In the midst of a developing revolution, it is necessary to maintain oneÕs principles and direction. Failure to do so can result in disorientation or, even worse, liquidation into the camp of the class enemy. The Communist League faced this crisis with the rise of petty-bourgeois democracy. Currlin Press, in association with the Albert Currlin Institute, is pleased to present the fourth in its 12-volume Essentials series, a part of the Workers' Library Collection. Included in this volume are both parts of Marx and Engels' Address of the Central Committee to the Communist League, as well as Revolution and Counterrevolution in Germany by Engels as background for the Address, and an introduction and endnotes by the Albert Currlin Institute.