In the same manner, and upon the same principles, may we explain, however complicated they appear, all the actions of animals, without allowing them either thought or reflection; the internal sense being sufficient to produce all their movements. The nature of their sensations alone remains to be elucidated, which, from what we have asserted, must be widely different from ours. “Have animals, it may be said, no knowledge, no consciousness of their existence? Do you deprive them of sentiment? In pretending to explain their actions upon mechanical principles, do you not in fact render them mere machines, or insensible automatons?”
If I have been rightly understood, it must have appeared that, far from divesting animals of all powers, I allow them every thing, thought and reflection excepted. Feelings they have, in a degree superior to ourselves. A consciousness they also have of their present, though not of their past existence. They have sensations, but they have not the faculty of comparing them, or of producing ideas: ideas being nothing more than associations of sensations.
Each of these objects let us examine in particular. That animals have feelings, and in a degree even more exquisite than ourselves, I think we have already evinced, by what we have said of the excellence of their senses relative to appetite. Like ourselves then, animals are affected by pleasure and pain; they do not know good and evil, but they feel it; what is agreeable to them is good, what is disagreeable is bad, and both are nothing more than relations, suitable, or contrary to their nature and organization. The pleasure of tickling, and the pain from a hurt, as they depend absolutely on an action more or less strong upon the nerves, which are the organs of sentiment, are alike common to man and other animals. Whatever acts softly upon these organs, is a cause of pleasure, and whatever shakes them violently, is a cause of pain. All sensations, then, are sources of pleasure, while they are moderate, and natural; but so soon as they become too strong, they produce pain, which, in a physical sense, is the extreme, rather than the opposite of pleasure.
A light too bright, a fire too hot, a noise too loud, a smell too strong, coarse victuals and severe friction, excite in us disagreeable sensations; whereas a delicate colour, a moderate heat, a soft sound, a gentle perfume, a fine savour, and light touch, please and move us with delight. Every gentle application to the senses, then, is a pleasure, and every violent shock a pain; and as the causes which occasion violent, happen more rarely in Nature than those which produce mild and moderate effects; and as animals, by the exercise of their senses, acquire in a little time the habit of avoiding every thing offensive or hurtful to them, and of distinguishing, and of approaching such as are pleasing; so without doubt they enjoy more agreeable sensations than disagreeable ones, and the amount of their pleasures exceed the amount of their pain.
In man, physical pleasure and pain form the smallest part of his sufferings or enjoyments. His imagination, never idle, seems perpetually employed to increase his misery; presenting to the mind nothing but vain phantoms, or exaggerated images. More agitated by these illusions, than by real objects, the mind loses its faculty of judging, and even its dominion; the will, of which it has no longer the command, becomes a burthen; its extravagant desires are sorrows; and, at best, its prospects are delusive pleasures, which vanish as soon as the mind, resuming its place, is enabled to form a judgment of them.
In searching for pleasure, we create ourselves pain; and seeking to be more happy, we increase our misery; the less we desire, the more we possess. In fine, whatever we wish beyond what Nature has given is pain; and nothing is pleasure but what she offers of herself. Nature presents to us pleasures without number; she has provided for our wants, and fortified us against pain. In the physical world, there is infinitely more good than evil; and therefore it is not the realities but the chimeras which we have to dread: it is not pain of body, disease, nor death that are terrible; but the agitation of the soul, the conflict of the passions, the mental anxiety, are those only we need apprehend.
Animals have but one mode of enjoying pleasure; the satisfying their appetite by the exercise of their sensations. We likewise enjoy this faculty, and have another mode of acquiring pleasure, the exercise of the mind, whose appetite is knowledge. This source of pleasure would be the more pure and copious did not our passions oppose its current, and divert the mind from contemplation. So soon as these obtain the ascendancy, reason is silenced; a disgust to truth ensues; the charm of illusion increases; error fortifies, itself, and drags us on to misery; for what misery can be greater than no longer seeing things as they are; to have judgment perverted by passions; to act solely by its direction, to appear in consequence unjust or ridiculous to others; and when the hour of self-examination comes, of being forced to despise ourselves?
In this state of illusion and darkness we would change the nature of our soul. She was given us for the purposes of knowledge, and we would employ her solely for those of sensation. Could we extinguish her light, far from regretting the loss, with pleasure should we embrace the lot of idiots. As we no longer reason but during intervals, and as these intervals are troublesome, and spent in secret reproaches, we wish to suppress them, and thus proceeding from one illusion to another, we at length endeavour to lose all knowledge and remembrance of ourselves.