Ricardo never concerns himself about the origin of surplus-value. He treats it as a thing inherent in the capitalist mode of production, which mode, in his eyes, is the natural form of social production. Whenever he discusses the productiveness of labour, he seeks in it, not the cause of surplus-value, but the cause that determines the magnitude of that value. On the other hand, his school has openly proclaimed the productiveness of labour to be the originating cause of profit (read: Surplus-value). This at all events is a progress as against the mercantilists who, on their side, derived the excess of the price over the cost of production of the product, from the act of exchange, from the product being sold above its value, Nevertheless, Ricardo’s school simply shirked the problem, they did not solve it. In fact these bourgeois economists instinctively saw, and rightly so, that it is very dangerous to stir too deeply the burning question of the origin of surplus-value. But what are we to think of John Stuart Mill, who, half a century after Ricardo, solemnly claims superiority over the mercantilists, by clumsily repeating the wretched evasions of Ricardo’s earliest, vulgarisers?
Mill says: “The cause of profit is that labour produces more than is required for its support.” So far, nothing but the old story; but Mill wishing to add something of his own, proceeds: “To vary the form of the theorem; the reason why capital yields a profit, is because food, clothing, materials and tools, last longer than the time which was required to produce them.” He here confounds the duration of labour-time with the duration of its products. According to this view, a baker whose product lasts only a day, could never extract from his workpeople the same profit, as a machine maker whose products endures for 20 years and more. Of course it is very true, that if a bird’s nest did not last longer than the time it takes in building, birds would have to do without nests.
This fundamental truth once established, Mill establishes his own superiority over the mercantilists. “We thus see,” he proceeds, “that profit arises, not from the incident of exchange, but from the productive power of labour; and the general profit of the country is always what the productive
