tical measure of the
forces of love, or hunger, or avarice, by which (among others) the whole
problem is worked out.

It seems to me, therefore, that we must accept the alternative which is
only mentioned to be repudiated by Jevons, namely, that Political
Economy, if not a "mathematical science," must be part of sociology. I
should say that it clearly is so; for if we wish to investigate the
cause of any of the phenomena concerned, and not simply to tabulate from
observations, we are at once concerned with the social structure and
with the underlying psychology. The mathematical methods are quite in
their place when dealing with statistics. The rise and fall of prices,
and so forth, can be stated precisely in figures; and, whenever we can
discover some approximation to a mathematical law (as in the cases I
have noticed) we may work out the results. If, for example, the price of
a commodity under certain conditions bears a certain relation to its
scarcity, we can discover the one fact when the other fact is given,
remembering only that our conclusions are not more certain than our
premisses, and that the observed law depends upon unknown and most
imperfectly knowable conditions. Such results, again, may be very useful
in various ways, as illustrative of the way in which certain laws will
work if they hold good; and, again, as testing many of our general
theories. If you have argued that the price of gold or silver cannot be
fixed, the fact that it has been fixed under certain conditions will of
course lead to a revision of your arguments. But I cannot help thinking
that it is an illusion to suppose that such methods can justify the
assertion that the science as a whole is "mathematical". Nothing,
indeed, is easier than to speak as if you had got a mathematical theory.
Let _x_ mean the desire for marriage and _y_ the fear of want, then
the number of marriages is a function of _x_ and _y_, and I can
express this by symbols as well as by ordinary words. But there is no
magic about the use of symbols. Mathematical inquiries are not fruitful
because symbols are used, but because the symbols represent something
absolutely precise and assignable. The highest mathematical inquiries
are simply ingenious methods of counting; and till you have got
something precise to count, they can take you no further. I cannot help
thinking that this fallacy imposes upon some modern reasoners; that they
assume that they have got the data because