作者：陆鸿基 Luk, Hung Kay, Bernard 年份：1980
FROM the Old Testament TO St. Thomas Aquinas
When as little children we made our first acquaintance with Catholic doctrine, we recited in the Catechism that a human being consists of a body of clay and a soul made in the image of God. At death, body and soul separate－the former decays and returns to earth, while the latter, which is immortal, comes before God for trial and reward or punishment eternal. The Catechism, true to its nature, did not tell us about the development of this doctrine from its ancient roots to its mediaeval fruition; rather, we were simply, and simplistically, handed the doctrine in its Tridentine fossilisation. Those were the days before Pope John XXIII convened the Second Vatican Council.
More recent developments in the Church have called for a broadening of the intellectual foundations of our understanding of the Catholic Faith. Such a task involves, among other things, breaking out of the confines of Western philosophy (which is not divinely inspired, but only accidentally grafted on to Christian teachings) towards more ecumenical interpretations of the Faith. This essay is an attempt to outline the evolution of the concept of the soul, in the hope of contributing to a popular appreciation of the role of Greek philosophy in the making of the Catechism doctrine. (1)
The concept of the soul that we have inherited was born of a fusion of a Jewish eschatology with Greek myths and speculations, and then nurtured in generations of Christian minds.
THE OLD TESTAMENT
The notion of a soul surviving after death is not readily discernible in the Bible. Hebrew monotheism, or the worship of Yahweh, was an ethnic religion; its central message was the contract between God and Israel, and the individual Israelite had significance only as a member of the Chosen People. It was the people as a whole that was rewarded or punished for its conduct, in this world. Belief in an individual hereafter was left rather vague.(2)
The Old Testament distinguished four elements in a human being.
There was the neshamah or 'breath' which comes and goes in the act of breathing.
There was the nephesh. The basic meaning of this word was 'throat'; eventually, the meaning expanded to include 'breath', 'desire', 'appetite', 'life', or 'self’. For example, the Book of Proverbs has: "A righteous man has regard for the nephesh [life] of his beast, but the mercy of the wicked is cruel." (RSV, Prov. 12:10). In Psalm 103: "Bless the Lord, 0 my nephesh [being]." And in Genesis 2:7; "Then the Lord God formed man of dust from the ground, and breathed into his nostrils the breath of life (ruach); and man became a nephesh [living being]."
There was the basar or 'flesh', which denotes the stuff of which the different parts of the body are made. This word was not used in a perjorative sense in the Old Testament.
Finally, there was the ruach, literally 'wind', a kind of life force bestowed from above, without which the psychophysiological composite of the nephesh-basar would have no life and no consistency. Sickness and sleep were considered loss of ruach; death was an almost total loss of it. The use of this word only became common with Ezekiel, during the Exile.(3)
These elements together formed a single psycho-physical organism. There was no dichotomy of body and soul. So long as a person was alive, each of the four constituents, including 'flesh', was alive too. Upon death, the composite whole was irreparably dissolved. Although the Yahwist thinkers could not envisage a complete personal extinction, they never defined what part of a human would survive death. Whatever it was (sometimes vaguely identified as the nephesh), descended beneath the earth to She'ol. This place of the dead was also variously described in different parts of the Old Testament as an awful pit, a walled city, or a land of dust and darkness. Descent to She'ol was the common fate of all, regardless of social or moral standing; and She'ol and its denizens were considered to be outside the interest or care of Yahweh. Thus, the life of the individual in the hereafter was not an important concern for the Yahwist religion, whose main business was the collective vigour of the Chosen People.(4)
This belief began to change during the Baby-lonian Exile(5th century BC), when questions began to be raised. If Yahweh had the power to save his Chosen People, why did he allow them to be overthrown and suffer in this way? Faced with this criticism, the emphasis on retribution began to shift from the communal to the personal, and from the this worldly to the hereafter. The concept of an almighty and just God demanded an eschatology that promised individual Israelites vindication after death for injustices suffered before it. This new trend was reflected in Ezekiel's vision of a post-mortem judgement and the resurrection of the dead: it was a restoration of the entire psycho-physical being, not immortality of a soul. By the time of Daniel (2nd century BC), these beliefs had received more concrete, if still largely communalistic and apocalyptic, treatment. In the Book of Enoch, however, a new development became evident. Not only was there going to be a final universal judgement at the end of the present world order, there were also individual judgements at the point of death. Instead of being a shadowy, undifferentiated place where all the dead were treated similarly for an indefinite time, She'ol was now compartmentalised into a place of refreshment, and other, hollow, places for the dead of different moral calibres. Thus the nephesh began to take on personality, as well as continuity with life in this world. The Pharisees around the time of Jesus Christ probably believed in rewards and punishments between death and the apocalyptic resurrection.
Among the Hellenised Jews of Alexandria, a very different concept arose. In Wisdom 9:15: "A perishable body weighs down the soul, and this earthly tent burdens the thoughtful mind." This dichotomy, in which the soul is all that counts, has more affinity with Plato's Phaedo than with the Hebrew tradition, as will be seen. Thus, it was not until late Old Testament times that the Jews came to believe in personal survival beyond death; except in a few instances, there was as yet no well-defined idea of an immortal soul.(5)
GREEK MYTHOLOGY
In the Hellenic tradition, the initial position was similar to that of the Hebrew. Homeric Greeks regarded the human being as a living organism compounded of three parts: a body (soma), a thymos or conscious self, and a psyche or life principle. A human being was only truly a human being when all three components were functioning harmoniously together as an inter-related whole, which was shattered by death. With the dissolution of the body, the thymos merged with the air, while the psyche was transformed into a shadowy replica of the living human known as the eidolon, and descended into Hades, an underground cavity rather like the original She'ol. These eidola had no memory, and were completely unconscious, insubstantial, and apathetic. Thus, the Greeks also had no notion of a personal survival after death, and Homer could speak of "the strengthless heads of the dead". Life in this world was the only full full and proper life.(6)
But there was another set of ideas about the soul among the Greeks, that of Orphism, a religious reform movement in the 6th century BC. The Orphics held that the key to human nature was the mythical murder and eating of Dionysos-Zagreus by the wicked Titans, sons of Earth, who were then blasted by the victim's father, Zeus. Because of their last meal, the ashes of the monsters contained elements of both Dionysos and the Titans. Out of these ashes arose humankind, with a dual nature－a material body which was a child of Earth, imprisoning an ethereal and immortal soul derived from a god. For the soul, the body (soma) was a tomb (sema). This soul or psyche combined the conscious self (thymos) and the unconscious life－principle (psyche) of the older Homeric conception, and came to be regarded as a preexistent conscious self that survived the death of the body. Because this divine psyche was tied to matter and to the evil inherent in it, it had to pass through a number of human or bestial incarnations lasting many centuries before it was sufficiently purified to return to the divine realm. This awful burden of births, deaths, and miseries, known as the transmigration of souls (metempsychosis) could be reduced only if an enlightened soul lived for three successive incarnations as a phi-losopher. Among the Pythagoreans, who formed one branch of the Orphic movement, the soul was associated with the 'higher' or intellectual faculties: for them, devotion to science was the highest form of purification of the soul.(7)
Thus arose a dichotomy between a divine, individual and immortal soul, and a material body. The soul and the body did not form one person: rather, they were an antagonistic duo, each with its own personality. This dichotomy was to become prominent in Plato's thought, and also influenced the Old Testament Book of Wisdom.
1.Jorg Splett, “Immortality”, in Karl Rahner, ed., Encyclopaedia of theology (NY, 1975), 678-689. New Catholic Encyclopaedia (NY, 1967), “Soul, Human, Immortality of”, XIII, 464-470. Cf. Ch’ien Mu, Linghun yu hsin (Taipei, 1978).
2.S.G.F. Brandon, The judgement of the dead (NY, 1967), 56-58. Cf. New Catholic Encyclopaedia, ibid.,467.
3.New Catholic Encyclopaedia, ibid., 449-450. C. Ryder Smith, The Bible doctrine of the hereafter (London, 1958), 1-9. Albert Gelin, The concept of man in the Bible (NY, 1968), 13-19.
4.Brandon, Judgement, 59. Smith, 3.
5.Brandon, 60-75. Gelin, 21. New Cath. Ency., XIII, 449-450, 467-468.
6.Brandon, 76-87.
7.Brandon, 88-96. Gelin, 20.
GREEK PHILOSOPHY
As philosophy began to emerge among the Greeks, the human being came to be considered within the framework of physis or basic principle of all growth and movement. The psyche came to be identified with whatever element each philosopher held as primary, e.g., fire, water, air or ether. In general, it was agreed that the psyche was material: while it was a source of growth and movement, it was not considered personal or immortal. On this, the pre-Socratic philosophers generally harked back to Homer rather than to the Orphics.(8)
Socrates and Plato took a different approach; it is difficult and here quite unnecessary to distinguish the two. Plato's idea of the soul was related to his theory of knowledge. The material world is marked by particularity and impermanence; sensual perception can only give us impressions of a confusing multiplicity of concrete objects subject to the vicissitudes of time. For Plato, that is misleading and is not real knowledge. What are reliable, because permanent, are concepts, Ideas or Forms (eidos). If that is the case with concepts of substantives, it is all the more true of abstract qualities such as beauty, justice, or truth, which are never embodied as such in concrete objects. Furthermore, concrete objects are never simple. A chair contains more than 'chairness' ; it also has 'woodness' , etc. A beautiful person contains not just 'beauty', but also has other qualities such as being 'human', and so on. So a concrete chair is less perfectly a chair than the Idea of a chair; and a beautiful person is less perfect than the Idea of beauty. What is more permanent and more perfect is of course also more important; and, Plato insists, also more real. Hence, the world of Ideas is more real than the world of concrete objects. The body with its distracting and entangling senses which inform one of concrete objects is the 'lower' part of a human being; thought, which alone informs one of the 'higher' world of Ideas, is the most important human activity; and what enables one to think is the soul, the 'higher' part of the human being. A successful life for a human being is therefore the intellectual life, the life of the soul, which alone can commune with the higher, more real world.
In the Phaedo, Plato's account of Socrates' last conversation with his friends, the distinctions between the soul and the body are made clear:
Did you ever behold [absolute justice, beauty, and goodness] with your eyes? ..... Or did you ever reach them with any other bodily sense? －and I speak not of these alone, but of absolute greatness, .....and of the essence or true nature of everything..... Is not the nearest approach to the knowledge of their several natures made by him who so orders his intellectual vision as to have the most exact conception of the essence of each thing which he considers? .....And he attains to the purest knowledge of them who goes to each with the mind alone, not introducing or intruding in the act of thought sight, or any other sense together with reason, but with the very light of the mind in her own clearness searches into the very truth of each; he who has got rid, as far as he can, of eyes and ears and, so to speak, of the whole body, these being in his opinion distracting elements which, when they infect the soul, hinder her from acquiring truth and knowledge－who, if not he, is likely to attain to the knowledge of true being?(10)
Not only is the soul higher than the body, the body also drags the soul down from intellectual heights. It is only when the soul is rid of the body that it can attain wisdom and purity:
For the body is the source of endless trouble to us by reason of the mere requirement for food; and is liable also to diseases which overtake and impede us in the search after true being: it fills us full of loves, and lusts, and fears, and fancies of every kind, and endless foolery, and in fact, as men say, takes away from us the power of thinking at all ..... It has been proved to us by experience that if we would have pure knowledge of anything we must be quit of the body－the soul in herself must hold things in themselves : and then we shall attain the wisdom which we desire, and of which we say that we are lovers; not while we live, but only after death; for if, while in company with the body the soul cannot have pure knowledge, one of two things follows－either knowledge is not to be attained at all, or, if at all, after death ..... And thus having got rid of the foolishness of the body, we shall be pure and hold converse with the pure, and know of ourselves the clear light everywhere, which is no other than the light of truth.(11)
The conclusion is that "the soul is in the very likeness of the divine, and immortal, and intellectual, and uniform, and indissoluble, and changeable." The care of the soul is the most important task in life: preparation for the soul to leave the body and return to the invisible world, the preparation for death. The fate of those who have neglected the soul and lived the life of the body will be reincarnation as beasts.(12)
It is clear then that Plato conceived of the human being as a composite, with soul and body being distinct substances; and in conformity with the theory of Ideas, it is the soul, not the body, that is real; it is the soul that is the person. At the end of the Phaedo, when Socrates was asked how he wanted to be buried, he said:
However you please, if you can catch me and I do not get away from you ...... I cannot persuade Crito, my friends, that the Socrates who is now conversing ..... is really I: he thinks I am the one whom he will presently see as a corpse .....After I drink the poison I shall no longer be with you, but shall go away to the joys of the blessed .....(13)
The Orphic influence in these passages is obvious. It will presently be shown how Plato's concept of the soul merged with Jewish eschatology to form a cornerstone of Christian thought.
Plato's disciple Aristotle started out with a concept of the soul similar to his master's, but it gradually developed into a very different and more subtle idea. Aristotle's emphasis was biological rather than religious; he was concerned to find in his work on the soul the principle of life rather than guidance for life. Yet his doctrine on the soul is more metaphysical than that of Plato.(14)
As a biologist, Aristotle was concerned to find a common definition for all living things.(15) This was his goal in the De Anima, his systematic general theory on the subject. In this treatise, he defined soul as "the first actuality of a natural body potentially possessing life. "(16) This terse definition requires explanation.
First, the terms he used. A 'body' is a substance, that is, "something which is neither predicated of a subject nor present in a subject", e.g., a human, a tree, a stone.(17) A 'natural body' is a body that is not made by human hands. 'Life' is "the capacity for self-sustenance, growth, and decay."(18) To understand 'potentiality' and 'actuality', it is necessary to delve further into the concept of substance.
As a class of existing things, substances may be divided into three:
matter, in the sense of pure matter without shape or form, which in itself is not an individual thing;
shape or form, which attributes individuality; and
the compound of the two.
In this analysis, matter is potentiality, form or shape is actuality.(19) For example, a piece of shapeless wax is potentially a statue; the shape that the wax acquires from a mold is actuality. The wax originally had the potential to be made into a statue, which potential was actualised when the statue was made. Similarly, certain natural bodies have the potential to be made into living beings; what actualises this potential is the soul.
Now, the term 'actuality' (or 'entelechy', or 'fulfillment') has two senses, which are analogous to
the possession of knowledge, and
the exercise of that knowledge.
For example, before a person has learnt what Aristotle means by the soul, one has the capability or potential for learning it. Once having learnt it, the person is capable of tracing the steps of the arguments, but does not need to do so; that person may be said to know, to have fulfilled the capability. This is analogous to the first actuality. This actualised knower may prefer to spend every waking moment retracing the arguments; that active exercise of the knowledge is analogous to the second actuality. Again, every person has the potential to study to be a historian. Once having fulfilled that potential (assuming that 'history' is a discreet subject), this person is a historian even in an undisturbed slumber (cf. first actuality). When researching and writing, he is a historian exercising the knowledge (cf. second actuality).(20)
To return to the definition of the soul. The natural body having a potential or capacity for life is related to its soul in a manner analogous to the knower's relation with the knowledge possessed, to the historian's relation with history. Without historical knowledge, one would not be a historian; without the shape provided by a mold, an amorphous piece of wax would not be a statue; without a soul, a natural body that has capacity for life would not be a living thing. Thus, a living thing is a compounded substance of body and soul, as matter and form. The soul, the form, is the first actuality of the life potential of the body, the matter. (The living thing－body and soul together－exercising its vital functions is second actuality. 'First' and 'second' are in ontological, and not necessarily temporal, order.) Thus, the soul is the cause and first principle of the living body, not only as the formal, but also as the efficient and the final cause, while the body is the material cause.(21)
Here, a few points need to be made.
Since form and matter are both substances, the soul is as substantial as the body; but the soul is not, of course, material, and therefore not corporeal.
Since a soul is the actuality of a particular potential, a human soul will not actualise a dog's body, nor vice versa; there is little, if any, room allowed for a Platonic transmigration of souls.
Since soul is form, and body matter, and the two compounded make up the living thing, "one need no more ask whether body and soul are one than whether the wax and the impression it receives are one."(22) It is also obvious that the soul must be spatially co-extensive with the body.(23) "Furthermore, the soul cannot exist without the body."(24) Hence, by this definition alone, Aristotle seems to have ruled out the immortality of the soul.(25)
But Aristotle goes further and introduces ideas on the hierarchy of nature into his discussions on the soul. "A thing lives if any one of the following is present in it－mind, sensation, movement or rest in space, besides the movement implied in nutrition and decay and growth." Of these vital functions, the most basic is the capacity to absorb food, because "it may exist apart from all other powers, but the others cannot exist apart from this in mortal beings". Hence, nutrition is found in all living things, from plants to humans. Similarly, animals have sensations, and among different sensations, touch is the most basic, being common to all animals.(26) Proceeding this way up a ladder, so to speak, one can enumerate the faculties of the soul: nutrition, appetite, sensation, locomotion, and thought, and rank living things accordingly.
Plants have the nutritive faculty only, but other living things have the faculty for sensation too. But if so sensation then also for appetite..... In addition to these senses some also possess the power of movement in space, and others again－viz., man and any other being similar or superior to him－have the power of thinking and intelligence.(27)
This, then, is Aristotle's ladder of souls. Just as there are higher and lower orders of life, so there are higher and lower kinds of souls－the higher souls possessing more faculties than the lower ones. This ladder may be roughly said to have three steps:
the souls of plants that are strictly nutritive ;
those of animals that are nutritive as well as sensitive; and
those of thinking and reasoning beings.
Are any of these living things immortal at all? Aristotle talks about biological reproduction－like nutrition, a faculty common to all living things－as being done for the sake of having "a share in the immortal and divine in the only way they can ....."(28) But this striving for the immortality of the species is not personal immortality, nor yet the kind of which Socrates assured his friends.
It has been noted above that Aristotle's definition of the soul seems to leave no room for immortality. There is, however, an escape hatch, so to speak, in his hierarchical scheme. For although the soul of a living thing is an inseparable whole exercising all the numerous vital functions, "in the case of the mind and the thinking faculty nothing is yet clear; it seems to be a distinct kind of soul, and it alone admits of being separated, as the immortal from the perish-able."(29) Elsewhere in the treatise, Aristotle elaborates on this point. Just as there must be a distinction between an art and its material, between the matter in a thing and its efficient cause, so there must be a distinction between an active mind and a passive mind within the soul. "Mind in the passive sense is such because it becomes all things", and its thinking is closest to perception－which, according to Aristotle, is a passive or neutral sense receiving messages from an active object and is temporarily actualised by the object. The active mind, on the other hand, "makes all things; this is a kind of positive stage like light; for in a sense light makes potential into actual colours. Mind in this sense is separable, impassive, and unmixed, since it is essentially an activity; for the agent is always superior to the patient, and the originating cause to the matter." He concludes:
[The active] mind does not think intermittently. When isolated it is its true self and nothing more, and this alone is immortal and overlasting (we do not remember because, while mind in this sense cannot be acted upon, mind in the passive sense is perishable), and without this nothing thinks.(30)
What does he mean? He has admitted above that he was not yet clear, and Greeks, Muslims, and Christians have debated this concept for more than two thousand years. This is indeed the most obscure part of his psychology. It is probable that he believed in a hierarchy reaching from the lowest beings to God, with the active reason of a human being among the highest members in the scale, yet still below God and other intelligences. Whether or not that is a correct interpretation of what was at the back of Aristotle's mind is not important for this essay; the main point here is that Aristotle admits of the immortality of the individual human soul, and thus enters the mainstream of discussions on that problem. After a certain metamorphosis, his psychology as outlined here became established Catholic doctrine.
To oversimplify a long and complicated story, that metamorphosis may be said to have taken place in two stages. First, a Judaeo-Christian eschatology merged with one form of the Platonic concept of the soul, resulting in the Augustinian doctrine that dominated the early middle ages; the emphasis of this teaching was the substantiality of the soul and its independence from the body. Second, the early mediaeval Christian idea was redefined by St. Thomas Aquinas in essentially Aristotelian terms in the 13th century; this redefinition emphasised the unity of the human being, of body and soul together. The Thomistic approach was officially adopted by the Church, especially by the Council of Trent.
8.New Cath. Ency., XIII, 447, 451. S.G.F. Brandon, Man and his destiny (Manchester, 1962), 174-184.
9.Sir R.W. Livingstone, Portrait of Socrates: being the Apology, Crito, and Phaedo of Plato in an English translation with introductions and notes (Oxford, 1953), 78-81. Cf. A.E. Taylor, Plato: the man and his work (7th ed., 1960), 180-193.
10.Livingstone, 100-101.
11.Ibid., 101-102.
12.Ibid., 126-129.
13.Ibid., 194. Cf. Antony Flew, “Immortality”, in Encyclopaedia of philosophy (NY, 1967), IV, 139-150; Herschel Baker, The image of man (NY,1947, 1961), 46-49, for Plato’s later views.
14.Wm. A. Hammond, transl., Aristotle’s psychology: a treatise on the principle of life (London, 1902), xxvi-xxvii. For stages of development of Aristotle’s psychology, see Sir David Ross, Aristotle, Parva Naturalia: a revised text with introduction and commentary (Oxford, 1955), 1-18; also, Ross, Aristotle (5th ed., London, 1964), 112.
15.Ross, Aristotle, 112, 129. Hammond, xv, xxi-xxii, xxvii, 1xxxiii.
16.W. S. Hett, transl., Aristotle: On the soul, Parva Naturalia, On breath (Cambridge, Mass, 1957), 69 (de Anima II, 1, 412b5 in the Greek Text). Cf. Ross, Aristotle, 134.
17.Hett, 67.
18.Ibid.
19.Ibid.
20.Ibid., 97-101. Ross, Aristotle, 134.
21.Hett, 87-88. Hammond, xxii.
22.Hett, 69, 79-80.
23.Hammond, xxii-xxiv. Baker, op. Cit., 60.
24.Hett, 79.
25.Flew, op. cit. Hammond,1xxxv. Ross, Aristotle, 131-132, 135.
26.Hett, 75.
27.Hett, 81-83. Hammond, 81-83. Ross, Aristotle, 129-131. Cf. Joseph Needham, Science and civilisation in China, II, 21-23.
28.Hett, 86-87.
29.Hett, 77.
30.Hett, 171, (De Anima, III, v, 430al0-25, in the Greek text), on the 'active mind' Ross, Aristotle, 135, 148-153, on 'active reason'. Hammond, lxxi-lxxxvi, on 'creative reason'. Also known in the middle ages as 'active intellect' or 'agent intellect' (intelligentia agens).
THE EARLY CHRISTAINS
The first Christians expected an imminent apocalypse.(31) The Jewish followers of Jesus believed that he was the Messiah of Israel, and that he would soon return to them as Lord of the Judgment, bring an end to this world, and resurrect the dead－ i.e., reconstitute their psycho-physical organisms. Their concept of the human being was still the traditional Hebrew one, essentially un-Hellenised, of a psycho-physical unity.(32) However, as more and more Christian converts were Greeks, and especially after the Romans destroyed Jerusalem and the central Church there, Hellenic dualism began to gain ground within the Christian faith. The Jewish eschatology of Last Judgment and resurrection of the dead now had to exist side by side with a more uniquely Christian eschatology of an immaterial soul of each person being judged individually at death and given everlasting reward or punishment, without waiting for the apocalypse and the resurrection of the body. How this development came about, and how the two eschatologies came to be reconciled, is beyond the scope of this essay. Suffice it to note here the process was a gradual one.(33) Even St. Paul, who considered his own mission as towards the Gentiles, never adopted the body and soul dichotomy of the Phaedo entirely. Although his attitude towards the body or flesh (soma and sarx respectively) was ambivalent, and he eventually came to distinguish between a lower, natural body (soma psychikon), and a nobler, spiritual body (soma pneumatikon), and left some hints of a body (soma) ,soul (psyche) , and spirit (pneuma) trichotomy, the soma was the self. He did not elaborate on body versus soul, but rather, on different tendencies within the self, the soma. (34)
THE PATRISTIC PERIOD
It was not until the Patristic period of doctrinal development that there began to emerge a clear distinction between body and soul. Athenagoras (fl. 177), self-styled Christian philosopher of Athens, first made the point of an immortal soul surviving the death of the body, and an eventual reunion of the two at the resurrection. St. Irenaeus attacked the Platonic idea of trans-migration of souls and their divinity, but insisted on an incorporeal, immortal soul, distinct from, but united to, a mortal body. Origen was the first among the Fathers to formulate the idea of the soul as a spiritual, rational substance. He also held that all souls of intelligent beings were created at once, in the beginning, pure, equal, and alike, and were put to the test by God. Except for the soul of Christ, all fell to some extent, and became angels, demons, or human souls. St. Gregory of Nyssa objected to this theory of creation, and held that the body and soul of each human were brought into existence together, but he did not know how. Nemesius (whom the Scholastics wrongly identified with Gregory) wrote the first summa of Christian psychology, the De natura hominis (ca. 400), in which he rejected the definitions of the soul of Plato, Aristotle, and Plotinus, and concluded that the soul was an incorporeal substance, subsistent in itself, not dependent on anything else for its being, yet intended for union with the body. He was unable to answer satisfactorily how the soul and the body were joined together. Tertullian tried to solve this problem by urging that Adam's soul alone was created by God, while all other human souls came into being by the act of biological generation. This 'traducian' theory (Adam as tradux or 'shoot') was never officially adopted by the Church.(35)
All these theories on the soul grew up in the Hellenistic world in the form of Christian polemics against:－
the Sceptics, Epicureans, and Stoics, who did not believe in life after death;
the Gnostics, who held an extreme dualism of body and soul, perhaps derived from Orphism and Platonism; and
the pagan neo-Platonists.
Of these three, the last had the most influence on Christian thought.
The most important, though not the earliest, neo-Platonist was Plotinus, a third-century Egyptian. His philosophical system was built around his psychology. The soul for him was an incorporeal reality which gave form to the body but owed nothing in return. With the soul were all the metaphysical qualities of pure intellect, unity, moving and vitalising power, and even matter. Among these, the greatest was intellect, and intellectual self-knowledge was the highest mode of subjective life. The human intellect bridges the realms of matter and mind, of which the latter was superior and illuminated. In fact, the intellect was one of the higher emanations from the First Mover, the One that is pure Being, or God, and by relying on intellect, the soul can free itself from corporeality and begin the long ascent to the One. Thus, for Plotinus, the soul is a created divinity, a part of the Universal Soul, whose destiny it is to return to merge into the One. This soul cannot sin or suffer, and has no individual mortality. Moreover, the body-soul dichotomy is absolute. It is obviously not a Christian conception.(36)
ST. AUGUSTINE
Unlike Plotinus, St. Augustine's Platonism was a Christian one. For Plotinus, all that matters is the flight of the soul to the One; historical events on earth are of no consequence. For Augustine, on the contrary, history has a goal, namely, the salvation of human kind by the Incarnation of God on earth. Worldly events therefore have eternal meaning. Furthermore, since God is all good, everything made by God must also be good, and that includes this world and human bodies. On the other hand, Augustine is true to the Platonic position that the ultimate good is spiritual, and is to be sought in the intelligible world of the soul, not the material world of the body. Hence, he is anxious to show the superiority of the soul to the body; and he defines the soul as a rational substance equipped to rule the body. By defining the soul as a substance, he asserts its independence from the body. He also borrows, with adaptation, Plato's proofs in the Phaedo of the immortality of the soul. However, he is also careful to say that neither is the human soul a part of the divine substance, nor is there only one soul for all of humanity; the former because the divine substance is indivisible, and the latter because each human has different and distinct lives and actions.
Now, if Augustine's definition of the soul guaranteed its independence from the body and its immortality, it accentuates another problem inherent in any dichotomous formulation: What is a human being Augustine's answer to that question is that a human being is a rational soul using a rational soul using a mortal and earthly body. The soul uses the body to keep in touch with the world of material objects and sensations, and it gives life to the body by mediating between it and the divine Ideas. But if the model is that of someone using an instrument or tool, the unity of the human being is called into doubt. Scripturally, the human being is a unity; further, retribution on the immortal soul after death would not be fair unless body and soul acted as a whole during life. This problem of the unity of the human being was one of the unsettled questions bequeathed by Augustine to the Middle Ages, and which none but St. Thomas Aquinas could resolve.(37)
ST. THOMAS QUINAS
Just as St. Augustine Christianised neo-Platonism, St. Thomas Aquinas has often been said to have "baptised" Aristotle. If in Augustine's thought, the fullness of Christian faith was always in advance of his philosophy, Aquinas was able to assert the independence of philosophy as well as its instrumentality for rationalising that faith.
Aquinas's conception of the human is basically the hylomorphism (from hyle, 'matter', and morphe, 'form') of Aristotle. He defines the soul as "the first actuality of a natural organic body having life in potentiality"; and as "the first principle by which we live, sense, move, and understand". However, these definitions have to be seen in a broader framework to show his solution to the problems bequeathed by Augustine.
Aquinas posits a hierarchical universe of actuality and potentiality. The more something is actualised, the higher it is in the hierarchy; the more it remains potentiality, the lower it is. Matter is potentiality, form is actuality. Undifferentiated matter is pure potentiality; it is the lowest on the scale. God is pure actuality; It is the highest. Only God is fully actualised; only God exists by Its own essence (God is, simply because of What It is.) Everything else exists because its potentiality for existence is actualised to a less complete degree.
Now, the human being stands in the middle of this hierarchy. It is composed of a certain material substance, and a form which actualises the material substance into a living body. This form is the soul. Since the soul can perform certain of its operations in which the body has no part, it must subsist by itself; i.e., it is a substance, an immaterial substance. As a substantial form, the human soul is higher than those forms which are wholly embedded in matter, such as the soul of a dog or the form of a chair, but lower than the angels which are forms completely separated from matter. The human soul possesses the degree of being that its nature, its location on the hierarchy calls for. Unlike an angel, it does not have enough actuality to attain its perfection in a separated state. It is incomplete in itself; it is a simple intellect whose light is so faint that it needs a body to perform most of its operations. At the same time, the body is just potentiality that requires a form to actualise it. So body and soul each need the other for its own completion. The human being that results from such a union of matter and form is a substantial union, not an accidental one. It is not a mixed being, because each component still subsists. It is neither an angel locked in a material prison, nor a spiritual motor driving a material shell, because the soul needs the body to complete itself. Both components are made by the one true God and are therefore both good, and both necessary. The human being is hence not one being made up of two other beings, because it is only the soul, the form, that actualises, that provides the act-of-being (esse), for the body, the potentiality. So there is only one act-of-being for the human unity, one being of two distinct substances (but not two real subjects or distinct existences). It follows that there can be only one substantial form or one soul for this human unity－a single indivisible soul that has all the rational, sentient, and nutritive powers, not three separate souls for various functions. And if the soul is indivisible, it cannot have been derived by division from the souls of one's parents. It can only have been individually created by God from nothing.
In this way, Aquinas guarantees the unity of the human being without endangering the immortality of the soul. The soul is immortal because all substantial forms are by definition immortal or incorruptible. Since the soul's existence does not depend on the body, but is derived from God, it cannot corrupt with the death of the body. Further, since the act-of-being and individuation of a thing are always found together, and both are therefore found in the soul, the human being does not lose its individuation by the death of the body. Finally, since the human being is a unity of soul and body, and neither is complete without the other, a reunion in the apocalyptic resurrection is not only reasonable but also necessary. Thus, Aquinas succeeds in completely harmonising Hellenic concepts with Hebrew eschatology. His is still a dualistic view of the human being, but it manages to avoid any extreme form of dichotomy.(38)
THE MAGISTERIUM
By the early 17th century, doctrines on the soul had received many official definitions by the Christian Church. While many of these definitions were not established as infallible dogma, they were issued by popes and councils in exercise of the magisterium of the universal Church, and constituted positions from which no Catholic might lightly depart. These positions, as summarised in the systematic index of the Enchiridion symbolorum, included the following: the human soul is not a part of the divine substance; it is created by God from nothing; it did not pre-exist, and is not generated by parents; it does not evolve from the sensitive to the rational; it is a substance; it is not one for all humans, but one for each; it is not naturally either good or bad; it is rational and intellectual, but is not by itself an object evident to cognition; it is immortal; it is united with the body, not accidentally, but is the form of the body truly as such and in the act-of-being; it is endowed with freedom, which can be proved from Scripture as well as from reason.(39) Such, in the main, was the doctrine of the soul which the Jesuit missionaries brought to Ming China.(40) Such too, was the basis of the pre-Vatican II teachings handed to us in the form of questions and answers on the nature of humankind. Its indebtedness to, and imprisonment by, Greek philosophy is evident. Where do we go from here?
31. Brandon, Man and his destiny, op. cit., 204-208.
32.Brandon, ibid., 208-211. J.A.T. Robinson, The body, a study in Pauline theology (London, 1966), 11-16.Gelin, op. cit., 23-24.
33.Brandon, ibid., 211-236.
34.Ibid., 211-224. Robinson, op. cit., 17-33.
35.Brandon, ibid., 224-236. New Cath. Ency., XIII. 452-455.
36.A. Hilary Armstrong, St. Augustine and Christian Platonism (Villanova, 1967), 4-9. Baker, op. cit., 94-96. Thomas Whittaker, The Neo-Platonists (4th ed., Cambridge, 1928), 40-53.
37.Etienne Gilson, The Christian philosophy of St. Augustine (NY, 1960), 44-55. F. Coppleston, S.J., A history of medieval philosophy (NY, 1972), 42-43. Armstrong, op. cit., 4-17.
38.Etienne Gilson, The Christian philosophy of St. Thomas Aquinas (NY. 1956). 174-199. Coppleston, ibid., 186-189. H.D. Gardeil, Introduction to the philosophy of St. Thomas (London, 1956), III: Psychology, 5-7, 14-42. A.C. Pegis, St. Thomas and the problem of the soul in the 13th century (Toronto,1934).
39.H.J.D. Denzinger, Enchiridion symbolorum: definitionum et declarationum de rebus fidei et morum, edited by J.B. Umberg, S.J. (Friburg, 1937), 'Index systematicus, VI-d, Anima humana '
40.Ai Ju-lueh (Giulio Aleni), S.J., Hsing-hsueh tsu shu (Hangchow, 1623; Shanghai, 1873), is the earliest and most complete example. Cf. the Jesuit edition of Aristotle's works published at Coimbra, Portugal, in the late 16th century, entitled Commentarii collegii conimbricensis e Societate Jesu (Vatican Library microfilms).