F.— ECONOMIC SCIENCE AND STATISTICS. 129 



least, indeterminate. But ray reflections upon the subject convince me 

 that there is a field of deliberation and inquiry for economists which has, 

 so far, only been casually and cursorily surveyed, but which uuist be 

 carefully explored before the economic case can be 2)Tesented. 



n. Methods of Inquiry. 



It has often and rightly been remarked that economics sufters as a 

 science because it is unable to avail itself of the method of agreement and 

 difference as an engine of discovery. The isolation of the presence of a 

 I^articular factor, in order to discern if some effect or concomitant is always 

 present ; the isolation of its absence, to determine whether the supposed 

 eSect or concomitant is always absent ; or, failing isolation, the association 

 of that factor with a wide variety of others, and the observation of absence 

 or presence of the antecedent with the presence or absence of the conse- 

 quent ; or again, the establishment of a quantitative relationship so that 

 small and large ' doses ' of the antecedent are accompanied by small and 

 large doses respectively of the consequent : all these methods of direct 

 experimentation ox^en to the phj'sical sciences are lacking to the economist. 

 At the most he can follow by induction, with all the dangers bi the false 

 cause or the multiple cause, from observation of conditions existing at 

 the same moment in different places, or at the same place at different 

 times. If he is told that a given economic condition is brought about by 

 a particular factor, such as a law or a social custom, he is seldom in a 

 position to try the absence of that law or custom directly. Even if he 

 docs, the other conditions will not remain constant, and a logical weakness, 

 if not a common-sense doubt, will exist. It will exist especially if some 

 human likes or dislikes are involved, with consequent sectional feeling or 

 sentiment. The precise economic effect of Prohibition, for example, is 

 open to dispute because of the difficulty of dispassionate observation and 

 reasoning where feelings as distinct from intellectual processes are involved. 



But the economist has one advantage over the physicist. If the 

 latter cannot actually remove the element in question from his phenomena 

 or introduce it at will, he is usually at a loss. It is not generally open to 

 him to imagine what would follow from its absence or presence, or to 

 reason from analogy. (And here I am not overlooking the immense 

 advances made by postulating, from observation of what are imagined 

 to be effects, certain qualities which any factor, operating as a cause, 

 would need to possess, and then elaborating what would follow from such 

 qualities if they really existed, and finding, under other or dift'erent circum- 

 stances, that those prognostications are verified. Working hypotheses of 

 this order are the commonplaces of science.) I am, rather, referring to 

 another kind of postulation from experience. We see about us a certain 

 set of economic conditions, and co-existent a certain law or custom. 

 Interest or ignorance, or superficial observation, or political prejudice, 

 may urge that they are related as cause and effect. But the economist 

 has to be wary and watchful. It is open to him to imagine an economic 

 world free from such a law or custom, and, by what he knows as to the 

 behaviour of the average man under the hodonic impulse, to work out a 

 new or hypothetical economic system. This type of economic psychology 

 is rendered more possible if there are, in fact, alreadv in existence a number 



1926 " K_ 



