This is an original translation not only of the main body of the work but also of a number of quotations from foreign authors. Page references thus usually indicate the original foreign sources.

In so far as possible, however, I have availed myself of existing translations and have referred to the following standard works:

Karl Marx: Capital, vol. i (transl. by Moore-Aveling, London, 1920); vol. ii (transl. by E. Untermann, Chicago, 1907); vol. iii (transl. by E. Untermann, Chicago, 1909)

The Poverty of Philosophy (translator’s name not given, London, 1936).

Sismondi’s introduction to the second edition of Nouveaux Principes is quoted from M. Mignet’s translation of selected passages by Sismondi, entitled Political Economy and the Philosophy of Government, London, 1847. No English translation exists of Marx’s Theorien Über den Mehrwert.

Unfortunately, not all the West European texts, and none of the Russian—except Engels’ correspondence with Nikolayon—were accessible to me, and I regret having been unable to trace some quotations and check up on others. In such cases, the English version follows the German text and will at least bring out the point the author wanted to make.

To save the reader grappling with unfamiliar concepts, I have converted foreign currencies and measures into their English equivalents, at the following rates:

20 marks—25 francs—$5—£1 (gold standard); 1 hectare—(roughly) 2·5 acres; 1 kilometre—⁵/₈ mile.

I am glad of this opportunity to express my gratitude to Dr. W. Stark and Mrs. J. Robinson for the helpful criticism and appreciation with which my work has met.

AGNES SCHWARZSCHILD