The Rentier (n.) multiplies as a nation grows rich — heirs living off their ancestors' labour and retirees off their own past — and since rentiers and lenders are one and the same, interest falls.
The Rentier (n.) cannot become the whole of society: if all capitalists turned money-lenders, interest would collapse and they would be forced back into industry — capitalism cannot run without capitalist production.
A Rentier (n.) is an industrialist who has feathered his nest and withdrawn — the more profitable the cycle, the more of them there are.
Rentier (n.) along with the landlord, the money-lender, and the government and its officials, face the industrial capitalist as buyers bringing money of their own, and what is always forgotten is the source from which they obtained that money.
Rentier (n.) and industrialists can become two classes only because profit can split into two kinds of revenue — the split comes first, the classes grow on it.
Rentier (n.) and lenders are one and the same class, so as the rentiers multiply, interest in old countries must tend to fall.