I just about forward the passage from Volume 3:

the realm of freedom actually begins only where labour which is 
determined by necessity and mundane considerations ceases; thus in the 
very nature of things it lies beyond the sphere of actual material 
production. Just as the savage must wrestle with Nature to satisfy his 
wants, to maintain and reproduce life, so must civilised man, and he 
must do so in all social formations and under all possible modes of 
production. With his development this realm of physical necessity 
expands as a result of his wants; but, at the same time, the forces of 
production which satisfy these wants also increase. Freedom in this 
field can only consist in socialised man, the associated producers, 
rationally regulating their interchange with Nature, bringing it under 
their common control, instead of being ruled by it as by the blind 
forces of Nature; and achieving this with the least expenditure of 
energy and under conditions most favourable to, and worthy of, their 
human nature. But it nonetheless still remains a realm of necessity. 
Beyond it begins that development of human energy which is an end in 
itself, the true realm of freedom, which, however, can blossom forth 
only with this realm of necessity as its basis. The shortening of the 
working-day is its basic prerequisite.

http://www.marxists.org/archive/marx/works/1894-c3/ch48.htm

> P.S.  I don't have the text to hand, but I think the obvious 
> contradictory text is the entry of/Capital/ III labelled "The Realm of 
> Necessity and the Realm of Freedom," which suggests unending needs.  
> But I think just generally that what capitalism shows (or has 
> uncovered or has generated) is that human needs and capabilities can 
> develop in many directions -- "the all-around development of the 
> individual" in the/Gotha Programme/ quotation below -- and there are 
> no limits to that development.
>
>