Keynes illustrating this doctrine should have cited Professor
Conn, whose name is sometimes associated with a one-sided
historical sect. The dicta and examples of Professors Cohn,
Roscher, Wagner, and other eminent Germans cited by Mr.
Keynes, attest the justice of the following observations :
" We must not . . . exaggerate the opposition between what may be called the classical English school and the new school. . . . The difference is strictly speaking one of degree only; and we find the opposition reduced to a minimum when we compare the actual procedure in the solution of given problems adopted by the best contemporary economists, whether they profess to belong to the new school, or are content to be classed with the old."
Contemplating separately the two functions of inductive reasoning so far as it is possible to distinguish in consideration processes that are inextricably intertwined in action we may first observe that Mr. Keynes in his analysis of the Deductive Method very correctly grounds abstract reasoning on what may be called " hypotheses " : in much the same sense as geometrical axioms have been so called. A perfectly straight line nowhere exists, says Mill ; and the rigidity of the " economic man " is even more hypothetical. At the same time it is not to be supposed that the hypotheses rests upon nothing. The hypothesis of the " economic man," is not, in the present state of society, as arbitrary as the hypothesis which might be entertained of a perfectly altruistic man. You could not say of these two assumptions that they were equally true or false and equally useful.
But, though the foundations of abstract reasoning do not rest upon nothing, they are seldom strong enough by themselves to sustain practical conclusions. To complete the supporting arch there is needed the consilience of specific experience. Mr. Keynes has surveyed with equal eye both parts of the scientific structure. The importance of ascertaining facts, the value of " history " in the wider Greek sense, is not underrated by him. He points out how history of bygone times is useful in illustrating and confirming economic theories. He holds, indeed, that " deduction from elementary principles of human nature also finds some place in the argument." But not in every case; for it is not true " that economic history never provides premisses for the economist or forms the basis of his doctrines."
But, while thus rendering to specific experience the things which belong to her province, Mr. Keynes gives no countenance to the pretensions of a one-sided " Historismus." " Mere description," he justly says, " cannot constitute a science ; and
