animals are multicellular, eukaryotic organisms of the kingdom Animalia (also called Metazoa). All animals are motile, meaning they can move spontaneously and independently at some point in their lives. Their body plan eventually becomes fixed as they develop, although some undergo a process of metamorphosis later on in their lives. All animals are heterotrophs: they must ingest other organisms or their products for sustenance.
Organized alphabetically by author.
- The fox knows many things, but the hedgehog one big one.
- Archilochus, in Plutarch Moralia.
- Oh, God, enlarge within us the sense of fellowship with all living things, our brothers the animals to whom Thou gavest the earth in common with us. We remember with shame that in the past we have exercised the high dominion of man with ruthless cruelty so that the voice of the earth, which should have gone up to thee in song, has been a groan of travail.
- I believe that animals have rights which, although different from our own, are just as inalienable. I believe animals have the right not to have pain, fear or physical deprivation inflicted upon them by us. … They have the right not to be brutalized in any way as food resources, for entertainment or any other purpose.”
- The Dodo never had a chance. He seems to have been invented for the sole purpose of becoming extinct and that was all he was good for.
- Will Cuppy, How to Become Extinct, 1941.
- 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.
- 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.
- As dogs, cats, horses, and probably all the higher animals, even birds, as is stated on good authority, have vivid dreams, and this is shewn by their movements and voice, we must admit that they possess some power of imagination. … Few persons any longer dispute that animals possess some power of reasoning. Animals may constantly be seen to pause, deliberate, and resolve. It is a significant fact, that the more the habits of any particular animal are studied by a naturalist, the more he attributes to reason and the less to unlearnt instincts.
- Sympathy beyond the confines of man, that is humanity to the lower animals, seems to be one of the latest moral acquisitions. It is apparently unfelt by savages, except towards their pets. … This virtue, one of the noblest with which man is endowed, seems to arise incidentally from our sympathies becoming more tender and more widely diffused, until they are extended to all sentient beings. As soon as this virtue is honoured and practised by some few men, it spreads through instruction and example to the young, and eventually through public opinion.
- Men will seem to see new destructions in the sky. The flames that fall from it will seem to rise in it and to fly from it with terror. They will hear every kind of animals speak in human language. They will instantaneously run in person in various parts of the world, without motion. They will see the greatest splendour in the midst of darkness. O! marvel of the human race! What madness has led you thus! You will speak with animals of every species and they with you in human speech. You will see yourself fall from great heights without any harm and torrents will accompany you, and will mingle with their rapid course.
- Leonardo da Vinci, The Notebooks of Leonardo Da Vinci (1938), XX Humorous Writings, as translated by Edward MacCurdy.
- Animals are such agreeable friends - they ask no questions, they pass no criticisms.
- George Eliot, Scences of a Clerical Life (1858).
- A horse is dangerous at both ends and uncomfortable in the middle.
- Ian Fleming, The Sunday Times (1966).
- Animals are always loyal and love you, whereas children you never know where you are.
- Christina Foyle, The Times (1993).
- Researchers find it very necessary to keep blinkers on. They don't want to admit that the animals they are working with have feelings. They don't want to admit that they might have minds and personalities because that would make it quite difficult for them to do what they do; so we find that within the lab communities there is a very strong resistance among the researchers to admitting that animals have minds, personalities and feelings.
- Thousands of people who say they "love" animals sit down once or twice a day to enjoy the flesh of creatures who have been utterly deprived of everything that could make their lives worth living and who endured the awful suffering and the terror of the abattoirs— and the journey to get there— before finally leaving their miserable world, only too often after a painful death.
- Jane Goodall The Ten Trusts (2003), p. xv.
- The more we learn of the true nature of non-human animals, especially those with complex brains and corresponding complex social behavior, the more ethical concerns are raised regarding their use in the service of man—whether this be in entertainment, as "pets," for food, in research laboratories, or any of the other uses to which we subject them.
- Jane Goodall Through a Window: My Thirty Years with the Chimpanzees of Gombe (2000), p. 245.
- I wanted to talk to the animals like Dr. Dolittle.
- Jane Goodall as reported in Brad Dunn, "Change of Scenery", When They Were 22: 100 Famous People at the Turning Point in Their Lives (2006), p. 51.
- Animals when in company walk in a proper and sensible manner, in single file, instead of sprawling all across the road and being of no use or support to each other in case of sudden trouble or danger.
- Well to understand animal thinking you've got to get away from a language. See my mind works like Google for images. You put in a key word; it brings up pictures. See language for me narrates the pictures in my mind. When I work on designing livestock equipment I can test run that equipment in my head like 3-D virtual reality. In fact, when I was in college I used to think that everybody was able to do that. And language just sort of, you know, gives an opinion. Like, oh, that's a good idea or oh, I just figured out how to design that.
- I designed a system holding a cattle in the meat plant, where they straddle a conveyor. And if you get things set up right they just walk in really quietly.
- And you've got to get the lighting right. They're afraid of the dark. If the lights were going, blasting in their eyes like the sun or there's a reflection on a shinny piece of metal moving, they're going to be afraid of that. And you get rid of those things their afraid of then their going to walk right in.
- You know, the things that scare a prey/species animal like cattle are a whole lot of little visual details that people just don't tend to notice. And one of the big problems they used to have is the people just wanted to get out there and yell and scream and push and shove and you know more and more prods. Rather than remove the things that the cattle were afraid of.
- Temple Grandin 
- Animals are the main victims of history, and the treatment of domesticated animals in industrial farms is perhaps the worst crime in history.
- The fate of farm animals is not an ethical side issue. It concerns the majority of Earth's large creatures: tens of billions of sentient beings, each with a complex world of sensations and emotions, but who live and die as cogs in an industrial production line.
- Next to the ridicule of denying an evident truth, is that of taking much pains to defend it; and no truth appears to me more evident, than that beasts are endow'd with thought and reason as well as men. The arguments are in this case so obvious, that they never escape the most stupid and ignorant.
- 'Tis from the resemblance of the external actions of animals to those we ourselves perform, that we judge their internal likewise to resemble ours; and the same principle of reasoning, carry'd one step farther, will make us conclude that since our internal actions resemble each other, the causes, from which they are deriv'd, must also be resembling.
- The very port and gait of a swan, or turkey, or peacock show the high idea he has entertain'd of himself; and his contempt of all others. This is the more remarkable, that in the two last species of animals, the pride always attends the beauty, and is discover'd in the male only. The vanity and emulation of nightingales in singing have been commonly remark'd […] All these are evident proofs, that pride and humility are not merely human passions, but extend themselves over the whole animal creation.
- '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.
- We have enslaved the rest of the animal creation, and have treated our distant cousins in fur and feathers so badly that beyond doubt, if they were able to formulate a religion, they would depict the Devil in human form.
- Siquidem et per naturam pleraque mutationem recipiunt, et corrupta in diversas species transformantur; sicut de vitulorum carnibus putridis apes, sicut de equis scarabei, de mulis locustae, de cancris scorpiones.
- Many creatures go through a natural change and by decay pass into different forms, as bees [are formed] by the decaying flesh of calves, as beetles from horses, locusts from mules, scorpions from crabs.
- Isidore of Seville Etymologiae Bk. 11, ch. 4, sect. 3; p. 221. Translations and page-numbers are taken from Ernest Brehaut An Encyclopedist of the Dark Ages: Isidore of Seville (New York: B. Franklin,  1964).
- To my way of thinking there’s something wrong, or missing, with any person who hasn’t got a soft spot in their heart for an animal of some kind. With most folks the dog stands highest as man’s friend, then comes the horse, with others the cat is liked best as a pet, or a monkey is fussed over; but whatever kind of animal it is a person likes, it’s all hunkydory so long as there’s a place in the heart for one or a few of them.
- Will James, Smoky, the Cow Horse (1929), Preface, p. v.
- So Jehovah blessed the last part of Job’s life more than the beginning, and Job came to have 14,000 sheep, 6,000 camels, 1,000 pairs of cattle, and 1,000 female donkeys. He also came to have seven more sons and three more daughters.
- True human goodness, in all its purity and freedom, can come to the fore only when its recipient has no power. Mankind's true moral test, its fundamental test (which lies deeply buried from view), consists of its attitude toward those who are at its mercy: animals. And in this respect mankind has suffered a fundamental debacle, a debacle so fundamental that all others stem from it.
- Cet animal est tres méchant;
Quand on l'attaque il se défend.
- This animal is very malicious; when attacked it defends itself.
- From a song, La Ménagerie, reported in Hoyt's New Cyclopedia Of Practical Quotations (1922), p. 30.
- At one time the benevolent affections embrace merely the family, soon the circle expanding includes first a class, then a nation, then a coalition of nations, then all humanity, and finally, its influence is felt in the dealings of man with the animal world. In each of these stages a standard is formed, different from that of the preceding stage, but in each case the same tendency is recognised as virtue.
- It is abundantly evident, both from history and from present experience, that the instinctive shock, or natural feeling of disgust, caused by the sight of the sufferings of men is not generically different from that which is caused by the sight of the sufferings of animals.
- There are many people who have undergone great suffering who seem to possess knowledge of the deepest recesses of human emotion unavailable to the rest of us. They may want to impart it, but we often cannot hear. Strangely enough, farm animals strike me in the same way.
- We are not just rather like animals; we are animals. Our difference from other species may be striking, but comparisons with them have always been, and must be, crucial to our view of ourselves.
- Mary Midgley, Beast and Man: The Roots of Human Nature (1979), Introduction.
- Granted that any practice causes more pain to animals than it gives pleasure to man; is that practice moral or immoral? And if, exactly in proportion as human beings raise their heads out of the slough of selfishness, they do not with one voice answer 'immoral,' let the morality of the principle of utility be for ever condemned.
- While a man was walking along a road, he became very thirsty and found a well. He lowered himself into the well, drank, and came out. Then [he saw] a dog protruding its tongue out with thirst. The man said: "This dog has become exhausted from thirst in the same way as I." He lowered himself into the well again and filled his shoe with water. He gave the dog some water to drink. He thanked God, and [his sins were] forgiven. The Prophet was then asked: "Is there a reward for us in our animals?" He said: "There is a reward in every living thing.
- Muhammad Fiqh-us-Sunnah, Volume 3, Number 104
- A prostitute was forgiven by Allah, because, passing by a panting dog near a well and seeing that the dog was about to die of thirst, she took off her shoe, and tying it with her head-cover she drew out some water for it. So, Allah forgave her because of that.
- Muhammad Bukhari 4:538
- Allah's Messenger (may peace be upon him) said: A woman was punished because she had kept a cat tied until it died, and (as a punishment of this offence) she was thrown into Hell. She had not provided it with food or drink, and had not freed her so that she could eat the insects of the earth.
- Muhammad narrated in Saheeh Muslim, Book 026, Number 5570
- Now what is it that moves our very hearts and sickens us so much at cruelty shown to poor brutes? … They have done us no harm and they have no power of resistance; it is the cowardice and tyranny of which they are the victims which make their sufferings so especially touching. Cruelty to animals is as if man did not love God. … There is something so very dreadful, so Satanic, in tormenting those who have never harmed us, who cannot defend themselves, who are utterly in our power.
- The creatures outside looked from pig to man, and from man to pig, and from pig to man again; but already it was impossible to say which was which.
- The industrialization — and brutalization — of animals in America is a relatively new, evitable, and local phenomenon: No other country raises and slaughters its food animals quite as intensively or as brutally as we do. No other people in history has lived at quite so great a remove from the animals they eat. Were the walls of our meat industry to become transparent, literally or even figuratively, we would not long continue to raise, kill, and eat animals the way we do.
- Michael Pollan, The Omnivore's Dilemma: A Natural History of Four Meals (New York: The Penguin Press, 2006), p. 333.
- I think that when friendship and perception of kinship ruled everything, no one killed any creature, because people thought the other animals were related to them.
- Animals are rational; in most of them logos is imperfect, but it is certainly not wholly lacking. So if, as our opponents say, justice applies to rational beings, why should not justice, for us, also apply to animals?
- Porphyry, On Abstinence from Killing Animals, translated by Gillian Clark (Bloomsbury, 2014), 3, 18, 1.
- MAN IS FUNDAMENTALLY AN ANIMAL. Animals, as distinct from man, are not machine-like, not sadistic; their societies, within the same species, are incomparably more peaceful than those of man. The basic question, then is: What has made the animal, man, degenerate into a machine?
When I say "animal," I do not mean anything bad, cruel or "base"; I am stating a biological fact. Man has developed the peculiar concept that he is not an animal at all, but, well — man; a creature which long since has shed that which is "bad," which is "animal." He demarcates himself in all possible ways from the bad animal and points, in proof of his "being better," to culture and civilization which distinguish him from the animal. He shows, in his whole behavior, his "theories of values," his moral philosophies, his "monkey trials" and such, that he does not want to be reminded of the fact that basically he is an animal, an animal, furthermore, which has much more in common with the "animal" than with that being which he asserts to be and dreams of being. The theory of the German Übermensch has this origin. Man shows by his maliciousness, his inability to live in peace with his kind, his wars, that what distinguishes him from the other animals is only his unbounded sadism and the mechanical trinity of the authoritarian concept of life, mechanistic science and the machine. If one looks at the results of civilization as they present themselves over long periods of time, one finds that these contentions of man are not only erroneous; more than that, they seem to be made expressly for the purpose of making man forget that he is an animal.
- Wilhelm Reich, critiquing prominent early 20th century ideas of Übermensch in The Mass Psychology of Fascism (1933), Ch. 10 : Work Democracy, Section 3 : Work Democracy versus Politics. The Natural Social Forces for the Mastery of the Emotional Plague.
- The emancipation of men from cruelty and injustice will bring with it in due course the emancipation of animals also. The two reforms are inseparably connected, and neither can be fully realized alone.
- Thus, because Christian morals leave animals out of consideration … therefore in philosophical morals they are of course at once outlawed; they are merely "things," simply means to ends of any sort; and so they are good for vivisection, for deer-stalking, bull-fights, horse-races, etc., and they may be whipped to death as they struggle along with heavy quarry carts. Shame on such a morality … which fails to recognize the Eternal Reality immanent in everything that has life, and shining forth with inscrutable significance from all eyes that see the sun!
- The Animals, you say, were "sent"
For man's free use and nutriment.
Pray, then, inform me, and be candid,
Why came they aeons before Man did,
To spend long centuries on earth,
Awaiting their Devourer's birth?
Those ill-timed chattels, sent from Heaven,
Were, sure, the maddest gift e'er given—
"Sent" for Man's usage (can Man believe it?)
When there was no Man to receive it!
- Henry S. Salt, The Sending of the Animals, as quoted in The Savour of Salt: A Henry Salt Anthology, Centaur Press, 1989, p. 55.
- What a piece of work is a man! How noble in reason! how infinite in faculty! in form, in moving, how express and admirable! in action how like an angel! in apprehension how like a god! the beauty of the world! the paragon of animals! And yet, to me, what is this quintessence of dust? Man delights not me; no, nor woman neither, though, by your smiling, you seem to say so.
- The animals themselves are incapable of demanding their own liberation, or of protesting against their condition with votes, demonstrations, or boycotts. Human beings have the power to continue to oppress other species forever, or until we make this planet unsuitable for living beings. Will our tyranny continue, proving that morality counts for nothing when it clashes with selfinterest, as the most cynical of poets and philosophers have always said? Or will we rise to the challenge and prove our capacity for genuine altruism by ending our ruthless exploitation of the species in our power, not because we are forced to do so by rebels or terrorists, but because we recognize that our position is morally indefensible? The way in which we answer this question depends on the way in which each one of us, individually, answers it.
- When a human being relates to an individual nonhuman being as an anonymous object, rather than as a being with its own subjectivity, it is the human, and not the other animal, who relinquishes personhood.
- What a pity and what a poverty of spirit, to assert that beasts are machines deprived of knowledge and sentiment, which affect all their operations in the same manner, which learn nothing, never improve, &c. […] Some barbarians seize this dog, who so prodigiously excels man in friendship, they nail him to a table, and dissect him living, to show the mezarian veins. You discover in him all the same organs of sentiment which are in yourself. Answer me, machinist, has nature arranged all the springs of sentiment in this animal that he should not feel? Has he nerves to be incapable of suffering? Do not suppose this impertinent contradiction in nature. […] The animal has received those of sentiment, memory, and a certain number of ideas. Who has bestowed these gifts, who has given these faculties? He who has made the herb of the field to grow, and who makes the earth gravitate towards the sun.
- There are two things for which animals are to be envied: they know nothing of future evils, or of what people say about them.
- Voltaire, Letter (1739).