Thus, Sismondi makes the fact of non-reproduction the criterion of income as distinct from capital for wages as well as for rent. In this, however, he is only right with regard to rent and the consumed part of capital profits; as for the part of the social product which is consumed in form of wages, it certainly does reproduce itself; it becomes the labour power of the wage labourer, for him a commodity by whose sale he lives, which he can bring to market again and again; for society it becomes the material form of variable capital which must reappear time and again in the aggregate reproduction of a year, if there is to be no loss. So far so good. Hitherto we have only learned two facts: the productivity of labour permits of the exploitation of the workers by those who do not work themselves, and exploitation becomes the actual foundation of the distribution of income owing to the divorce of the worker from his means of production. But we still do not know what is capital and what income, and Sismondi proceeds to clarify this point, starting as usual with Robinson Crusoe: 'In the eyes of the individual all wealth was nothing but a provision prepared beforehand for the time of need. Even so, he already distinguished two elements in this provision ... one part which he budgets to have at hand for immediate or almost immediate use, and the other which he will not need until it is to afford him new production. Thus one part of his corn must feed him until the next harvest, another part, reserved for sowing, is to bear fruit the following year. The formation of society and the introduction of exchange, permit to increase this seed, this fertile part of accumulated wealth, almost indefinitely, and this is what is called capital.'[164] Balderdash would be a better name for all this. In using the analogy of seed, Sismondi here identifies means of production and capital, and this is wrong for two reasons. First, means of production are capital not intrinsically, but only under quite definite historical conditions; secondly, the concept of capital covers more than just the means of production. In capitalist society--with all the conditions Sismondi ignores--the means of production are only a part of capital, i.e. they are constant capital. Sismondi here lost his thread plainly because he tried to establish a connection between the capital concept and the material aspects of social reproduction. Earlier, so long as he was concerned with the individual capitalist, he listed means of subsistence for the workers together with means of production as component parts of capital--again a mistake in view of the material aspects of the reproduction of individual capitals. Yet as soon as he tries to focus the material foundations of social reproduction and sets out to make the correct distinction between consumer goods and means of production, the concept of capital dissolves in his hands.