Sismondi, we see, has thus fallen into MacCulloch's trap. Instead of waiving an answer to the problem of accumulation which refers to the production of luxuries, he pursues his opponent into this field without noticing that the ground under his feet has shifted. Here he finds two causes for complaint. For one thing, he has moral objections to MacCulloch's allowing the capitalists instead of the workers to benefit by the surplus value, and is side-tracked into polemising against distribution under capitalism. From this digression, he unexpectedly reverts to the original problem which he now formulates as follows: the capitalists, then, consume the entire surplus value in luxuries. Let it be so. But could anyone increase his consumption as rapidly and indefinitely as the progress of labour productivity makes the surplus value increase? And in this second instance, Sismondi himself abandons his own problem. Instead of perceiving that it is the lack of consumers other than workers and capitalists which accounts for the difficulty in capitalist accumulation, he discovers a snag in simple reproduction because the capitalists' capacity to consume has physical limits. Since the absorptive capacity of the capitalists for luxuries cannot keep up with labour productivity, that is to say with the increase in surplus value, there must be crises and over-production. We have encountered this line of thought once before in the _Nouveaux Principes_--so Sismondi himself was manifestly not quite clear about the problem at all times. And that is hardly surprising, since one can really come to grips with the whole problem of accumulation only when one has fully grasped the problem of simple reproduction, and we have seen how much Sismondi was at fault in this respect.