We know to-day for certain that the rise of communal possession in land was always inseparably connected with the introduction of slavery, and that one cannot be thought of without the other. But to wish to imagine equality in addition to the collective possession of primitive society is to a great extent a distortion of the facts of history. Whatever facts we may produce from the actual and not merely imaginary primitive history of property would be so many arguments against Proudhon's contention. His economic argument is just as untenable, that labour should lead to equality. All work, according to Proudhon, is the effective of a collective force, which is equal to the resultants of the forces of the single individuals who form the labour group. Consequently, the product of labour is the property of the whole community, and every worker has an equal claim to it. This is, briefly, the argument which, from premises that are possibly correct, draws conclusions that are entirely false. Proudhon gives the following example: "Two hundred grenadiers placed the obelisk of Luxor on its pedestal in a few hours, and yet we do not believe that one man could have performed the same work in two hundred days. The collective force is greater than the sum of individual forces and individual efforts. Therefore the capitalist has not rewarded the labourer fairly when he pays wages for one day multiplied by the number of day-labourers employed by him." It will be seen that Proudhon here proceeds from the assumption that the value of a product of a labour is a firmly established and easily fixed amount, as John Grey and Rodbertus had taught before him; for only in this case could it be exactly stated how great the claim is which belongs to a labourer. In fact, the characteristic feature of Proudhon's theory of value lies in his endeavour to determine and fix values; that is, to use his own dialectic jargon, according to the synthetic solution of the antithesis of value in use and value in exchange, in which our economic life fluctuates. Supply and demand, considered by others as the factors which regulate and determine value, are to him only forms which serve to contrast with one another the value in use and value in exchange, and to cause these values to combine. From justice, which ought to be the foundation of society, he concludes the necessity, and from general obedience of life to law the possibility, of a determination of values. Even this value, thus determined, will be a variable amount, a proportionate figure, similar to the index which in the case of chemical elements gives their combining weights. "But this value will none the less be strictly fixed. Value may alter, but the law of values is unalterable; indeed, the fact that value is capable of alteration only results from its being subject to a law whose principle is essentially fluctuating, for it is labour measured by time." (_Contradictions_, i., "On the Theory