surplus (over and above any contribution there may be from forced saving out of wages), which, unlike other kinds of investment, creates no further problem by increasing productive capacity (not to mention the huge new investment opportunities created by reconstruction after the capitalist nations have turned their weapons against each other).

All this is perhaps too neat an account of what our author is saying. The argument streams along bearing a welter of historical examples in its flood, and ideas emerge and disappear again bewilderingly. But something like the above seems to be intended. And something like it is now widely accepted as being true. Rosa Luxemburg, as we have seen, neglects the rise in real wages which takes place as capitalism develops, and denies the internal inducement to invest provided by technical progress, two factors which help to rescue capitalism from the difficulties which it creates for itself. She is left with only one influence (economic imperialism) to account for continuous capital accumulation, so that her analysis is incomplete. All the same, few would deny that the extension of capitalism into new territories was the mainspring of what an academic economist has called the ‘vast secular boom’ of the last two hundred years,[56] and many academic economists account for the uneasy condition of capitalism in the twentieth century largely by the ‘closing of the frontier’ all over the world.[57] But the academic economists are being wise after the event. For all its confusions and exaggerations, this book shows more prescience than any orthodox contemporary could claim.

JOAN ROBINSON

Cambridge.