The fundamental idea of the labour theory is foreign to no one；everybody has frequently enough had practical occasion to apply it. But for this， Ricardo's system would never have obtained its great hold， and this circumstance may prepare us to expect in the future ever new formulations of the labour theory， should it not be possible meantime to purify theoretically the popular view， and lead it back from its exaggerations， which are easily traceable to the imperfection of popular reasoning， into its true and incontestable form.(1*)NOTES：
1. In his Werththeorien und Werthgesetz， in Conrad's Jahrbucher for 1888， W. Scharling， one of the latest writers upon the theory of value， has again traced it to the fundamental motive of the labour theory， although with considerable amplification and modification. He derives value from the difficulty of attainment， or， more exactly， from the amount of effort which he who wishes to acquire an object is spared by attaining his end through exchange. I shall not at this point dwell on Scharling's positive work， but rather refer the reader， in regard to his fundamental motif， to the succeeding chapter. Only， in passing， I may note that， among the efforts which are to give the standard to price， Scharling includes that (p. 558) "which it costs (at an auction)to distance other bidders，" or what it costs "to overcome an owner's disinclination to part from his goods." Both of these efforts have their origin in nothing else than the payment of that very price whose standard they are supposed to explain. In this sense there might be included among the difficulties of attainment the fact that thing must be paid for with money， while people are bound to be economical with money. His views on the theory of marginal utility are given， in an illustration cited by B鰄m-Bawerk， of a boy to whom "the pleasure of eating an apple is more than seven times but less than eight times that of eating a plum." "Let us Suppose" continues Scharling "that the father comes and says to his boy： 'Our neighbour has given you permission to pull as many apples from his garden as you wish'；the boy will at once alter his opinion as to the relation between apples and plums， although his taste for and his enjoyment in consuming the fruit remains unchanged. But the effort which the possession of one apple saves him from putting forth， is no longer the same." To my mind this illustration， which Scharling advances in opposition to the theory of marginal utility， is really a proof of that theory. In what way has the situation changed after the father's speech？ Clearly that the boy may now have as many apples as he will， while formerly he had only one， i.e. the available supply has been increased to superfluity. And thus the result is attained which the theory of marginal utility demands； the valuation of the apples is entirely altered.
Scharling's opposition would be justified if it were directed against a theory which made value depend simply upon utility and not on marginal utility. In our theory， along with utility， all the influences are weighed which determine the degree of utilisation， and of estimation of utility， by the supply； indeed， even those influences which determine the amount of supply by the conditions of production.
