Carl Menger

There must be forces in operation within one’s organism that remedy the disturbed state, or there must be external things acting upon it that by their nature are capable of producing the state we call satisfaction of our needs.

1. A human need.

2. Such properties as render the thing capable of being brought into a causal connection with the satisfaction of this need.

3. Human knowledge of this causal connection.

4. Command of the thing sufficient to direct it to the satisfaction of the need.

Our investigation thus far yields, as a first result, the proposition that the goods-character of goods of second order is dependent upon complementary goods of the same order being available to men with respect to the production of at least one good of first order.