By BRETT T. FEGER
ON April 23, 2019, the Permanent Council of the Bishops Conference of France (CEF) looked to Psalm 8 for the title of their most recent published document: “What is man that you are mindful of him? Elements of Catholic anthropology.” This document tackles a host of issues within the Church’s discourse on man and society. The French bishops reflect on the distortion that relativism has caused as well as a discussion of natural law, human nature, and its dignity. The bishops contrast natural law with the ‘law of nature,’ which is an egalitarian philosophy that places man on the same level as brute animals. This philosophy is a result of a secular society that denies the reality of natural law and no longer cares to ask, “what is man?” Although other major points were discussed in the CEF’s article, I will focus on the difference between man and brute. This topic is quite large and can be engaged from many angles, both naturally and philosophically. However, for the sake of brevity, I will consider the fact that man is different from brute animals by simple observation of posture. In his Summa theologiae I, question 91, article 3, Aquinas treats the disposition of man’s body. More specifically, he explains why it is fitting that this body is different from the bodies of plants and brute animals. Considering posture generally is important because it is part of the movement of all animals. The movement of an animal is normally the first external sensible that we perceive. Furthermore, upon observing an animal in motion, we tend to ask subsequent questions about the nature of this or that particular animal or group of animals.
In ST I, q. 91, a. 3, Aquinas provides three objections that are still relevant to this egalitarian debate on the ontological difference between man and brute. Objections 1 and 2 can be considered as one. This objection holds that if man is the noblest of animals, then he should have the sharpest senses, quickest movement, and other advantages, such as a good body covering and natural body armor. However, it is not the case that man bests the beasts in each of these qualities. Regarding senses and movement, Aquinas uses the examples of a dog’s keen sense of smell and the swift flight of a bird. Nonetheless, the disposition of man’s body does not require the best sight, hearing, movement, body covering, or natural armor because these things are unnecessary for perfect rational operation. Aquinas’s reply to objection 2 is fitting: “Instead of these, he has reason and hands whereby he can make himself arms and clothes, and other necessaries of life, of infinite variety.” Not only have the hands of man produced weapons and clothes, they have helped to build up cultures around the world.
In Origin of the Human Species, Dennis Bonnette treats, among other topics, the distinctions of natural species. He notes that activities particular to human beings flow from the distinctive human powers of intellect and will: “In the entire animal kingdom, only human beings exhibit arts and crafts, enjoy humor, erect great civilizations and universities, produce inventions at will, make deliberate use of tools, create new languages, and make genuine progress.” Of course, more can be said regarding humor and language, but it is outside the scope of this article to delineate between human intellective life and brute sentient life. Nevertheless, Bonnette’s points are undeniable to natural reason. The aforementioned activities are rational activities that manifest man’s rational nature and the difference in kind, not simply degree, between man and brute animal. Furthermore, the carrying out of rational activities is a result of an upright posture.
Every instrument has a proper end and must be suitable for a proper object of action. A shovel is made to dig soil not to trim bushes. This inability to trim bushes is a lack in the shovel, but the inventor of the shovel did not make the shovel to complete such a task. Aquinas uses the example of a saw being made out of iron instead of glass. A glass saw would be more beautiful, but it would be unable to fulfill its proper end of cutting wood. Thus, “every artist intends to give to his work the best disposition; not absolutely the best, but the best as regards the proposed end.” The same is true for God as the artist of man. “Since matter is for the sake of the form, and instruments are for the action of the agent”, then man, as a rational being with intellect and will, must have a body that is suited to rational operation. The nature of a being is revealed in activities that are proper to it: operatio sequitur esse (operation follows existence). For man, his rational nature is manifested in rational activities.
The third objection provided by Aquinas would seem to fit the ‘law of nature’ philosophy best as it nearly equates man with brute: “Further, man is more distant from plants than he is from the brutes. But plants are erect in stature, while brutes are prone in stature. Therefore man should not be of erect stature.” However, man is erect in stature unlike any brute animal. In his reply to objection 3, Aquinas provides four reasons why it is fitting for man to have an upright posture. Firstly, the senses are situated chiefly in the face for many animals; however, man is not like the other animals (i.e., brutes) that have their faces turned toward the ground “for the purpose of seeking food and procuring a livelihood.” Instead, man’s face is erect so that through the senses, predominantly by sight, “he may freely survey the sensible objects around him, both heavenly and earthly, so as to gather intelligible truth from all things.” Secondly, with the head erect, the brain is “lifted up above other parts of the body”, which provides greater freedom for acts of the interior powers. These powers allow man to receive sensible forms, to retain and preserve these forms in the imagination, to perceive what the senses do not, and to store these forms in the memory. Thirdly, if man’s stature were prone on all four limbs then the utility of the hands would cease, as they would need to be used as forefeet. Such a utility of the hands would conflict with the ability of the hands to manifest rational activity, as previously mentioned. Aquinas’ fourth reason follows that if man’s hands were forefeet, then he would be obliged to procure his food with his mouth. It would then be necessary for him to have a morphological change to his mouth, lips, and tongue. Aquinas says that the mouth would have to protrude, the lips would have to be thick, and both the lips and tongue would have to be harder so that exterior things could not hurt them. The most important resulting effect of such a morphological change would be to hinder reason’s proper operation, which is speech, the rational activity that manifests man’s rational nature most clearly. Lastly, Thomas provides a pithy, and slightly comical, summary that illustrates the distinction of the physical dispositions between plant, animal, and man:
Nevertheless, though of erect stature, man is far above plants. For man's superior part, his head, is turned towards the superior part of the world, and his inferior part is turned towards the inferior world; and therefore he is perfectly disposed as to the general situation of his body. Plants have the superior part turned towards the lower world, since their roots correspond to the mouth; and their inferior part towards the upper world. But brute animals have a middle disposition, for the superior part of the animal is that by which it takes food, and the inferior part that by which it rids itself of the surplus.
The superior part of the world toward which man’s superior part is turned is heaven and heavenly things. Seeking heavenly things is the proper end of all rational activity and the rational nature of man. To act otherwise is to go against man’s nature. From what Thomas has showed us, it makes sense that no brute animal is structured for seeking higher things.
In the egalitarian debate about the nature of man and all other animals, or the natural law and the ‘law of nature,’ Aquinas’ analysis of the physical disposition of man’s posture provides a groundwork from which a meaningful conversation can be had with evolutionary materialists who reduce man to a mere animal. Thomas derives a greater intelligibility from the statures of animals, which is helpful most especially for those who question the reality of man’s significance in the cosmos.
 Thomas Aquinas, Summa theologiae, Newadvent.org, http://www.newadvent.org/summa/1091.htm#article3. It is interesting to note that in his second discourse on the origin of humanity entitled “On the human being,” St. Basil the Great (d.379) teaches on the relationship between man’s structure and activity given to him by God. In Aquinas’ teaching on the disposition of man’s body, he does not reference St. Basil; however, being the sapiential theologian that Aquinas is in following the tradition of both the East and the West, it would seem that Aquinas is greatly influenced by Basil’s anthropological considerations.
 It would be unbecoming for man to walk around with an armadillo-like covering, horns, claws, wings, and bat-like ears. Moreover, it would be unfitting for him to have these traits along with an upright posture.
 Dennis Bonnette, Origin of the Human Species, (Atlanta: Rodopi, 2001), 46.
 Cf. ST I, q. 78, a. 4. Thomas is referring to the common sense, imagination, and the powers of estimation and memory.
 Emphasis mine.