Mill’s second, and closely related, proposition
is based on a fundamental distinction
between activities that affect ‘chiefly’ individuals’
own interests and those that also
affect the interests of others beyond
those (e.g. one’s own children) who are
not yet regarded as independent, autonomous
beings. In a liberal society, he insists, the
pursuit of one’s own interests that do not
affect others is entirely the province of the
individual, within which one must be free to
do as one pleases without the law’s interference.
Where others’ interests are affected,
however, the state may be justified in regulating
the activity – although even there it
should recognize the presumptive superiority
of private ordering and often stay its
hand, out of prudence and a concern for
individual liberty (Mill, [1859–61] 1951).
Obviously, these two domains of the private
and public are neither self-defining nor easy
to measure empirically. More to the point,
the permissible scope of the modern state
turns on precisely where and how the
boundary line between them is to be drawn,
an issue discussed more fully below.