If we suppose that, together with these advantages, the military character
of a people remains, or is improved, it must follow, that what is gained in
civilization, is a real increase of strength; and that the ruin of nations
could never take its rise from themselves. Where states have stopped short
in their progress, or have actually gone to decay, we may suspect, that
however disposed to advance, they have found a limit, beyond which they
could not proceed; or from a remission of the national spirit, and a
weakness of character, were unable to make the most of their resources, and
natural advantages. On this supposition, from being stationary, they may
begin to relapse, and by a retrograde motion in a succession of ages,
arrive at a state of greater weakness, than that which they quitted in the
beginning of their progress; and with the appearance of better arts, and
superior conduct, expose themselves to become a prey to barbarians, whom,
in the attainment, or the height of their glory, they had easily baffled or
despised.

Whatever may be the natural wealth of a people, or whatever may be the
limits beyond which they cannot improve on their stock, it is probable,
that no nation has ever reached those limits, or has been able to postpone
its misfortunes, and the effects of misconduct, until its fund of
materials, and the fertility of its soil, were exhausted, or the numbers of
its people were greatly reduced. The same errors in policy, and weakness of
manners, which prevent the proper use of resources, likewise check their
increase, or improvement. The wealth of the state consists in the fortune
of its members. The actual revenue of the state is that share of every
private fortune, which the public has been accustomed to demand for
national purposes. This revenue cannot be always proportioned to what may
be supposed redundant in the private estate, but to what is, in some
measure, thought so by the owner; and to what he may be made to spare,