As a mathematical discipline, economic Science is ultimately _quantitative,_ and it remains so, even when it makes use of the smallest possible number of numerical and algebraical signs (even when it is not _mathematical Economy_ in the strict sense of the word). The attempts, both of philosophism and historicism, which claim to deny Economy, by criticizing its abstractness and its arbitrariness, and to make it philosophical (or as they say _psychological_) and historical are therefore to be reproved. If Economy do not give the universal truth of Philosophy, nor the particular truth of History, Philosophy and History are in their turn incapable of making the smallest calculation: if Economy have not eyes for the true, Philosophy and History have not arms to break and to dominate the waves of fact, which would oppress man with their importunity and finally prevent him from seeing. Hence the absurdity of _philosophism_ and _historicism_; hence too, the sound tendency of Economy to constitute itself _pure_ Economy, free of _practical_ questions, which are also, it is clear, historical, not abstract and scientific questions. [Sidenote: _The two degenerations: extreme abstracticism and empiristical disaggregation._] But economy has in itself other enemies besides these that are external, in so far as it is certainly a mathematical discipline, but an applied mathematic, that is to say, one that assumes empirical data. These empirical data can be infinitely multiplied, and hence result infinite economic propositions, each distinct from the other; and on the other hand, they can be regrouped, simplified and unified, so as finally to return to the indistinct _x._ If the first tendency prevail, we have what is called economic empiricism, a cumbrous mass of disaggregated propositions; if the second, a very general formula, which sometimes does not even preserve the smallest vestige of that concept of human action from which it started, and becomes altogether confounded with the formulæ of arithmetic, of algebra and of the calculus. Sound economic Science must be at once abstract and empirical, in accordance with its nature, connecting and unifying disaggregate propositions; but it must not allow distinction to be lost in unity, for the one is as necessary as the other. Those who are unacquainted with the generalities of Economic Science, and those acquainted only with its details, are alike incapable, though for different reasons, of calculating the economic consequences of a fact. The first see all the facts as one single fact, the second, all the facts as different, without any arrangement by similarities and hierarchies. The question as to the relative proportion of generalities and particulars to be given in treatises, is one that has been much discussed, but since this has only a didascalic and pedagogic importance, it is only possible to answer it, case for case, according to the nature of the various scholastic institutions that are held in