[162] The conservative function of valuation may be further illustrated by reference to the well-known principle of marginal utility of which we have already made mention (p. 307 above), and which has played so great a part in modern economic theory. The value of the unit quantity of a stock of any commodity is, according to this principle, measured by the least important single use in the schedule of uses to which the stock as a whole is to be applied. Manifestly, then, adherence to this valuation placed upon the unit quantity is in so far conservative of the whole schedule and the marginal value is a "short-hand" symbol expressive of the value of the whole complex purpose presented in the schedule. Moreover, the increase of marginal value concurrently with diminution of the stock through consumption, loss, or reapplication is not indicative so much of a change of purpose as of determination to adhere to so much of the original program of consumption as may still be possible of attainment with the depleted supply of the commodity. [163] Thus except on this condition we should deny the propriety of speaking of the value of a friend or of a memento or sacred relic. The purpose of accurate definition of the function of such objects as these in the attainment of one's ends is foreign to the proper attitude of loving, prizing, or venerating them. We may ethically value the _act_ of sacrifice for a friend or of solicitous care of the memento, but the object of our sacrifice or solicitude has simply the direct or immediate "qualitative" emotional character appropriate to the kinds of activity to which it is the adequate stimulus. [164] _History of Philosophy_ (TUFT's translation), p. 117. [165] _Cf._ PROFESSOR J. R. ANGELL's article, "Relations of Structural and Functional Psychology to Philosophy," _Decennial Publications of the University of Chicago_, Vol. III, pp. 10-12; also _Philosophical Review_, Vol. XII, No. 3. _Cf._ also MR. SCHILLER's essay on "Axioms as Postulates" in _Personal Idealism_. [166] From this point on this paper is an expansion of some paragraphs, pp. 11-13, in an article on "Existence, Meaning, and Reality," printed from Vol. III of the First Series of the _Decennial Publications of the University of Chicago_. [167] P. 22. [168] Pp. 22, 23; italics mine. [169] P. 25. [170] P. 26. [171] p. 36; italics mine. [172] Pp. 22, 23; italics mine. [173] P. 307. [174] P. 327. [175] P. 23; italics mine. [176] _Cf._ p. 34; also p. 22. [177] P. 35. [178] This warns us that in the phrase, "a plan of action," the term "action" must be more inclusive than it is in much current discussion. It must not be limited to gymnastic performance. It must apply to any sort of activity planned for, and which, when it arrives, fulfils the plan. This, I take it, is the import of the paragraph at the top of p. 7 of PROFESSOR JAMES's _Philosophical Conceptions and Practical Results_. [179] P. 270. [180] Pp. 270, 271. [181] P. 276.