Thomas was born in Marseilles, and was a student of Alexis Paccard and Leon Vaudoyer at the École des Beaux-Arts in Paris. He won the first Prix de Rome in 1870, and became the youngest winner of the French Academy in Rome from February 15, 1871 to December 31, 1874. In 1875 he studied the Temple of Apollo at Miletus, and his study of the Temple of Athena at Priene earned him a medal at the Exposition Universelle (1878).
- Louis Auvray, Revue artistique et littéraire, 1869, Paris : Aux bureaux de la revue, page 63.
- André Gabriel, Tarek Charara, Guide de l'architecture des monuments de Paris, Paris : Alternatives, 1998, page 281. ISBN 2-86227-148-9.