THE THEORY OF THE COLLAPSE OF CAPITALISM The idea that capitalism was in a final, its mortal, crisis dominated the first years after the Russian revolution. When the revolutionary workers' movement in Western Europe abated, the Third International gave up this theory, but it was maintained by the opposition movement, the KAPD, which adopted the theory of the mortal crisis of capitalism as the distinguishing feature between the revolutionary and reformist points of view. The question of the necessity and the inevitability of the collapse of capitalism, and the way in which this is to be understood, is the most important of all questions for the working class and its understanding and tactics. Rosa Luxemburg had already dealt with it in 1912 in her book The Accumulation of Capital, where she came to the conclusion that in a pure, closed capitalist system the surplus value needed for accumulation could not be realised and that therefore the constant expansion of capitalism through the trade with non-capitalist countries was necessary. This means that capitalism would collapse, that it would not be able to continue to exist any longer as an economic system, when this expansion was no longer possible. It is this theory, which was challenged as soon as the book was published from different sides, which the KAPD has often referred to. A quite different theory was developed in 1929 by Henryk Grossmann in his work Das Akkumulations und Zusammenbruchsgesetz des Kapitalistischen Systems (The Law of Accumulation and Collapse of the Capitalist System). Grossman here deduces that capitalism must collapse for purely economic reasons in the sense that, independently of human intervention, revolutions, etc., it would be impossible for it to continue to exist as an economic system. The severe and lasting crisis which began in 1930 has certainly prepared people's minds for such a theory of mortal crisis. The recently published manifesto of the United Workers of America makes Grossman's theory the theoretical basis for a new direction for the workers' movement. It is therefore necessary to examine it critically. But to do this a preliminary explanation of Marx's position on this question and the past discussions connected with it cannot be avoided.