpezat (act 1, scene 2; act 2).  The opera was later revised by the composer and was premiered at the same opera house on 13 April 1898.

Supporting paragraphs: Thaïs (novel) Thaïs (opera)
Answer: opera of the same name