What more useful than all the passions of the mind, ambition, vanity, love, anger?
But how oft do they break their bounds, and cause the greatest convulsions in society?
There is nothing so advantageous in the universe, but what frequently becomes pernicious, by its excess or defect; nor has Nature guarded, with the requisite accuracy, against all disorder or confusion.

The irregularity is never perhaps so great as to destroy any species; but is often sufficient to involve the individuals in ruin and misery.
On the concurrence, then, of these four circumstances, does all or the greatest part of natural evil depend.

Were all living creatures incapable of pain, or were the world administered by particular volitions, evil never could have found access into the universe: and were animals endowed with a large stock of powers and faculties, beyond what strict necessity requires; or were the several springs and principles of the universe so accurately framed as to preserve always the just temperament and medium; there must have been very little ill in comparison of what we feel at present.

What then shall we pronounce on this occasion?
Shall we say that these circumstances are not necessary, and that they might easily have been altered in the contrivance of the universe?
This decision seems too presumptuous for creatures so blind and ignorant.

Let us be more modest in our conclusions.