Marxian Political Economy PART SEVEN IN THE preceding three articles we saw how surplus value arises in production. We also developed the concepts of absolute and relative surplus value, and of the means by which the production of absolute and relative surplus value takes place. It may be recalled that absolute surplus value is produced by elongation of the working day beyond the point at which the labourer has produced an amount of value equivalent to the value of his labour power. It thus ^forms the general groundwork of the capitalist system, and the starting point for the production of relative surplus value." ' For, production of relative surplus value presupposes a division of the working day between necessary and surplus labour, and thus a lengthening of the working day beyond necessary labour, that is, it presupposes production of absolute surplus value. Relative surplus value is produced by shortening necessary labour time, that is, by decreasing the portion of a working day of given length that is expended in reproducing labour power. This occurs primarily through technical changes that increase the productivity of labour. So, for relative surplus-value production to be at all significant, techniques must be constantly ^revolutionized9. This requires as its basis the capitalist mode of production. Viewing the matter in terms of the organization of the labour