and (as physical
science is commonly and very properly studied first) may be said to
presuppose them, taking up the complex phenomena where physical science
leaves them.

Now this, it will be found, is a precise statement of the relation in
which Political Economy stands to the various sciences which are
tributary to the arts of production.

The laws of the production of the objects which constitute wealth, are
the subject-matter both of Political Economy and of almost all the
physical sciences. Such, however, of those laws as are purely laws of
matter, belong to physical science, and to that exclusively. Such of
them as are laws of the human mind, and no others, belong to Political
Economy, which finally sums up the result of both combined.

Political Economy, therefore, presupposes all the physical sciences; it
takes for granted all such of the truths of those sciences as are
concerned in the production of the objects demanded by the wants of
mankind; or at least it takes for granted that the physical part of the
process takes place somehow. It then inquires what are the phenomena of
_mind_ which are concerned in the production and distribution [8] of
those same objects; it borrows from the pure science of mind the laws of
those phenomena, and inquires what effects follow from these mental
laws, acting in concurrence with those physical one. [9]

From the above considerations the following seems to come out as the
correct and complete definition of Political Economy:--"The science
which treats of the production and distribution of wealth, so far as
they depend upon the laws of human nature." Or thus--science relating to
the moral or psychological laws of the production and distribution of
wealth."

For popular use this definition is amply sufficient, but it still falls
short of the complete accuracy required for the purposes of the
philosopher. Political Economy does not treat of the production and
distribution of wealth in all states of mankind, but only in what is
termed the social state; nor so far as they depend upon the laws of
human nature, but only so far as they depend upon a certain portion of
those laws. This, at least, is the view which must be taken of Political
Economy, if we mean it to find any place in an encyclopedical division
of the field of science. On any other view, it either is not science at
all, or it is several sciences. This will appear clearly, if, on the one
hand, we take a general s