Difference in Kind Between Human Beings and Other Animals

 

A. Conceptual Thought

We know what a thing is like through its actions. For example, we discover what a metal is or that a thing is alive through its distinctive actions. The actions of a thing are just the unfolding or fulfillment of what it is, and so, as the scholastic slogan put it, action follows being (agere sequitur esse).  Our argument will be that human beings fundamentally differ from other animals because they perform actions which manifest a transcendence of matter not possessed by other animals. Human beings perform spiritual actions, that is, actions performed without bodily organs. From this it follows that an aspect of the human being, the human soul, transcends matter, and as a consequence cannot simply be the product of purely physical forces.  From these points we conclude that human beings are radically different in kind, not just in degree, from other animals. 

        A first step in the argument is the claim that human beings perform acts of understanding, or conceptual thought, and that such acts are fundamentally different kinds of acts than acts of sensing, perceiving, or imagination. An act of understanding is the grasping of, or awareness of, a nature shared in common by many things. In Aristotle’s memorable phrase, to understand is not just to know water (by sensing or perceiving this water), but to know what it is to be water.[1] By our senses and perceptual abilities we know the individual qualities and quantities that modify, or have modified, our sense organs—this color or this shape, for example. But by understanding (conceptual thought), we apprehend a nature held in common by many—not this or that water, but what it is to be water. The object of the sensory powers, including imagination, is always an individual, a this at a particular place and a particular time, a characteristic, such as this red, this shape, this tone, which is thoroughly conditioned by space and time.

    The contrast is evident upon examination of language. Proper names refer to individuals, or groups of individuals that can be designated in a determinate time and place.  Thus, “Winston Churchill” is a name that refers to a determinate individual, whereas the nouns “human,” “horse,” “atom,” and “organism” are common names. Common names do not designate determinate individuals or determinate groups of individuals (such as “those five people in the corner”). Rather, they designate classes. Thus, if we say, “Organisms are composed of organs, tissues and cells,” the word “organisms” designates the whole class of organisms, a class that extends indefinitely into the past and indefinitely into the future. All syntactical languages distinguish between proper names and common names. 

    But a class is not an arbitrary collection of individuals. It is a collection of individuals that have something in common.  There is always some feature, some nature or property, that is the criterion of membership for the class. Thus, the class of organisms is all, and only those, that have the nature of living, bodily substance. And so, to understand the class as such, and not just be able to pick out individuals belonging to that class, one must understand the nature held in common.  And to understand the class as a class (as we clearly do in reasoning) one must mentally apprehend the nature or property held in common by the members of the class, and compare this to those individual members. Thus, to understand a proposition such as, “All organisms require nutrition for survival,” one must understand a nature or universal content designated by the term “organisms”: the term designates the nature or feature which entities must have in them in order to belong to that class. 

    Human beings quite obviously are aware of classes as classes. That is, they do more than group individuals into a class based on a perceived similarity; they are aware of pluralities as holding natures or properties in common.[2]  For example, one can perceive, without a concept, the similarity between two square shapes or two triangular shapes, something which other animals do as well as human beings. But human beings also grasp the criterion, the universal property or nature, by which the similars are grouped together.[3]

    There are several indications that this is so. First, many universal judgments require an understanding of the nature of the things belonging to a class. If I understand, for example, that every organism is mortal, because every composite living thing is mortal, this is possible only if I mentally compare the nature, organism, with the nature, composite living thing, and see that the former entails the latter. That is, my judgment that every composite living thing can be decomposed and thus die, is based on my insight into the nature of a composite living thing. I have understood that the one nature, subject to death, is entailed by the other nature, composite living being, and from that knowledge I then advert to the thought of the individuals which possess those natures. In other words, I judge that individual composite living beings must be included within the class of individuals that are subject to death, but I judge that only in virtue of my seeing that the nature, being subject to death, is necessitated by the nature, composite living being. This point is also evident from the fact that I judge that a composite living being is necessarily capable of death.[4] By the senses, one can grasp only an individual datum. Only by a distinct capacity, an intellect, only by apprehending the nature of a thing, can one grasp that a thing is necessarily thus or so. 

    Another example will illustrate this point. When children arrive at the age at which they can study logic, they provide evidence of the ability to grasp a nature or property held in common by many. They obviously do something qualitatively distinct from perceiving a concrete similarity. For example, when studying elementary logic, the child (or young man or woman) grasps the common pattern found in the following arguments: 

 

A.    If it rains then the grass is wet.

The grass is not wet.

Therefore, it is not raining.

B.     If I had known you were coming, I would have baked you a cake.

But I did not bake you a cake.

So, (you can see that) I did not know you were coming. 

            We understand the difference between this type of argument, a modus tollens argument, and one that is similar but invalid, namely, the fallacy of affirming the consequent (If A then B, B, therefore A). But, what is more, we understand why the fallacy of affirming the consequent is invalid—namely, some other cause (or antecedent) could be, or could have been, present to lead to that effect (or consequent). A computer, a mechanical device, can be programmed to operate according to the modus tollens and to react differently (give a different output for) words, or rather, marks, arranged in the pattern of the fallacy of affirming the consequent. But understanding the arguments (which humans do) and merely operating according to them because programmed to do so (the actions of computers) are entirely different types of actions. The first does, while the second does not, require the understanding or apprehending of a form or nature as distinct from its instances.[5]  That is, the first, but not the second, requires a grasp of the universal or abstract nature.[6]

    That event, which we can call an insight, is a mental act that is funda­mentally distinct, though obviously related to, sensation, perception, or imagina­tion. The universal nature or form is the object of the act of under­standing. But whatever exists as physical is an individual, tied to a particular place and time. So, the term of the intellectual act is a non-physical content. And the intellectual act is a non-physical act. When someone understands the point of the difference between modus tollens and the fallacy of affirming the consequent, he sees that the conclusion necessarily follows in the one case, and is invalid, and does not necessarily follow in the other case. But one does not grasp necessities, or the lack of necessities, by one’s senses, imagina­tion, or any bodily act.[7] What one senses, perceives, or imagines—what one grasps in bodily cognitive acts—is always a this, with a parti­cular, albeit sometimes vague, contour. But the point or the truth that one grasped in grasping the nature of the modus tollens argument equally applies not just to this argument or to that one, but to every possible instance of it, whether the argument be about horses, or electrons, or argument forms them­selves. In short, what one grasps in an insight is a nature, property, or form that can be (and usually is) instantiated in many, innumerable cases and which grounds explanations for why things (or relations, as in logic) are as they are..[8]               

    The capacity for conceptual thought in human beings radically distin­guishes them from other animals. This capacity is at the root of most of the other distinguishing features of human beings. Thus, syntactical language, art, architecture, variety in social groupings and in other customs,[9] burying the dead, making tools, religion, fear of death (and elaborate defense mechanisms to ease living with that fear), wearing clothes, true courting of the opposite sex,[10] free choice and morality—all of these and more, stem from the ability to reason and understand.  Conceptual thought makes all of these specific acts possible by enabling human beings to escape fundamental limitations of two sorts. First, because of conceptual thought, human beings’ actions and con­scious­ness are not restricted to the spatio-temporal present. Their awareness and their concern go beyond what can be perceived or imagined as connected immediately with the present.[11] Second, because of conceptual thought, human beings can reflect back upon themselves and their place in reality, that is, they can attain an objective view, and they can attempt to be objective in their assessments and choices. Other animals give no evidence at all of being able to do either of these things; on the contrary, they seem thoroughly tied to the here and now, and unable to take an objective view of things as they are in themselves, or to attempt to.[12] 

    Note that if the analysis just given is substantially correct, then the power of conceptual thought is not just different in degree from other capacities (such as perceptual thought and instinct) but is different in kind. This means that a being either has this capacity or not, even though, as we will indicate more fully later, a being may have a basic natural capacity for conceptual thought long before he or she develops that capacity to the point where it is imme­diately exercisable (so an infant, for example, has the basic natural capacity for conceptual thought even though it will be months before he or she actually has a concept). Thus, every human being, including human infants and unborn human beings, has this natural capacity for conceptual thought, but a horse or a dog simply and altogether lacks this capacity.  It is sometimes argued that perhaps some nonhuman animals do have minds like humans do, only at a diminished level. Perhaps, it is speculated, it is only the complexity of the human brain, a difference only in degree, that distin­guishes humans from other animals. Perhaps other primates are intelligent but they have lacked the opportunities to manifest their latent intelligence. But such speculation is misguided.  While intelligence is not directly observable, it is unreasonable to think that an intelligence of the same type as human intelligence, no matter how diminished, would not manifest itself in at least some of its characteristic effects.[13] If a group of beings possesses a power, and possesses that power over many years (even decades or centuries), it is implausible to think that such a power would not be actualized. 

    The fundamental difference between human beings and other animals is quite obvious to the unprejudiced eye. Human beings have literally trans­formed most landscapes on planet earth by structuring materials according to their intelligent purposes. Other animals, by contrast, have left few lasting effects, and these—fossils—by accident.  Some other animals do build struc­tures for protection and warmth, for example, the beaver’s dam and the bee’s hive. Yet it is obvious that these animals build such quasi-stable structures from instinct rather than from intelligence.  This is evident from the fact that their manner of building is invariant among members of the species, and invar­iant across generations. If they understood and planned what they were doing, as human beings do, inevitably they would begin to devise various and perhaps improved ways of building. Nothing of that sort occurs. This of course is in marked contrast with the variation and improvement through generations in the art of building among human beings. Only human beings have the art of building; that is, only human beings conceive the intelligible purpose and design for what they construct. Only human beings conceive what they are doing, as opposed to blindly following a (genetically determined) sequence of acts which, by natural selection or by the creator’s extrinsic design (or both), usually produces success. 

    This points up a more general difference between human beings and non­human animals.  There is a marked invariance of general pattern of living among nonhuman animals and their societies. Human beings, on the other hand, display great variety, not only in houses and cities, but also in dress, customs, courting practices, and societal arrangements. True, because of their common human nature, there is an underlying sameness among human beings —the different cultures pursue the same basic purposes or goods of life, health, friendship, family, learning, aesthetic experience, and so on. Yet there is great variety in the manners of pursuing these common basic purposes. By contrast, other animals not only pursue the same ends within their species (notably lacking such goods as learning for its own sake, skillful performance as true artistic endeavor, and aesthetic experience, that is, experience of the beautiful for its own sake), but they also pursue these ends in a manner that is uniform among all the members of their species and in the same way from generation to generation. 

    Again, human beings do, while other animals do not, form political socie­ties. Other animals form societies according to instinct, as evidenced by the specific invariance of the structures of their societies, and by their same­ness across generations.[14] Human beings form ideas or concepts of how their societies should be structured, and express these in the form of constitutions (written or unwritten), and then to a certain extent (never fully) live up to those constitutions. Thus, because of his capacity for conceptual thought and reasoning, man is a political animal, not just a social animal (many other animals also being social).

    Conceptual thought also grounds the human being’s unique ability to make tools to be used indefinitely into the future. Nonhuman animals are able to per­­ceive a concrete relation, such as the spatial relation between two sticks and a concrete object they now wish to retrieve, and build a tool on a specific occasion. But human beings fashion tools that they plan to use for a variety of situations in the future. And, what is more, only human beings mass produce tools; for, evidently, only they are able to grasp the nature of the tool in abstraction from this or that concrete instance. If nonhuman animals had the capacity for true conceptual thought, then they would make tools based on concepts of how they could be used, and thus they would mass produce them and, by now, would have conceived of replaceable parts for tools. Nothing even approaching this, of course, has been observed.  

    Again, human beings deliberate about their actions. True, the smell of tasty food spontaneously attracts a healthy human being just as it attracts a non­human animal. But the human being goes further. The human being begins to reflect on the different possible actions he could perform in relation to the food. Of each action he understands both advantages and disadvantages. He is able to understand that eating the food (an act that he can understand as well as imagine) is, though good in one respect, bad in another, because it might negatively impact forms of fulfillment such as health and religion. Thus, unlike other animals, the human being understands different aspects of the same concrete particular:  these are intelligible but not imaginable or percep­tible features or aspects. This ability, at least in part, is what enables the human being to make free choices. 

    Rationality is not merely a capacity whose actualization is isolated from the other activities that a human being performs. Rather, as the logic of definition indicates, “rational” refers not just to the activity or even just the capacity, but to the distinct kind of being of the human species, which involves a fundamentally different way of being an animal. Among organisms, each new specific difference indicates not just a new and isolated capacity, but a distinctive way of being an organism, or a distinctive way of being an animal. Thus the specific difference, sensing, as in a sensing organism, that is, an animal, refers not just to the capacity for sensation. Rather, the organism’s whole mode of living, principally its mode of obtaining nourishment and reproduction, is affected by its capacity to sense and perceive. Similarly, conceptual thought changes how human beings perform most of their other activities.[15] The rationality of a rational animal, a human being, affects his or her whole mode of life—how he obtains food, reproduces, gathers in groups, seeks shelter.  In other words, his rationality specifies his mode of being an organism and his mode of being an animal.