ten lire, thus attaining the maximum satisfaction for himself with the least means that is naturally at his disposal on that occasion. The individual B, making boast of his magnificence, lights his cigarette with a banknote of a hundred lire, thus likewise attaining for himself the greatest satisfaction to which he aspired, with the least means that he possessed, namely, by burning that paper money. But if this be so, we have here a question, not of greatest and least, but of individual ends and of relative means adopted, or (owing to the unity of means and ends already noted), of actions individually different. [Sidenote: _Economic Science founded upon empirical concepts, but not empirical or descriptive._] Certainly, it is quite possible to abstract in a greater or less measure from the infinite variety of actions and to construct a series of types or concepts of classes and of empirical laws, thus rendering uniform the formless, within certain limits. Thus is obtained the concept of bread and of the consumption of bread, and of the various portions of bread and of other objects, for which a portion of bread can be exchanged, and so on. In this way are full philosophico-historical reality and the method of logical necessity and of realistic observation of facts abandoned for a feigned reality and for a method of arbitrary choice, which, as we know, has its good reasons for existing in the human spirit, and does great service by the swift recall and easy control of the requisite knowledge. And if Economy consisted in the establishment of a series of laws and examples in the above sense (or when understood in this way), it would join the number of the descriptive disciplines; and in that case there would be no necessity for us to speak of it further, for it would suffice to refer back to what has already been said of the relations of the Philosophy of the practical with practical Description, classes, rules, and casuistic. But economic Science is not descriptive, and is not developed according to the following formula: goods are divided into the classes _a, b, c, d, e,_ etc., and the class _a_ is exchanged with the class _b_ in the proportion of I to 3, the class _b_ with the class _c_ in the proportion of I to 5, etc. In such a formula is always understood the _up and down,_ the _for the most part,_ and _the very nearly:_ the classes _with their ups and downs_ are as stated; the exchanges take place _for the most part_ in the proportions stated; if things are to-day _very nearly_ thus, to-morrow they will be so _very nearly,_ in a different way.