It is necessary to classify the vaious goods according to their inherent characteristics. To learn the place that each good occupies in the causal nexus of goods. And finally to discover the economic laws that they are subject to.
Our well being at any point of time to the extent that it depends upon the satisfaction of our needs is assured if we have at our disposal the goods required for their direct satisfaction.
If we have sufficient amount of bread, we are in a position to satisfy our need for food directly. The causal connection between the bread and satisfaction of our need is rather a direct one.
The same applies to other goods that can be used to satisfy our direct needs. we call them goods of first order.
We find a large number of things which posses the goods characters but are not put in direct causal connection to satisfy our needs. NOT goods of first order like flour, salt, labour, etc...
All these and by far more are incapable of directly satisfying human needs.
They are still treated as goods in human economy just like goods of first order due to the fact that they serve to produce other goods of first order to satisfy human needs. Hence indirectly capable of satisfying human needs.
The same goods-character that apply to goods of first order apply to goods of second order and can be put in an indirect causal connection to satisfy human needs.
Goods having an indirect causal relationship with the satisfaction of human needs differ in the closeness of this relationship. But it has shown that this difference doesn't affect the goods-character in anyway.
To designate the order of a particular good is to indicate only that this good in some particular employment has a closer or distant causal relationship to satisfy human need. Hence the order of a good is nothing inherent in itself.0