e above attempt to frame a stricter definition of the science than
what are commonly received as such, may be thought to be of little use;
or, at best, to be chiefly useful in a general survey and classification
of the sciences, rather than as conducing to the more successful pursuit
of the particular science in question. We think otherwise, and for this
reason; that, with the consideration of the definition of a science, is
inseparably connected that of the _philosophic method_ of the science;
the nature of the process by which its investigations are to be carried
on, its truths to be arrived at.

Now, in whatever science there are systematic differences of opinion
--which is as much as to say, in all the moral or mental sciences, and
in Political Economy among the rest; in whatever science there exist,
among those who have attended to the subject, what are commonly called
differences of principle, as distinguished from differences of
matter-of-fact or detail,--the cause will be found to be, a difference
in their conceptions of the philosophic method of the science. The
parties who differ are guided, either knowingly or unconsciously, by
different views concerning the nature of the evidence appropriate to the
subject. They differ not solely in what they believe themselves to see,
but in the quarter whence they obtained the light by which they think
they see it.

The most universal of the forms in which this difference of method is
accustomed to present itself, is the ancient feud between what is called
theory, and what is called practice or experience. There are, on social
and political questions, two kinds of reasoners: there is one portion
who term themselves practical men, and call the others theorists; a
title which the latter do not reject, though they by no means recognise
it as peculiar to them. The distinction between the two is a very broad
one, though it is one of which the language employed is a most incorrect
exponent. It has been again and again demonstrated, that those who are
accused of despising facts and disregarding experience build and profess
to build wholly upon facts and experience; while those who disavow
theory cannot make one step without theorizing. But, although both
classes of inquirers do nothing but theorize, and both of them consult
no other guide than experience, there is this difference between them,
and a most important difference it is: that those who are called
practical men require