SECT. XXV. Of Sleep.


The natural attendant of food is sleep; in which the animal forbears
not only all his outward motions, but also all the principal inward
operations which might too much stir and dissipate the spirits. He
only retains respiration, and digestion; so that all motions that
might wear out his strength are suspended, and all such as are
proper to recruit and renew it go on freely of themselves. This
repose, which is a kind of enchantment, returns every night, while
darkness interrupts and hinders labour. Now, who is it that
contrived such a suspension? Who is it that so well chose the
operations that ought to continue; and, with so just discernment,
excluded all such as ought to be interrupted? The next day all past
fatigue is gone and vanished. The animal works on, as if he had
never worked before; and this reviving gives him a vivacity and
vigour that invites him to new labour. Thus the nerves are still
full of spirits, the flesh smooth, the skin whole, though one would
think it should waste and tear; the living body of the animal soon
wears out inanimate bodies, even the most solid that are about it;
and yet does not wear out itself. The skin of a horse, for
instance, wears out several saddles; and the flesh of a child,
though very delicate and tender, wears out many clothes, whilst it
daily grows stronger. If this renewing of spirits were perfect, it
would be real immortality, and the gift of eternal youth. But the
same being imperfect, the animal insensibly loses his strength,
decays and grows old, because everything that is created ought to
bear a mark of nothingness from which it was drawn; and have an end.