derangement of his body, which obliges him to furnish its remedy, he
would not be warned of the necessity of preserving the existence he has
received. Without wants man would be an insensible machine, similar to a
vegetable; like that he would be incapable of preserving himself; he
would not be competent to using the means required to conserve his
being. To his wants are to be ascribed his passions; his desires; the
exercise of his corporeal functions; the play of his intellectual
faculties: they are his wants that oblige him to think; that determine
his will, that induce him to act; it is to satisfy them or rather to put
an end to the painful sensations excited by their presence, that
according to his capacity, to the natural sensibility of his soul, to
the energies which are peculiar to himself, he gives play to his
faculties, exerts the activity of his bodily strength, or displays the
extensive powers of his mind. His wants being perpetual, he is obliged
to labour without relaxation, to procure objects competent to satisfy
them. In a word, it is owing to his multiplied wants that man's energy
is kept in a state of continual activity: as soon as he ceases to have
wants, he falls into inaction--becomes listless--declines into apathy--
sinks into a languor that is incommodious to his feelings or prejudicial
to his existence: this lethargic state of weariness lasts until new
wants, by giving him fresh activity, rouse his dormant faculties--throw
off his stupor--re-animate his vigour, and destroy the sluggishness to
which he had become a prey.

From hence it will be obvious that evil is necessary to man; without it
he would neither be in a condition to know that which injures him; to
avoid its presence; or to seek his own welfare: without this stimulus,
he would differ in nothing from insensible, unorganized beings: if those
evanescent evils which he calls _wants_, did not oblige him to call
forth his faculties, to set his energies in motion, to cull experience,