he ultimate judgment of history Marx will have a place in social
science analogous with that of Galileo in physical science."[19] In
exile, and often desperate poverty, Marx worked out with infinite care
the scientific basis of the generalization--first given to the world in
the Communist Manifesto--that social and political institutions are the
product of economic forces. In all periods there have been antagonistic
economic classes whose relative power is determined by struggles between
them. "Freedman and slave," he says, "patrician and plebeian, lord and
serf, guild master and journeyman, in a word, 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 reconstruction of society at large, or in the
common ruin of the contending classes."[20] Here is a summary of that
conflict which Professor Small declares "is to the social process what
friction is to mechanics."[21] It may well be that "the fact of class
struggle is as axiomatic to-day as the fact of gravitation,"[22] yet,
when Marx first elaborated his theory, it was not only a revolutionary
doctrine among the socialist sects, but like Darwin's theory of
evolution it was assailed from every angle by every school of
economists. The important practical question that arises out of this
scientific work, and which particularly concerns us here, is that this
theory of the class struggle forever destroyed the old ideas of
revolution, scrap-heaped conspiracies and insurrections, and laid the
theoretical foundations for the modern working-class movement.

Actually, it was utopian socialism that was destroyed by this new
theory. It expressed itself in at least three diverse ways. There were
groups of conspirators and revolutionists who believed that the world
was on the eve of a great upheaval and that the people should prepare
for the moment when suddenly they could seize the governments of Europe,
destroy ancient institutions, and establish a new social order. Another
form of utopianism was the effort to persuade the capitalists themselves
to abolish dividends, profits, rent, and interest, to turn the factories
over to the workers, to become themselves toilers, and to share equally,
one with another, the products of their joint labor. Still another form
of utopian socialism was that of Owen, Fourier, and Cabet, who
contemplated the establishment of