Wealth and Land
Cantillon begins with a basic definition of wealth: the things that contribute to the maintenance, convenience, and enjoyment of life.
Much of what man consumes is taken from the land - the minerals in the soil itself as well as the substances provided by the plants an animals that dwell upon it.
Man also consumes the resources of rivers and oceans - the water itself, the substances of plants and animals that dwell within it, as well as those creatures and materials on the ocean floor.
However, he considers the bounty of bodies of water to be common to all - a man may own a plot of land, but not a river or an ocean, and Cantillon reckons the resources of water to be "common to all."
It is the labor of man that fashions the raw materials of nature into items of wealth (capable of being used by man to achieve the maintenance, convenience, and enjoyment of life). Few items can be used in their natural state but require some work to fashion them into useful objects. Even those items that can be used in their natural state require the work of man to gather and convey.