They are accused of being a nation in the nation, of being...a kind of international sect without real homeland; above all, of carrying in their blood a need for lucre, a love for money, a prodigious intelligence for business which, in less than a century, has led to the accumulation of enormous fortunes in their hands. But these separatist Jews, so poorly absorbed into the nation, overly avid, obsessed with the conquest of gold, are in fact the creation of Christians, the work of our eighteen hundred years of imbecilic persecution.

I don't think we need to show off such a person-fake Alsatian and fake Catholic, who exploits the parish priests, the good sisters, the religious communities, and lets it be known that he is in love with you, as if a daughter of the Rouvres might consider a usurer from Frankfurt, and a married man too! 

Aaron is described as "a small round man with a blotchy face, perspiring and pot-bellied, with the manner of a Frankfurt money-lender, despite the English cut of his coat, the red gardenia in his button-hole, despite the shine on his hat and his shoes". He is absurd and repulsive but he is rich and when Maud's cynical scheme to marry Maxime and yet retain Julien as her lover collapses, she sells herself to Aaron. "There will be some bad years...but I'll know how to break him in, the Jew! He is married, but one can divorce. And one day, who knows? No one quibbles about the past of the wife of a banker when she has an income of eight hundred thousand francs."