From what we have already observed on the general characteristics of human
nature, it has appeared that man is not made for repose. In him every
amiable and respectable quality, is an active power, and every subject of
commendation an effort. If his errors and his crimes are the movements of
an active being, his virtues and his happiness consist likewise in the
employment of his mind; and all the lustre which he casts around him, to
captivate or engage the attention of his fellow creatures, like the flame
of a meteor, shines only while his motion continues; the moments of rest
and obscurity are the same. We know, that the tasks assigned him frequently
may exceed, as well as come short of, his powers; that he may be agitated
too much, as well as too little; but cannot ascertain a precise medium
between the situations in which he would be harassed, and those in which he
would fall into languor. We know that he may be employed on a great variety
of subjects, which occupy different passions; and that, in consequence of
habit, he becomes reconciled to very different scenes. All we can determine
in general is, that whatever be the subjects with which he is engaged, the
frame of his nature requires him to be occupied, and his happiness requires
him to be just.

We are now to inquire, why nations cease to be eminent; and why societies
which have drawn the attention of mankind by great examples of magnanimity,
conduct, and national success, should sink from the height of their
honours, and yield, in one age, the palm which they had won in a former.
Many reasons will probably occur. One may be taken from the fickleness and
inconstancy of mankind, who become tired of their pursuits and exertions,
even while the occasions that gave rise to those pursuits; in some measure,
continue; another, from the change of situations, and the removal of
objects which served to excite their spirit.