Who is Henri Fagerolles from The Masterpiece and what is their importance?

Henri Fagerolles is a true child of the Paris streets. He joined the group of radical, and he has great ideas about reality in art, but he is sadly willing to compromise his ideals in order to further his career. Enamored by money and position, he allows himself to be used by Irma Bécot, a successful courtesan, known throughout Paris for her palatial mansion and fine clothes.