114 Irving Fisher — Mathematical investigations 



Wicksteed .'"^ "The diagrammatic method of studying economics 

 may be regarded from three points of view : (I) many teachers find 

 in it a stimulating and helpful appeal to the eye and use it as a 

 short and telling way of making statements and registering results. 

 (II) a few students treat it as a potent instrument for giving pre- 

 cision to hypotheses in the first instance and then for rigorously 

 analysing and investigating the results that flow from them. (Ill) 

 a very few investigators (among whom I think Ave must rank 

 Jevons), have hoped ultimately to pass beyond the field of pure 

 hypotheses and analysis and to build up constructive results upon 

 empirical curves of economic phenomena established by observa- 

 tion." 



Fox'Loell\ [speaking of the mathematics of Jevons and Marshall] : 

 " It has made it impossible for the educated economist to mistake 

 the limits of theor}^ and practice or to repeat the confusion which 

 brought the study into discredit and almost arrested its growth." 



Auspitz unci Liehen:\ " Wir haben uns bei unseren Untersuch- 

 ungen der analytischen Methode und namentlich der graphischen 

 Darstellung bediehnt, nicht nur weil sich diese Behandlungsweise 

 iiberall, wo sie iiberhaupt anwendbar ist, und namentlich in den 

 naturwissenschaftlichen Fachern glanzend bewahrt hat, sondern 

 hauptsilchlich auch darum weil sie eine Prazision mit sich bringt, 

 welche alle aus vieldeutigen Wort-definitionen entspringender Miss- 

 verstiindnisse ausschliest." 



Edgetcorth .-g * * * " the various effects of a tax or other impedi- 

 ment, which most students find it so difficult to trace in MilFs labori- 

 ous chapters, are visible almost at a glance by the aid of the mathe- 

 matical instrument. It takes Prof. Sidgwick a good many words to 

 convey by Avay of a particular instance that it is possible for a 

 nation by a judiciously regulated tariff, to benefit itself at the 

 expense of the foreigner. The truth in its generality is more clearly 

 contemplated by the aid of diagrams. * * * ^ There seems to be a 

 natural affinity between the phenomena of supply and demand, and 

 some of the fundamental conceptions of mathematics, such as the 

 relation between function and variable * * * and the first principle 



*0n certain passages in Jevons' "Theory of pol. eeon." Quart. Jour. Econ., 

 April, '89, p. 293. 



f The Economic Movement in England, Quart. Jour. Eeon., Oct., '88. 



X Untersuchuugen. Preface, p. xiii. 



^ Address before Brit. Assoc, as president of the section on economic science 

 and statistics. PiTblished in Nutxuc, Sept. 19, '89, p. 497. 



