It is the rate of investment which governs the rate of saving, and not vice versa. - Joan Robinson

The fundamental differences between Marxian and traditional orthodox economics are, first, that the orthodox economists accept the capitalist system as part of the eternal order of Nature, while Marx regards it as a passing phase in the transition from the feudal economy of the past to the socialist economy of the future.

Voltaire remarked that it is possible to kill a flock of sheep by witchcraft if you give them plenty of arsenic at the same time. The sheep, in this figure, may well stand for the complacent apologists of capitalism; Marx's penetrating insight and bitter hatred of oppression supply the arsenic, while the labour theory of value provides the incantations.

In all the talk in the Principles (as opposed to the formal analysis) it is not the saving of rentiers but the energy of entrepreneurs which governs accumulation.