in the theory of value and prices.
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of the differential calculus ; especially in its application to thedetermination of maxima and minima .” [It seems to] “supply topolitical economy what Whewell would have called ‘appropriateand clear ’ conceptions. * * * Algebra and geometry are to ordinarylanguage in political economy somewhat as quaternions are toordinary algebraic geometry in mathematical physics ” (QuotesMaxwell on quaternions : “ I am convinced that the introduction ofthe ideas as distinguished from the operations and methods * * *will be of great use.”)
Again :* “ I do not mean that the mathematical method shouldform part of the curriculum as we make Greek obligatory for thestudents of philosophy. But may we not hope that the higher pathwill sometimes be pursued by those candidates who offer specialsubjects for examination.”
Marshall :\ “ It is not easy to get a clear full view of continuityin this aspect without the aid either of mathematical symbols ordiagrams. * * * * experience seems to show that they give a firmergrasp of many important principles than can be got without theiraid ; and there are many problems of pure theory, which no onewho' has once learnt to use diagrams will willingly handle in anyother way.
The chief use of pure mathematics in economic questions seemsto be in helping a person to write down quickly, shortly and exactly,some of his thoughts for his own use : and to make sure that he hasenough, and only enough, premises for his conclusions (r. e. that hisequations are neither m6re nor less in number than his unknowns).But when a great many symbols have to be used, they become verylaborious to any one but the writer himself. And though Ooumot’sgenius must give a new mental activity to every one who passesthrough his hands, and mathematicians of calibre similar to hismay use their favorite weapons in clearing a way for themselves tothe center of some of those difficult problems of economic theory,of which only the outer fringe has yet been touched ; yet it isdoubtful whether any one spends his time well in reading lengthytranslations of economic doctrines into mathematics, that have notbeen made by himself. A few specimens of those applications of ‘mathematical language which have proved most useful for my ownpurpose have, however, been added in an Appendix.”