He provided the unorganised aspirations, which by this time were known as socialism, with a formula which was at once definite, intelligible, and comprehensive, and had all the air of being rigidly scientific also.

By this means thoughts and feelings, previously vague and fluid, like salts held in solution, were crystallised into a clear-cut theory which was absolutely the same for all; which all who accepted it could accept with the same intellectual confidence; and which thus became a moral and mental nucleus around which the efforts and hopes of a coherent party could group themselves.
Such was the feat accomplished by Karl Marx, through his celebrated treatise on Capital, which was published between fifty and sixty years ago, and which has, since then, throughout all Europe and America, been acclaimed as the Magna Charta, or the Bible, of "scientific socialism." Whatever may be the change which, as a theory, socialism has subsequently undergone--and changes there have been which will presently occupy our attention--it is with the theory of Marx, and the temper of mind resulting from it, that socialism, regarded as a practical force, begins; and among the majority of socialists this theory is predominant still.

In view, therefore, of the requirements of logic, of history, and of contemporary facts, our own examination must begin with the theory of Marx likewise..