lace accorded to this book by European socialists may
be gathered from the preface to the French edition by G. Sorel, one of
the most prominent socialists of France.

He says: "The publication of this book marks a date in the history of
socialism. The work of Labriola has its place reserved in our libraries
by the side of the classic works of Marx and Engels. It constitutes an
illumination and a methodical development of a theory which the masters
of the new socialist thought have never yet treated in a didactic form.
It is therefore an indispensable book for whoever wishes to understand
something of _proletarian ideas_. More than the works of Marx and Engels
it is addressed to that public which is unacquainted with socialist
preconceptions. In these pages the historian will find substantial and
valuable suggestion for the study of the origin and transformation of
institutions."

The economic development of the United States has reached a point where
the growth of the Socialist Party must henceforth go forward with
startling rapidity. That the publication of this volume may have some
effect in clarifying the ideas of those who discuss the principles of
that party, whether with voice or pen, is the hope of the

TRANSLATOR.

ESSAYS ON THE MATERIALISTIC CONCEPTION OF HISTORY

I.

In Memory of the Communist Manifesto 7

II.

Historical Materialism 93

ESSAYS on the Materialistic Conception of History

PART I

IN MEMORY OF THE COMMUNIST MANIFESTO.

I.

In three years we can celebrate our jubilee. The memorable date of the
publication of the Communist Manifesto (February, 1848) marks our first
unquestioned entrance into history. To that date are referred all our
judgments and all our congratulations on the progress made by the
proletariat in these last fifty years. That date marks the beginning of
the new era. This is arising, or, rather, is separating itself from the
present era, and is developing by a process peculiar to itself and thus
in a way that is necessary and inevitable, whatever may be the
vicissitudes and the successive phases which cannot yet be foreseen.

All those in our ranks who have a desire or an occasion to possess a
better understanding of their own work should bring to mind the causes
and the moving forces which determined the genesis of the Manifesto, the
circumstances under which it appeared on the eve of the Revolution which
b