114 Irving Fishei—Mathematical investigations

Wicksteed “The diagrammatic method of studying economicsmay be regarded from three points of view : (I) many teachers findin it a stimulating and helpful appeal to the eye and use it as ashort 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 rigorouslyanalysing and investigating the results that flow from them. (HI)a very few investigators (among whom I think we must rankJevons ), have hoped ultimately to pass beyond the field of purehypotheses and analysis and to build up constructive results uponempirical curves of economic phenomena established by observa-tion.”

Foxioell\ [speaking of the mathematics of Jevons and Marshall] :“ It has made it impossible for the educated economist to mistakethe limits of theory and practice or to repeat the confusion whichbrought the study into discredit and almost arrested its growth.”

Auspitz und Lieben:\ “ Wir haben uns bei unseren Untersuch-ungen der analytischen Methode und namentlich der graphischenDarstellung bediehnt, nicht nur weil sich diese BehandlungsweiseUberall, wo sie tlberhaupt anwendbar ist, und namentlich in dennaturwissenschaftlichen Fachern gl&nzend bewahrt hat, sondernliauptsachlich auch darum weil sie eine Prazision mit sich bringt,welche alle aus vieldeutigen W ort-definitionen entspringender Miss-verstandnisse ausschliest.”

Edgeworth .•§ * * * “ the various effects of a tax or other impedi-ment, which most students find it so difficult to trace in Mill ’s 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 toconvey by way of a particular instance that it is possible for anation by a judiciously regulated tariff, to benefit itself at theexpense of the foreigner. The truth in its generality is more clearlycontemplated by the aid of diagrams. * * * * There seems to be anatural affinity between the phenomena of supply and demand, andsome of the fundamental conceptions of mathematics, such as therelation between function and variable * * * and the first principle

* On certain passages in Jevons’ “ Theory of pol. econ.” Quart. Jour. Econ. ,April, ’89, p. 293.

f The Economic Movement in England, Quart. Jour. Econ. , Oct., ’88.

| Untersuchungen. Preface, p. xiii.

Address before Brit. Assoc, as president of the section on economic scienceand statistics. Published in Nature , Sept. 19, ’89, p. 497.