A Problem in Philosophy.
By the Very Rev. HUGH POPE, O.P., S.T.M., DOCT. S. SCRIPT.
CATHOLIC TRUTH SOCIETY of IRELAND No. Dd0352a (1932).
I. THE PROBLEM STATED.
"THIS is eternal life," says Christ, "to know You, O Father, and Jesus Christ whom You have sent"; even more explicitly Saint John: "We shall be like Him, because we shall see Him as He is"; and Saint Paul: "We see now through a glass in a dark manner, but then face to face. Now I know in part, but then I shall know even as I am known." Here are the plain statements of revelation, and, since truth is one, they cannot be in conflict with reason, though they may be beyond reason's comprehension. Moreover, no theory of knowledge which excludes such ultimate vision of God on the ground that it is impossible can be valid. Yet the initial difficulty will be patent to all: how can the human intellect, which functions in dependence on material things through the senses and imagination, grasp a purely spiritual immaterial Being, namely God Himself? We propose to show how the Scholastic philosophers faced the problem; and we shall have to begin by stating briefly the Aristotelian and Scholastic theory of human knowledge.
Man is compounded of an
intellectual, spiritual, immaterial soul working in and through a material
corruptible body. Hence, he has a double principle of knowledge, the senses and
the intellect. Sense-perception is the act of a bodily organ I see or touch this
individual book or man. Intellectual knowledge, on the contrary, is not the act
of a bodily organ but of a spiritual or immaterial faculty. Hence, it is solely
concerned with what is immaterial and therefore universal, that is with genera,
species, natures, essences, substances if you will, but not with individuals.
It is concerned solely with the universal, with the immaterial natures or
essences lying behind the sensible phenomena of individual material things. But
precisely because these latter do shroud immaterial natures, man's intellectual
knowledge must be conditioned by its relation to the senses. How, then, is the
gap between mere sense-impressions and intellectual perceptions bridged over?
It can hardly be questioned that the imagination serves as the bridge, for it
seems in some way to share the characteristics of both sense and intellect, to
be partly material, partly spiritual.
Thus, Aristotle taught that the sense-impression, the image on the retina of the eye for instance, produced a similar image in the imagination, and that this latter image served as the connecting link between the senses and the intellect. To the intellect, he attributed two functions which he named the active and passive intellects or the intellectus agens and the intellectus possibilis. The function of the former was to consider apart from their material veils the actual nature or essence of the thing thus presented by the senses to the imagination. The eye, for example, sees a triangle in other words, a material representation of a triangle is impressed on the retina. If we now close our eyes, we can, without further recourse to the sensible image, call up an imaginary triangle of shadowy and blurred outline and only less clear than the concrete sharply outlined picture on the retina. The "active" intellect now comes into play. Its sole object is the spiritual or immaterial; hence in the presentation of the object by the imagination the active intellect considers solely the immaterial nature of a triangle whether equilateral, isosceles, or what. The image thus acquired or "abstracted" is termed the impressed image or species impressa.
From the active intellect, it passes to the passive intellect which is thus rendered actually and no longer merely potentially, understanding. The clear-cut idea thus formed of a triangle is the universal because spiritual and immaterial concept of a triangle. It is "universal" in the sense that it carries with it no determinations or limitations as to size or any particular qualifications of triangles in general. This image or universal concept is known as the species expressa and as such is stored up in the passive intellect for future use. From the fact that the reception of the impressed image made the intellect no longer potentially but actually understanding, this image is termed the "form" as being the "informing" principle of such actual understanding. This is summed up in the phrase: "intelligible in actu est intellectus in actu."
Certain consequences of this doctrine will be manifest:
(a) Since the intelligible truth in question is received into a faculty, it can only be there in proportion to the capacity of the recipient. Hence, though all truth is of its nature intelligible, it will not follow that our intelligence of it will be proportioned to its intelligibility; nor does it follow that every individual human intellect will grasp equally the same intelligible truth.
(b) While the human intellect is itself immaterial and spiritual, it is yet compelled to function through the senses and imagination. Hence no purely spiritual nature, no nature, that is, which cannot by reason of its immaterial character be presented in a form which appeals to the senses and imagination, can as such be within the scope of the human intellect. The intellect can, for instance, argue to the existence of such a nature, but cannot know that nature in itself. Thus, we can argue that God must exist and that He cannot be this or that because of the imperfections such ideas connote; but we cannot know that His essential nature is precisely this or that.
These principles seem at first
sight to exclude the possibility of man's attaining to the intellectual vision
of the nature of God Who is pure Intelligence and Who consequently has no
relationship to material things save as their Creator.
II. INTELLIGENCE, DIVINE AND HUMAN.
When we pass from the human intelligence to the divine, we can argue that God must needs be an Intelligence, indeed the Supreme Intelligence; further, that since His nature is identified with His existence else He would not be the First Cause and would be only potentially existing, at least at some conceivable moment prior to His actual existence. He must therefore be His own act of intelligence. Moreover, He must understand Himself by Himself, since any other way of understanding Himself would involve a transition from potentiality to actuality, and that is inconceivable in the Supreme Being or First Cause.
Such philosophical positions
may seem, at first sight, to contradict Saint Paul's statement: "Then I
shall know even as I am known," and Saint John's: "We shall see Him
as He is." Yet the Schoolmen, who accepted the declarations of revelation,
also accepted the epistemological principles of Aristotle the Stagirite. Is
their reconciliation of these opposing factors a mere tour de force, a
magnificent piece of intellectual hair-splitting, or is it an absolute triumph
of genius? If the former, it is hard to understand how the mightiest of
intellects down the subsequent ages have been unable to detect any flaw in their
Nor must we imagine that the
Schoolmen's difficulty lay simply in reconciling their theory of knowledge with
the data of revelation. That difficulty was grave enough, but it was immensely
increased by certain other speculations of which the modern world has totally
lost sight, but which are of the profoundest importance for the right
understanding of the problem we are discussing.
III. ANGELIC INTELLIGENCES.
The divine and human intelligences may be regarded as the two extremes in the scale of intelligent beings. The one is His own existence and His own intelligence, and therefore purely immaterial or spiritual; the other is an intelligent being functioning through and in a material organism and receptive of existence rather than actually being its own nature. Now it is at least conceivable that between these two extremes there exist intelligences which
(a) are caused and not self-produced, and which are therefore not their own existence but receive it and thus are distinct from God the Uncaused Being, while
(b) they are distinct from men in that they are pure intelligences having no relation to matter.
The whole of antiquity as well as the whole of revelation demands the existence of such intermediate beings. Revelation knows them as "angels," Greek philosophy as "separated substances" "separated," that is, as having no relation to matter. Among the Jews, the Sadducees stood alone in repudiating the idea of angels; among Christian thinkers, Origen alone claimed a material character for them. Here we shall take the existence of such "separated" substances for granted, partly because of revelation, partly because, while reason may not be able rigidly to demonstrate their existence, it can at least bring forward arguments which have satisfied the greatest thinkers of all ages. It is the angels who are referred to in the "visibilium et invisibilium" (the visible and the invisible) of the Nicene Creed. As regards their nature, it will be sufficient to point out here that, since such "separated" substances are immaterial, there is no room in them for numerical, apart from specific distinction; hence all angels must be specifically distinct from one another; further, since they are purely immaterial they must be incomparably more glorious than the most glorious material sun or constellation; lastly, in opposition to Aristotle's view, they are a vast multitude.
We have, then, three grades of
intelligent beings: God, angels and men. But we must of course understand the
word grades cautiously. For it would obviously be wrong to suppose that there
is only a difference of degree between the Supreme Intelligence and the
intelligences which He has created. If there were only a difference of degree
there would be no difficulty in the idea of beatific vision, for we could
readily imagine that a gradual purification of the human intelligence would
finally result in a comprehension of the Supreme Intelligence. But no clear
thinker could suppose that we can predicate of God and His creatures being and
its attributes in any univocal sense; what His creatures are, God is in a
super-eminent fashion, since He is the Cause of all they are and possess. A man
is not the picture he produces. This will become clearer if we examine by the
light of reason how each of these intelligences the divine, the angelic and the
God knows all things by His own
self-subsisting nature which is identified with His actual understanding, and
this latter is, in conjunction with His will, the cause of all things. In
Himself He knows Himself and all things possible and actual intuitively. At the
other extreme, men know through the two-fold medium of sense and intellect, and
these two work together so that human understanding is conditioned by the
material organism in which the intelligence dwells and through which it functions.
Angels know by their very nature, which is pure intelligence, totally
independent of matter. They are subsisting though not self-subsisting or
self-produced intelligences. Consequently, they can have no such things as
sense impressions, nor can they have the imagination's concepts. Hence, in them
there is no place for the work of abstraction such as the human active
intellect performs. Being simply intelligences they must understand by their
very nature, and all intelligible truth must naturally be knowable by them.
IV. THE DIFFERENCE BETWEEN THE HUMAN
AND THE ANGELIC INTELLIGENCE
Now since the human intelligence is not an angel, it is not a separated substance; yet it is separable; it can, on the dissolution of the body, become what is known as the anima separata (separated soul) or, in the language of the modern spiritualist, the "discarnate soul," and in that state it can, though in a limited fashion, function. If now we can discover what is the proper, connatural, object of the separated substance, how it knows and what; if, again, we can discover what is the proper, connatural object of the separated or discarnate soul, what it can know and how, we shall be well on the way to the solution of the problem: how can the human soul see the essence of God, in which vision revelation places our ultimate beatitude?
It is clear that a separated
substance, being a pure intelligence, knows by its own nature; its one function
is to understand. It will also follow that everything that is intelligible in
other words all truth is its natural object, just as all that possesses
colour is the natural object of the human eye. Therefore, the separated
substance naturally knows God. But to what extent? In other words: do the
natural powers of a separated substance or angel lead him to a knowledge of the
Essence of God, or simply to the fact of His existence? Now an angel is
created, therefore, he is an effect of God, and consequently no analysis of
that effect will demonstrate the nature or afford comprehensive knowledge of
the cause that produced it, though it will enable us to argue about it. And
this simply because no finite effect of an Infinite Cause can totally represent
it, nor can it, in consequence, lead us to more than a partial and inadequate
knowledge of its Cause. At the same time an angel, being an intelligence,
recognizes himself as an effect of the First Cause, and in the same way
understands other angels; yet, for the same reason as above, such knowledge
will not enable him to arrive at a knowledge of God's essence. Hence, Saint
separated substance by its own substance (or nature) knows of God
(a) that He exists,
(b) that He is the Cause of all things,
(c) that He transcends them all, and
(d) that He is far removed not only from all things that are, but from all things that the created mind can possibly conceive.
This knowledge of God we too possess in our degree. For from effects we know that God exists, that He is the Cause of all things, that He transcends them all and is far removed from them all; and this is the final and most perfect stage of our knowledge in this life. Hence says Denis (the Areopagite) We are joined to God as to something unknown, and this because while we know of God what He is not, what He really is remains totally hidden from us. . . . .
however a nature that is lower in the scale attains at its very best only to
what is least in a nature that is above itself in the scale, it will follow
that knowledge such as the above must be possessed by the separated substances
in a degree far transcending the way in which we possess it."
The separated substances, he concludes, know with greater certainty and clarity than we do that God exists.
But what about the discarnate
soul, or soul that has passed from the tabernacle of the body? Is it like the
angels? Does it know as they know? Clearly, it cannot know more than they know;
therefore, it cannot possibly attain by its natural powers to a knowledge of
the essence of God. If it is to see God, as revelation demands, this can only
be through the bestowal of some power to which it has no right and which we
therefore term "supernatural." But it is an axiom of the Schools that
"grace or God's gift does not destroy, but perfects, nature." The
problem then, is to discover how the human intellect which, on Aristotle's
principles, can only know when a similitude of the thing known enters the
percipient mind and even then only through the medium of an image in the
imagination can see the Essence of God without the intervention of any such
similitude and without the imaginary presentment of the object known which
Aristotle and the Scholastics demand. If these two points are absolutely and in
all circumstances essential to human understanding, then it would seem to
follow that vision of the essence of God is not merely due to a supernatural
gift but demands a radical change in human nature; and this is impossible.
V. SAINT THOMASS TREATMENT OF THE PROBLEM.
Saint Thomas treats of the Vision of God by the human soul in various places of the Summa Theologica and under various aspects. Thus he deals with our knowledge of God's nature as seen in His works, also with that knowledge of God which is faith, with our intuitional knowledge of His nature which is our immediate concern here with that same knowledge as constituting the very essence of our ultimate happiness, and, finally with the same Beatitude as a state to which we are led through Christ's life, death, and resurrection.
The actual question with which
we are concerned is dealt with almost at the opening of the Summa; for
after treating of God's existence and attributes, Saint Thomas opens his
twelfth (Question) Quaestio: "How God may be known by us." He
is dealing, be it noted, with real knowledge, knowledge, that is, of the nature
of God as distinct from our knowledge of His existence, which the Saint has
already discussed. He begins by asking whether "any created intellect can
see the essence of God," and his affirmative answer is based on Saint
John's words: "We shall see Him as He is." In his discussion of the
question, after pointing out that because God is supremely knowable in Himself
it will not follow that created intellects can therefore know Him, any more
than the splendour of the sun enables a bat to see it, Saint Thomas proceeds to
show that the conclusion at which some have therefore arrived, namely, that the
created intellect can never arrive at the vision of God's essence, is false.
His argument is that since the ultimate perfection of man must lie in his
highest function, that, namely, of understanding, it will follow that if the
created intellect can never know the essential nature of God either it will
never attain to final happiness at all, or that happiness must lie in something
other than God; a conclusion "which is contrary to our faith." Moreover,
since the perfection of every single thing lies in the attainment of its
principle, it will follow that the ultimate perfection of the rational nature
must lie in the intellectual attainment of God. "Further, such a
conclusion (that the created intellect can never arrive at the vision of God's
essence,) is opposed to reason. For there is in man a natural desire of knowing
the cause of any effect he sees, so that if the mind were unable to attain to
the first cause of things this natural desire would remain unsatisfied. Hence
we must simply concede that the Blessed do see the essence of God."
This argument is not meant to be a demonstration in the strict sense; for its basis is revelation and not pure reason.
But while the argument from desire may not perhaps be absolutely convincing to all minds it seems clear that to question it would involve questioning the justice of the Creator of our nature with its desires.
Granting, however, that such knowledge is possible, Saint Thomas next asks whether such vision of God's essence is through the medium of some likeness of God. For all knowledge seems to involve the presence of the object known in the percipient, not of course in its physical nature but in an image of it, just as the image of a stone is formed on the retina of the eye which sees it: "If the object seen and the principle of the visual power were one and the same it would follow that the percipient must derive from the same thing both its visual power and the form whereby it sees. It is clear however that God is the Author of the intellectual powers and can be seen by the intellect; and since created intellectual powers are not God's essence it remains that they can only be some participative likeness of Him Who is the Primal Intelligence." Only in this sense, he concludes, can we say that God's essence is seen through the medium of some likeness of God, namely, that the intellectual faculty is itself an intellectual light derived from the First Light. But of the thing seen, the divine essence, there can be no image or likeness in the mind for the compelling reason that, no created image can mirror the Infinite.
By this exclusion of all images
of God in the mind that sees His essence, Saint Thomas might seem to be placing
this beatific vision in a category apart. But he is careful to show that this
is not his intention at all by formulating this point as a difficulty which
tells against himself. "The intellect actually understanding is the thing
actually understood. But that can only be when the intellect is informed by
an image of the thing understood. If then God is actually seen by the created
intellect He must be seen by some likeness or image." His answer is brief:
"The divine essence is God's very existence. Consequently, just as other
intelligible forms (natures) which are not their own existence are united to
some mode of existence whereby they inform the intellect and thus reduce it
to actual understanding, so the divine essence is united to the created
intellect as something actually understood; and of itself it reduces the
intellect to actual understanding." In other words: if we are to see God,
then God must in some way be in us according to the norm of all vision, whether
sensible or intellectual. But whereas other things enter our intellect by a
likeness or image of themselves, this is impossible in the case of the vision of
God; for no image can mirror the Infinite, and of course, if the medium were
merely a finite image then it would not be the essence of God that we see but
something short of it. Some might feel that this solution of the difficulty,
that all vision demands a likeness in the percipient, was merely a counsel of
despair: no other way is possible; this one, then, must be true. But Saint
Thomas really argues: No other solution is possible; but this one is possible; therefore,
it is true. The question, then, is: how is it possible? How can the very essence
of God enter into our minds?
It is somewhat remarkable that
here in the Summa Theologica Saint Thomas gives us but little
information on this point. The divine essence, he, says, is united to the
created intellect as something actually understood; of itself it reduces the
intellect to actual understanding; but he does not discuss how this can be.
Elsewhere, however, he enters into details. Faith, he insists, demands
such vision; reason also demands that perfect happiness can only consist in the
most perfect exercise of our highest faculty, the intellect; only the supremely
intelligible can satisfy this condition; therefore our final happiness must
consist in the vision of God Himself as our ultimate and in the case of rational
creation our immediate principle or Cause "as our faith declares."
Now this vision cannot be through any image of God, since any image which was
not God Himself could only lead to analogical and therefore insufficient
"It remains then," he
concludes, "that that whereby the created intellect sees God in His
essence must be that divine essence itself. Not of course that the divine
essence should be the informing principle of the intellect itself (for that
would make the human intellect God), but that it stands to it as its informing
principle. Hence, just as from a form (or specific principle) which is part of
a thing, and from matter, one actual thing is produced, so though in
different fashion from the divine essence and the created intellect there
results one thing in understanding, while, that is, the intellect understands
and the divine essence is understood by means of itself."
Is this Pantheism? Does it mean
that the created intellect and the divine essence become one thing? If so, it
is Pantheism. But Saint Thomas is careful to point out that this is not what he
means: "This does not mean," he says, "that the divine essence
becomes the informing principle of the created intellect as though it were a
part of its essential being, but that in the actual act of understanding, the
divine essence stands to the created intellect in the same way as a form (or
specifying principle) stands to matter of which it is an actual part in
But even so, Saint Thomas has not yet explained how this can be. He finds, however, in the Commentary of Alexander [of Aphrodisias] on Aristotle's De Anima an illustration which serves his purpose. "Whenever two things are received into a third and one is more perfect than the other, the more perfect is related to the less perfect just as a form (or specifying principle) is related to the material that it perfects; light, for example, is the perfecting principle of colour when both are in the ether. Consequently, since the created intellect which is in the created substance is less perfect than the divine essence also existing in it (he means in beatific vision), that divine essence will, in a sense, stand to that created understanding in the same proportion as a form (or specifying principle). We find a sort of parallel to this in nature: a subsisting thing cannot, if it is in any way conjoined to matter, be the form (or specifying principle) of any other matter; a stone, for instance, cannot be the specifying principle of any other matter. But a self-subsisting immaterial thing can become the informing principle of matter, as is evident in the case of the soul. Similarly, then, in a certain sense the divine essence, which is pure act, becomes the specifying principle of the intellect as actually understanding, though totally different from it in actual being. Hence the Master says that the union of the body with the rational soul is a kind of type of the union of the beatified rational soul with God."
Elsewhere Saint Thomas speaks
of this presence of the divine essence in the soul as the "illapse"
of the Deity into the soul. "The divine essence," he teaches,
"sufficiently represents itself (to the intellect), and consequently when
it is united to the intellect as its form the latter sees of God Himself not only
that He exists but also what He is."
VI. THE LIGHT OF GLORY.
But there remains a further problem: We have already seen that the created intelligence which sees God is itself a participated likeness of Him Who is the Primal Intelligence, and that consequently the created vision of God is intelligence meeting Intelligence, light meeting Light. But it still remains true that it is but a human and created or finite thing and that it is still a case of a finite light and intelligence meeting the Infinite; or, as Aristotle expresses it: "the difficulty of understanding things arises from ourselves and not from the things themselves; for even with regard to the most patent things our intellect is like the eye of a bat looking at the sun." The bat of course has eyesight, just as a man has; it is simply a question of degree; so that for a bat to be able to gaze at the sun his eyesight would need no change in its nature, it would merely require strengthening. So, too, with the human intellect. If a thing is true, it is intelligible and therefore has some relation to all intellectual beings. Hence for the human intellect to elicit an act of understanding of the Supreme Being involves no change in its nature; if such change were requisite, then that human being would cease to be a human being; consequently, for the human intellect to understand God its powers must simply be intensified. We have a parallel to this in the "light of faith," which contradicts no power of the intellect but enables it to admit truths which it does not understand but accepts on authority. And since the created intellectual light is already a participation in the divine intelligence, any further intensification of this light will only mean a further participation in the divine intelligence; it is in this sense that Saint Peter terms grace a participation in the divine nature; and grace does not destroy but perfects nature. There must be added, then, to the created intellect, if it is to see the divine essence, some intensification of its natural light, and this, says Saint Thomas, "is the light of the divine glory; of it the Psalmist speaks when he says: In Your light we shall see light." This light is not God Himself, it is not a new faculty, it is not charity, rather is it a supernatural habit strengthening the intellect to elicit an act which though in perfect conformity with its powers is yet beyond them if unaided. This light Saint Thomas also calls gratia consummata. We must be careful, however, when we speak of this light of glory as an intensification: "No intensive increase of the natural powers would suffice, for this vision is not of the same nature as the natural vision of the created intellect. . . . There must then be an increase of the intellectual power by its obtaining some new disposition." In other words, some added power which is supernatural, beyond our nature, that is, but not contrary to it.
So far, then, we have seen how
the vision of God's essence by the created intellect, whether Angelic or human,
involves no contradiction. According to Aristotle's teaching all knowledge
demands the reception of the thing known unto the percipient in some form or
other, and in this divine vision God, Who is known or seen, Himself enters the
mind; He is both that which is seen and that whereby He is seen. Again, the
human intellect has a certain affinity for all truth; intelligence and
intelligibility are in a sense correlatives. And though the divine essence is
infinitely distant from the human intelligence, this is not the distance of
opposition or contradiction; for that the human mind should claim the power to
see God is not like the ear claiming to see or the eye to hear. But at the same
time this infinite transcendence of the divine above the human does mean that
the human mind cannot by its natural powers see the supremely intelligible,
namely God, any more than to use Aristotle's expression a bat can see the
sun. If then it is to see God the human intelligence must receive some new
disposition fortifying it for the task.
VII. THE PHANTASMA.
But a peculiar difficulty remains when it is a question of the human intelligence as distinct from the angelic. For an angel, or separated substance, is a pure intelligence; he is immaterial or spiritual. The human intelligence, however, as we saw at the outset, dwells in a corporeal framework through and by which it functions. Through the ever-open doors of the senses, impressions are conveyed to the mind through the medium of the imagination, and for the registering of every fresh intellectual impression or idea, recourse must perforce be had to these presentations by that faculty. But if this recourse to imagination's presentations is connatural to the human intellect it would seem that in beatific vision, where there is no place for the imagination, either the whole nature of our intellectual operations must be radically changed and we thus cease to act as human beings or the place of the imagination must be supplied by something similar to the "Light of glory," or the dependence of the intellect on the imagination must be confined to this material sensible life wherein the intellect has perforce to function through the bodily organism.
VIII. THE ARABIAN PHILOSOPHERS.
We have taken for granted Aristotle's epistemology and his views on the constitutive elements of the human species. But in the thirteenth century those ideas either were not fully grasped, or were presented in a distorted fashion, or owing to an extravagant notion of the real character of the separated substances the human intellect was conceived of as being itself a separated substance, or at least as possessing such affinity with angelic natures that it could naturally know them and that its ultimate beatitude consisted in such knowledge.
These aberrations of the
Arabian philosophers were due, at least in part, to the fact that, as Saint
Thomas points out, "the question whether the human soul can, while still
joined to the body, understand the separated substances, Aristotle undertook to
answer; but since his answer is not to be found in any of his works that have
come down to us, his followers were led to indulge in all sorts of answers to
The story of the Arabian school
of Platonist and Aristotelian philosophers is an exceedingly interesting one.
It was founded by Alexander of Aphrodisias in the second century after Christ,
and to him succeeded in the three following centuries the Platonist
commentators Proclus, Porphyry and Simplicius. When the Emperor Justinian
closed this Platonist School in A.D. 529, it passed to Persia and Syria, where
Aristotle's works were translated by the Christians at Nisibis and Edessa, as
also at Baghdad. It was in this latter centre that the Arabians became
acquainted with Aristotle's philosophical system, though, at the same time
Byzantium was serving as a focus for Aristotelian studies under Photius,
Nicetas and Comnenus, and especially at a later period under Michael of Ephesus
in the twelfth century. These twin streams of interpretation from Persia,
Syria, Arabia and the Moors on the one hand, and from Athens and Constantinople
on the other, converged on the University of Paris in the twelfth century.
Most of the theological
speculations of these Arabians were ultimately derived from Proclus, whose
influence appeared especially in the famous treatise De Causis, the
authorship of which is unknown, but which exercised a profound influence on the
theological thought of the Middle Ages. Proclus himself had taught as an echo
of Plato that there existed a series of hypostatised, universal ideas which
constituted a hierarchy of causes, and this notion runs, as we shall see,
throughout the Arabic speculation of the time of the Scholastics.
The best known among the Arabian philosophers are Alkindi, (circa 870); Alfarabi (died circa 950); Avicenna or Ibn Sina (980-1037); Algazel, or Gazali (1059-1111). All these represented the strictly Eastern tradition. From North Africa or Moorish Spain came Avempace or Ibn Badsha (died 1138); Abubacer or Ibn Bekr (1100-1185); and, most famous of all, Averroes or Ibn Roshd (1126-1198) it is to him that Saint Thomas refers when he speaks of "the Commentator," just as by "the Philosopher" he means Aristotle. Avicebron, author of the Fons Vitae often quoted by Saint Thomas, was really a Jew and not a Moor; his true name was Salomon ben Gabirol.
It must not be thought that
because Saint Thomas fought so strenuous a battle against these teachers he
therefore condemned them utterly. He clearly regarded them as giant intellects,
and treats them with real respect. At times, he even uses Avicenna as an
acknowledged authority, though he points out that in addition to his errors on
the question we have been discussing Avicenna held the strange notion that evil
was limited to this side of the moon, also that he erred touching
predestination and prophecy. Avempace he seems to have only known through the
writings of Averroes; at any rate he speaks of him as "Avempace quidam."
Algazel he often refers to, also to Avicebron.
To return, however, to the
speculations of the Arabian teachers of the twelfth and thirteenth centuries.
They held that we could have a complete understanding of the angels. But is
this true? Can we know the natures or essences of separated substances? Can we
know them as they really are in themselves and not merely the fact that they
exist, as well as certain conclusions as to what their natures are or rather
ought to be? The question is not a frivolous one; for many of the Arabian
philosophers for example Avempace and even the early Aristotelian
commentator Alexander, maintained that we really could know the nature of the
angels; they even held that ultimate human beatitude consisted precisely in
such knowledge. Saint Thomas terms the arguments by which Avempace supported,
his view "frivolous," and rightly, because no speculative knowledge
of which we are conscious can do more than show that such natures exist; it can
never show us what they really and essentially are in themselves. But the ideas
of Alexander demand fuller consideration. For while he held that our passive
intellect was an integral but corruptible portion of our nature and that
consequently it could never arrive at any knowledge of the angelic nature,
Alexander also taught and this was the false doctrine that ate into the heart
of the philosophy and theology of the twelfth and thirteenth centuries,
especially in the University of Paris that the active intellect was no part
of man but was itself an angel or separated substance, also that it was the
active principle of intelligence in us and finally took the place of the
passive intellect whereby we are actually understanding. And since this active
intellect became, according to Alexander, our informing principle and was
itself an angel, we not only became angels specifically if such a thing were
possible but by means of this separated substance we ultimately came to know
all other separated substances and in such knowledge lay our ultimate happiness.
It is easy to see that such a
doctrine destroyed the reality of the human species, negatived the immortality
of the soul, and made the revealed doctrine of man's ultimate vision of the
essence of God fantastic. In Saint Thomas's day, this doctrine was in
possession, and its hold was intensified by the support it received from the
greatest of all the Arabians, Averroes. Moreover, this doctrine was presented
as being solidly based on Aristotle's teaching. These facts afford us an idea
of the gravity of the task devolving on the Christian teachers of that day who
would show that the truths of revelation, for example the immortality of the
soul and its future vision of the essence of God, were by no means in conflict
with sound reason and since the mighty authority of Aristotle had been
invoked were not in conflict with what Aristotle the Stagirite really had
The views of Alexander were
peculiarly dangerous from the very fact that they seemed to adhere so closely
to Aristotle's teaching. For whereas Avempace held that by ever-growing
refinements of mental abstraction we ultimately attained to a knowledge of the
separated substances a view which Saint Thomas dubs "frivolous,"
Alexander had taught nothing so trivial as this. Nor, for he was a true
disciple of Aristotle, had he fallen into the ridiculous error held later by
Avempace of supposing that images in the imagination could be a medium for
arriving at a knowledge of the purely immaterial. Like Aristotle, too, he had
always insisted that the active intellect was the principle of actual
knowledge. But his twofold error lay in making the passive intellect corruptible
and the active intellect something external to man, something eternal and
self-subsisting, yet the actual principle of man's knowledge.
But Averroes, the greatest of all the Arabians, felt so keenly the enormity of making the passive intellect corruptible that he went to the opposite extreme and regarded both it and the active intellect as imperishable, eternal, self-subsisting principles apart from man.
He argued that our intellectual
faculties can understand both speculative principles and even the active
intellect itself. He also maintained that it was this latter, namely, the
active intellect, which put us in positive possession of speculative principles
and thus made them actually known; moreover, that in the intelligible order,
this active intellect was really the informing principle of such speculative
principles. Hence, by our gradually increasing grasp of speculative principles
the active intellect became more and more a part of us. And if, in the process
of time, we men were able, by assiduous study, to make all speculative
principles our own we should find that we had completely absorbed into
ourselves the separated self-subsisting substance or angel known by these
philosophers as the active intellect, and should, have thus acquired full knowledge
of the essence of a separated substance; in this would have lain our beatitude.
Against all these views Saint
Thomas shows that according to Aristotle's positive teaching the intellectual
soul is the "form" or specifying principle of the body; that it is in
very deed its effective as well as its final cause; further, that since the
intellect whether active or passive is simply a faculty of the soul it
cannot be, as the Arabians insisted, a "separated" substance, but must
be an essential part of man.
Moreover, the soul is immortal;
that is to say, it is not a "form" or specifying principle which
perishes with the body. This is not simply a question of revelation and
therefore of faith, but a principle which can be proved by reason. The
consequence is that quite apart from revelation it is demonstrable that man's
final happiness can never be attained in this world. And while nothing but God
can satisfy the cravings of the soul, revelation teaches that that same soul
shall as a matter of fact enjoy ultimately the vision of God's very essence.
Such vision must, then, be possible. Lastly, because "grace does not
destroy, but perfect, nature," that vision must be exercised by the soul
in a manner which does no violence to the nature of the intellect. But that God
Himself should enter the soul and thus become both the goal of beatific vision
and its medium, and that the created intellect, to elicit such an act of
vision, must demand such supernatural "fortification" of its powers
as is expressed in the term light of glory, lumen gloriae these
difficulties, though very real, are, to Saint Thomas's thinking, trifling
compared to the difficulty arising from the fact that the human intellect
necessarily understands through the medium of phantasmata or the imagination's
concepts. For here, we have a fundamental fact. At every turn, Saint Thomas
repeats it: "We cannot," he says, for example, "even reflect
upon things of which we already possess knowledge without turning to these
phantasmata though he [Avicenna] denies this." "But this very fact,"
Saint Thomas continues, "makes it all the more difficult to see how the
separated soul can understand. For then there will be no phantasmata, since
both for their apprehension and preservation these require the organs of the
The solution, for him, lies in
the fact that the human intellect is a light whose connatural object is truth
or all intelligible things. So long as it dwells in the body, it can only
arrive at truth through the medium of the senses and the imagination. But once
separated from the body it will be "like the angels"; it will be a
separated substance, though incomplete in the sense that it will always retain
its relationship to the body in which it dwelt; indeed it will be in a
"violent state" until it is rejoined to it. But it is "separated,"
and therefore must understand precisely as the angels understand; all truth
must be accessible to it. Saint Thomas proves step by step that man's full
beatitude cannot be realised in this world. For this beatitude must lie in the
knowledge of God, yet the ordinary vague knowledge of God we all have or can
have will not suffice, nor will demonstration of His existence such as
speculative science can afford satisfy us, nor the knowledge which is faith since
that, of its nature, supposes a certain baffling obscurity incompatible with
"For reasons like
these," he concludes, "Alexander and Averroes made man's ultimate
happiness consist, not in human knowledge such as arises from speculation, but
in man's union with a separated substance, a union which they thought possible
in this life. Aristotle, on the contrary, since he realised that in this life
we have no other means of arriving at knowledge except through speculation,
maintained that man could not attain to perfect happiness save in some
proportionate fashion. This shows us to what straits these brilliant minds were
reduced. We, however, are freed from such straits if we grant, as we have
proved, that man can attain true happiness after this life since his soul is
immortal, and that in that state the soul understands in the same way as do
separated substances. [. . . . .] Hence man's ultimate happiness will lie in
that knowledge of God which the human mind has after this life, knowing Him,
that is, in the same way as the separated substances know Him.
"Hence it is that the Lord promises us a reward in heaven, and Saint Matthew says that the saints shall be like the angels, who always see God in Heaven."
"If the passive intellect is, despite its union with the body, incorruptible and independent of matter for its existence, as we have shown above, it follows that its present state of compulsion to understand through material things is an accident arising from the soul's union with the body. Consequently, when the soul comes to be separated from the body the passive intellect will be able to understand things that are intelligible in themselves, namely separated substances, and this through the light of the active intellect which is a likeness in the soul of the intellectual light which is in the separated substances. This is the teaching of our faith touching our understanding of separated substances after death, but not during this life."
Elsewhere Saint Thomas
expresses the same doctrine with even greater fulness: "If the human soul
were receptive of abstract and universal notions in the same way as are the
separated substances it would, since its intellectual powers are the least in
the scale [of intelligent beings], have only most imperfect knowledge, for it
would only know things in a general and confused fashion. Consequently, for its
knowledge to be perfected and distinct in detail, it must gather its knowledge
of truth from individual things; and the light of the active intellect is
necessary in order that things may be received into the soul in a higher
fashion than they actually exist in matter. Consequently, again, for the
perfection of its intellectual operations the soul was necessarily united to
the body. At the same time we cannot doubt but that through the movements of
the body and the soul's occupation with sensible things the soul is hindered
from receiving the influences of separated substances; for we see that people
when asleep, and therefore freed from the action of the senses, receive certain
revelations which do not happen to them when in the full possession of their
senses. When, then, the soul is wholly separated from the body it will be more
fully receptive of influences coming from the separated substances, in this
sense, that then by such influence it will be able to understand without having
recourse to the imagination's concepts, a thing that it cannot now do. At the
same time this influence will not cause such perfect and detailed knowledge as
that which we now receive through the medium of the senses save in the case of
those souls which, in addition to the aforesaid natural influence, shall
receive another and supernatural influence fitting them to know all things most
fully and to see God Himself."