_Laws of Motion, common to every Being of Nature.--Attraction and
Repulsion.--Inert Force.--Necessity._


Man is never surprised at those effects, of which he thinks he knows the
cause; he believes he does know the cause, as soon as he sees them act
in an uniform and determinate manner, or when the motion excited is
simple: the descent of a stone, that falls by its own peculiar weight,
is an object of contemplation to the philosopher only; to whom the mode
by which the most immediate causes act, and the most simple motion, are
no less impenetrable mysteries than the most complex motion, and the
manner by which the most complicated causes give impulse. The uninformed
are seldom tempted either to examine the effects which are familiar to
them, or to recur to first principles. They think they see nothing in
the descent of a stone, which ought to elicit their surprise, or become
the object of their research: it requires a NEWTON to feel that the
descent of heavy bodies is a phenomenon, worthy his whole, his most
serious attention; it requires the sagacity of a profound experimental
philosopher, to discover the laws by which heavy bodies fall, by which
they communicate to others their peculiar motion. In short, the mind
that is most practised in philosophical observation, has frequently the
chagrin to find, that the most simple and most common effects escape all
his researches, and remain inexplicable to him.

When any extraordinary, any unusual, effect is produced, to which our
eyes have not been accustomed; or when we are ignorant of the energies
of the cause, the action of which so forcibly strikes our senses, we are
tempted to meditate upon it, and take it into our consideration. The
European, accustomed to the use of GUNPOWDER, passes it by, without
thinking much of its extraordinary energies; the workman, who labours to