on some previous annual labour that has been hoarded. This question of past labour, however, as the foundation of all present labour, brings us to the very first beginning which is as meaningless with regard to the economic development of mankind as it is for the natural development of matter. The scheme of reproduction grasps the social process as perpetually in motion, as a link in the endless chain of events, it neither wants to demonstrate its initial origin, nor should it do so. The social reproductive process is always based on past labour, we may trace it back as far as we like. Social labour has no beginning, just as it has no end. Like the historical origin of Herodotus' Lake Moeris, the beginnings of the reproductive process in the history of civilisation are lost in the twilight of legend. With the progress of techniques and with cultural development, the means of production change their form, crude paleoliths are replaced by sharpened tools, stone implements by elegant bronze and iron, the artisan's tool by steam-driven machinery. Yet, though the means of production and the social organisation of the productive process continually change their form, society already possesses for its labour process a certain amount of past labour serving as the basis for annual reproduction. Under capitalist methods of production past labour of society preserved in the means of production takes the form of capital, and the question of the origin of this past labour which forms the foundation of the reproductive process becomes the question of the genesis of capital. This is much less legendary, indeed it is writ in letters of blood in modern history. The very fact, however, that we cannot think of simple reproduction unless we assume a hoard of past labour, surpassing in volume the labour annually performed for the maintenance of society, touches the sore spot of simple reproduction; and it shows that simple reproduction is a fiction not only for capitalist production but also for the progress of civilisation in general. If we merely wish to understand this fiction properly, and to reduce it to a scheme, we must presume, as its _sine qua non_, results of a past productive process which cannot possibly be restricted to simple reproduction but inexorably points towards enlarged reproduction. By way of illustration, we might compare the aggregate fixed capital of society with a railway. The durability and consequently the annual wear and tear of its various parts is very different. Parts such as viaducts and tunnels may last for centuries, steam engines for decades, but other rolling stock will be used up in a short time, in some instances in a few months. Yet it is possible to work out an average rate of wear and tear, say thirty years, so that the value of the whole is annually depreciated by one thirtieth. This loss of value is now continually made good by partial reproduction of the railway (which may count as repairs), so that a coach is renewed