Moderate differentialists like Aristotle and Kant credited animals with “lower” mental/psychic phenomena like sentience, emotions, moods and perception, while denying the “higher” faculties of intellect and reason, including the capacity for genuine belief. In the same vein, Sellars (1957), Davidson (1985), Brandom (1994) and McDowell (1996) grant sentience or consciousness, while balking at intentional states like belief and desire. Against this stance, I shall rebut a priori philosophical objections against the idea of intentionality in animals, and present positive arguments in its favor.
Intentional verbs occur mainly in three sentential forms:
| I | S | Vs (thinks/believes/desires, etc.) | that p |
| II | S | Vs (intends/wants/plans, etc.) | to Φ |
| III | S | Vs (loves/desires/thinks about, etc.) | X |
According to orthodoxy, the verbs that can replace “V” denote different types of intentional attitudes, and the substitution instances of “that p,” “to Φ” or “X” their contents. Prima facie, sentences of type (I) state a proposition-oriented – or “that-ish” – attitude, those of type (II) an action-oriented – or “to-ish” – attitude, and those of type (III) an object-oriented attitude. Nonetheless, it is customary to subsume all forms of intentionality under the heading “propositional attitude,” on the tacit assumption that all intentional verbs signify attitudes towards propositions. This by itself militates against the idea of animal intentionality, for the term “proposition” carries linguistic connotations. It begs fewer questions to speak of “intentional states” or “thinking.” Furthermore, it is sheer dogmatism to insist that in order to desire a peanut or intend to play, animals must put themselves in relation to abstract propositions. Intelligent animals can devote their attention to, and hence think about objects or events (type III), and they can intend to do things (type II). What is controversial is whether the range of their thinking and intending is confined to the “here and now” or includes episodic memory and expectations concerning future eventualities (see Clayton et al. 2000; Mulcahy and Call 2006).
As regards animal intentionality of type I, a serious doubt arises out of the connection between contents, concepts and language. Donald Davidson illustrates it through an example of Malcolm’s:
Suppose our dog is chasing the neighbor’s cat. The latter runs full tilt toward the oak tree, but suddenly swerves at the last moment and disappears up a nearby maple. The dog doesn’t see this maneuver and on arriving at the oak tree he rears up on his hind feet, paws at the trunk as if trying to scale it, and barks excitedly into the branches above. We who observe this whole episode from a window say, “He thinks that the cat went up that oak tree.”
(Malcolm 1972–73: 13)
According to Davidson, however, Malcolm’s dog cannot, strictly speaking, believe anything, because he lacks language (Davidson 1985: 474–8; 1984: 155). Davidson’s stance is shaped by an influential line of reasoning, the “lingualist master-argument” (Glock 2010):
| Concept thesis | Thinking (type I intentional states) requires concept-possession. |
| Language thesis | Concept-possession requires language. |
| Lingualist conclusion | Thinking requires language. |
| Dumbness thesis | Animals lack language. |
| Differentialist conclusion | Animals cannot think. |
The argument is valid; whether it is sound depends on its three premises. My contribution brackets the dumbness thesis and tackles the other two premises in turn.
The most potent argument for the concept thesis derives from representationalism, which regards intentional states as relations between a subject S and a propositional content. In the case of Malcolm’s dog, it would have to be a relation of believing towards the propositional content that the cat is on the oak tree. But a propositional content is a mental or abstract entity; and that entity, according to mainstream representationalism, in turn consists of building blocks, concepts such as cat, going up and oak tree. By these lights, therefore, S cannot think that the cat went up the oak tree unless it possesses all of these component concepts.
One protective measure against the concept thesis postulates nonpropositional or “nonconceptual contents” (see Bermúdez and Cahen 2015). This response accepts that intentional verbs signify attitudes towards objects of a special kind, namely contents; it parts company by insisting that, in addition to propositional contents consisting of concepts (the contents of human thinking), there are “proto-propositional” contents consisting of nonconceptual components, notably sensory representations of a spatial kind (the contents of animal thinking and prereflective human perception). Unfortunately, it remains unclear how something can both be a content of a type I sentence, i.e. a signified by a that-clause, and proto-propositional, i.e. falling short of being a proposition. Furthermore, this rejection of the concept thesis creates a congruity problem. The distinction between different types of content counts against ascribing one and the same belief to humans and animals. It suggests that “Both Sarah and the dog believe that p” is not so much a falsehood as a zeugma – a potentially comical crossing of categories like “Both the exam and the chair were hard.” For “Sarah believes that p” comes out as “Sarah stands in the relation of believing to the thought that p” while “The dog believes that p” comes out as “The dog stands in the relation of believing to the protothought that p.” Some versions of nonconceptualism welcome this incongruity by insisting that animals represent in map-like, information-theoretic or analogue “formats” (respectively, Camp 2007; Allen 2013; Beck 2013), which resist faithful paraphrase in type I idiom. But this amounts to replacing the conceptual framework that laypeople and cognitive scientists successfully apply to animals. It remains to be shown that such novel characterizations of nonlinguistic cognition and conation are as illuminating as those couched in standard that-ish format. Indeed, the revisionist conceptual framework must ultimately allow explanation in terms of our established mental concepts, at least if they are to address our questions about the nature and extent of animal belief and rationality.
Another objection against the concept thesis reconceives rather than abandons the apparatus of intentional verbs and noun-clauses. It maintains that talk about “contents,” whether conceptual or not, amounts to a misleading reification (Glock 2013). For one thing, the building-block model transposes the part/whole relation from the spatial and temporal sphere to a sphere – abstract entities – to which, ex hypothesis, neither spatial nor temporal notions apply. What is said or thought has genuine components only to the extent to which its linguistic expression has components.
For another, S’s thinking that p is not a bona fide relation between S and an object that p, whether with or without components, whether abstract or mental. Admittedly, noun-clauses like “that the cat went up the oak tree” or “what Sarah believes” are, grammatically speaking, the objects of beliefs. Nevertheless, they no more refer to genuine objects than the quantifier in “Clare desires nothing.” Properly analyzed, beliefs and desires are not genuine relations; instead they are, roughly speaking, dispositional properties of a creature. Although the sentences we use in ascribing thoughts to S include that-clauses with components, our ascriptions do not presuppose a prior ascription of the corresponding concepts. Instead, they are based on the subject manifesting certain perceptual capacities, attitudes and emotions. These manifestations include forms of behavior, postures and facial expressions which higher animals share with human beings.
This rebuttal of the concept thesis presupposes that animals can believe or know things; since they can be correct or mistaken as to how things are, they can have beliefs. Precisely that is contested by other considerations in favor of the concept thesis, which do not rely on representationalism. Starting out from the observation that a belief is something that “can be true or false” (1985: 479), Davidson in effect reasons along the following steps:
Step (i) is contentious, however, since it bars a necessarily omniscient being (God) from believing things and rules out belief in necessary truths. Even if we set aside these exotic cases as irrelevant to the question of animal belief, objections remain. Step (ii) goes astray, insofar as it makes the possibility of believing dependent on second-order beliefs – beliefs about beliefs – to the effect that a previously held belief is mistaken. A simple change can lead S from the false belief that pto the true belief that not-p. S can recognize a mistake not just through thinking about its own prior belief, but also through correcting its behavior – notably through the deliverances of its senses – by pursuing a persistent goal in a more apposite manner. That S recognizes that things are other than S previously believed can be manifested in nonlinguistic reactions, such as surprise and disappointment. Findings suggesting that monkeys can recognize mistaken beliefs of their own in wager games (Kornell et al. 2007) put further pressure on Davidson’s reasoning. If there is self-regarding metacognition in animals, either such cognition is nonconceptual – contrary to (iii) and the concept thesis – or nonlinguistic creatures can possess the concept of a mistake, contrary to the language thesis. Finally, concerning (iv), why shouldn’t S be able to correct her beliefs by adopting a new perspective herself, rather than by conversing with another subject?
There is a possible response to this challenge. If S changes her perspective and subsequently alters her reactions to the objective situation, how can she distinguish correcting an objective error committed at time t1 from the situation having changed by t2? One option is the communication with another subject, who has held the situation fast in sight without altering her perspective. But couldn’t S, while altering her perspective, keep the object in sight to a degree sufficient for ruling out pertinent changes? If so, triangular communication is not necessary for a grasp of the idea of objective truth. Indeed, unless S could trust her own individual ability to gauge the objective situation, how could she rely on the more presumptuous and precarious process of communication to undergird her judgment? Consequently, if triangular communication were necessary to assess the world objectively and hence for the idea of objective truth, as Davidson’s argument assumes, it would not be sufficient, as he also contends.
Lingualist arguments against the possibility of animal belief are uncompelling. In addition, there are two reasons for positively accepting that some animals actually do have beliefs. The first arises from the connection between belief and knowledge. Intelligent animals command a sizable repository of “knowledge-how.” They know, for example, how to crack nuts, hide provisions, entice a potential mate, etc. Such knowledge is not easily separated from knowledge-that. To know how to open a box is, among other things, to know that doing so requires lifting its lid. But now: S can only possess knowledge-that if it can also possess the corresponding beliefs. The pair knowledge/belief comes as a double-pack. To be more precise, the notion of believing must be available as a fallback option for characterizing the epistemic standing of a subject, if the latter exercises its cognitive abilities yet without acquiring knowledge. Even if not every case of knowing that p implies believing that p (as the tripartite conception of knowledge would vouchsafe), the capacity for knowledge presupposes the capacity for believing. To err is not just human! In animals, error manifests itself primarily in their behaving in ways that, though guided by their senses, are inadequate given the de facto situation (on the assumption of certain goals). Finally, the circumstances and causes of animal error are not just the stuff of anecdotes like that of Malcolm; they have been documented through ethology to the same extent as those of animal knowledge.
A second argument for animal belief revolves around the most basic cognitive ability. Higher animals are capable of perceiving their physical and social environment in various sense modalities. The crucial point is that they are capable not just of perceiving “things” (including organisms and events), but also of perceiving “facts” (cp. Dretske 2004). Animal perception does not just take the form
It can also take the form
This is demonstrated by the connection between perception and complex animal behavior.
Consider a dog that has learned not to grab anything when it is lying on the table but only when it is lying in his bowl. This dog now sees a bone on the table, but refrains from grabbing it and instead looks on, panting. Yet as soon as the bone is placed in the bowl, the dog goes for it. This mundane sequence is not explained by the dog simply perceiving discrete objects – the bone, the table and the bowl. It can only be explained in terms of the following opposition:
Why? Because at both t1 and t2, the dog can see bone, table and bowl. So perception of the conglomeration formed by these three objects cannot explain the difference in its reactions at t1 and t2. One might respond that the problem vanishes if spatial relations like x being on y are among the objects that the dog can perceive. However, simply perceiving three distinct objects – bone, table, x being on y – does not explain the dog’s behavior. Such an explanation is only in the offing if it can also perceive that the bone stands in the relation of being on to the table at one moment, to the floor at the next. And in that case, we are back with perceiving that p.
But, it might be objected, this behavior can be explained behavioristically. We only posit
Now, what sort of stimulus is this supposed to be? Is it purely proximal and physiological, like the pain stimuli to which even oysters react? This behaviorist fairy tale ignores the distinction between lower animals and higher ones like dogs, cetaceans and primates, which possess a range of different sense organs and corresponding sensory centers in the brain. Primates, at any rate, score well in the standard tests for object permanence and identification (Seed and Tomasello 2010: 409).
The alternative is to admit that the dog reacts not just to a proximal stimulus, but to perceived information. Yet how can this information be specified if not as a perceived fact? An apparent way out of this quandary might be as follows: what the dog perceives is not that the bone is on the table or in the bowl; what he perceives is “bone on table” or “bone in bowl.” However, if the determinants “on table” and “in bowl” are used restrictively, to indicate which bone the dog perceives, this does not explain the divergent behavior of the dog, which perceives the same bone at t1 and t2. Alternatively, if they are used as ellipses for “lying on the table” and “lying in the bowl,” this explains the divergent behavior of the dog alright. Yet to perceive the bone as lying in the bowl is to perceive – albeit by another name – that the bone is lying in the bowl. One way or another, the dog’s behavior can only be explained on the assumption of factual perception, perception that.
The second step in my argument simply pays due deference to the slogan seeing is believing. From “S sees that p” (the sun is shining, etc.), we may conclude either “S knows that p” (where “seeing” is used factively) or “S believes that p” (where it is not). But both “knowing that p” and “believing that p” are cases of “thinking that p” in the sense that is relevant here. One cannot resist this second step by rejecting these implications for the case of animals without a compelling argument to the effect that “sees that p” is systematically ambiguous as between humans and animals; and no such argument is in the offing. Consequently, the lingualist master-argument now faces a dilemma. Either the concept thesis is wrong, since we are compelled to ascribe thinking (perceptual beliefs) without imputing concepts. Or all animals capable of fact perception possess concepts, in which case the language thesis is wrong, since animals have many concepts.
With respect to animal concepts, Kant and McDowell, among others, occupy the differentialist corner: animals can perceive, yet lack concepts of any kind. In the assimilationist corner are empiricists and many cognitive scientists, who have no qualms about ascribing complex concepts to animals. An intermediate position maintains that animals can possess some concepts, namely those that can be manifested in nonlinguistic behavior (e.g. Bekoff and Jamieson 1991: 19–20; DeGrazia 1996: 154–8). Their concepts may rarely be the ones we use in ascribing thoughts to them. For the discriminations which underlie animal behavior need not coincide with our verbal classifications, either extensionally – i.e. by grouping together the same objects – or intensionally – i.e. by grouping objects according to the same properties. A dog might group cats together with hamsters or distinguish black cats from all others; and even if it groups all and only cats together, it might recognize them by smell rather than visually. But this by itself is no obstacle to ascribing to animals concepts, albeit ones that differ from ours. Accordingly, what kind of concepts we should ascribe depends on empirical investigations into the parameters governing animal behavior.
Whether this alternative to the language thesis holds water naturally depends on what one makes of concepts and concept-possession. According to one account, concepts are principles of discrimination, and to possess a concept is to have the ability to recognize or discriminate different types of things (Price 1953: 355; Dupré 2002: 229). On this construal, some animals possess concepts. Both in the wild and in the laboratory, they distinguish between a host of different colors, tastes, sounds, shapes, stuffs, quantities, types of creatures, etc. Moreover, many of these discriminations are learned rather than innate.
Proponents of the language thesis protest that this account of concepts falls prey to a reductio ad absurdum.
Unless we want to attribute concepts to butterflies and olive trees, we should not count the mere ability to discriminate between red and green or moist and dry as having a concept, not even if such selective behavior is learned.
(Davidson 1997: 25)
Fortunately, however, these absurdities do not follow from treating concepts as powers of discrimination. Olive trees do not discriminate between moist and dry soil, since discrimination is a prerogative of sentient creatures. We must distinguish between mere differential reaction to causal inputs, which is a universal feature of physical phenomena, and discrimination, which is tied to perceptual capacities. Nevertheless, even proponents of animal concepts ought to accept that conceptualization requires more than discrimination. But what?
A common answer runs: S must not just be capable of “recognizing an F” but of “recognizing something as an F or recognizing it to be an F.” This answer allows of different elaborations. According to Allen and Hauser, S must be able to recognize an F on the basis of several different properties, notably on the basis of properties which transcend perception. Preferably these properties should even be essential rather than accidental to F’s (1996: 51).
This proposal explains why a subject that can recognize, e.g., a carburetor, only by its shape does not possess the concept of a carburetor. But an appeal to discrimination can also guarantee this result. For such a subject lacks the ability to discriminate between carburetors and things shaped like carburetors or between non-carburetors and carburetors of a novel design. Furthermore, the proposal rules out the possibility of distinguishing between perceptual and more abstract concepts, or between having more or less rich concepts of an F. Thus, the possession of everyday color concepts only requires mastery of one way of telling, and a purely perceptual one at that. It is even less plausible to suppose that one has the concept of an F only if one distinguishes F’s by those features which we regard as essential to F’s. To be sure, for a subject S capable of distinguishing between essential and nonessential properties, what concept of an F that S possesses may depend on what properties S regards as essential to being F. That capacity is clearly lacking in animals. However, distinguishing essential from accidental properties is prerequisite only to a theoretical understanding of concepts, not to their mere possession. We cannot exclude the possibility of baboons possessing the concept of an alpha male simply because they cannot regard some properties possessed by all alpha males – being the highest-ranking male – as essential, and others – e.g. being strong and aggressive – as inessential, i.e. as not required by the very concept of an alpha male.
A less-presumptuous explanation of “recognizing x as F” runs as follows: S does not just react differently, depending on whether or not x is F; rather, S classifies x as (non-)F. This, in turn, means S decides between distinct options: Is x F or not? Is x F or G? What is more, S is capable of doing this in a deliberate and considered manner (Glock 2010). These provisos add a normative dimension to the capacity to discriminate. By contrast to a purely mechanical disposition, classification can be correct or incorrect, since the sorting of things into F’s and non-F’s is to be measured against distinguishing features of F’s that S herself regards as standards for treating something as F in her sorting behavior.
It might be objected that such classification amounts to what is traditionally known as “judgment,” and thereby to an answering of questions of the form “Is x F or non-F?” and “Is x F or G?” Accordingly, classification would be tied to language after all; except that questions, though linguistic, are in the first instance the fallout from problems. Animals face problems of discrimination, and some of them can solve these by distinguishing things according to their properties in a deliberate and considered manner. Thus, chimpanzees can choose tools, e.g. for nut-cracking, in a way that is not just intelligent instead of mechanical, but also premeditated rather than simply based on trial and error.
There is an even more demanding conception, according to which S only possesses the concept of an F if S can draw inferences from the fact that x is F. At this juncture, the language thesis can be backed up by the “the intrinsically holistic character of the propositional attitudes,” the alleged fact that “to have one is to have a full complement” (Davidson 1985: 473). Since at least some members of that complement are definitely beyond the ken for animals, they lack even the simple beliefs commonly ascribed to them. Malcolm’s dog cannot believe of an object that it is a tree,
unless we suppose the dog has many general beliefs about trees: that they are growing things, that they need soil and water, that they have leaves or needles, that they burn. There is no fixed list of things someone with the concept of a tree must believe, but without many general beliefs there would be no reason to identify a belief as a belief about a tree, much less an oak tree.
(Davidson 1985: 475)
For one thing, Davidson contends that specific concepts that occur in our attributions even of simple thoughts presuppose general beliefs, with which animals cannot be credited. But his examples are far from compelling. He suggests that S can only believe that the cat went up the oak or that the sun is behind clouds if S also knows that trees burn and that clouds consist of water vapor. This would restrict the possession of many beliefs to moderately educated contemporaries. Furthermore, it implies that any alteration in general beliefs amounts to a conceptual change, with the consequence that two scientific theories featuring incompatible empirical claims cannot be talking about the same phenomena. As Davidson candidly admits, his holism implies that the Ptolemeans could not believe that the earth is flat, since this would amount to rejecting a belief that he treats as constitutive of our concept of the earth.
Like other proponents of the language thesis, Davidson has another string to his bow, namely general holistic principles. But these are threatened by a dilemma: they are either too strong, since they would also exclude plausible cases of human thought, or too weak, since they cannot rule out all types of animal thought. The strongest holistic principle runs:
Principle (A) is excessively restrictive. Humans can believe the axioms of Euclidean geometry without believing all the theorems entailed by them. According to a modally mitigated version, S only needs to be capable of believing (learning, understanding) the consequences of its beliefs:
Even (B) is too demanding, however. For it is possible to believe the Euclidean axioms without even being capable of understanding all of the theorems. It is more plausible to maintain that S need be capable of appreciating only some rather than all of the things entailed by S’s beliefs:
According to (C), if a human being is incapable of even grasping any of the theorems entailed by Euclid’s axioms, he cannot believe the axioms either. However, (C) only offers moderate support to the language thesis. There are animals capable of appreciating some consequences of simple perceptual beliefs. That Malcolm’s dog consistently barks up the oak tree by itself does not manifest a belief that the cat is not in the maple tree; but if he continues to ignore the maple tree, even when prompted by us to attend to it, that would begin to suggest that he has the belief. Even nonlinguistic creatures can, in principle, be guided not just by what they perceive, but also by what follows from what they perceive.
On the other hand, the failure of this lingualist reasoning does not imply that a creature could entertain just a single belief. Indeed, the complex and flexible demeanor required for conceptual belief is incompatible with a behavioral repertoire capable of exhibiting just a single belief. Still, the web of which any belief must be part need not extend as far as the web of sophisticated human thought. What kind of network is required may depend on the belief and the creature concerned. From the fact that an animal lacks our web of beliefs and our concepts, it does not follow that it has no beliefs and no concepts.
As a last resort, a holistic defender of the language thesis can raise the bar for concept-possession even higher. It does not suffice for S to be capable of entertaining some consequences of a purported belief; S must also be able to infer these consequences.
Whether animals can draw theoretical and/or practical inferences is connected to the issue of animal rationality. A venerable tradition conceives of reason as a capacity to justify one’s beliefs and actions, paradigmatically by deriving them from less-contentious assumptions. Thinking (believing/desiring) that p is a precondition for drawing inferences and hence for the faculty of reason. In both theoretical and practical reasoning, one moves from one or more thoughts, the premises, to another thought, the conclusion. According to (D), the reverse also holds, since beliefs and desires are the prerogative of subjects capable of reasoning. Reasoning must be held apart from intelligence. Roughly speaking, intelligence is the ability to solve problems – notably novel ones – in a flexible way, one which is not predetermined genetically or epigenetically. It therefore presupposes a capacity for learning. Learning, for its part, ranges from routines of strict conditioning, as in the case of pigeons and rats in a Skinner box, through the “trial and error” procedure of capuchin monkeys in the trap-tube task, to the insight and foresight displayed by some great apes and corvids in the employment and production of tools. Even here, however, it is controversial whether it involves inferences from premises to conclusions. For it remains unclear how such ratiocination can be ascribed to subjects without language (see Glock 2009).
Recall, however, the ancient tale of the dog of Chrysippus (Sorabji 1993: 26). In chasing a prey of which it has lost the scent, this dog reaches a crossroad; it sniffs down the first path, then sniffs down the second path, then it immediately follows the third without sniffing. Empirical studies suggest that dogs can at best pull off such a feat with prior training. Nevertheless, it is an intelligible capacity for a nonlinguistic creature. And the most plausible explanation of that capacity is that it evinces a disjunctive inference (“p or q or r; neither p nor q; ergo r”). A recent alternative (Rescorla 2009) appeals to Bayesian probabilistic reasoning, yet the latter would appear to be more cognitively demanding than simple disjunctive inference. To be sure, a nonlinguistic creature cannot silently consult logical principles, whether deductive or probabilistic. But even our intelligent performances are rarely accompanied by conscious consultations of this kind.
This leaves one residual worry. Although humans need not actually verbalize their reasoning, even in the imagination, they are capable of doing so. In the absence of this option, the question arises of what in an animal’s behavior could correspond to the “ergo” of linguistic reasoning. This point may be unanswerable in the case of dogs. But in apes, there can be an analogue to our “ergo.” In the context of encountering and pondering a problem, certain gestures and grimaces, followed by renewed activity, can naturally be interpreted as marking the point when the penny dropped. Even if this is an anthropomorphic interpretation in the case of chimpanzees, there were not-yet-linguistic hominins – let’s say homo erectus – whose facial expressions, demeanor and gestures are so close to ours as to make such a description inevitable. Consequently, there is no compelling reason for supposing that nonlinguistic subjects are in principle incapable of drawing inferences. To what extent some primates and marine mammals actually engage in disjunctive and transitive reasoning is the topic of ongoing research (see Andrews 2015: 96–105).
Andrews, K. (2010) “Animal Cognition,” in E. N. Zalta (ed.), The Stanford Encyclopedia of Philosophy, www.science.uva.nl/~seop/entries/cognition-animal/ offers a succinct, well-informed and up-to-date account. Lurz, R. (2009a) “Animal Minds,” in The Internet Encyclopedia of Philosophy, www.iep.utm.edu/ani-mind/ is also recommended, discussing not just cognition but also consciousness. Lurz, R. (ed.) (2009b) The Philosophy of Animal Minds, Cambridge: Cambridge University Press assembles recent contributions on a similarly wide range of issues – including animal inference and methodological questions – and places them within the context of the emerging subdiscipline that provides its title.
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