God has also given hunger and thirst to animals, to compel them to feed and maintain themselves by replacing that which is used up and which disappears imperceptibly.  These appetites are of use also to prompt them to work, in order to procure a nourishment meet for their constitution, and which may avail to invigorate them.  It was even found necessary by the Author of things that one animal very often should serve as food for another.  This hardly renders the victim more unhappy, since death caused by diseases is generally just as painful as a violent death, if not more so; and animals subject to being preyed upon by others, having neither foresight nor anxiety for the future, have a life no less tranquil when they are not in danger.  It is the same with inundations, earthquakes, thunderbolts and other disorders, which brute beasts do not fear, and which men have ordinarily no cause to fear, since there are few that suffer thereby.

10.  The Author of Nature has compensated for these evils and others, which happen only seldom, with a thousand advantages that are ordinary and constant.  Hunger and thirst augment the pleasure experienced in the taking of nourishment.  Moderate work is an agreeable exercise of the animal’s powers; and sleep is also agreeable in an altogether opposite way, restoring the forces through repose.  But one of the pleasures most intense is that which prompts animals to propagation.  God, having taken care to ensure that the species should be immortal, since the individual cannot be so here on earth, also willed that animals should have a great tenderness for their little ones, even to the point of endangering themselves for their preservation.  From pain and from sensual pleasure spring fear, cupidity and the other passions that are ordinarily serviceable, although it may accidentally happen that they sometimes turn towards ill:  one must say as much of poisons, epidemic diseases and other hurtful things, namely that these are indispensable consequences of a well-conceived system.  As for ignorance and errors, it must be taken into account that the most perfect creatures are doubtless ignorant of much, and that knowledge is wont to be proportionate to needs.  Nevertheless it is necessary that one be exposed to hazards which cannot be foreseen, and accidents of such kinds are inevitable.  One must often be mistaken in one’s judgement, because it is not always permitted to suspend it long enough for exact [415] consideration.  These disadvantages are inseparable from the system of things:  for things must very often resemble one another in a certain situation, the one being taken for the other.  But the inevitable errors are not the most usual, nor the most pernicious.  Those which cause us the most harm are wont to arise through our fault; and consequently one would be wrong to make natural evils a pretext for taking one’s own life, since one finds that those who have done so have generally been prompted to such action by voluntary evils.