This new nobility gradually became as well marked and as exclusive as the old patriciate.
But if differed from the old patriciate in this, that, while the privileges of the old patriciate rested on law, or perhaps rather on immemorial custom, the privileges of the new nobility rested wholly on a sentiment of which men could remember the beginning.
That is to say, it consisted of the remains of the old patriciate, together with those plebeian families any members of which had been chosen to curule offices.
The cause of the difference seems to be that, while the origin of the patriciate was exactly the same at Rome and at Athens, the origin of the commons was different.
The Spartan patriciate could afford to disfranchise some of its own members.