There are elements in Crusoe's environment that contribute to his welfare but which are not now scarce with regard to his ends. Nonscarcity is also called "superabundance."
For example, the air he breathes contributes to his welfare. But it is immediately available to him in such abundance that he does not need to take any action with regard to it.
However, this was not the case an hour ago, when, immediately after his shipwreck, he was drowning. At that time, air was not abundant. It was scarce. So he had to take action with regard to it. He had to purposefully swim to the surface of the water and take hold of a piece of flotsam in order to get air. At that time air was an object of action.
But now on the island, air is superabundant (nonscarce), and so it requires no action. Therefore, it is not a means (good). Superabundant things are "not the object of any action. They are general conditions of human welfare."[15]
However, Crusoe's personal energy and time are scarce, and therefore they are means (goods) and objects of human action.
Means are necessarily always limited, i.e., scarce with regard to the services for which man wants to use them. If this were not the case, there would not be any action with regard to them. Where man is not restrained by the insufficient quantity of things available, there is no need for any action.[16]