Rationality Aboard 
Noah's Ark

Jonah S. Bossewitch
Junior Seminar
Proffessor Margret Wilson
January 8, 1996

	"Jack did indeed climb the stairs, and Wright reports that a large gray tabby head poked cautiously into the room.  Wright was at the time reading a massive tome.  Jack looked at the book, and at Wright.  His hair stood on end, and he backed down the stairs, warily keeping his eyes on the dangerous philosopher at work.  Wright consulted Plato, Nietzsche, and Montaigne, wanting to know whether Jack's behavior suggested respect for philosopher's.  As a result of his researches, he concluded that the fact that human beings do philosophy is evidence that unlike cats, they are irrational and may even lack a concept of self.  When he asked Jack about this, Jack said that the whole point of being a cat is that you don't descend to such nonsensical behavior."
Vicki Hearne, "The Philosopher's Cat"
	After thousands of years of living on this planet, Mankind is still not quite sure what to make of his surroundings.  In particular, we have not yet determined how we should interact with our fellow creatures, including other humans.  Part of the problem is that many people need to know the nature of the being that they are dealing with in order to decide how to treat him.  While Biologists have classified all of life into Kingdoms, Phylums, etc,  these divisions do not address the question that we are asking.  We need to know how we ought to treat others, and not just other homo sapiens, but everyone from algae and fungus, to dolphins and chimps.  Traditionally, the answer to this question is a function of the mental capabilities of the 'other' that we're dealing with.  The trouble begins when we try to figure out who has got which mental capabilities.
	The fact that philosophers are skeptical about animal minds comes as no surprise.  Philosophers have a compulsive habit of questioning the most basic assumptions that most of us take for granted.  This practice has led many to doubt the existence of the external world, other (human) minds, and the possibility of any justified beliefs.  John Searle characterizes the skeptical stance as one which seriously asks the epistemological question 'How do you know?'  Searle dismisses the importance of this line of questioning claiming that "epistemology is of relatively little interest in philosophy and daily life.  It has a little corner of interest where we are concentrating on such things as how to understand certain traditional skeptical arguments, but our basic relationships to reality are seldom matters of epistemology." 

John R. Searle, "Animal Minds" in Midwest Studies in Philosophy, XIX (1994): p. 217.

Ibid., p. 218.

	It is strange hearing Searle talk this way, considering that philosophers make a living off  asking 'How do you know that?'  Epistemological considerations appear at every level of an argument, and need to be taken seriously since the logical validity of a proof depends on them. Since it seems that 'How do you know?' questions can be asked infinitum, they must be bracketed at some point to get the argument off the ground.  However, this by no means diminishes the importance of the challenges that lie outside of the scope of an argument.  Their resolution could have a domino effect should it turn out to contradict a previous assumption.  In this way, much of philosophy is inter-related and epistemology can not be sealed off from the rest of philosophy the way that particle physics is (probably) sealed off from evolutionary biology.  In particular, philosophy of mind, complete with its epistemology, is intimately related to moral philosophy, which in turn has everything to do with daily life.  

Or, at least until you hit a self-evident truth (although not everybody believes that there are such facts).

	Deciding which assumptions to treat as given is not an arbitrary process.  If a certain assumption is controversial, it will be seriously challenged by anybody with dissenting views.  Some skeptical hypotheses are more commonly believed than others, for reasons we shall discuss later.  Many people simply do not consider the reality of animal consciousness as obvious as Searle does.  In this instance, epistemology does have a tremendous impact on philosophy and daily life since many people assume, sometimes implicitly, that animals do not have minds.
	Most moral systems, from Aristotle to Kant, refer or depend on the mental capabilities of the participants.  This connection makes a great deal of sense considering, in a nutshell, that you cannot hurt something that does not experience pain.  Rationality and consciousness also work their way into these various systems, often as crucial prerequisites for moral consideration, treatment as a person, and basic rights.  This is the point where epistemology becomes very practical, since it is not good enough to personally know that animals have minds.  If someone believes that animals do have minds, he may also have a moral obligation to fight for animal rights.  This might require finding a way, hopefully through rational discourse, to convince skeptics who do not see the "obvious."  

"We state the function of man to be a certain kind of life, and this to be an activity or actions of the soul implying a rational principle, and the function of a good man to be the good and noble performance of these."  Nicomachean Ethics, I.7, 1098a13.

See the "Formula of the End in Itself" where Kant states that "what serves the will as a subjective ground of its self determination is an end; and this, if it is given by reason alone, must be equally valid for all rational beings."  Groundwork of the Metaphysics of Morals, 66.

	Finally, from a philosophy of mind perspective, there is a great deal to learn from the investigation of animal minds.  Just as animal bodies can serve as models of human bodies in the scientific laboratory, animal minds can serve as models of human minds in the philosophical laboratory.  Animal behavior may actually provide a basis for empirical testing and confirmation of various theories of mind ranging from knowledge representation to consciousness.  It is hard to imagine how Searle could dismiss the importance of this project, unless he is afraid of putting his theories to the test.
	There is a long philosophical tradition claiming that rationality is exclusively a human quality.  At the same time, it sometimes seems that rationality is defined as the quality that humans possess and animals do not.  This significantly weakens the first claim, since what we are trying to determine is whether such a quality exists, and if so, we want more than a label for it.  In order to carry out this investigation, we must first analyze what we mean when we use the umbrella term 'rational'.  It turns out that rationality is a very complex concept that is much harder to break down than some might guess.  While Descartes might insist that we all know what he meant by a 'rational soul', his stubbornness should not fool us into believing that there is nothing more to say.  We have an obligation to demand that the term be explicitly defined.
	In the past few decades tremendous strides have been made in our understanding of human rationality.  Borrowing from the lessons learned in computer science and backed up by neurophysiological evidence, many philosophers now view the mind as a conglomeration of distinct modules.  Each of these modules has specific processing abilities, and the ability to communicate with some of the others.  The modularity of mind approach to has led cognitive scientists to propose a taxonomy of rationality that demonstrates the modularity of the mind on the computational level.  The term 'rational' now indicates the set of computational processes that comprise rational thought.
	This "rational set" includes familiar processes such as deduction, induction, association, knowledge representation, pattern recognition, calculation ,and creativity.  According to this view, rationality is the ability to preform these computations correctly.  There is no separate rationality module, or to put it another way, 'rationality' is not a member of the rational set.  With this in mind it becomes evident that any meaningful investigation into animal rationality needs to address the individual processes that are rationality.  We cannot answer the question 'Are animals rational?' until we know the answers to the questions 'Can animals represent knowledge?', 'Can animals reason deductively?', 'How about inductively?', 'Can they form associations?' etc...
	In fact, once we have some answers to the specific cognitive tasks that an average member of a given species can preform, the question of rationality may become trivial.  Which of these processes are necessary and sufficient for someone to qualify as rational?  Any cutoff point would be subject to the challenge that it is completely arbitrary.  We may find that when speaking about rights as a function of rationality, we need to replace the vague concept of rationality with the specific capabilities of an organism. 
	In his paper Rational Animals, Donald Davidson claims that the ability to have propositional attitudes should be the criterion of rationality, and attempts to resolve our inquiry into rationality on theoretical grounds.  Propositional attitudes are simple propositions (i.e. 'the cat ran up the tree') attached to an attitude, such as a belief, desire, or intention ('I believe that the cat ran up the tree').  Davidson argues that the nature of propositional attitudes is such that "to have one is to have a full complement," and having any propositional attitude requires "the gift of tongues."  He also makes the separate claim that thinking and reasoning rely on propositional attitudes, and cannot transpire without them.  This argument yields Davidson's conclusion that "a creature can not have a thought [a fortiori, the capacity to reason] unless it has language."  Davidson is careful to distinguish his position from similar ones that equate thinking to linguistic activity.  He does not think that each thought must correspond to a sentence that expresses that thought, merely that a condition of thinking is that the creature possess language. 

Donald Davidson, "Rational Animals", Dialectica, 36 (1982): p. 318.

Ibid. p. 318.

Ibid. p.320.

	The claim that propositional attitudes are a condition for rationality,  seems to undercut our earlier taxonomic approach.  Davidson holds that if a creature does not have language, it will not be able to represent knowledge, reason logically, form associations, recognize patterns, or perform any other cognitive task which help constitute rationality.  We need not investigate the cognitive abilities of non-linguistic creatures because, according to Davidson, they have none.   This argument rests on the separate claims that language is a condition for propositional attitudes, and that thinking and reasoning depend on propositional attitudes.  A demonstrated weakness in either of these claims challenges the criterion of rationality that Davidson proposes.  
	Sometimes, when it comes to matters as theoretical and abstract as these, it is helpful to turn to nature for assistance.  Instead of trying to hash out all of these issues a priori, we ought to ask the animals, and the people who know the most about them, what they think about all of this.  By turning our attention towards the behavior of an organism, we can temporarily circumvent the issue of propositional attitudes and focus on specific functional abilities.  This opens up the possibility of empirically testing what animals are capable of, and passes the question of animal rationality over to science.  Should we find that some non-linguistic creatures are in fact capable of thinking, it may force some philosophers to rework parts of their theories.  On the other hand, it is doubtful that any animal will stop thinking once he discovers that it is theoretically impossible for him to be doing so.
"To answer these questions it is helpful to bear in mind the distinction between the function of thinking and the underlying procedures that it relies on.  The late David Marr (1982) referred to this distinction as one between the computational level (what the mind is doing) and the algorithmic level (how it is doing it)."  

P.N. Johnson-Laird, "A Taxonomy of Thinking" The Psychology of Human Thought.  Cambridge: Cambridge University Press. (1988): p.429.

	Marr's advice helps us understand the error in asserting that thinking depends upon propositional attitudes.  Use of propositions attached to propositional attitudes is one way to compute the functions involved with thinking, but it may not be the only way.  Davidson concedes that not all human thought is carried out in propositions, but the creature must have the capacity to form propositional attitudes for these thoughts to 'count' as thoughts.  But, if there is a class of thoughts that does not rely upon propositional attitudes, why can't a non-linguistic creature conduct its reasoning with thoughts restricted to that class?  These operations can be labeled as thoughts or non-thoughts, but whether or not these operations occur is an empirical fact.  To claim that an animal can preform a particular cognitive tasks is  separate from the claim that he does it the same way that humans do.  In terms of qualifying as a member of the "rational club" it should not matter how you preform your computations (i.e. which algorithms you employ), rather we should be concerned with the quality of your functional skills.
	Although computations may not rely on propositions, it is safe to say that no computation could proceed without the ability to represent knowledge.  Knowledge representation varies tremendously, ranging from the binary state of a transistor to a rich linguistic concept.  Rudimentary representations of knowledge, such as a mechanical sensor, limit the computations that a system can perform.  The notorious thermostat can only represent two states of its environment, 'too cold', and 'not too cold.  From this knowledge it can deduce 'the temperature gauge is straight6turn on' or 'the temperature gauge is bent6turn off'.  On the other hand, a rich network of concepts enables an equipped system to preform a correspondingly rich number of inferences about the world.  Philosophers disagree over how sophisticated a representation needs to be for it to be considered a belief.  However, our first concern is the ability of non-linguistic creatures to form representations, and even full fledged concepts.  Later we will worry about whether these concepts should be called beliefs. 
	Without resorting to complicated laboratory setups, it is easy to observe animals interacting with the world.  According to Kant's formulation of mental processes, it would be impossible for a creature with sense organs to perceive the world without some basic concepts.  First, a Kantian framework demands that certain a priori concepts, like space and time, must be present for perception to take place at all.  Furthermore, the ability to model an entire scene as your sensory input changes over time requires a synthesis of your experiences.  This "synthesis of the manifold of intuition" involves principles, memory, and imagination, which all involve the manipulation of concepts.  Also, the fact that animals can recognize patterns (their owners face/scent, predators, prey, etc.) testifies to their ability to store concepts, recall them later for comparison, and judge whether they are the same or different from some other concept (usually the one that is currently being perceived).  Numerous anecdotes concerning animal behavior confirm that it is possible for non-linguistic creatures to possess conceptsBernard Rollin, (1989) "Thought without Language", The Unheeded Cry. Oxford University Press..  But, how complicated a concept can an animal possess?

Immanuel Kant, The Critique of Pure Reason.

"We have just seen that there is little reason to deny concepts to animals; that standard philosophical gymnastics, however tortured, simply cannot touch the plain, commonsensical fact, embodied in all cultures of all ages, that animals do anticipate and remember, and that this is how they learn and fear.  And if this entails having concepts, as surely it does, then animals have concepts, which should come as no surprise if they are to deal with the world.  They certainly behave as if they had concepts, and the best explanation for this behavior is that they do have them."

	Edward Wasserman was interested in the problem of animal conceptualization and cleverly designed a series of experiments designed to test this ability.  He opted to use pigeons because of their powerful visual systems that are relied upon as heavily as human's visual systems.   The pigeons were first trained to sort pictures of cars, cats, chairs, and flowers.  After being trained on 40 slides with 10 members of each category, the birds were then shown a set of new slides that they had never seen before.  After training, the pigeons correctly responded over 75% of the time (the level of chance was 25%).  The next set of experiments showed that pigeons could learn disjoint concepts, like 'car or cat', which are more abstract and higher level than the simple concepts.  Finally, birds were trained to distinguish between arrays of 16 identical icons, and arrays of 16 differing icons, representing the concepts of sameness and difference.  In all instances the birds performed about as well as groups of preschool children.  Wasserman concluded that these experiments "support the conclusion that conceptualization is not unique to human beings.  Neither having a human brain nor being able to use language is therefore a precondition for cognition."     

Edward Wasserman, "The Conceptual Abilities of Pigeons", American Scientist, The Scientific Research Society. Volume 83 (May-June 1995): p. 246.  Wasserman's "experiments on the cognitive abilities of pigeons employed an updated version of the Skinner box, a simple but effective experimental apparatus developed in 1930.  Color slides were shown to the pigeon on a frosted plastic viewing screen covered with a clear plastic key.  Four response keys, each a different color, could be illuminated or left dark during various stages of each experiment, and a food hopper provided the reinforcement when a pigeon pecked a correct response key."

Ibid. p. 255.

	A rich network of concepts is only the first hurdle to overcome for full fledged reasoning to take place.  Many psychologists insist that inferential reasoning must be governed by formal syntactical rules that are linguistic constructions (e.g. if p then q).  Thus, even if we grant langugeless creatures a rich network of concepts, without language their manipulation of these concepts, and consequently their reasoning abilities, will be severely limited.  However, we do not need to look any further than our own species to find instances of reasoning that do not rely on formal rules of inference.  This finding does not directly inform us how animals think, rather, it gives us an alternative model for how they might think, and opens up the possibility of reasoning without propositions or language.
	Phillip Johnson-Laird has done extensive work in the area of mental processing, and has argued that much of human reasoning is preformed by constructing 'mental models' of the situation and not by employing propositional rules.  A mental model is a representation that "may be a vivid image or a fleeting abstract delineation - its substance is of no concern.  The crucial point is that the conclusion can be read off in almost as direct a fashion as from an actual array of objects... Images, too, have these properties, but models need not be visualizable, and unlike images, they may represent several distinct sets of possibilities."  

P.N. Johnson-Laird, (1984)  Space to Think, Proceedings of the Conference on: Language and Space, University of Arizona, March 17-19, 1994. p. 1.

	Consider the inference:  A cat is on the right of a rosebush.  A Frisbee is between the cat and the rosebush.  Therefore, the Frisbee is on the right of the rosebush.  Some psychologists have argued that in humans these premises are represented propositionally, and the inference is carried out by applying formal rules to these propositions.  They claim that these representations rely on some type of predicate-argument structure, such as the predicate calculus.  Conclusions are derived using syntactical rules of inference, and the entire procedure is language based.  This contrasts with the model method of inference in which the ssssstructure of the model corresponds to the structure of what it represents.  Thus, a mental model of this situation must have the same structure as the diagram below.  Many experiments have been conducted to try and unravel the mystery of how we reason.  They suggest that many types of reasoning, including spatial, temporal, and inductive, involve mental models as opposed to propositional rules.

See Hagert, 1984; Ohlsson, 1984.

The preceding premises might look something like this:  (›x)(›y)(›z)[cat(x) & Frisbee(y) & rosebush(z) & Right-of(x,z) & Between(y,x,z)].

	Mental models have a number of advantages over formal rules.  First, metal models provide a definite decision procedure which allows the subject to know that there is no valid conclusion, while the predicate calculus is provably without one.  Second, models easily extend to inductive inferences that are very common in everyday life, whereas it is very difficult to apply formal rules to these types of inferences.  Furthermore, experimental evidence supports the hypothesis that various types of human inferences are carried out with mental models.  Subjects consistently preformed better on problems that only required them to consider one model, as opposed to multiple models, even though the one model problems required longer formal derivations than the multiple model problems.  Also, the model theory offers predictions of the types of errors that subjects make.  "Erroneous conclusions arise because reasoners fail to consider all the models of the premises, and so these conclusions should tend to be consistent with the premises (i.e. true in at least one of them) rather than inconsistent with the premises (i.e. not true in any model of them).  The results corroborated with this prediction of the model theory."  Finally, it takes more time for subjects to read the premises and respond to the questions in multiple model problems than in one model problems, a phenomena that is unaccountable for according to the formal rule theory.  This evidence suggests that human reasoning is carried out using functionally spacial models, and not just when thinking about space.

"An inference is valid if its conclusion holds in all the possible models of the premises, and it is invalid if it fails to hold in at least one of the possible models of the problem."  Johnson-Laird, p. 8.

Johnson-Laird, p. 22.

	Alone, the theory of mental models does not directly address the issue of animal cognition but it is easy to see the role that it might play in this debate.  However, once we have demonstrated the possibility of non-rule based reasoning, it is easier for us to imagine how animals might be thinking.  The theory provides us with a clear model of how a non-linguistic creature might carry out his reasoning tasks.  We can still put off the question of 'attitudes' (at what point should a representation be considered a belief?) and speak about the reasoning abilities of animals.  Imagine a dog who pushes his food bowl out of the rain to prevent his kibbles from getting soggy.  This behavior clearly requires some mental processing including inductive inferences about what water has done to his food in the past, deductive inferences about pushing the bowl under waterproof protection, and the underlying concepts of cause and effect.  Even without postulating any beliefs, it is still irrational to deny that languageless creatures cannot exhibit rational behavior that is the product of rational thought (i.e. specific cognitive processes).  But, can all animal behavior be understood without postulating beliefs?
	Although beliefs are not be necessary for all aspects of rational thought, their presence implies a complexity in processing that testifies to a creatures rationality.  We have seen that some components of reasoning do not require language, in opposition to the claim that rationality cannot exist without language. So, how seriously should we take the claim that beliefs, and other attitudes, are also language dependant?
	One approach to the issue of propositional attitudes has been proposed by Daniel Dennet, and helps clarify the confusion that this topic has spawned.  Dennet groups propositional attitudes (beliefs, desires, hopes, intentions, etc..) together under the heading of folk psychology.  He argues that "while a belief is a perfectly objective phenomenon, it can be discerned only from the point of view of one who adopts a certain predictive strategy, and its existence can be confirmed only by an assessment of the success of that strategy."  He calls this strategy the intentional strategy, or adopting the intentional stance.  Essentially, the intentional stance is a heuristic that is used to understand and predict a system's behavior.  "To a first approximation, the intentional strategy consists of treating the object whose behavior you want to predict as a rational agent with beliefs and desires and other mental stages."  The intentional stance is used in much the same way as a physical stance, or a design stance.  For example, in order to operate an alarm clock, you do not need to be familiar with all of the internal physical mechanisms that underlie its operation.  If you know what it is designed to do, you can forego the physical stance and describe and predict its operation simply by glancing at it.  Similarly, the intentional stance allows us to make sense of the exceedingly complex behavior of highly sophisticated systems.

Daniel Dennet, (1987) "True Believers" The Intentional Stance, MIT Press, p. 15.

	Instead of considering intentions to be the product of a particular mental state, Dennet considers any system whose behavior warrants it, an intentional system.  However, Dennet also believes that there is a definite fact of the matter about which systems truly warrant intentional treatment.  Since we can take the intentional stance with just about anything, from plants to lightning bolts, we need a way to determine when we are justified in doing so.  Dennet argues that we are justified in disqualifying certain applications of the intentional stance when a practical  alternative is available.  In some cases though, the only practical strategy is the intentional one, since it provides us with predictive power we can not get with any other.  

"In a locale with late spring storms, you should plant apple varieties that are particularly cautious about concluding that it is spring - which is when they want to blossom...  Lightning, always wants to find the best way to the ground, but sometimes it gets tricked into taking second best paths."  Dennet, p. 22.

	Inability to practically utilize other strategies (like the physical stance) could be an artificial limitation that is a function of our stupidity, but Dennet counters this objection.  He argues that it is when it comes to truly intentional systems it is impossible to "fully grasp its internal operation without the aid of this anthropomorphizing" and that there are "patterns in human behavior that are describable from the intentional stance, and only from that stance, and that support generalizations and predictions."  In this sense, whether or not a system has beliefs, or deserves being treated intentionally, is an objective fact that reflects the complexity of that system. 

Dennet, p. 23, 25.

	Having accepted that there is a "real" line between believers and non-believers (systems not capable of belief) how are we to decide which systems fall on which side of the line?  While Dennet's account of intentionality might not appeal to everybody, at least it provides a rough criterion for when a representation should be considered belief.  When it comes to attributing attitudes to languageless creatures, we cannot make sweeping generalizations.  Rather, we need to investigate the behavior of specific species, and even specific individuals.  While Lobsters might be capable of limited conceptual and reasoning skills, they still may not qualify for intentional treatment.  On the other hand, the mental abilities of dogs, horses, and pigeons are far superior to those of crustaceans, suggesting that we should not lump together all languageless creatures.  If we do find any languageless species that warrant adopting the intentional stance, it will challenge the claim that attitudes are language dependant. 
	Matters become a little tricky when it comes to judging if an animals behavior justifies the intentional stance.  You might think that the best people to classify an animals behavior are the ones who spend the most time around them, like the trainers, handlers, and pet owners.  The problem is that people who spend a lot of time with animals, also usually love them. When an animal lover insists upon using intentional terms they are instantly accused of being overly sentimental, and of being too biased to make an objective judgment.  Vicki Hearne, an animal trainer and philosopher, has replied to this standard objection by pointing out an inconsistency.  If you're having an operation, who would you trust more - the surgeon who loves medicine and healing, or the one who does it for the paycheck?  In fact, it seems that in most fields, loving the subject matter contributes to the credibility of an expert.  When it comes to animals, why should loving the subject matter count against a professional assessment?
	 Animal workers frequently claim that postulating metalistic states is the only way to make sense of situations involving animals.  Without adopting the intentional stance, animal behavior is unpredictable and often unmanageable.  D.O. Hebb demonstrated that zoo keepers who were barred form using intentional terms could not perform their jobs properly.  Hearne testifies that from her own experiences, she felt it would be impossible to train or work with an animal without adopting the intentional stance.  She also points out that most of the great trainers also use mentalistic language when teaching and describing their work.  However, we need not rely on the animal handlers insistence that the intentional stance is the only one that makes sense.

D.O. Hebb, "Emotion in man and Animal," Psychology Review, 53 (1946).

"I noticed that in obedience and riding classes, people with training in the behavioral sciences hadn't much chance of succeeding with their animals, and that the higher the degree held by the person, the worse the job of training was likely to be.  And one of the reasons that I was the audience for so many lectures on the wrongness of the trainers' way of thinking and talking was that the psychologists and philosophers had to bring their animals to me because they couldn't housebreak them, induce them to leave off chewing up the children or, in the case of horses, get them to cross the shadow of a pole laid on the ground."

Vicki Hearne, Adam's Task: Calling Animals by Name, Vintage Books, 1982. p. 12.

	  Training serves as an empirical test of which stances are warranted, bolstering the claim that adopting the intentional stance with some animals is necessary.  If successful training depends upon the use of intentional terms, and meaning them, then we have met Dennet's criterion for the objective existence of attitudes.  If trainers and handlers cannot do their jobs without postulating these attitudes,  there is no practical alternative to the intentional strategy, and its use is fully justified.
	The claim that many languageless creatures deserve the postulation of intentions does not deny that language vastly expands a creatures mental abilities.  Indeed, language "opens the floodgates of desire attribution and... enables us to formulate highly specific desires."  Searle distinguishes between intentional states that are impossible without a language from those that do not require one.  Language dictates what types of intentional states are possible for a creature, but its absence does not imply the complete absence of all intentional states. Although they may be invoked with language in humans, there exists a subclass of intentional states that do not require language, and this subclass allows us to justify languageless creature's potential for having intentional states. 

Dennet, p. 20.

Searle outlines five categories of thoughts that he thinks are impossible to have without a language. The list includes intentional states that: (1) are about language. (2) are about facts which have language as partly constitutive of the fact. (3) represent facts that are so remote in space and time from the animal's experience as to be unrepresentable without language. (4)  represent complex facts, where the complexity cannot be represented without language. (5) represent facts where the mode of presentation of the fact locates it relative to some linguistic system.  The list is not intended to be comprehensive, but is intended as a start.