Introduction
Now,Footnote 1 it is a greater dignity to exist in something nobler than oneself than to exist by oneself. Hence the human nature of Christ is of a greaterFootnote 2 dignity than ours, from this very fact that in us, being existent by itself, it has its own personality, but in Christ it exists in the Person of the Word. Thus to perfect the species belongs to the dignity of a form, yet the sensitive part in man, on account of its union with the nobler form which perfects the species, is more noble than in brutes, where it is itself the form which perfects.Footnote 3
Animals with Thinking Caps/Souls Cloaked in Bodies
In a magnificent recent essay, Matthew Boyle argues against what he calls ‘additive’ theories of rationality and in favor of the ‘transformative’ view of rationality that he finds sketched by John McDowell and others.Footnote 4 Additive theories hold that we share some cognitive and conative capacities with nonrational animals, but that an extra capacity—the rational capacity—allows us to reflect on the adequacy of our reasons to believe the testimony of our senses or to follow where desire might lead. Unlike nonrational animals, rational animals can step back and consider what to think and what to do. Reason makes this possible for human beings.
Boyle mounts powerful arguments against the widespread Anglophone philosophical tendency to treat rational animals as, in effect, primates with thinking caps. Additive theories of rationality, Boyle shows, face difficulties very like the problem of explaining mind-body interaction and the problem of explaining the unity of mind and body that haunt Cartesian dualism.
In a tantalizing footnote, Boyle points to Aquinas as a source of inspiration for the arguments against additive theories:
The problems I raise for additive theories of rationality are modeled on difficulties Aquinas raises for views that hold that a rational animal has a sensitive ‘soul’ that is not intrinsically rational and a further ‘soul’ in virtue of which it is rational—a position Aquinas associates with Plato.Footnote 5
The alternative picture of rationality that Boyle sketches for us is what he calls the transformative view, the view that our capacities for perception and desire ‘must be themselves informed by our rationality, in a way that renders them distinct in species (although certainly the same in genus) as the perceptual and desiderative capacities of nonrational animals.’Footnote 6 Boyle does not provide a full-fledged account of the transformative alternative to the additive picture, but mounts a tremendously powerful case that this is what is needed.
According to Boyle, then, Aquinas helps to lay the paving stones along the via negativa by which we are alerted to the need for a properly transformative theory of human rationality. But I will urge that Aquinas has more to offer than reasons to reject additive theories. Aquinas's positive account of human mindedness offers what Boyle calls a transformative theory.
Tracing the alternative to additive theories that we can find in Aquinas requires taking on board something of his metaphysics, which may be why Boyle keeps Aquinas's positive contribution at a distance. It is hard to engage contemporary Anglophone analytic philosophy in the idiom of Aquinas's metaphysics. And it is virtually impossible to remove all thought of God from the metaphysics. Neither of these points, all on its own, is reason enough to avoid the metaphysics, of course. The two taken together do not add up to a reason to avoid the metaphysics either. And the metaphysics that Aquinas built supports the arguments that he mounted against the versions of Platonism current in his day—the very arguments that Boyle found helpful.Footnote 7
Contemporary Anglophone philosophy needs an alternative to the view of human beings as brutes with thinking caps. The analogous challenge Aquinas faced was developing an alternative to the view that humans are souls wearing their bodies like garments. In both cases, what is at stake is the unity of the human being. Boyle seeks a unified account the rational animal. Aquinas develops a unified account of the intellectual animal.
Aquinas's account informs his discussion of both the varieties of nonhuman animal conation and cognition, and his treatment of the difference between merely sentient animals and human beings. It informs his discussion of the differences between higher and lower intellects as well.
He articulated his understanding of the union of soul and body in terms of an Aristotelian metaphysics of matter and form. Anton Pegis describes the result this way:
One need not deny that St Thomas learned philosophy from Aristotle or that Aristotle was the common teacher of the schoolmen of the thirteenth century in order to insist that the Angelic Doctor, among others, formulated highly original and sometimes even un-Aristotelian notions in the current language of the Philosopher . . . Why could [Aquinas] not have endowed old Aristotelian notions with a strength and a depth of meaning that still baffle the historian by their seemingly innocent combination of the old and the new?Footnote 8
I am in a position to evaluate neither the originality of Aquinas's understanding of the unity of the human being nor its innocence. What I will do instead is explore some of his work as providing a transformative account of human mindedness. I will start with a brief discussion of his understanding of the human being, give some attention to the varieties of animal souls he discusses, set us alongside other animals (occasionally casting a glance in the direction of angels along the way) and then pause over Aquinas's treatment of resurrection. I will spend most of my time coming at the distinctiveness of the intellectual animal from below (we are the highest of animals), remarking in passing on the view from above (ours is the lowest kind of intellect). Throughout, I aim to highlight the transformative character of his treatment of essentially embodied intellects.
The Human Being as Substance
The Aristotelian notions that Pegis finds remade by Aquinas are at least those of body and soul brought together with those of form and matter. Aquinas holds with the Aristotelian understanding of matter as what can take form,Footnote 9 and of body as enformed matter. In this sense, any body actualizes its form. Bodies are, for Aquinas following Aristotle, substances. And any given substance is an individual in virtue of its substantial form, which keeps it numerically identical through changes.
For Aquinas, as for Aristotle, there is such a thing as substantial change—as, for example, in the generation of a substance. Substantial change is not, for these thinkers, the alteration of a substance that remains numerically identical through change. The topic is complicated, has far-reaching implications, and is beyond the scope of this essay, turning on an understanding of matter which is only matter relative to substantial change.Footnote 10 But substantial change is what is at issue in birth, in death, and in such things as a lion eating an antelope.
Living things are paradigmatic instances of substances for Aquinas and Aristotle, and living things come in kinds. The form of any individual living thing is its kind. And the kinds in question organize the activities, parts, and processes of living things of the relevant kinds.
Working in the idiom of contemporary analytic practical philosophy and treating the terms used to pick out kinds of organisms—in effect, substantial forms—as the wider contexts that set the framework necessary for apprehending individual living things as such, Michael Thompson, puts the point this way:
…if a language contains any representations of the . . . class of organisms—‘actual objects’ for which actuality takes the form of life—it must also include a battery of what we may call ‘life-descriptions’. Such would be, for example: representations of parts as organs or ‘members’; representations of particular sorts of goings-on as vital operations . . . and so forth . . . And, of course, what falls under such descriptions and such concepts will be different in different ‘wider contexts’. And so, if there is to be thinking of organisms or a representation of life at all, then the thinking and speaking subject must have some means of apprehending the various sorts of ‘wider context’—the various ‘life forms’, as I will call them. Even the most pedestrian case of life-description, say, that the cat is drinking milk, must make an implicit claim about the relevant ‘form’ or ‘context’—that for it, or in it, the events before us add up to drinking; or that what the creature is doing is drinking, for such as it is.Footnote 11
Thompson argues that any understanding of the activities characteristic of any individual living thing—he restricts his attention to organisms—depends upon an implicit understanding of the individual's life form, and that judgment about life forms is irreducible to the sorts of judgment more commonly treated by contemporary logicians. Judgment about life forms, for example, cannot be treated as a variety of statistical judgment, nor as Fregean universal judgment, nor as ordinary general judgment hemmed in by ceteris paribus clauses. Although sentences expressing the content of a life form judgment will be classed as generic sentences by linguists (and by some philosophers of language), when the ‘genera’ in question are forms of life, the judgments will reveal the distinctive patterns that Thompson is careful to trace.Footnote 12
What Thompson calls a ‘life form’ and treats by way of careful consideration of the kinds of judgment and understanding that rely upon grasp of forms of life, Aquinas will treat as soul—a topic for metaphysics. The soul is the substantial form of a living thing. Following Aristotle, Aquinas gives an account of soul as the principle of unity for a living thing.Footnote 13 As such, the soul makes an individual living thing the one thing that it is. If the living thing has parts, then the soul is responsible for both the diversity of its parts and for their order and functioning. If the living thing is an organism, then its body is made to be an individual body by the soul. As what unifies the individual and orders and organizes its activity, any living thing's substantial form is operative in the whole of that living thing throughout the living thing's life.
All of this is familiar to anyone who has spent any time working with Aquinas's metaphysics. I will take the point about the soul's presence in the whole of the living thing that it unifies in a slightly unusual direction. My aim is to urge that Aquinas's understanding of the human being—the intellectual animal—provides a transformative understanding of intellect in a sense more radical than the alternative Boyle was seeking.
Intellect, in the relevant sense, is not the same as what Anglophone analytic philosophers mean by ‘reason’. In contemporary mainstream Anglophone philosophy, reason signifies cognitive capacities and their exercise, and rationality signifies some sort of excellence in the exercise of cognitive capacities. There are debates about the nature and scope of cognitive capacities and their exercise. These debates will not concern me here. The Anglophone philosopher's reason is, for Aquinas, a discursive mode of intellectual activity. Not all modes of intellectual activity are, for Aquinas, discursive.
For example, on Aquinas's view, angelic cognition and judgment are importantly different from ours. Obviously they do not learn through the senses. They are intellectual creatures without organs—immaterial intellectual beings. More importantly, they are not discursive intellectual beings. They do not compose and divide in thought. They do not operate by advancing from thought to thought. They do not infer. Aquinas writes:
[The] lower, namely, the human intellects obtain their perfection in the knowledge of truth by a kind of movement and discursive intellectual operation; that is to say, as they advance from one known thing to another. But if, from the knowledge of a known principle they were straightaway to perceive as known all its consequent conclusions, then there would be no discursive process at all. Such is the condition of the angels, because in the truths which they know naturally, they at once behold all things whatsoever that can be known in them.Footnote 14
Angelic intellect is higher than human intellect.
Boyle focuses on what a Thomist will treat as aspects of animal apprehension and of appetite—Boyle's ‘perception’ and ‘desire’. Aquinas shows an early and interesting form of respect for the varieties of appetitive and apprehensive capacities on display in the lives of different kinds of animals, as well as a lively interest in what makes the intellectual animal different from all the rest.
Aquinas accepts the ancient thought that different kinds of plants have different kinds of vegetative souls, and that different kinds of animals have different kinds of sensitive souls. He is like modern and contemporary philosophers in at least one respect—the more like the human being a species of nonhuman animal seems to be, the higher it climbs on a ladder of kinds of organism, and the greater its characteristic specific powers appear (these are, in effect, two ways of making the same point). In a mood of reverence that only those of us who have grown extraordinarily sensitized to concerns about environment, climate, and biodiversity in recent years can so much as approach, Aquinas's discussions of nonhuman species of organism take place against a background understanding that every kind of substance has something of the divine in it.Footnote 15
Of Animals
In an early work, Aquinas remarks on aspects of nonhuman animal apprehension and appetite that have something of reason in them:
It should be noted . . . that not only in the apprehensive powers but also in the appetitive there is something which belongs to the sensitive soul in accordance with its own nature and something else according as it has some slight participation in reason, coming into contact at its highest level of activity with reason at its lowest . . . Thus the imaginative power belongs to the sensitive soul in accordance with its own nature, because forms received from sense are stored up in it, but the estimative power, by which an animal apprehends intentions not received by the senses, such as friendship or hostility, is in the sensitive soul according as it shares somewhat in reason . . . The same principle is verified also in regard to the appetitive power. The fact that an animal seeks what is pleasurable to its senses (the business of the concupiscible power) is in accordance with the sensitive soul's own nature; but that it should leave what is pleasurable and seek something for the sake of a victory which it wins with pain (the business of the irascible), this belongs to it according as it in some measure reaches up to the higher appetite.Footnote 16
It is hard to separate the most complex operations of nonhuman animal apprehension and appetite from their simplest human counterparts. H. H. Price put a related point this way:
It is possible that in some creatures the capacity of recognizing their food or their enemies is unlearned, ‘instinctive’ as we say; and that the function of sense-experience is merely to actualize these already existing recognition powers. But in most animals, perhaps in all, sensation has another function as well. It enables one to learn from experience, and thereby to respond more effectively to one's environment. To put it rather extravagantly, sense-experience exists for the sake of induction.Footnote 17
Following Aristotle, Aquinas distinguishes three levels of animal awareness, corresponding to distinctive modes of experience. There are animals, he thinks, that live their lives fixed in one place for whom ‘the influence of sensible objects in the surrounding environment gives rise to nothing but collated awareness of immediate sensations; and in these forms there is no such thing as memory.’Footnote 18 He contrasts these with animals that have memory, and so have internally organized apprehension [sunt prudentia] that allows them to make provisions for the future on the basis of memory of the past.Footnote 19 Finally, among those animals that move about and have memory, there are some that can be trained and others that can't.Footnote 20 The ones that can be trained are capable of a wide range of behavioral modification on the basis of experience.
We need not take Aquinas's categorization of nonhuman animals on board in order to recognize that, for Aquinas, the species of animal under consideration shapes its modes of apprehension, its passions, and its appetites.Footnote 21 The operation of all of these aspects of sentient life is geared to what is good or bad for the kind of animal in question, and specific difference informs the character and scope of cognitive and conative powers accordingly. The substantial form—the life form, the kind of living thing in question—is fully present in every part of an animal, responsible for both the different parts and the mode of all vital processes characteristic of an animal of its kind. More than this, even, the powers characteristic of the sensitive soul reach up toward reason. The more complex the cognitive capacities necessary to account for the daily survival of the individual member of a species (and for the ongoingness of its form through reproduction of the species), the more complete the species of sentient soul. For Aquinas, not every sort of sentience is, in Price's phrase, ‘made for induction’. However, the varieties of sentient soul that organize the lives of those species that we, too, will treat as animals whose activities require learning from experience—learning what to pursue; learning what to avoid; learning how to go for or flee from things, frequently with the help of more mature members of the species when they are young—such kinds of animal (many mammals, for instance, and some birds), such sentient souls do seem to enform sensory processes that are made for induction. For Aquinas, this is true of the higher kinds of sentient souls.
Aquinas's story about this can look, to modern eyes, like an Aristotelian variant of the crassest and least tenable form of empiricism imaginable, in which different sensory modalities somehow cooperate in providing something very like raw sense-data that can be made into an image—a phantasm—which is then somehow both the image of a particular (a particular state of affairs? a particular predator? a particular friend? a particular kind of threat? a particular edible thing?—it is hard to say) and an image that can be stored and re-deployed when this sheep, say, runs away from that wolf—not necessarily the same wolf from which our poor sheep fled last week.Footnote 22 Whether the sheep's understanding that wolves are to be avoided is connected to a past moment of its own terror when wolves were trying to take down a member of its flock, or communicated to our sheep by other sheep when our sheep was just a lamb, Aquinas's story sounds very like a story in which some primitive form of generalization from discrete sense-impressions—its own, or those of older members of the flock—equips our sheep to flee, not just this very wolf or that very wolf, but wolves (on sight, on smell, or upon hearing the bleating rush of other members of the flock).
I recognize that it is easy to read Aquinas's story this way. But I do not think that the text forces a reading that anyone schooled in analytic philosophy and familiar with articulate twentieth century philosophical scorn for myths of the given will rightly dismiss. Aquinas is exquisitely sensitive to the difficulty of describing and theorizing the highest forms of animal intelligence and of seeing both their relations to the varieties of conceptual intelligence characteristic of human mindedness and the ways in which the intellectual animal's mental life is nevertheless distinct from anything to be found among other animal species. Aquinas's treatment of nonhuman animal intelligence is itself subtle and complicated. John Deely outlined some of the care Aquinas takes with the topic this way:
…the phrase used to distinguish the second level of animal life from the first—ratione praesentiae memoriae, quaedam animalia ‘aliquid prudentiae habere possunt’—does not have a univocal meaning even in the order of animal consciousness. Not only is it necessary to aver that ‘dicitur prudentia aliter in brutis animalibus, et aliter homnibus inesse,’ but also that ‘dicitur prudentia aliter in brutis secundi gradus cognitionis, et aliter in brutis tertius gradus inesse.’ In the former case, prudentia means ‘an innately structured repertoire of interaction responses’; in the latter case, it means ‘able to learn from experience’.Footnote 23
What we find in Aquinas is not a prescient precursor to a wildly implausible empiricist story about animals forming concepts on the basis of something akin to a flow of sense data (occasioned by proximity to something else). What we find is a principled discussion of different modes of animal perception based in part on thought about what a given species of animal needs to be able to do in order to stay alive and perpetuate its species. And the account of animal perception crucially turns on analogy to the most complete case, namely, the perceptual capacities of the highest sort of animal—the human being. Ours is the central case. The analogy to other animals is based on the central, most perfect, most complete sort of sentience, and that sort is integrated with rationality. Notice that is hard to see how one could, even now, discuss these matters in a way that was not, in exactly this way, analogical.
Of Humans in this Life and the Next
One kind of animal—the kind whose soul is intellectual, the one kind of animal whose soul qua intellectual can survive without its body, albeit in a radically impoverished and ultimately unsustainable wayFootnote 24—integrates the higher cognitive powers with the operations of sentience. That animal is the human being.
Aquinas treats the human soul as part of a human person—a part that can continue to exist postmortem. For Aquinas, however, the postmortem, separated human soul is not itself a human being. It is not itself a person. The disembodied human soul is in a radically unnatural state—a state in which its characteristic operations, depending as they do upon embodiment, are severely circumscribed.
So, unlike other sentient creatures, the human being has a spiritual soul—an intellect—and the human body is matter enformed by intellect. The human intellect, like any intellect for Aquinas, works with universals—its characteristic activity concerns understanding natures or forms. Natures and forms are immaterial. But its grasp of these matters is discursive and progressive. In this, as I mentioned, its intellectual life is different from the intellectual lives of angels.
Human intellects are the substantial forms of human beings. Human beings are animals, and hence, sentient creatures with the powers that the tradition assigns to organisms as such. It is obvious that the disembodied human soul cannot exercise capacities for nutrition, reproduction, perception, or any other aspect of human life actualized through bodily organs or activities. As such, an individual human soul existing postmortem cannot exercise its characteristic apprehensive and appetitive capacities.
In a late work, wrestling with the question of the promised resurrection of one and the same human being as a reunion of form and matter, Aquinas remarks:
The numerical identity [of the resurrected person] is not frustrated on the ground that the corporeity recovered is not numerically the same, for the reason that it corrupts when the body corrupts. If by corporeity is meant the substantial form by which a thing is classified in the genus of corporeal substance, such corporeity is nothing else than the soul, seeing that there is but one substantial form for each thing. In virtue of this particular soul, this animal is not only animal, but is animated body, and body, and also this thing existing in the genus of substance. Otherwise the soul would come to a body already existing in act, and so would be an accidental form. The subject of a substantial form is something existing only in potency, not in act. When it receives the substantial form it is not said to be generated merely in this or that respect, as is the case with accidental forms, but is said to be generated simply, as simply receiving existence. And therefore the corporeity that is received remains numerically the same, since the same rational soul continues to exist.Footnote 25
He continues:
Consequently, since union is a kind of relation, and therefore an accident, its numerical diversity does not prevent the numerical identity of the subject; nor, for that matter, does numerical diversity among the powers of the sensitive and vegetative soul, if they are supposed to have corrupted. For the natural powers existing in the human composite are in the genus of accident; and what we call ‘sensible’ is derived, not from the senses according as sense is the specific difference constituting animal, but from the very substance of the sensitive soul, which in man is essentially identical with the rational soul.Footnote 26
I take it that Aquinas's treatment of the promised resurrection of the human being, and his argument that the resurrection can only be miraculous, are of a piece with his understanding of the human being as the intellectual animal, and of the substantial form of any human being as active in all of that person's bodily parts and vital processes.
Stephen Brock puts the point this way:
To say rational . . . is already, implicitly, to say animal . . . Rationality is a mode of intellect—of the quality of being, in a way, all things—and hence it implies a dimension of pure immateriality. But it is a mode that is intrinsically connected to the life of the senses, and therefore to the sense-organs; and to the vegetative functions and the physical ingredients that constitute the organs; and to matter itself.Footnote 27
In this sense, Aquinas's transformative account is more pervasive than what Boyle seems to have envisioned. Rationality, by Aquinas's lights, becomes the principle of unity not just for human mental life, but for the whole life of the human being.
A Concluding Remark
I began by explaining the shape of the gauntlet that Boyle throws down at the feet of analytic philosophy. The challenge, as Boyle sees it, is to account for the unity of the human being as a rational being, rather than an animal with a mysterious extra capacity for stepping back and reflecting on its grounds for belief and action. I called the mysterious add-on a ‘thinking cap’. My aim has been to argue that Aquinas provides a powerful alternative to this picture—a deeply transformative account of rationality, where rationality is the name of the characteristic mode of human intellectual activity.
It could be objected that Aquinas's account of the unity of the human being goes too far. It is one thing to provide a transformative account of human sentience. That seems right and proper, if only because refusing to do so leaves one open to a host of objections of the kinds so beautifully explained by Boyle. But surely we don't want to get stuck with a transformative account of digestion, or kidney function, or any of the other bodily activities involved in the survival of the living individual from one day to the next!
I take it that Aquinas's account of the unity of the intellectual animal does not require that we look for special, discursive modes of cardio-pulmonary functioning. The powers of the soul, after all, do not operate in exactly the same way in all of the operations coordinated and unified by that soul. What it does require is that we think of the human being as a unified creature, and of human bodily functioning as a specific mode of generic animal biological functioning. And this ought not to be difficult. Our digestive processes are unlike equine digestion. Cardio-pulmonary functioning in the human being is unlike canine cardio-pulmonary functioning. Canine sight is different from canine digestion, even though both actualize the canine form of life. And so on. Human mindedness is a distinctive variety of animal mindedness, but I take it that it would be mad to insist that how a human being is faring mentally has no effect upon her bodily health, just as it would be mad to insist that the life of the mind is in no way affected by such things as indigestion, illness, or injury.
Aquinas's understanding of the human being as the intellectual animal instead gives us a powerfully unified picture of human life that has, I think, important insights to offer even those of us who do not want to take on board the whole of the metaphysics, beautifully set in its theological frame.