<< Didn't Marx -- or was it Engels -- say that a communist society
would be not the end of history but the beginning of a truly
human history?
>>
It's at the conclusion of the (in)famous Preface to the Contribution to the Critique of Political Economy (1859), where, after laying out the rather technological determinist description of the transition between historical epochs as driven by fetteringof the forces of produiction, Marx continues, "This social formation [bourgeois society], therefore, brings the prehistory of human society to a close." See variously, but I have to habd Ticker's Marx-Engels Reader, 2d ed, p. 5.
--jks