How does Aquinas think the body and soul are related to one another? How does the doctrine of the resurrection of the body necessarily distinguish Aquinas' position from that of Plato or Aristotle?

For Aquinas, the presence of the soul in humans is evident, indeed obvious. Any explaination of Aquinas’ philosophy must allow the first assumption that he does, Aquinas was not interested in proving the existence of the soul, but in discovering the nature of it’s character. However, Aquinas did also need to prove that the soul was immaterial or spiritual in nature, otherwise his philosophy could be open to the objection that though the presence of a type of soul was evident, it could be a simple function of matter, of the body. For Aquinas, the soul was closely related to the body and it is this fact that will ultimately distinguish his position from that of Plato and Aristotle, his main influences on this matter, especially with regards to the doctrine of the resurrection; "...by late antiquity Christian theologians held soul to be immortal but defined body as that which falls and must therefore rise again."(1) It in is this belief that we can find the differences between the works of Aquinas and these two Greek philosophers. Before we can understand how Aquinas thought the body and soul to be related, we must first be made aware of the understanding of Plato and Aristotle and of the beliefs of the Christians of Aquinas’ time.

For early Christians, the awakened resurrected body was the person, whereas "..to later theologians it was a component (albeit an essential component) of the person."(2) During the Middle Ages there was much concern over the body, and this resulted in pious practices like those of keeping entrails in caskets, finger reliquaries and reports of incorrupt corpses. Bynum suggests that "The materialism of this eschatology expressed not body-soul dualism but rather a sense of self as psychosomatic unity.... it was a concept of self in which physicality was integrally bound to sensation, emotion, reasoning, identity-and therefore finally to whatever one means by salvation."(3) It seems that it was theologians like Aquinas that went some way into successfully unifying this body-soul dichotomy, to him the person was only a person with a body. For Aquinas people are composite individuals, "Aquinas’s position on what people amount to is to say that he adopts a position midway between the extremes of Dualism and Physicalism. He denies that people are essentially incorporeal. So he is not a Dualist. But neither does he think people are nothing but collections of physical processes. So he is not a physicalist either."(4)

Plato sharply opposed body and soul through his theory of Forms, "...the Forms assumed three main guises: 1) thoughts in the mind of God, collectively entertained by his Word or Intelligence, his Logos; 2) moral and spiritual ideals, to some extent personified and thus identified with, or similar to, the angels of Hebrew tradition; and 3) God’s constructive designs, the prototypes of the created world."(5) Plato placed a lot of stress upon the soul as an important ontological position, and though important, it was an often had an ambiguous role in Plato’s dialogues. Plato did not consider the soul as just a "harmony" or a part of the body, but that the soul transcended the capacities and capabilities and the body and matter, that the soul ruled the body. Also, Plato "...and his followers held that the intellectual soul is not united to the body as form to matter, but only as mover to a thing moved, saying that the soul is present in the body as a sailor in a ship...."(6)

Aristotle, on the other hand, had more of an influence over Aquinas than Plato did, "Aquinas was strongly influenced by Aristotle’s pronouncements in the "De anima" concerning the dependence of psychical activities on physiological conditions."(7) Aristotle held that the body was the tool of the soul at best, or a trap at worst, and that it was in fact the soul that was the reality behind the human. For Aristotle "..the soul is entirely form and not susceptible to any a mixture of matter. Any matter alleged to exist in it would not be the soul itself but simply the first of the objects animated by the soul."(8) However, Aristotle rejected Plato’s theory of Forms in his later writings, and found the notion of unchanging being to be more important. There were souls, composed of the "quintessence", the fifth element, which is purer than the four material elements (earth, fire, air and water) of which the body was seen to be composed. However it must be noted to avoid confusion that "Aristotle thought that people are not two things, mind and body, but complex unites both mental and physical."(9) It was this idea that replaced Plato’s theory of souls and bodies and inspired Aquinas. For Aristotle, and in some ways for Aquinas too, people are ensouled bodies. To speak of a soul for Aristotle, is to speak of the substance of the body, so in a certain sense this is somewhat Platonic as we are speaking perhaps of the form of the body. But this form is not the universal and unchanging form of Plato, and it is a form which is compound with matter, with the body. For Aquinas, it did not exist as a universal before union with the body, as it did not exist at all before the body did. Aquinas maintained that each soul was created, and dependant, on God, and that the human soul depended on the human body for human characteristics - they do not have intrinsic characteristics as Plato’s forms did.

It is from Aristotle’s assertion that the soul and body are two separate substances, but are also a complex compound, that Aquinas relates his notion of body and soul. Aquinas denied that the body was derived from a bodiless form and that the soul activates it’s own spiritual matter. The soul for Aquinas, is the form of the body as it is for Aristotle, and he calls this "entelecheia" as Aristotle does, but Aquinas used the term "hylomorphism" to describe the single form in humans, in this sense the body was the matter of the soul. Apart from each other, the body and soul was not a complete person and death was the dividing of soul from body. This is the basis of Aquinas’s middle position between Dualism and Physicism. However it must be noted that this middle position was not Monistic either, the wholeness and unity of the person relies on the distinction of soul and body, as well as their compatibility. It our post-Cartesian understanding, this may be difficult to accept. Aquinas affirms the psycho-physical unity of the person, that "personhood" requires such hylomorphic unity as a complete substance, and in doing so rejects Plato’s theory that the body was the instrument of the soul. Instead Aquinas asks "As Aristotle says, there is no more reason to ask whether soul and body make one thing than to ask the same about the wax and the impression sealed on it..."(10) and that the soul of humans remains the same after death even though the body disintegrates "..a city remains a city even if the population turns over through birth, death, and migration; a fire remains a fire if one keeps feeding it logs, even if all of the logs are consumed."(11) For Aquinas then, if we were a collection of things, we would not be a unity.

For Aquinas, the soul is the first basic principle of all living things, and this principle is found to rest mainly in what he called "anima" - which for Aquinas means something like "Principle of Life". This was equivalent, but not exactly the same as, Aristotle’s "psyche". Aquinas reasons that there must be "..some principle of life which distinguishes living things from non-living things, and this cannot be body.... if it were a body, it would follow that any material thing would be living, which is simply not the case."(12) So the body is alive because something is making it so, this is the anima, it makes a living thing living by definition, and is found in varying degrees in nature, forming a hierarchy of influence in life. This is revealed in the capabilities of the living thing in which anima is found, it is not found in non-living things. Plants have a vegetative soul, as all they are capable of is the limited amount of activity found in plant life: nourishment and reproduction. Animals on the other hand have sensitive souls as they are capable of sensation as well as the lower activities of nourishment and reproduction. Finally for Aquinas, humans have rational souls, as we are capable of rationality and will, as well as the other previous capabilities. "All these activities manifest the immateriality or spirituality of the mind, and so of the human soul, the nature of which is made clear by its higher activities.."(13) This rationality and will are not physical processes however, though the body is necessary for this rationality and will to take place, so "For Aquinas, my (rational) soul subsists because I have an intellectual life which cannot be reduced to what is simply bodily."(14). This is because the intellect can conceive of that which is incorporeal, and so it follows that is must itself be incorporeal. If it were material, it would not be able to reach beyond material concepts as it would have no familiarity with them. Though there are distinct faculties that are of an obviously physical nature, they only exist when the sensitive soul exists as a part of the body. So one can see when the body and soul are one, but when the soul has left the body, sight (and all other bodily functions) cease - when the soul is no longer part of the body, it dies.

Aquinas does not believe the human being survives death. The final breakdown or destruction of the body signals death and the departure of the soul. Separated, the soul and body do not make a unified person, but it is that lost unity that defined personhood and as people are very much part of the physical world for Aquinas, on the souls departure, personhood is left behind also. However, the soul continues to exist, and though the human body has died, the soul cannot. However, it is God that wills or does not will the continued survival of the soul after death, and this surviving part is purely intellectual, the locus of thought and will. For Aquinas "..it is better for the soul to be united to the body than not to be united to it, since it is naturally the form of the body. This line of thought tends to suggest that the resurrection of the body is to be expected..."(15) and "For Aquinas, however, personal identity requires bodily continuity. For me to live again, he says, there must be a human body."(16) So it is here, in the concept of the resurrection of the body, that we find Aquinas’s major departure from the notions of body and soul as espoused by Plato and Aristotle; "The immortality of souls seems then to demand the future resurrection of bodies..."(17) because it is only in the resurrection of the body and reunification of the body and soul that Aquinas sees as immortal life of the original person. If the soul were to continue incorporeal and as immortal alone, the original human would not be there, and so there would not be immortality of that original person. Though Aquinas saw the soul as separable from the body at death, Aristotle did not, "To say that it is the form of the human body is, for Aristotle, to say that it is inseparable from that body."(18) Aristotle considered only the human intellect (nous) to be immortal (which was separate from the entelechy) but for Aquinas nous was a part of anima, and so immortality meant different things for these two thinkers.

For a time the teeth and bones were seen as seeds ready to sprout in resurrection, because only the body can rise, because only the body can fall. But Aquinas rejected these eschatological metaphors of return and rebirth, and instead saw the resurrection of the body as a miracle of God. He feels that God will eventually do this, and Aquinas is seen to hint "...at the Platonic argument from desire as a proof of resurrection: God would not leave soul forever with its desire either for immortality or for body unfulfilled."(19) Aquinas does not seem to place too much importance on body - it is the expression and completion of the soul and united they are perfect. Aquinas thought that the soul carried the integrity of the body within it, and at the resurrection, the body is only an expression of the souls glory, it is the matter of the soul, but is not the actual original body. (This point was widely debated by theologians who were very much concerned about the originality and integrity of the body, and the place of things like hair and genitals and such in heaven).

So, Aquinas’s doctrine of the resurrection is seen to result in a somewhat different position concerning body and soul, than Plato or Aristotle. For Aquinas integrity and the Aristotelian notions of substance and hylomorphic unity are the most important points, which lead him to distinguish what happens to the body and soul at death, what personhood is and how this is affected by death and finally by resurrection. It is Aquinas’s emphasis on God as the thing which all souls depend upon and who causes resurrection that is the major point of departure from the two Greeks, "God himself is the cause... He needs no other model for the resurrection besides himself."(20) and "For the soul lives through grace and the body lives through the soul and both of these are effects of God’s power."(21) It is also in the emphasis on the personhood of the unified soul and body at resurrection and of this continued immortality that we find a departure from Platonic and Aristotelian thought in Aquinas. Though Aquinas draws upon Platonic philosophy and even more heavily upon Aristotle, his definitions, and ultimately the resurrection, significantly distinguish his position and mark him out as a major contributor to Christian thought and the philosophy of self-hood.

  • (1) "The Resurrection of the Body" C. W. Bynum, p13.
  • (2) ibid., p14
  • (3) ibid., p11
  • (4) "Aquinas: God and Action" D. B. Burrell p209.
  • (5) "Philosophy in Christian Antiquity" C. Stead, p29.
  • (6) "Thomas Aquinas" F. Copleston, p161.
  • (7) "Thomas Aquinas" F. Copleston, p162.
  • (8) "Philosophy of Thomas Aquinas" E. Gilson p161.
  • (9) "Aquinas: God and Action" D. B. Burrell p209.
  • (10) ibid., p210
  • (11) "The Resurrection of the Body" C. W. Bynum, p239.
  • (12) "Aquinas: God and Action" D. B. Burrell p212.
  • (13) "Thomas Aquinas" F. Copleston, p164.
  • (14) "Aquinas: God and Action" D. B. Burrell p213, parenthesis is my addition
  • (15) "Thomas Aquinas" F. Copleston, p168.
  • (16) "Aquinas: God and Action" D. B. Burrell p218.
  • (17) "Thomas Aquinas" F. Copleston, p168.
  • (18) ibid. p168.
  • (19) "The Resurrection of the Body" C. W. Bynum, p236.
  • (20) "Summa Theologia LV" St Thomas Aquinas, p67.
  • (21) ibid., p75.

Bibliography

Aquinas, T., "Summa Theologia LV" (Blackfriars 1976)

Burrell, D. B. "Aquinas: God and Action"

Bynum, C.W., "The Resurrection of the Body" (Columbia University Press 1995)

Copleston, F., "Thomas Aquinas" (Harper and Row Publishers, Inc. 1976)

Gilson, E., "The Philosophy of St. Thomas Aquinas" (W. Heffer and Sons Ltd., Cambridge 1924)

Stead, C., "Philosophy in Chrisitan Antiquity" (Cambridge Univeristy Press 1994)

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