All this time, it appears, Marx has been tackling the problem from a wrong approach. No intelligent purpose can be served by asking for the source of the money needed to realise the surplus value. The question is rather where the demand can arise--to find an effective demand for the surplus value. If the problem had been put in this way at the start, no such long-winded detours would have been needed to show whether it can be solved or not. On the basis of simple reproduction, the matter is easy enough: since all surplus value is consumed by the capitalists, they themselves are the buyers and provide the full demand for the social surplus value, and by the same token they must also have the requisite cash in hand for circulation of the surplus value. But in this showing it is quite evident that under conditions of accumulation, i.e. of capitalisation of part of the surplus value, it cannot, _ex hypothesi_, be the capitalists themselves who buy the entire surplus value, that they cannot possibly realise it. True, if the capitalised surplus value is to be realised at all, money must be forthcoming in adequate quantities for its realisation. But it is quite impossible that this money should come from the purse of the capitalist class itself. Just because accumulation is postulated, the capitalists cannot buy their surplus value themselves, even though they might, _in abstracto_, have the money to do so. But who else could provide the demand for the commodities incorporating the capitalised surplus value? 'Apart from this class (the capitalists), there is, according to our assumption--the general and exclusive domination of capitalist production--no other class but the working class. All that the working class buys is equal to the sum total of its wages, equal to the sum total of the variable capital advanced by the entire capitalist class.'[144] The workers, then, are even less able than the capitalist class to realise the capitalised surplus value. Somebody must buy it, if the capitalists are still to be able to recover the capital they have accumulated and advanced; and yet--we cannot think of any buyers other than capitalists and workers. 'How can the entire capitalist class accumulate money under such circumstances?'[144] Realisation of the surplus value outside the only two existing classes of society appears as indispensable as it looks impossible. The accumulation of capital has been caught in a vicious circle. At any rate, the second volume of _Capital_ offers no way out. If we should now ask why Marx's _Capital_ affords no solution to this important problem of the accumulation of capital, we must bear in mind above all that this second volume is not a finished whole but a manuscript that stops short half way through.