pparel of our civil society, far enough from the meanings
which religion and art give to life, there remains, grows and develops
the elementary structure of society which supports all the rest. The
anatomical study of this underlying structure is economics. And as human
society has several times changed, partially or entirely, in its most
visible exterior form, or in its ideological, religious or artistic
manifestations, we must first find the cause and the reason of these
changes, the only ones which historians relate, in the transformations
more hidden, and at first less visible, of the economic _processus_ of
this structure. We must set ourselves to the study of the differences
which exist between the various forms of production when we have to deal
with historic epochs clearly distinct and properly designated; and when
we have to explain the succession of these forms, the replacing of one
by the other, we must study the causes of erosion, and of the
destruction of the form which disappears; and finally when we wish to
understand the historic fact determined and concrete, we must study the
frictions and the contrasts which take their rise from the different
currents, that is to say, the classes, their subdivisions and their
intersections which characterize a given society.

When the Manifesto declared that all history up to the present time has
been nothing but the history of class struggles and that these are the
cause of all revolutions as also of all reactions, it did two things at
the same time, it gave to communism the elements of a new doctrine and
to the communists the guiding thread to discover in the confused events
of political life the conditions of the underlying economic movement.

In these last fifty years the generic foresight of a new historic era
has become for socialists the delicate art of understanding in every
case what it is expedient to do, because this new era is in itself in
continual formation. Communism has become an art because the
proletarians have become, or are on the point of becoming, a political
party. The revolutionary spirit is embodied to-day in the proletarian
organization. The desired union of communists and proletarians is
henceforth an accomplished fact.[10] These last fifty years have been
the ever stronger proof of the ever growing revolt of the producing
forces against the forms of production. We "utopians" have no other
answer to offer than this lesson from events to those