PREFACE.
John Stuart Mill * asserted that he had left nothing in the laws of valuelor any future economist to clear up. Until 1871 this statement doubtlesshad much the force of dogma. Even Jevons made preliminary obeisancebefore proceeding to break the ground afresh with the mathematical in-strument. Jevons with characteristic candor expressly disclaimed finality ;tbut few of his followers have realized with his clearness and honesty theneed of further analysis along the lines which be laid down.
The truth is, most persons, not excepting professed economists, are sat-isfied with very hazy notions. How few scholars of the literary and his-torical type retain from their study of mechanics an adequate notion offorce! Muscular experience supplies a concrete and practical conceptionbut gives no inkling of the complicated dependence on space, time, andmass. Only patient mathematical analysis can do that. This natural aver-sion to elaborate and intricate analysis exists in Economics and especiallyin the theory of value. The very foundations of the subject require newanalysis and definition. The dependence of value on utility, disutility, andcommodity, the equality of utilities, the ratio of utilities, the utility of acommodity as a function of the quantity of that commodity solely, or ofthat commodity and others conjointly, are subjects, the neglect of whichis sure to leaye value half understood, and the mastery of which claims,therefore, the first and most patient effort of the economic scientist.
These form the subject matter of the following memoir which is a studyby mathematical methods of the determination of value and prices.
Much germane to the subject has been omitted because already elabo-rated by others. Cases of discontinuity belong to almost every step, tomodify or extend the continuous case. But the application of this cor-rection has been thoroughly worked out by Auspitz und Lieben. Multipleequilibrium and monopoly value are omitted for a similar reason.
The two books which have influenced me most are Jevons : “Theory ofPolitical Economy,” and Auspitz und Lieben: “Untersuchungen ueber dieTheorie des Preises.” To the former I owe the idea of marginal utility andof mathematical treatment in general, to the latter the clear conception ofthe “symmetry” of supply and demand and the use of rate of commodityin place of absolute commodity, and to both many minor obligations.
t Pol. Eeon., Pref. 3rd ed.