Page:The wealth of nations, volume 1.djvu/44

 one of the most prominent exponents in the direction above referred to. His avowed aim is to amend the laissez-faire economy so as to leave room under certain circumstances for industrial action by government. His work on political economy, published in 1883, is so well known that it is unnecessary to say more about it here.

The late Professor Jevons may be roughly classed as belonging to this school. Value he expresses in terms of what he calls the "final utility" of a commodity, that is the degree of need for it, at the moment, on the part of the consumer. This degree of utility is determined by the supply, and the supply in turn is dependent on the cost of production or the labor expended on it. This, it will be seen, does not absolutely differ from the labor theory of Adam Smith, and still less from Ricardo's; but the mathematical language in which this writer exhibits much of his reasoning is pedantic, and often meaningless. Some of his equations are perhaps useful as a concise mode of expression: others appear to illustrate the impossibility of dealing with abstract ideas by mathematical processes. He is, consequently, often credited with the obviously absurd theory that the ultimate criterion of value is the current estimation of a commodity, or, to use the ill-chosen Jevonian expression, "the final degree of utility." Such a theory, like many others of a similar kind, would confound the essence or the substance of a thing with its mere phenomenal expression or manifestation. No one denies, or ever has denied, that supply and demand enter into the temporary value or the price of anything, but this is very different from confounding the mere expression of value in any particular instance with that value which constitutes the substance of every economic object, and without which that