2 
The alternative interpretation of aging is social. With 
the evolution of capitalism it is seen to pass from its 
competitive to its monopolistic (and imperialistic) phase. 
The pioneers of this outlook have been 
Hilferding ( 1910 ) and Luxemburg (1913) by their 
affirmation of the existence of a new phase of capitalism, 
characterised by monopoly elements and by imperialism. 
The elaboration of a theory of stagnation on this basis 
has been possible only after Kalecki and Keynes had 
provided the analytical tools in the form of a consistent 
theory of effective demand. 
The third inspiration of stagnation may be called dogmatic. 
It was the conviction of Karl Marx that all class systems 
sooner or later must decay and die on account of inner 
contradictions. Actually the approach just described 
which is based on monopoly capitalism might be regarded 
as filling in this Marxian program with a concrete and 
consistent theory. For Marx himself it was not possible 
to develop such a theory because he did not anticipate 
the stage of monopoly capitalism. 
Instead of it we find in Marx quite a different theory 
which in fact does not fit into the above program 
of decay arising from inner social contradictions at all: 
It is the theory of the declining rate of profit, based 
on nothing but a supposed technological law ( increasing 
organic composition of capital ) which acts from the 
outside, as it were like a deus ex machina, on the 
develoment of capitalist society. This is, in spite of 
its authorship, a very un-Marxian theory.