The exchangeable value of all commodities rises as the difficulties of their production increase.

In the same manner if any nation wasted part of its wealth, or lost part of its trade, it could not retain the same quantity of circulating medium which it before possessed.

Every transaction in commerce is an independent transaction.

The variation in the value of money, however great, makes no difference in the rate of profits.

After all the fertile land in the immediate neighbourhood of the first settlers were cultivated, if capital and population increased, more food would be required, and it could only be procured from land not so advantageously situated.

The factors left out of the Ricardian equation are falling wages and idle capacity.

Labour, like all other things which are purchased and sold... has its natural and its market price.