A letter from Dmitrii Blagoev, Bulgarian Social Democrat and later leader of the Communist Party of Bulgaria, has been preserved in the archive of A. N. Potresov at the International Institute of Social History in Amsterdam. In reply to an inquiry fromD. Kol'tsov, who was preparing a Russian edition of Alphonse Thun's well-known history of the Russian revolutionary movement, Blagoev wrote twelve pages describing his activity in 1883–85 as a member of the first significant Social Democratic circle in Russia. Kol'tsov published extracts from the letter in his edition of Thun, including the Social Democratic program which Blagoev had published in Bulgaria subsequent to his expulsion from Russia in 1885. Kol'tsov's pen, however, struck out some of the more interesting biographical passages, and corrected Blagoev's good, if somewhat erratic Russian. It is particularly interesting to note Blagoev's references to the intellectual bases for a socialist Weltanschauung in the middle 1880's: Lassalle, Lavrov and Chernyshevskii appear beside Marx in the posts of honor. No less interesting is the question which Blagoev raised in this letter – whether the lack of clarity of Socialist views in 1885 was connected in any way with the rise of Economism among workers and socialist intellectuals in the Russian capital during the closing years of the last century. Literature on the Blagoev circle is not lacking, but there is a shortage of sound studies on the relationships between Marxism and indigenous Russian political philosophies between 1880 and 1895.