That the strivings of some members of a given society conflict with the strivings of others, that social life is full of contradictions, that history shows us struggle between peoples and societies, as well as within them, and furthermore the alternation of periods of revolution and reaction, peace and war, stagnation and rapid progress or decline — these facts are well known. Marxism provided the guiding thread that made it possible to discover regularity in what appears to be a labyrinth and chaos, namely: the theory of class struggle. Only the study of the totality of strivings of all members of a given society or group of societies is capable of leading to a scientific determination of the result of these strivings. And the source of contradictory strivings is the difference in the position and conditions of life of those classes into which each society breaks down. "The history of all hitherto existing societies," writes Marx in the *Communist Manifesto* (with the exception of the history of primitive communism — Engels adds later), "has been the history of class struggles. Freeman and slave, patrician and plebeian, lord and serf, guild-master and journeyman, in short, oppressor and oppressed, stood in constant opposition to one another, carried on an uninterrupted, now hidden, now open fight, a fight that each time ended either in a revolutionary reconstitution of society at large or in the common ruin of the contending classes… The modern bourgeois society that has sprouted from the ruins of feudal society has not done away with class antagonisms. It has but established new classes, new conditions of oppression, new forms of struggle in place of the old ones. Our epoch, the epoch of the bourgeoisie, possesses, however, this distinctive feature: it has simplified the class antagonisms. Society as a whole is more and more splitting up into two great hostile camps, into two great classes directly facing each other — Bourgeoisie and Proletariat." Since the great French Revolution, European history has revealed with particular clarity in a number of countries this actual underlying basis of events — the struggle of classes. And already the epoch of Restoration in France brought forth a series of historians (Thierry, Guizot, Mignet, Thiers) who, in generalizing what was taking place, could not fail to recognize the struggle of classes as the key to understanding all of French history. And the most recent epoch, the epoch of the complete victory of the bourgeoisie, of representative institutions, of broad (if not universal) suffrage, of cheap newspapers circulating among the masses, etc., the epoch of powerful and ever-widening unions of workers and unions of employers, etc., has demonstrated even more graphically (though sometimes in a rather one-sided, "peaceful," "constitutional" form) the struggle of classes as the motive force of events. The following passage from Marx's *Communist Manifesto* will show us what demands of objective analysis of the position of each class in modern society, in connection with the analysis of the conditions of development of each class, Marx made upon social science: "Of all the classes that stand face to face with the bourgeoisie today, the proletariat alone is a genuinely revolutionary class. All the other classes gradually decay and finally disappear in the face of modern industry; the proletariat is its special and essential product. The middle strata — the small manufacturer, the small trader, the handicraftsman, the peasant — all these fight against the bourgeoisie to save from extinction their existence as fractions of the middle class. They are therefore not revolutionary, but conservative. Nay more, they are reactionary, for they try to roll back the wheel of history. If by chance they are revolutionary, they are so only in view of their impending transfer into the proletariat; they thus defend not their present, but their future interests, they desert their own standpoint to place themselves at that of the proletariat." In a series of historical works (see Bibliography) Marx provided brilliant and profound examples of materialist historiography, analyses of the position of each individual class and sometimes various groups or strata within a class, demonstrating concretely why and how "every class struggle is a political struggle"{65}. The passage we have cited illustrates what a complex network of social relations and transitional stages from one class to another, from the past to the future, Marx analyzes in order to account for the entire resultant of historical development.

The most profound, comprehensive, and detailed confirmation and application of Marx's theory is his economic doctrine.