[149] _Ibid._, pp. 129-30. Some of the extraordinary earning power or ability of the laborer may be the result of education and training for which sacrifices have been made. Such abilities are “_immaterial capital_,” and the part of the whole wages due to them is really profit on this capital (p. 130). Then wages of skilled or professional labor may contain rent for inborn talents, _profit_ for abilities acquired through the sacrifice called abstinence, and _wages_ for the real disutility of labor incurred. “Forty pounds a year would probably pay all the labour that [a lawyer] undergoes in order to make, we will say, £4,000 a year. Of the remaining £3,960 probably £3,000 may be considered rent” (p. 134). “The intellectual and moral capital of Great Britain far exceeds all her material capital, not only in importance, but even in productiveness.” _Ibid._ [150] P. 114. [151] P. 112. The payment of rent in every case is but the wedging in of a slice between value and the remuneration for cost of production. [152] Pp. 100-101. [153] P. 129. [154] In an unobtrusive position further on in the book he adopts the labor-command standard, but without discussion. “The best standard of value for philosophical purposes appears to be the command of labour.” This appears to be an uncritical and passing acquiescence in the views of Malthus. [155] _Principles_, 6th ed., vol. i, pp. 546-7. The language is uncritical. Absolute limitation of supply is not a case of difficulty of attainment, but a case of value apart from questions of difficulty of attainment. Senior’s analysis was superior. [156] Vol. i, p. 552. [157] Vol. i, p. 561. [158] Vol. i, p. 589. [159] Vol. i, p. 568. [160] The socialists’ attacks upon abstinence as a cost are really directed against the _ethical_ coördination of it with labor. [161] Vol. i, p. 574. [162] Vol. i, pp. 569-70. [163] Vol. i, p. 507. [164] Mill emphasizes the fact that he is considering the causes of variations in values. It remains true that both he and Ricardo should have considered the causes of statical aberration of values from the standard of labor cost. [165] It may be useful to recall the explanation Ricardo made of his position with regard to this point. “I have not said, because one commodity has so much labour bestowed upon it as will cost £1000 and another so much as will cost £2000 that therefore one would be of the value of £1000 and the other of the value of £2000, but I have said that their value will be to each other as two to one.... It is of no importance to the truth of this doctrine, whether one of these commodities sells for £1100 and the other for £2200, or one for £1500 and the other for £3000.” (Gonner ed. Ricardo’s _Principles_, p. 39.) The interest qualification signifies that the commodities may exchange at other ratios than two to one. [166] Vol. i, p. 566. [167] Vol. i, pp. 566-7. [168] Vol. i, p. 590.