Humans and Other Animals
A Sense of ‘Otherness’
The walls they’d kept between us, to exact the work of war,
Had crumbled and were gone forevermore […]
The ones who call the shots won’t be among the dead and lame,
And on each end of the rifle we’re the same.
Humans use a variety of tactics to deal with the emotions involved in killing or causing suffering. One of these tactics, which has been prominent in the history of philosophical and religious thought in the West, is to set up a dichotomy between ‘us’ and ‘them.’
The lyrics to the song ‘Christmas in the Trenches,’ which are quoted above, illustrate how the ‘walls’ we set between ourselves and the ‘others’ are sufficient to blind us to the things we have in common with the ‘others.’ In the song, after the soldiers have met and discovered that they aren’t in fact as different as they have been led to believe, they are no longer able to kill one another as easily as before. When the narrator says that he has learnt that “on each end of the rifle we’re the same,” he is saying that he can no longer see any relevant differences between himself and his enemy that would justify doing something to the enemy which he would not want someone to do to him.
Humans, again and again, have justified enslaving and exploiting humans of other races by classifying them as “subhuman” – in other words, not part of the “us,” but part of the “them.” For instance, when the Spaniards began colonizing the Americas in the fifteenth and sixteenth centuries, they slaughtered and enslaved the natives on the pretext of the natives’ being “bestial,” “inferior” and “more stupid than asses.” When humans wish to exploit other races, they place the “others” into a different category so as to be able to justify their own tyranny.
We have fabricated the same sort of conceptual barriers between ourselves and other animals, in order to be able to come to terms with our violence towards them. Most thinkers in the West, over the last few thousand years, have proposed qualities that humans alone possess – “rationality,” “intellect,” a “soul” – to establish the uniqueness of humanity and affirm the ‘otherness’ of animals. Descartes, for example, called animals “thoughtless automatons,” with the explicit intention of justifying anything we wish to do to them – a clear example of erecting a conceptual barrier in order to be able to dismiss our actions towards other animals.
In this chapter I intend to show, not that humans and other animals are the same, but that many other animals are similar enough to us to merit our recognition of their kinship with us. I look at the distinctions that have been made between humans and other animals, and some of the recent discoveries that have been made about the capabilities of non-human animals.
There are, however, both constructive and destructive ways in which humans distinguish themselves from animals. Recognizing how we are different from animals can also serve a purpose.
Accepting that there are differences between ourselves and animals allows us to look at the nature of other animals more objectively (i.e. from a distance) and treat an animal according to who it is, rather than according to that part of ourselves we see in it. On the other hand, we have to be sure that distancing ourselves from animals in this way does not cause us to lose sight of our kinship and similarities with them, which might lead us to form the sort of conceptual barrier that we looked at in the last section.
One of my teachers has said that he feels it is degrading to look at ourselves as animals, because associating ourselves with animals seems to be “limiting” or “base.” But this would only be true if we view animals themselves as being “base.” Recognizing our kinship with animals does not mean that we have to deny our own qualities of justice, beauty, idealism, or nobility, for if we possess these qualities, then these qualities are also a part of the animal kingdom. Just as I need not feel limited as a result of the aspects of evil that I see in humanity, humans need not limit themselves as a result of the “base-ness” they see in other species. Through observing with patient and non-judgmental eyes the rest of our fellow creatures with whom we share the earth, we may find our own true place in the world and explore our unique individuality.
All things are always changing,
But nothing dies. The spirit comes and goes,
Is housed wherever it wills, shifts residence
From beasts to men, from men to beasts, but always
It keeps on living. As the pliant wax
Is stamped with new designs, and is no longer
What once it was, but changes form, and still
Is pliant wax, so do I teach that spirit
Is evermore the same, though passing always
To ever-changing bodies.
Pythagoras, in the sixth century bc, is said to have introduced into Greece the notion of the transmigration of souls. Pythagoras believed that following death, the soul of a person left the body and was reincarnated into another body. It is important for the purposes of our topic to note that he did not limit the scope of this process to humankind. The soul of an animal could be reborn into a human body, and the soul of a human, following death, could be reborn into an animal body. Pythagoras’ belief in the spiritual kinship of all creatures serves as the basis for his principled vegetarianism.
Pythagoras may have derived some of the foundations for his beliefs from Eastern thought. The following story about a Tibetan lama speaking to a group of New Yorkers sheds some light on Eastern thought regarding transmigration:
How (he was asked), if souls transmigrated, could human beings have increased their numbers so much in the last couple of centuries? Where did the extra souls come from for all these new people, and especially for all these new Americans? “Yes indeed”, responded the lama with concern. “And have you ever wondered where all those buffaloes went to?”
The issue of the capacity for language has played an important role in the discussion of humanity’s place amongst the animals. Language is perhaps the most oft-cited characteristic in humanity’s attempts to draw categorical distinctions between itself and the rest of earth’s creatures. Although humanity has used a wide variety of criteria for distinguishing itself from the rest of the animal kingdom, more often than not the proposed traits relate back in some way to our capacity for language. ‘Rationality,’ ‘politics’ and ‘consciousness,’ among our most commonly championed qualities, have all been said to depend on our possession of language.
Prior to the fifth century bc in Greece, ‘voice’ and ‘language’ were scarcely distinguished from one another, and various species of animals, with their distinctive vocalizations, were thought to possess languages of their own, which were, however, unintelligible in the same way that the languages of foreign peoples were. By the time of Aristotle, however, thoughts on the matter had changed. Aristotle drew a sharp line between “voice” and “speech,” granting the former but denying the latter to non-human animals, declaring that “man is the only animal who enjoys [the gift of speech],” and that the vocalizations of other animals can express nothing more than “pleasure and pain.”
Nowhere in my research have I heard anyone argue that non-human animals are incapable of communicating amongst one another – for, indeed, such a belief would be wholly impossible to substantiate. Instead the question revolves around the much-disputed issue of which sorts of communication should qualify as “language.” Since language is so central to humanity’s definition of itself, we would seem to have quite a strong vested interest in ensuring that our definition of language excludes other animals; that is, if we are so insistent upon being unique. As Stephen Clark has said:
[I]t is not that we have discovered [animals] to lack a language but rather that we define, and redefine, what Language is by discovering what beasts do not have. If they should turn out to have the very thing we have hitherto supposed language to be, we will simply conclude that language is something else again. [...] We define our own being by opposition to Theirs, and if They turn out to be rather different from our fantasy we will merely invent another and more subtle distinction.
Language II: Prairie Dogs
Dr. Con Slobodchikoff, a professor in the Biology Department at Northern Arizona University, discovered an incredibly versatile and complex form of communication amongst the prairie dogs of North America, a highly social relative of ground squirrels.
Prairie dogs live in distinct colonies made up of underground burrows. They were named because of the high-pitched bark they produce when they observe a predator near their colony. “A decade ago,” writes Slobodchikoff, “biologists thought that the alarm barks of prairie dogs were simply vocal expressions of fear […] a way of relieving the nervous tension associated with the frightening situation.” Slobodchikoff discovered that not only does a prairie dog’s bark serve to warn its fellows of danger, but it actually involves both semantics (meaning) and syntax (grammar), providing the other prairie dogs with specific information about the predator. Slobodchikoff was able to show that prairie dogs formed “abstract labels” which corresponded with the type of predator, as well as information about the predator’s colour, shape and speed, and, in the case of a human predator, whether or not a gun is being carried. He also showed conclusively that other prairie dogs are able to understand and respond to the specific information contained within a bark. Studying a prairie dog’s call even demonstrates that prairie dogs can identify and communicate the presence of a particular predator, i.e. a specific individual, and remember that predator’s typical hunting techniques, so as to respond appropriately. Slobodchikoff, using spectral analysis, has been able to isolate which parts of the bark contain these various pieces of information. Even more interestingly, prairie dog language seems to be culturally transmitted. Within a colony, the sound used to represent a particular predator is pronounced exactly the same way by each individual, but between colonies, pronunciation differed:
The two colonies that were the farthest apart, separated by twelve miles, had strong differences in pronunciation, analogous to human regional dialects. Colonies that were relatively close together, within a mile apart, had fairly similar pronunciations. This suggested that the calls might be learned by juvenile animals from their parents, just like human dialects, rather than being determined by some genetically controlled instinct for calling in a precise way.
Language III: Parrot Talk
“For it is highly deserving of remark, that there are no men so dull and stupid, not even idiots, as to be incapable of joining together different words, and thereby constructing a declaration by which to make their thoughts understood; and that on the other hand, there is no other animal, however perfect or happily circumstanced, which can do the like. Nor does this inability arise from want of organs: for we observe that magpies and parrots can utter words like ourselves, and are yet unable to speak as we do, that is, so as to show that they understand what they say […]”
One of the difficulties in studying the minds of non-humans through spoken language is that most animals lack the organs that are necessary for emulating the sounds of human speech. For instance, since chimpanzees’ vocal tracts are not able to create the full range of vowels, attempts at teaching them to communicate through speech could never be successful.
Parrots, however, are well known as possessing the ability to create a wide variety of vocal sounds, including noises such as the ringing of a doorbell, and are also capable of reproducing the sounds of human speech. Most people expect that when a parrot says a word, it does not understand the meaning behind what it is saying, and instead it is mindlessly repeating a sound that it has been taught. Irene Pepperberg, working with an African grey parrot named Alex, discovered that parrots have a much higher level of understanding than had previously been imagined.
Pepperberg observed the way parrots are typically taught to speak, and figured out why this method, which involved repeating a phrase over and over again to the birds, was not effective in allowing the birds to learn the meaning behind what they were saying.
“For instance, how is any parrot supposed to learn that ‘Hello!’ is a greeting given by people when they first see each other if its main experience of the word is to have it repeated many times by people standing in front of it for minutes or even hours at a time?”
Now we might be able to see more clearly the reason that parrots generally appear to be speaking nonsense: they are taught nonsense! Pepperberg used a more sensible method, allowing two people to have meaningful conversations, with Alex present, about something of interest to Alex, such as toys or food. Alex would witness the ‘student’ being rewarded for giving the right name for an item, and being told “no” and having the object taken away for giving the wrong name. When Pepperberg and her assistants first began this process, Alex would watch the proceedings with great interest. Then, Alex began to take part, saying the name for objects that he wanted. Pepperberg then began practicing with Alex the same way that she had done with her assistant. Alex rapidly learnt the names for various objects, and was able to recognize them even in varying forms and colours. He could also distinguish how many objects were being shown to him, regardless of their size or shape. Pepperberg taught him to answer questions such as “What’s this?”, “How many?” and “What colour?”, to which he was able to give the appropriate information in spoken response.
At Pepperberg’s request, Alex picks up the “blue” object, demonstrating his ability to deal with generalized concepts.
What does it mean to be conscious? American Heritage Dictionary defines being conscious as:
1.a. Having an awareness of one's environment and one's own existence, sensations, and thoughts. b. Mentally perceptive or alert; awake. 2. Capable of thought, will, or perception.
Friedrich Nietzsche (1844-1900) held that consciousness arose in humanity “under the pressure of the necessity for communication,” and, this necessity not being present in other animals, that humans alone possess consciousness. “[T]he subtlety and strength of consciousness,” Nietzsche says, “are always in proportion to the capacity for communication of a man (or an animal).” There may be some degree of truth to this idea, since being forced to communicate our inner states to others requires that we be clear about them ourselves. However, I think that Nietzsche was mistaken, because communication does not enable consciousness itself, but rather it enables one person to share in the consciousness of another person. Language provides evidence of consciousness, rather than a foundation for consciousness.
I really have no method of determining whether or not the other humans around me are conscious, since I cannot actually experience the world through their eyes. However, I feel justified in assuming that they are conscious, since there is no evidence to the contrary. I know that I myself am conscious, and from this fact I extrapolate that other people, and many animals, most likely have some sort of consciousness as well.
I view the denial of consciousness in non-human animals as a form of ‘species-based solipsism.’ Solipsism is the philosophical belief that nothing exists beyond one’s own experience, that everybody else around oneself is a product of one’s imagination, and that there are no other minds beyond one’s own.
Solipsism may be a stage in human psychological development. As a young child, I remember having strange thoughts around awareness, wondering why it was that I experienced the world while other people did not, and why my awareness came from within myself and not from within others. I imagined this through the metaphor of a bubble:
Why is it that I am myself, that I am the only bubble on the surface of the water? Why is it that all the things of which the world is aware happen within me? Why am I the only one who is aware?
As I grew older, however, I outgrew these solipsistic thoughts by realizing that other people experience the world in the same sort of way that I do, despite the fact that I cannot know what they are thinking or feeling.
The development of an individual shares common threads with the development of humanity as a whole, and a portion of humanity has become stuck at the solipsistic stage regarding the way it views animals. To deny that other animals share with humans an experience and an awareness of the world is to be lost within a solipsistic species-bubble, ignoring the existence of minds beyond our own.
Awareness of Time
I have also heard it said that animals are not aware of time. However, simply because their timing does not always correspond to our artificial temporal constructs is no reason to say that animals cannot be connected to the flow of time and the seasons. Yet there have also been cases in which animals demonstrate that they are able to adjust to artificial human time constructions. Here are two examples:
Sheila Hocken’s guide-dog quickly and spontaneously learned to take her every Friday, without needing to be told the day, to the places where she did her weekend shopping. More remarkably, feral cats who were fed once a week learned to turn up in advance on the day when the feeds were due. This sort of thing is not really surprising if you think of the complexities of life in the wild.
Self-consciousness is a difficult topic to address. It is even harder to define than consciousness itself, and, like consciousness, it is confined to the realms of subjective experience. This puts it just beyond the reaches of our explanatory powers, and yet it is a fascinating subject to explore. American Heritage Dictionary defines ‘self-conscious’ as “aware of oneself as an individual or of one's own being, actions, or thoughts.” This self-evident and circular definition will have to suffice for now.
Many people consider self-consciousness to be related to, and dependent upon the ability to use language, and thereby limited to humanity. Their argument says that without language, we can have no concept of “I”, which is necessary to be able to compare oneself with and separate oneself from the world, thereby developing a consciousness of oneself as a distinct entity. I see various problems with this argument:
We have already seen that the boundaries we set between human ‘language’ and animal communication are fairly arbitrary, and that sometimes the methods of communication used by animals may be properly termed ‘language,’ and thus language may not be used, directly or indirectly, as a criterion for establishing a gulf between humans and other animals.
Even for an animal that lacks both language and conceptual thought, it seems possible to me that a sense of oneself as a distinct entity could be reached experientially through a feeling of physical separation from the world.
Chimpanzees and orangutans exhibit behaviour that makes it clear that they possess self-awareness of some sort. In experiments, chimpanzees have been able to recognize that their reflections in a mirror represent their own bodies. While under anesthesia, a mark was placed onto a chimp’s head on a spot that it couldn’t see without using a mirror. When the chimp awoke, it didn’t notice the mark on its head until it saw itself in a mirror. Then the chimp examined the mark with its hand, clearly demonstrating that it knew the mark was on a part of its own body, since it touched its own body while looking at the reflection.
Chimps examine themselves in a mirror, clearly showing that they have an awareness of their own bodies.
Descartes and Mechanism
Descartes said that language is the litmus test for determining whether or not a creature possesses a soul. He used this criterion to prove that animals “are only sensory and mechanical, whereas humans, having animal bodies but also the capacity for speech, are the only creatures in possession of an immortal, rational soul. For various reasons, he would not have been able to defend this argument today, although it is still commonly used. One reason is that we would not attribute a soul or consciousness to a computer, despite the development of digital technologies that are capable of following grammatical rules and of using words or symbols to express various conditions or say how items relate to one another. Thus, being able to use symbols to represent inner states cannot be an indication of consciousness, nor can a lack of this ability signify a lack of consciousness.
A defender of Descartes’ general position might modify the argument to say that while a computer may be able to follow grammatical rules and use words as symbols, there are no intentions behind the symbols that it uses, that they are merely programmed responses to a stimuli. Yet by doing so, Descartes’ argument for the singular nature of humanity would fall apart, because it would be difficult to demonstrate that human language is any less a programmed symbolism than in the case of the computer.
With the invention of mechanical toy animals, the possibility of understanding living animals in terms of mechanical principles was introduced to us, and with the development of computer technology we began to see ourselves as machines as well. In the time of Descartes (1596-1650), mechanical toy animals were first being designed and built, which may have contributed to Descartes’ view of animals.
Descartes, although calling animals machines, may not have strictly denied that animals are capable of feeling pain, but Descartes’ followers in later years certainly interpreted his ideas to mean that animals are insentient:
They administered beatings to dogs with perfect indifference, and made fun of those who pitied the creatures as if they felt pain. They said that the animals were clocks; that the cries they emitted when struck, were only the noise of a little spring that had been touched, but that the whole body was without feeling. They nailed poor animals up on boards by their four paws to vivisect them and see the circulation of the blood which was a great subject of controversy.
Take the case of the fox, which the inhabitants of Thrace employ before they attempt to cross a frozen river, by letting it loose before them. If we saw him at the edge of the water approaching his ear very near to the ice in order to listen if, at a distance or near by, he can hear the noise of the water running underneath, and recoiling or advancing according as he perceives the ice to be thick or thin, should we not be justified in assuming that the same ideas pass through his head as would pass through ours, and that his natural sense has taught him to reason and conclude somewhat as follows: ‘That which makes a noise, moves; that which moves is not frozen; that which is not frozen is liquid, and yields under a weight.’? For to attribute this to an acute sense of hearing, without any reasoning or concluding, is an absurd notion, and not to be imagined.
In the history of Western thought, dating back to the Ancient Greeks, the ability to “reason” has been persistently proclaimed as the source of the vast gulf that lies between “mankind” and the “brute creation.” Descartes, for instance, writing about the absence of language in animals, has said “This does not merely show that the brutes have less reason than men, but that they have none at all.” The debate still continues to this day. However, like our concepts of language, our concept of reason shifts, when necessary, in order to ensure that it continues to exclude other animals, so that we may maintain the conceptual chasm between humans and animals that allows us to exploit them. Richard Sorabji has written:
It all sounded rather grand, when Aristotle said that [humans] have reason and [animals] don’t. But under pressure, the Stoics retreated to the position that at least they don’t have syntax. The moral conclusion was meant to be ‘They don’t have syntax, so we can eat them.’
Georg Büchner’s short story, Lenz, sheds some light on an important aspect of what we mean when we speak of someone as being “reasonable” or “sane.” Throughout the story, Lenz, the main character, is considered to be ‘insane’, but near the end of the story, he is recognized by the world as being “reasonable”:
He seemed completely reasonable, spoke with the people. He did everything as the others did it; but there was a horrible emptiness in him, he could no longer feel fear or desire, his existence was for him a necessary burden.
The key phrase is that he “did everything as the others did it.” This illustrates what we often actually mean when we say that someone is “reasonable”—we mean that the person is acting or speaking within the limits of what we believe to be ‘normal.’ In fact, part of Webster’s definition of insanity reads:
Specifically, in law, any form or degree of derangement or unsoundness, permanent or temporary, that makes a person incapable of what is regarded legally as normal, rational conduct or judgment: it usually implies a need for hospitalization.
When someone does something that conflicts with our concept of ‘rational’ behaviour, we consider the person to be insane, or at least to be having a moment of insanity. But what does it actually mean to be insane, to be devoid of ‘reason’? Recently I came to realize that being sane is like following a trail through the woods, whereas being insane is like bushwhacking through the wilderness. When the flow of a person’s thoughts follows a standard pattern or a well-established route, especially if it leads to a conclusion that we desire, then we consider that person to be sane. On the other hand, a person who forsakes the norm and forges out on his or her own, we label as ‘insane’.
I believe that our classification of ‘sane’ and ‘insane’, ‘reasonable’ and ‘unreasonable’ are the result of our judgment and our expectations. No human is truly sane, and thus the myth of human ‘reason’ cannot be maintained. When an animal appears to us to be irrational, it is following a different path than we are, or it has had the courage to travel without a path. We humans – so easily and so tightly bound to the few paths that we have chosen – fear the dangers of wandering into the wilderness of the unknown.
Non-human animals appear in varying degrees to share with us the quality of compassion. In one psychological experiment, captive monkeys were forced to choose between causing another animal to suffer, and starving. These monkeys were placed into a situation in which they were only given food if they pushed a button that caused another animal to receive an electric shock. The other animal was visible to the monkey through a one-way mirror, and the monkey, unless it pressed the button, would not be given any food. Eighty-seven percent of the hungry monkeys refused to let the other animal be shocked for the sake of receiving food, even to the point of starvation. The experiment was designed to demonstrate that other animals do not have a sense of ethics or compassion, but it backfired, because, as Ingrid Newkirk has said, it became clear that “the monkeys who are in the experiment have more ethics than the experimenters who designed it.”
Conclusion to Chapter One: Humans and Other Animals
“Animals share with us the privilege of having a soul.”
In this chapter we looked at the way in which we have conceptually distanced ourselves from other animals as a method of justifying our abuse of them, and examined various criteria that have been said to establish humanity’s claim to superiority. I focused on language in particular, since it is probably the most commonly cited difference between humans and other animals, in addition to being one of my own passionate interests.
The study of animal cognition and animal communication will play a central role in my life’s work. In response to an email that I sent him, Con Slobodchikoff, the scientist studying prairie dog language, replied:
Many of my colleagues find it difficult to believe the results I am getting, because of the pervasive paradigm among scientists that animals are not capable of semantics/language. However, with time, more and more scientists are beginning to realize that the evidence is pretty persuasive, and are beginning to develop experiments of their own with other animal species.
Animal communication is a field of study with a large potential for growth, and one that fascinates me intensely. I will be exploring it further next year, and then probably for the rest of my life.
Through observing and interacting with other animals we can learn to recognize their individuality, and at the same time learn more about ourselves. We must beware of falling into either extreme: failing to recognize the ways in which we differ from other animals, or else denying our kinship and all that we share with them.
 From the song Christmas in the Trenches by John McCutcheon.
 This topic is taken up by James Serpell in his book, In the Company of Animals: A Study of Human-Animal Relationships, New York: Cambridge University Press, 1996.
 Jim Mason, An Unnatural Order: Uncovering the Roots of Our Domination of Nature and Each Other, New York: Simon and Schuster, 1993. PP. 229-231
 In a letter to Henry More, Descartes wrote “Thus my opinion is not so much cruel to animals as indulgent to men […] since it absolves them from the suspicion of crime when they eat or kill animals.” The letter was reprinted in Animal Rights and Human Obligations (ed. Tom Regan and Peter Singer, New Jersey: Prentice-Hall, Inc., 1976. P.66)
 ed. Kerry S. Walters and Lisa Portmess, Ethical Vegetarianism: From Pythagoras to Peter Singer, Albany: State University of New York Press, 1999. p. 19
 Ibid., p. 13
 Mary Midgley, “Embarrassing Relatives: Humans & Other Intelligent Animals”, in Books and Writers, p. 40.
 “Stimme und eigentliche Sprache wurden in vorsophistischer Zeit wohl kaum genau unterschieden; die einzelnen Tierarten mit ihren charakteristischen Stimmen schienen ihre je besonderen Sprachen zu haben, die aber ebensowenig wie die gewisser Fremdvölker verstanden wurden.” Quoted from Tier und Mensch im Denken der Antike: Studien zur Tierpsychologie, Anthropologie und Ethik (Urs Dierauer, Amsterdam: Verlag B. R. Grüner B. V., 1977. p. 12)
 From Aristotle’s ‘Politics,’ excerpted in Political Theory and Animal Rights (ed. Paul A.B. Clarke and Andrew Linzey, London: Pluto Press, 1990. p. 6)
 Stephen R. L. Clark, The Moral Status of Animals, Oxford: Clarendon Press, 1977. p. 96
 ed. Michael Tobias and Kate Solisti-Mattelon, Kinship with the Animals, Oregon: Beyond Words Publishing, 1998. pp. 65-75
 René Descartes, ‘Discourse V’  in John Veitch (tr) René Descartes: A Discourse on Method, Everyman edn (London: Dent, 1912). Reprinted in Political Theory and Animal Rights (ed. Paul A.B. Clarke and Andrew Linzey, London: Pluto Press, 1990. p. 16)
 Marian Stamp Dawkins, Through Our Eyes Only?: The Search for Animal Consciousness, New York: Oxford University Press, 1998. p. 119
 Ibid., p. 120-124
 Strangely, however, Nietzsche also considered consciousness to be a dangerous disease.
 ed. Paul A.B. Clarke and Andrew Linzey, Political Theory and Animal Rights, London: Pluto Press, 1990. p. 45
 Solipsism is more a “mental illness, a form of megalomania, than a tenable philosophical position.” Nigel Warburton, Philosophy: The Basics, 2nd edn., N.Y.: Routledge, 1995. p. 102
 Midgley, Mary, Animals and Why They Matter, USA: University of Georgia Press, 1983. p. 58
 Among some skeptics there is also some level of doubt about the existence of self-consciousness in a portion of humanity. When, at one point in a discussion with David Gill on the topic of self-consciousness in animals, I asked him in exasperation: “Well, when you see a man walking down the street, what way do you have of knowing that he is conscious of himself?” he responded: “None, really. In fact, he’s probably not!”
 Donald Griffin, Animal Minds, Chicago: University of Chicago Press, 1992. p. 249
 See Descarte’s letters, reprinted in Animal Rights and Human Obligations (ed. Tom Regan & Peter Singer, , USA: Prentice-Hall Inc., 1976. pp. 13-19
 The word ‘intention’ in this context would seem to imply an emotional component.
 Angus Taylor, Magpies, Monkeys, and Morals: What Philosophers Say about Animal Liberation, Ontario: Broadview Press, 1999. p. 29
 Leonora Rosenfield, From Animal Machine to Beast Machine, New York: Octagon Books, 1968. p. 54
 Montaigne (1533-92), quoted in Political Theory and Animal Rights (ed. Paul A.B. Clarke and Andrew Linzey, London: Pluto Press, 1990. p. 65)
 Quoted in Animal Rights and Human Obligations (ed. Tom Regan and Peter Singer, New Jersey: Prentice-Hall, Inc., 1976. p. 15)
 Richard Sorabji, Animal Minds and Human Morals: The Origins of the Western Debate, London: Gerald Duckworth & Co., 1993. p. 2
 “Er schien ganz vernünftig, sprach mit den Leuten. Er tat alles, wie es die andern taten; es war aber eine entsetzliche Leere in ihm, er fühlte keine Angst mehr, kein Verlangen, sein Dasein war ihm eine notwendige Last.” Georg Büchner, “Lenz”, Büchner’s Werke, Aufbau-Verlag, Berlin und Weimar, 1967. p. 135
 From the Latin word “norma” meaning “rule.” Thus, to act “normally” is to act in accordance with a given set of rules or expectations.
 Webster’s New World Dictionary, College Edition, The World Publishing Company, USA, 1953-1966.
 From a speech that Ingrid Newkirk, the co-founder and president of PETA (People for the Ethical Treatment of Animals), presented on March 4, 2000.
 January 18, 2000.