reasoning, and accepted the conclusion as true wherever the conditions
assumed were realized; but he proceeded to point out, that, in point
of fact, the conditions are not realized over the greater portion of
the world, and, as a consequence, that the rent actually paid by the
cultivators to the owners of the soil by no means, as a general rule,
corresponds with that portion of the produce which Ricardo considered
as properly "rent." The real regulator of actual rent over the greater
part of the habitable globe was, he showed, not competition, but
custom; and he further pointed out that there are countries in which
the actual rent paid by the cultivators is governed neither by the
causes set forth by Ricardo, nor yet by custom, but by a third cause
different from either,--the absolute will of the owners of the soil,
controlled only by the physical exigencies of the cultivator, or by
the fear of his vengeance if disturbed in his holding. The recognition
of this state of things threw an entirely new light over the whole
problem of land-tenure, and plainly furnished grounds for legislative
interference in the contracts between landlords and tenants. Its
application to Ireland was obvious; and Mill himself, as the world
knows, did not hesitate to urge the application with all the energy
and enthusiasm which he invariably threw into every cause that he
espoused.

In the above remarks, I have attempted to indicate briefly some few of
the salient features in Mill's contributions to the science of
political economy. There is still one more which ought not to be
omitted from even the most meagre summary. Mill was not the first to
treat political economy as a science; but he was the first, if not to
perceive, at least to enforce the lesson, that, just because it is a
science, its conclusions carried with them no obligatory force with
reference to human conduct. As a science, it tells us that certain