The Lessons of Spain: The Last Warning (1937)
“The tragic experience of Spain is a terrible - perhaps final - warning before still greater events, a warning addressed to all the advanced workers of the world. ‘Revolutions,’ Marx said, ‘are the locomotives of history.’ They move faster than the thought of semi-revolutionary or quarter-revolutionary parties. Whoever lags behind falls under the wheels of the locomotive, and consequently - and this is the chief danger - the locomotive itself is also not infrequently wrecked.”