XX.19 On commerce in a monarchy
It is contrary to the spirit of commerce for it to be carried on by nobility in a monarchy. “That would be damaging to the cities,” say emperors Honorius and Theodosius, “and take away the means of buying and selling between merchants and plebeians.” 
It is against the spirit of monarchy for commerce to be carried on by nobility. The custom that allowed commerce to the nobility in England is one of the things that has most contributed to the weakening of the monarchical government.