economic science, it illustrates by its success one cardinal truth, and
by implication it bears witness to another. The first truth is that, no
matter how desirable any object may be which is obtruded on the
imagination of anybody, nobody will bestir himself in a practical way to
demand it until he can be persuaded to believe that its attainment is
practically possible. The other is this: that the possibilities of
redistributing wealth depend on the causes by which wealth is produced.
All wealth, says Marx, can practically be appropriated by the
labourers. But why? Because the labourers themselves comprise in their
own labour all the forces that produce it. If its production
necessitated the activity of any persons other than themselves, these
other persons would inevitably have some control over its distribution;
since if it were distributed in a manner of which these other persons
disapproved, it would be open to them to refuse to take part in its
production any longer; and there would, in consequence, be no wealth, or
less wealth, to distribute.

Let us, then, examine the precise sense and manner in which this theory
of labour as the sole producer of wealth is elaborated and defended by
Marx in his Bible of Scientific Socialism. His argument, though the
expression of it is very often pedantic and encumbered with superfluous
mathematical formulæ, is ingenious and interesting, and is associated
with historical criticism which, in spite of its defects, is valuable.
Marx was, indeed, foremost among those thinkers already referred to who
first insisted on the fact that the economic conditions of to-day are
mainly a novel development of others which went before them, and that,
having their roots in history, they must be studied by the historical
method. He recognised, however, that for practical purposes each age
must concern itself with its own environment; and his logical
starting-point is an analysis of wealth-production as it exists to-day.