For this later development in the classical line of political economy, Mr. Keynes's book may fairly be taken as the maturest exposition of the aims and ideals of the science; while Professor Marshall excellently exemplifies the best work that is being done under the guidance of the classical antecedents. As, after a lapse of a dozen or fifteen years from Cairnes's days of full conviction, Mr. Keynes interprets the aims of modern economic science, it has less of the "hypothetical" character assigned it by Cairnes; that is to say, it confines its inquiry less closely to the ascertainment of the normal case and the interpretative subsumption of facts under the normal. It takes fuller account of the genesis and developmental continuity of all features of modern economic life, gives more and closer attention to institutions and their history. This is, no doubt, due, in part at least, to impulse received from German economists; and in so far it also reflects the peculiarly vague and bewildered attitude of protest that characterises the earlier expositions of the historical school. To the same essentially extraneous source is traceable the theoretic blur embodied in Mr. Keynes's attitude of tolerance towards the conception of economics as a "normative" science having to do with "economic ideals," or an "applied economics" having to do with "economic precepts."[13] An inchoate departure from the consistent taxonomic ideals shows itself in the tentative resort to historical and genetic formulations, as well as in Mr. Keynes's pervading inclination to define the scope of the science, not by exclusion of what are conceived to be non-economic phenomena, but by disclosing a point of view from which all phenomena are seen to be economic facts. The science comes to be characterised not by the delimitation of a range of facts, as in Cairnes,[14] but as an inquiry into the bearing which all facts have upon men's economic activity. It is no longer that certain phenomena belong within the science, but rather that the science is concerned with any and all phenomena as seen from the point of view of the economic interest. Mr. Keynes does not go fully to the length which this last proposition indicates. He finds[15] that political economy "treats of the phenomena arising out of the economic activities of mankind in society"; but, while the discussion by which he leads up to this definition might be construed to say that all the activities of mankind in society have an economic bearing, and should therefore come within the view of the science, Mr. Keynes does not carry out his elucidation of the matter to that broad conclusion. Neither can it be said that modern political economy has, in practice, taken on the scope and character which this extreme position would assign it.