A System of Logic, by John Stuart Mill  Chapter VII.  Of The
Chemical, Or Experimental, Method In The Social Science.  § 1.
The laws of the phenomena of society are, and can be, nothing
but the laws of the actions and passions of human beings united
together in the social state. Men, however, in a state of
society are still men; their actions and passions are obedient
to the laws of individual human nature. Men are not, when
brought together, converted into another kind of substance, with
different properties; as hydrogen and oxygen are different from
water, or as hydrogen, oxygen, carbon, and azote, are different
from nerves, muscles, and tendons. Human beings in society have
no properties but those which are derived from, and may be
resolved into, the laws of the nature of individual man. In
social phenomena the Composition of Causes is the universal law.
Now, the method of philosophizing which may be termed chemical
overlooks this fact, and proceeds as if the nature of man as an
individual were not concer