Let us confine ourselves within the animal’s machine, which has three things that never can be too much admired: First, it has in it wherewithal to defend itself against those that attack it, in order to destroy it. Secondly, it has a faculty of reviving itself by food. Thirdly, it has wherewithal to perpetuate its species by generation. Let us bestow some considerations on these three things.
SECT. XXIII. Of the Instinct of the Animal.
Animals are endowed with what is called instinct, both to approach useful and beneficial objects, and to avoid such as may be noxious and destructive to them. Let us not inquire wherein this instinct consists, but content ourselves with matter of fact, without reasoning upon it.
The tender lamb smells his dam afar off, and runs to meet her. A sheep is seized with horror at the approach of a wolf, and flies away before he can discern him. The hound is almost infallible in finding out a stag, a buck, or a hare, only by the scent. There is in every animal an impetuous spring, which, on a sudden, gathers all the spirits; distends all the nerves; renders all the joints more supple and pliant; and increases in an incredible manner, upon sudden dangers, his strength, agility, speed, and cunning, in order to make him avoid the object that threatens his destruction. The question in this place is not to know whether beasts are endowed with reason or understanding; for I do not pretend to engage in any philosophical inquiry. The motions I speak of are entirely indeliberate, even in the machine of man. If, for instance, a man that dances on a rope should, at that time, reason on the laws and rules of equilibrium, his reasoning would make him lose that very equilibrium which he preserves admirably well without arguing upon the matter, and reason would then be of no other use to him but to throw him on the ground. The same happens with beasts; nor will it avail anything to object that they reason as well as men, for this objection does not in the least weaken my proof; and their reasoning can never serve to account for the motions we admire most in them. Will any one affirm that they know the nicest rules of mechanics, which they observe with perfect exactness, whenever they are to run, leap, swim, hide themselves, double, use shifts to avoid pursuing hounds, or to make use of the strongest part of their bodies to defend themselves? Will he say that they naturally understand the mathematics which men are ignorant of? Will he dare to advance that they perform with deliberation and knowledge all those impetuous and yet so exact motions which even men perform without study or premeditation? Will he allow them to make use of reason in those motions, wherein it is certain man does not? It is an instinct, will he say, that beasts are governed by. I grant it: for it is, indeed, an instinct. But this instinct is an admirable sagacity and dexterity, not in the beasts, who neither do, nor can then, have time to reason, but in the superior wisdom that governs them. That instinct, or wisdom, that thinks and watches for beasts, in indeliberate things, wherein they could neither watch nor think, even supposing them to be as reasonable as we, can be no other than the wisdom of the Artificer that made these machines. Let us therefore talk no more of instinct or nature, which are but fine empty names in the mouth of the generality that pronounce them. There is in what they call nature and instinct a superior art and contrivance, of which human invention is but a shadow. What is beyond all question is, that there are in beasts a prodigious number of motions entirely indeliberate, and which yet are performed according to the nicest rules of mechanics. It is the machine alone that follows those rules: which is a fact independent from all philosophy; and matter of fact is ever decisive. What would a man think of a watch that should fly or slip away, turn, again, or defend itself, for its own preservation, if he went about to break it? Would he not admire the skill of the artificer? Could he be induced to believe that the springs of that watch had formed, proportioned, ranged, and united themselves, by mere chance? Could he imagine that he had clearly explained and accounted for such industrious and skilful operation by talking of the nature and instinct of a watch that should exactly show the hour to his master, and slip away from such as should go about to break its springs to pieces?
SECT. XXIV. Of Food.
What is more noble than a machine which continually repairs and renews itself? The animal, stinted to his own strength, is soon tired and exhausted by labour; but the more he takes pains, the more he finds himself pressed to make himself amends for his labour, by more plentiful feeding. Aliments daily restore the strength he had lost. He puts into his body another substance that becomes his own, by a kind of metamorphosis. At first it is pounded, and being changed into a liquor, it purifies, as if it were strained through a sieve, in order to separate anything that is gross from it; afterwards it arrives at the centre, or focus of the spirits, where it is subtilised, and becomes blood. And running at last, and penetrating through numberless vessels to moisten all the members, it filtrates in the flesh, and becomes itself flesh. So many aliments, and liquors of various colours, are then no more than one and the same flesh; and food which was but an inanimate body preserves the life of the animal, and becomes part of the animal himself; the other parts of which he was composed being exhaled by an insensible and continual transpiration. The matter which, for instance, was four years ago such a horse, is now but air, or dung. What was then either hay, or oats, is become that same horse, so fiery and vigorous—at least, he is accounted the same horse, notwithstanding this insensible change of his substance.
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.
SECT. XXVI. Of Generation.
What is more admirable than the multiplication of animals? Look upon the individuals: no animal is immortal. Everything grows old, everything passes away, everything disappears, everything, in short, is annihilated. Look upon the species: everything subsists, everything is permanent and immutable, though in a constant vicissitude. Ever since there have been on earth men that have taken care to preserve the memory of events, no lions, tigers, wild boars, or bears, were ever known to form themselves by chance in caves or forests. Neither do we see any fortuitous productions of dogs or cats. Bulls and sheep are never born of themselves, either in stables, folds, or on pasture grounds. Every one of those animals owes his birth to a certain male and female of his species.