Productive activity, if we leave out of sight its special form, viz., the useful character of the labour, isnothing but the expenditure of human labour-power. Tailoring and weaving, though qualitativelydifferent productive activities, are each a productive expenditure of human brains, nerves, and musclesand in this sense are human labour.

They are but two different modes of expending human labour-powerOf course, this labour-power, which remains the same under all its modifications, must have attained acertain pitch of development before it can be expended in a multiplicity of modes. But the value of acommodity represents human labour in the abstract, the expenditure of human labour in general. And justas in society, a general or a banker plays a great part, but mere man, on the other hand, a very shabbypart, [14] so here with mere human labour. It is the expenditure of simple labour-power, te, of thelabour-power which, on an average, apart from any special development, exists in the organism of everyordinary individual. Simple average labour, it is true, varies in character in different countries and atdifferent times, but in a particular society it is given. Skilled labour counts only as simple labourtensified, or rather, as multiplied simple labour, a given quantity of skilled being considered equal to agreater quantity of simple labour. Experience shows that this reduction is constantly being made. Acommodity may be the product of the most skilled labour, but its value, by equating it to the product ofsimple unskilled labour, represents a definite quantity of the latter labour alone. [15] The differentportions in which different sorts of labour are reduced to unskilled labour as their standard areestablished by a social process that goes on behind the backs of the producers, and, consequently, appearto be fixed by custom. For simplicity's sake we shall henceforth account every kind of labour to beunskilled, simple labour, by this we do no more than save ourselves the trouble of making the reductioJust as, therefore, in viewing the coat and linen as values, we abstract from their different use-values,it is with the labour represented by those values: we disregard the difference between its useful forms,weaving and tailoring. As the use-values, coat and linen, are combinations of special productive activitieswith cloth and yam, while the values, coat and linen, are, on the other hand, mere homogeneouscongelation of undifferentiated labour, so the labour embodied in these latter values does not count byvirtue of its productive relation to cloth and yarn, but only as being expenditure of human labour-powerTailoring and weaving are necessary factors in the creation of the use-values, coat and linen, preciselybecause these two kinds of labour are of different qualities; but only in so far as abstraction is made fromtheir special qualities, only in so far as both possess the same quality of being human labour, do tailoringand weaving form the substance of the values of the same articlesCoats and linen, however, are not merely values, but values of definite magnitude, and according to ourassumption, the coat is worth twice as much as the ten yards of linen. Whence this difference in theirvalues? It is owing to the fact that the linen contains only half as much labour as the coat, andnsequently, that in the production of the latter, labour-power must have been expended during twicethe time necessary for the production of the former

While, therefore, with reference to use-value, the labour contained in a commodity counts onlyqualitatively, with reference to value it counts only quantitatively, and must first be reduced to humanlabour pure and simple. In the former case, it is a question of How and what, in the latter of How much?How long a time? Since the magnitude of the value of a commodity represents only the quantity oflabour embodied in it, it follows that all commodities, when taken in certain proportions, must be equalin valueIf the productive power of all the different sorts of useful labour required for the production of a coatremains unchanged, the sum of the values of the coats produced increases with their number. If one coatrepresents x days' labour, two coats represent 2x days labour, and so on. But assume that the duration ofthe labour necessary for he production of a coat becomes doubled or halved In the first case one coat isworth as much as two coats were before: in the second case, two coats are only worth as much as onewas before, although in both cases one coat renders the same service as before. and the useful labourembodied in it remains of the same quality. But the quantity of labour spent on its production has alteredAn increase in the quantity of use-values is an increase of material wealth. With two coats two men canbe clothed, with one coat only one man. Nevertheless, an increased quantity of material wealth maycorrespond to a simultaneous fall in the magnitude of its value. This antagonistic movement has its originin the two-fold character of labour. Productive power has reference, of course, only to labour of someuseful concrete form, the efficacy of any special productive activity during a given time being dependenton its productiveness. Useful labour becomes, therefore, a more or less abundant source of products, inaffects the labour represented by value. Since productive power is an attribute of the concrete usey oproportion to the rise or fall of its productiveness. On the other hand, no change in this productiveforms of labour, of course it can no longer have any bearing on that labour, so soon as we makeabstraction from those concrete useful forms. However then productive power may vary, the samelabour, exercised during equal periods of time, always yields equal amounts of value. But it will yield,during equal periods of time, different quantities of values in use; more, if the productive power rise,fewer, if it fall. The same change in productive power, which increases the fruitfulness of labour, and, inonsequence, the quantity of use-values produced by that labour, will diminish the total value of thisincreased quantity of use-values, provided such change shorten the total labour-time necessary for theirproduction; and vice versaOn the one hand all labour is, speaking physiologically, an expenditure of human labour-power, and inits character of identical abstract human labour. it creates and forms the value of commodities. On theother hand, all labour is the expenditure of human labour-power in a special form and with a definite aimand in this, its character of concrete useful labour, it produces use-values. [16]