Stammler holds forth at length against economics regarded as a science in itself, which has its own laws and which has its source in an original and irreducible economic principle. It is a mistake, he says, to put forward an abstract economic science and subdivide it into economic science relating to the individual and social economic science. There is no ground of union between these two sciences, because the economics of the isolated individual offers us only concepts which are dealt with by the natural sciences and by technology, and is nothing but an assemblage of simple natural observations, explained by means of physiology and individual psychology. Social economics, on the other hand, offers the peculiar and characteristic conditions of the _externally binding rules_, under which activities develop. And what can an economic principle be if not a hypothetical maxim: the man who wishes to secure this or that object of subjective satisfaction must employ these or those means, 'a maxim which is more or less generally obeyed, and sometimes violated'? The dilemma lies then between the natural and technological consideration and the social one: _there is no third thing_. '_Ein Drittes ist nicht da!_' This Stammler frequently reiterates, and always in the same words. But the dilemma (whose unfortunate inspiration he owes to Kant) does not hold, it is a case of a trilemma. Besides the concrete social facts, and besides the technological and natural knowledge, there is a third thing, viz., the economic principle, or hedonistic postulate, as it is preferred to call it. Stammler asserts that this third thing is not _equal in value_ to the two first ones, that it comes as a _secondary_ consideration, and we confess that we do not clearly understand what this means. What he ought to prove is that this principle _can be reduced_ to the two former ones, viz., to the technical or to the social conditions. This he has not done, and indeed we do not know how it could be done. That economics, thus understood, is not social science, we are so much the more inclined to agree since he himself says as much in calling it _pure_ economics, _i.e._, something built up by abstraction from particular facts and hence also from the social fact. But this does not mean that it is not applicable to society, and cannot give rise to inferences in _social economics_. The social factor is then assumed as a medium through which the economic principle displays its influence and produces definite results. Granted the economic principle, and granted, for example, the legal regulation of private property in land, and the existence of land differing in quality, and granted other conditions, then the fact of rent of land arises of necessity. In this and other like examples, which could easily be brought forward, we have laws of social and political economics, _i.e._, deductions from the economic principle acting under given legal conditions. It is true that, under