Rudolf Hilferding was a leading early twentieth-century socialist theoretician and politician. Born in Austria, Hilferding moved to Berlin to advance his left-wing career, working as a socialist educator, editor, writer, party leader, and Weimar-era parliamentarian. Having studied medicine in Vienna, Hilferding unexpectedly made his name in the field of Marxist political economy with his magnum opus Finance Capital (1910). Hilferding even ascended to the lofty halls of power, twice serving as German finance minister, once at the height of hyperinflation and again at the advent of the Great Depression. Even today, economists mull over Hilferding’s ideas, intellectual historians pore over his countless publications, and political historians marvel at Hilferding’s uncanny ability to befriend conservative political opponents. William Smaldone’s compilation and translation of Rudolf Hilferding’s German-language letters, held at the International Institute for Social History in Amsterdam, can shed even more light on this committed socialist intellectual. Smaldone presents this correspondence in three groups: first, there are letters from Hilferding to Karl Kautsky; second, there are letters from Leon Trotsky to Hilferding; third and finally, the most extensive correspondence is with Paul Hertz. A handful of misplaced umlauts and dates notwithstanding, Smaldone has pulled off a triumph in translating decades of handwritten documents. Moreover, Smaldone has crafted helpful introductions and provided even more crucial footnotes to aid the reader in deciphering Hilferding’s intellectual, social, and political worlds.

The first set of letters center on Karl Kautsky and are where this collection shines the brightest. Kautsky was the chief theoretician of Germany’s turn-of-the-century Social Democratic Party, defending Marxism from revisionism and, likewise, resisting the radical views of Rosa Luxemburg and Vladimir Lenin. These letters begin in 1902 with Hilferding’s early forays into Marxist theory when Kautsky served as a mentor. The letters continue through Hilferding’s stint in elected office and beyond, ending only in 1937. Because of the vagaries in the fates of interwar socialists and their papers, this collection primarily contains letters from Hilferding to Karl Kautsky or to his wife Luise Kautsky. One is left to read between the lines as to what Kautsky had written to Hilferding.

The second and smallest set of only twenty-two letters are from Leon Trotsky to Hilferding. Trotsky’s correspondence from 1907 to 1912 is hampered by the Russian revolutionary’s own German-language ability. Trotsky exasperatedly assured Hilferding: “I am not nearly as dumb in the Russian language as in the German translation” (193). Perhaps because of these linguistic hurdles, Trotsky’s correspondence is often straightforward, marked by incessant requests for financial favors, repeated reminders for payment for publications, and strategizing about writing for the Russian market. After a series of slights, Trotsky breaks off his previous “political friendship” with Hilferding in late 1912 or early 1913 (212). This translated correspondence offers insights into Trotsky’s day-to-day concerns as a Russian émigré in Habsburg Vienna, but these letters largely lack the theoretical heft of the correspondence from Hilferding to Kautsky.

Around half of all the translated letters are grouped in the Paul Hertz collection and date from 1933 to 1937. Hertz had served in local and national socialist politics during the Weimar Republic, and he had become one of the leaders in the exiled German Socialist Party based in Prague. The vast majority of these letters relate to socialist émigré publications, redrafted party platforms, and jockeying among exiled German-speaking socialists. The letters between Hilferding and Hertz are augmented by longer memoranda, as well as correspondence from other émigré socialists including Siegmund Crummenerl, Fritz Heine, and Friedrich Stampfer, among others. The Hertz letters will be of particular interest to scholars working on exiled social democrats of the 1930s or on socialist positioning between fascism in continental Europe and the communism of Soviet Russia.

William Smaldone first encountered these letters as a doctoral student, marveling then at “the lives of the people whose world they revealed” (vii). This correspondence then formed the archival backbone of Smaldone’s Rudolf Hilferding: The Tragedy of a German Social Democrat (1998). Scholars are lucky that Smaldone has returned to this earlier material to publish it in translation. In particular, these letters serve to humanize socialist thinkers in a way that theoretical works never can. This is especially true in one private letter sent by Rudolf Hilferding’s second wife in 1935. Rose Hilferding joined her husband in exile in Zurich and was distressed at what she found: “I’ve never seen him so downcast, hopeless, and disconsolate. He just dragged himself around, couldn’t work, slept for hours, ate practically nothing at all, was irritable, and unapproachable. … He wrote every day and then tore up what he’d written” (357). Smaldone’s translation offers us a moving glimpse into the depressed and exiled Hilferding fretting about a future for socialism and for himself. That we can read these letters in translation today is a testament that Rudolf Hilferding’s work and ideas can and do still matter.