SECTION 3

   PRODUCTIVENESS AND INTENSITY OF LABOUR CONSTANT.                           LENGTH OF THE WORKING-DAY VARIABLE

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   The working-day may vary in two ways. It may be made either longer or shorter. From our present data, and within the limits of the assumptions made on p. 487 [v. 35 MECW p. 520] we obtain the following laws:

   (1.) The working-day creates a greater or less amount of value in proportion to its length — thus, a variable and not a constant quantity of value.

   (2.) Every change in the relation between the magnitudes of surplus value and of the value of labour-power arises from a change in the absolute magnitude of the surplus-labour, and consequently of the surplus value.

   (3.) The absolute value of labour-power can change only in consequence of the reaction exercised by the prolongation of surplus-labour upon the wear and tear of labour-power. Every change in this absolute value is therefore the effect, but never the cause, of a change in the magnitude of surplus value.

   We begin with the case in which the working-day is shortened.

   (1.) A shortening of the working-day under the conditions given above, leaves the value of labour-power, and with it, the necessary labour time, unaltered. It reduces the surplus-labour and surplus value. Along with the absolute magnitude of the latter, its relative magnitude also falls, i.e., its magnitude relatively to the value of labour-power whose magnitude remains unaltered. Only by lowering the price of labour-power below its value could the capitalist save himself harmless.

   All the usual arguments against the shortening of the working-day, assume that it takes place under the conditions we have here supposed to exist; but in reality the very contrary is the case: a change in the productiveness and intensity of labour either precedes, or immediately follows, a shortening of the working-day. [5]

   (2.) Lengthening of the working-day. Let the necessary labour time be 6 hours, or the value of labour-power 3 shillings; also let the surplus-labour be 6 hours or the surplus value 3 shillings. The whole working-day then amounts to 12 hours and is embodied in a value of 6 shillings. If, now, the working-day be lengthened by 2 hours and the price of labour-power remain unaltered, the surplus value increases both absolutely and relatively. Although there is no absolute change in the value of labour-power, it suffers a relative fall. Under the conditions assumed in 1. there could not be a change of relative magnitude in the value of labour-power without a change in its absolute magnitude. Here, on the contrary, the change of relative magnitude in the value of labour-power is the result of the change of absolute magnitude in surplus value.

   Since the value in which a day's labour is embodied, increases with the length of that day, it is evident that the surplus value and the price of labour-power may simultaneously increase, either by equal or unequal quantities. This simultaneous increase is therefore possible in two cases, one, the actual lengthening of the working-day, the other, an increase in the intensity of labour unaccompanied by such lengthening.

   When the working-day is prolonged, the price of labour-power may fall below its value, although that price be nominally unchanged or even rise. The value of a day's labour-power is, as will be remembered, estimated from its normal average duration, or from the normal duration of life among the labourers, and from corresponding normal transformations of organised bodily matter into motion, [6] in conformity with the nature of man. Up to a certain point, the increased wear and tear of labour-power, inseparable from a lengthened working-day, may be compensated by higher wages. But beyond this point the wear and tear increases in geometrical progression, and every condition suitable for the normal reproduction and functioning of labour-power is suppressed. The price of labour-power and the degree of its exploitation cease to be commensurable quantities.

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                                            Footnotes

   5. “There are compensating circumstances ... which the working of the Ten Hours' Act has brought to light.” (Rep. of Insp. of Fact. for 31st Oct. 1848,” p. 7.)

   6. “The amount of labour which a man had undergone in the course of 24 hours might be approximately arrived at by an examination of the chemical changes which had taken place in his body, changed forms in matter indicating the anterior exercise of dynamic force.” (Grove: “On the Correlation of Physical Forces.”)