There are, similarly, three types of economic theory. At the one extreme we have theories of "intrinsic" value, which would place economic value outside the wills of men. The mediaeval discussions of "just price" often illustrate this notion. It creeps not infrequently into judicial opinions,--to which such notions are essentially congenial! The working economist of our own day has found little use for it, but in periods when economic change was slow it suggested itself not unnaturally to men, as an explanation of the seeming impersonality of market phenomena, and as a practical idea for combatting extortion and injustice. Something of the idea is involved in a sentence of Shakspere's:[29] "But value dwells not in particular will; It holds his estimate and dignity As well wherein 'tis precious of itself As in the prizer." At the opposite extreme would be those economists, as Professor Davenport and Jevons, who find no value for a good except in the minds of individual men, so that there may be as many different values as there are different men. That something social and objective exists in the market place can hardly be denied, but when pressed for an account of it, these writers reduce it to a bare, abstract, mathematical ratio.[30] Each individual mind is shut up within its own limits, inscrutable to other minds, and there can be no psychological phenomena which include activities in many minds, for this view. In between these two extremes, is the social value theory of the present writer. Economic value is not intrinsic in goods, independent of the minds of men. But it is a fact which is in large degree independent of the mind of any given man. To a given individual in the market, the economic value of a good is a fact as external, as objective, as opaque and stubborn, as is the weight of the object, or the law against murder. There are individual values, marginal utilities, of goods which may differ in magnitude and in quality from man to man, but there is, over and above these, influenced by them in part, influencing them much more than they influence it, a social value for each commodity, a product of a complex social psychology, which includes the individual values, but includes very much more as well. Our theory puts law, moral values, and economic values in the same general class, _species_ of the _genus_, social value, alike in their psychological "stuff" and character, to be explained by the same general principles, even though differentiated in their functions, and in the extent to which they depend on various factors in the social situation. They are parts of a social system of motivation and control. They are the _social forces_, which govern, in a social scheme, the actions of men.