And if the world does not in all respects correspond to our wishes, is this the fault of science, or of those who would impose their wishes on the world? All the mammals — and many other animals as well — experience emotions: fear, lust, hope, pain, love, hate, the need to be led. Humans may brood about the future more, but there is nothing in our emotions unique to us. On the other hand, no other species does science as much or as well as we. How then can science be “dehumanizing”?

Are [animals] not furnished with most feelings similar to our own? They indisputably evince in an eminent degree most of the same passions. Things which affect us, generally seem to affect them in the same way; and at least the following sensations and passions are common to both, viz. hunger, desire, emulation, love of liberty, playfulness, fear, shame, anger, and many other affections though they are destitute of the power of laughter. But little occasion have they to exercise such a faculty!

Animals cry. At least, they vocalise pain or distress, and perhaps call for help. Most people believe, therefore, that animals can be unhappy and also that they have such feelings as happiness, anger and fear. But there is a tremendous gap between the common sense viewpoint and that of official science on this subject. The ordinary layperson readily believes that his dog, her eat, their parrot or horse, feels. They not only believe it but have constant evidence of it before their eyes. All of us have extraordinary stories of animals we know well. Yet, by dint of rigorous training and great efforts of the mind, most modern scientists — especially those who study the behaviour of animals — have succeeded in becoming almost blind to these matters.

When looking into the eyes of an animal, how can we not see intelligence and a being in there; how can we not know that they have thoughts and feelings? Animals are sentient beings

Most of the more complex emotions are common to the higher animals and ourselves. Every one has seen how jealous a dog is of his master's affection, if lavished on any other creature; and I have observed the same fact with monkeys. This shews that animals not only love, but have the desire to be loved.

'Tis evident, that sympathy, or the communication of passions, takes place among animals, no less than among men. Fear, anger, courage and other affections are frequently communicated from one animal to another [...] And 'tis remarkable, that tho' almost all animals use in play the same member, and nearly the same action as in fighting; a lion, a tyger, a cat their paws; an ox his homs; a dog his teeth; a horse his heels: Yet they most carefully avoid harming their companion, even tho' they have nothing to fear from his resentment; which is an evident proof of the sense brutes have of each other's pain and pleasure.

The lower animals, like man, manifestly feel pleasure and pain, happiness and misery. Happiness is never better exhibited than by young animals, such as puppies, kittens, lambs, &c., when playing together, like our own children. Even insects play together, as has been described by that excellent observer, P. Huber, who saw ants chasing and pretending to bite each other, like so many puppies.
The fact that the lower animals are excited by the same emotions as ourselves is so well established, that it will not be necessary to weary the reader by many details. Terror acts in the same manner on them as on us, causing the muscles to tremble, the heart to palpitate, the sphincters to be relaxed, and the hair to stand on end. Suspicion, the offspring of fear, is eminently characteristic of most wild animals. Courage and timidity are extremely variable qualities in the individuals of the same species, as is plainly seen in our dogs. Some dogs and horses are ill-tempered and easily turn sulky; others are good-tempered; and these qualities are certainly inherited.

The professional and financial interest in continuing animal experimentation helps to explain at least some resistance to the notion that animals have a complex emotional life and are capable of experiencing the higher emotions, such as love, compassion, altruism, disappointment and nostalgia. To acknowledge such a possibility implies certain moral obligations. If chimpanzees can experience loneliness and mental anguish, it becomes more wrong to use them for experiments in which they are isolated and anticipate daily pain.

Besides love and sympathy, animals exhibit other qualities connected with the social instincts which in us would be called moral.

Animals do not possess this ability. We call it “self-awareness” or the ability to think about your very thought process.

Do dogs feel for humans something akin to religious ecstasy? What other strong or subtle emotions are felt by animals that do not communicate with us?

We find amongst animals, as amongst men, power of feeling pleasure, power of feeling pain; we see them moved by love and by hate; we see them feeling terror and attraction; we recognize in them powers of sensation closely akin to our own, and while we transcend them immensely in intellect, yet, in mere passional characteristics our natures and the animals' are closely allied. We know that when they feel terror, that terror means suffering. We know that when a wound is inflicted, that wound means pain to them. We know that threats bring to them suffering; they have a feeling of shrinking, of fear, of absence of friendly relations, and at once we begin to see that in our relations to the animal kingdom a duty arises which all thoughtful and compassionate minds should recognize - the duty that because we are stronger in mind than the animals, we are or ought to be their guardians and helpers, not their tyrants and oppressors, and we have no right to cause them suffering and terror merely for the gratification of the palate, merely for an added luxury to our own lives.

Dumb creatures have not human feelings, but have certain impulses which resemble them: for if it were not so, if they could feel love and hate, they would likewise be capable of friendship and enmity, of disagreement and agreement. Some traces of these qualities exist even in them, though properly all of them, whether good or bad, belong to the human breast alone.

Machines do not have feelings... This is not to say that no inanimate objects have feelings -- toys are loaded with feelings, for instance, and only a monster would break the heart of a rag doll.