4 THE HUMAN SOUL

CHAPTER 4

THE HUMAN SOUL

4.1 Al-Kindî
4.2 Ar-Râzî
4.3 Ibn-Masarra
4.4 Ishâq ibn-Hunayn
4.5 Qustâ ibn-Lûqâ
4.6 Ishâq ibn-Sulaymân al-Isrâ’îlî
4.7 Al-Fârâbî
4.8 Miskawayh
4.9 Ibn-Sînâ
What is the soul?
Relationship with the body
The senses
The four intellects
The intellect in act
The Agent Intellect
Intellect-soul
Immortality
The soul’s origin with the body
No reincarnation/ resurrection
4.10 Ibn-Gabirol
4.11 Ibn-Bâjja
4.12 Ibn-Tufayl
4.13 Ibn-Rushd
Sensitive powers
The intellect
Knowledge and appetite
The unicity of substantial form
4.14 Moshe ben Maimon
4.15 Thomas Aquinas

Following Aristotelian tradition, the Arab philosophers held that man has five exterior senses and other interior ones. Besides these sense-based cognitive powers, all these philosophers held that each man has an intellect by which he knows. As for details, each philosopher went his own way.

4.1 Al-Kindî

The problem that al-Kindî and later philosophers faced was to reconcile the immaterial activity of the intellect with the fact that the human soul animates a physical body. If form is proportionate to matter and the soul is the substantial form of a body, how can it have an immaterial activity? Al-Kindî did not speak of the soul as the form of the body, but as a complete substance independent and separable from the body, and he praises Plato for this teaching.⁽¹⁾ As for body-soul relationship, for al-Kindî, the brain is “the seat of all psychic power”.⁽²⁾

In his Risâla fî l-`aql al-Kindî distinguishes four intellects:

(1) the intellect which is always in act; this is eternal, and al-Kindî lets the reader suppose that this intellect is God, but he does not call it God later al-Fârâbî will propose an Agent Intellect between God and man;

(2) the intellect in potency, which is the human soul in the state of ignorance; note that al-Fârâbî denies a distinction between the soul and its sensitive or intellective powers;

(3) the intellect that has passed from potency to act, having acquired (mustafâd), through the influence of the first intellect, intelligible forms and having identified with them; this refers to habitual knowledge;

(4) the manifest intellect (zâhir), that is, the soul actually considering what it knows.⁽³⁾

4.2 Ar-Râzî

For ar-Râzî, the rational soul is immortal because it is a complete and immaterial substance. (The concupiscible and the irascible souls perish.)⁽⁴⁾ It existed alone but in its stupidity desired to be united with matter. To return to its original happiness it must purify itself by study of philosophy. Otherwise, according to the ideas of Pythagoras and Plato attributed to him by his critics, it must purify itself through a cycle of reincarnations, maybe even by becoming an animal.⁽⁵⁾

4.3 Ibn-Masarra

Ibn-Masarra developed the idea that the human soul is guided by the “great soul” (an-nafs al-kubrâ) of the heavenly world and the separated intelligences beyond.⁽⁶⁾ He distinguishes four souls: the vegetative, animal and rational souls, and a separate intelligence, to which the human soul is related like the moon to the sun.⁽⁷⁾ In man there is the body, an animal soul and a divine spirit, which is the truth (al-haqq) which was breathed into Adam.⁽⁸⁾ He defines spirit as “a light airy body”,⁽⁹⁾ whereas the soul is a power flowing into bodies from the heavenly spheres and has no stability.⁽¹⁰⁾

4.4 Ishâq ibn-Hunayn

To this translator of Greek works into Arabic is attributed a Kitâb an-nafs which does not simply repeat what Aristotle said, but advances some ideas that anticipate those of later philosophers. Like Plato, he said that the rational soul is a substance like the pilot in a ship, and not like a material form; it is a separated intellect.⁽¹¹⁾ In this life it needs the imagination, but after death it will not forget anything, because it has no need of an instrument.⁽¹²⁾

4.5 Qustâ ibn-Lûqâ

From this translator and author one work has survived, al-Firq bayn an-nafs wa-r-rûh, on the difference in man between the spirit and the soul. “The animal spirit” (ar-rûh al-hayawânî) is a subtle physical substance that resides in the heart and in the brain; it is corruptible, whereas the soul is distinct from the body and incorruptible. The animal spirit is an instrument of the soul in animating the body, whereas “the psychic spirit” (ar-rûh an-nafsânî) in the brain serves as an intermediary for sensation and moving the body.⁽¹³⁾

4.6 Ishâq ibn-Sulaymân al-Isrâ’îlî

In the course of defining a wide range of philosophical terms, Ishâq ibn-Sulaymân distinguishes three kinds of intellects: (1) one which is always in act with an ever present knowledge of all things, (2) one which is in potency, before actualization, (3) an actualized intellect, having received knowledge from the senses through the imagination.⁽¹⁴⁾

As for the soul, he is aware of the difference between Plato, who makes the soul an extrinsic principle of motion, and Aristotle, who makes it the form of a body. Of the various kinds of soul, he recognizes one which animates the heavenly sphere and is the cause of generation here below. On this earth there are rational, animal and vegetative souls.⁽¹⁵⁾

The human soul operates through a vital “spirit”, based in the heart and influencing the whole body. It is a bodily substance that dissolves with the body, whereas the soul is incorporeal and survives bodily death.⁽¹⁶⁾ The soul of man is an exterior principle to the body, whereas “nature” is an interior principle; Ishâq offers various definitions of “nature”, none of which is Aristotelian.⁽¹⁷⁾

4.7 Al-Fârâbî

Al-Fârâbî adopted Aristotle’s hylomorphic structure of nature, but gave it his own interpretation. Matter, of course, is the subject of form, which it possesses either in act or in potency. But matter is not pure potency; it is a subject which receives or puts on a form, and the form is given by an exterior agent; it does not come from the matter. This is a reading of Aristotle according to the teaching of Plato.⁽¹⁸⁾

Another curiosity of the teaching of al-Fârâbî on this subject is that he seems to believe in the multiplicity of forms in the same individual. “A body becomes the matter of another body either by giving it its form completely or by taking on something of its form.”⁽¹⁹⁾ Al-Fârâbî applies this idea to the human soul, where he sees each lower power as the matter of the power immediately above it.⁽²⁰⁾ He says the same thing about the relationship of the four intellects which he distinguishes in human knowledge.⁽²¹⁾ Although, in his ad-Da`âwî al-qalbiyya, he says that man has only one soul, in his Falsafa Aristûtâlîs he takes a very clear position for the multiplicity of forms or of souls in an individual.⁽²²⁾

Al-Fârâbî distinguishes four intellects in a different way from al-Kindî: Man has vegetative, sensitive and intellective powers. Among the latter,

(1) man is born with an intellect that is rational (nâtiqa) in potency (the possible intellect of Aristotle); this intellect is also called the material intellect (hayûlânî).

(2) By receiving first receiving first intelligible principles it becomes an intellect in act (munfa`al = bi-l-fi`l).

(3) When this intellect progresses to the perfection of knowledge, it becomes the acquired intellect (mustafâd); in this way it becomes “divine” (ilâhî), because it is in contact with God through the world of spirits separated from matter.⁽²³⁾ In his Falsafa Arisûâlîs, al-Fârâbî goes so far as to say that the different stages of the intellect make a distinction in nature (abî`a) and essence (jawhar).⁽²⁴⁾

(4) Man is incapable by himself of coming out of his condition of materiality without the action of the Agent Intellect. This power, postulated by Aristotle, which Saint Thomas holds is individual to each man, was interpreted by the Greek commentators as the lowest of the heavenly spirits, distinct from individual men but giving them all understanding. Al-Fârâbî accepted this idea and identified this intellect with the “faithful spirit” (ar-rûh al-amîn) and “the holy spirit” (rûh al-qudus) of the Qur’ân, which Muslims understand as being the angel Gabriel.

The job of the Agent Intellect, according to al-Fârâbî, is first of all to impress in the possible intellect the first principals of understanding, such as the principle of contradiction. Then it helps people to reach happiness by inspiring in them (if it finds them ready) a higher knowledge.⁽²⁵⁾ Al-Fârâbî does not say the Agent Intellect is necessary for further knowledge, but explains that images coming from the exterior senses pass through the common sense and the imagination to the “power of discretion” [the cogitative] which prepares them for being understood by the intellect.⁽²⁶⁾

In his Ta`lîqât al-Fârâbî remarks that by dreams and premonitions man has a natural contact with “the first”, that is, with heavenly spirits.⁽²⁷⁾ He continues to say that the work of the imagination is to prepare the intellect to receive intelligible forms from “the giver of forms”.⁽²⁸⁾ He also says that the Agent Intellect influences even the souls of heavenly bodies;⁽²⁹⁾ that may be because in this work he speaks of numerous agent intellects, each in a different level of perfection;⁽³⁰⁾ these refer to the separated intellects corresponding to each heavenly sphere, as is explicitly said in the Risâla fî ithbât al-mufâraqât.

Does the Agent Intellect have as cosmic function for al-Fârâbî, as it does for Ibn-Sînâ? In his large treatises on siyâsa he says nothing of the sort. In a reply to questions asked of him, he simply says that forms come to matter by the action and passion of sensible things.⁽³¹⁾ In the important opusculum on the meaning of the intellect (Risâla fî l-`aql) he says that forms are given to matter by the Agent Intellect,⁽³²⁾ and that the heavenly bodies, which are the primary agents on earthly bodies, give the Agent Intellect the material in which it works.⁽³³⁾ In his Falsafa Arisûâlîs, where he raises the question formally,⁽³⁴⁾ he says that the heavenly bodies, with the help of the Agent Intellect, can act on earthly elements and bodies and cause things to exist, but the Agent Intellect alone acts on the human intellect, while natural things have their proper natural causes; for example man gives birth to man. In his Zaynûn al-kabîr al-yûnânî he is more precise:

This intelligence constantly understands the First and constantly understands whatever is under the First. Forms come necessarily from it, but the souls of the spheres help it in preparing causes for the reception of forms from it, just as a doctor does not give health, but prepares causes for the reception of health.⁽³⁵⁾

In his Risâla fî l-`aql al-Fârâbî says that the Agent Intellect, being in full act and possessing all forms, knows all things, and from it comes the material existence of these forms.⁽³⁶⁾ This idea goes back to Plato’s world of forms and is completely contrary to Aristotle, for whom only the possible intellect has knowledge.

I must remark, lastly, that the work Kitâb maqâlât ar-rafî`a fî usûl `ilm at-tabî`a, in its style and doctrine, appears unauthentic. It is a treatise which presents a hierarchy in man consisting of the intellect, the spirit and the soul, where the intellect, which is supreme, lives with the spirit in the heart, while the soul lives in the brain.

4.8 Miskawayh

As the other Arab philosophers, Miskawayh sees intellectual activity, which distinguishes man from the beasts, as the reason for saying that the human soul is a substance distinct from the body,⁽³⁷⁾ having an accidental relationship with the body.⁽³⁸⁾ As a simple substance, it is not distinct from the intellect and it knows “by its essence”.⁽³⁹⁾ It is not merely the mover of the body,⁽⁴⁰⁾ but knows itself by turning itself totally into the totality of its essence.⁽⁴¹⁾ In this movement it is (as Plato said) as a whole both mover and moved.⁽⁴²⁾

Coming to knowledge, Miskawayh says that our intellect is actualized by another intellect which is always in act.⁽⁴³⁾ That intellect is the first of God’s creatures.⁽⁴⁴⁾ Elsewhere Miskawayh speaks of “agent intellects” corresponding to the heavenly bodies.⁽⁴⁵⁾ Just as the heavenly bodies lie one over the other, so the heavenly spirits are arranged in a hierarchy.⁽⁴⁶⁾ Although he does not expatiate on the function of the Agent Intellect, Miskawayh attributes to it the origin of the first principles of reason which, according to him, do not come from the senses.⁽⁴⁷⁾

Miskawayh anticipates Ibn-Rushd in speaking of the unicity of the soul or intellect:

A substance which is not as body is indivisible... If we sometimes speak otherwise that is by way of metaphor. For if we say that a particular soul has such and such a condition or that the universal soul has such or such a form, we are not affirming a bodily division, but we wish to deny that individuals that are multiple by accident are governed by multiple souls. We give tentative names to that governance, even if it is not really like that, to help us to understand. For example, humanity is in men, even if it differs by matter and complexion; in reality it is one in concept. Just as a stamp is different according as it is made on clay or wax or lead or silver, according to the difference of matter, nevertheless it remains one in itself. Thus we say that the power designated by humanity is one, even if it differs according to matter. This power governs all matter as it is the matter of this power. It is like a man who builds a house out of clay, or makes a jug for water or a boat from wood, or makes of whatever matter whatever it is capable of receiving and which satisfies his plan.⁽⁴⁸⁾

But this passage does not agree with al-Fawz al-asghar, where Miskawayh says that one of the pleasures of the separated soul is the company of other souls that resemble it.⁽⁴⁹⁾

4.9 Ibn-Sînâ

What is the soul?

As for Ibn-Sînâ, in his Ahwâl an-nafs, he first looks for a definition of the soul;⁽⁵⁰⁾ he concludes that the soul must be related to the body, but in the case of man it is an extrinsic mover and is not “impressed” in the body or mixed with it; if we want to call it a form, it is not like something dwelling in the body but like its governor.⁽⁵¹⁾ In the words of ash-Shifâ’:

The soul is not impressed in the body nor does it subsist in it, but its special relationship (ikhtisâs) with it is after the manner of individual configuration (hay’a), which attracts the soul to look after an individual body, with an essential and special providence for it.⁽⁵²⁾

Elsewhere Ibn-Sînâ goes as far as saying that the soul is the “form” by which the body exists and acts.⁽⁵³⁾

In any case, in his essence (anniyya), man is not his body, but he is his soul, in spite of the fact that those who are immersed in the world of sense think otherwise.⁽⁵⁴⁾

In ash-Shifâ’, Ibn-Sînâ holds that every soul, even that of plants, is a substance (jawhar) and not an accident (`arad); it is distinct from the body and gives it its consistence and existence. But, he says, not every substance is necessarily separable. Speaking of the question of intermediate forms, Ibn-Sînâ holds that there is no other actual form but the soul, and that the soul of an animal is the cause of its specific animal activities, like sensation, and also of its vegetative functions.⁽⁵⁵⁾ In the case of man, vegetation, sensation and intellection do not come from three souls, but only one. Ibn-Sînâ says that on this point he differs from Plato (and implicitly from al-Fârâbî).⁽⁵⁶⁾

But we should not forget that when he writes about chemistry, Ibn-Sînâ attacks those who hold that in a composite the elements lose their own forms to take on the sole form of the compound. Rather, he says that earth and fire retain their own substantial forms when they are part of flesh, and only their active qualities are modified.⁽⁵⁷⁾

Relationship with the body

In ar-Ru’yâ wa-t-ta`bîr, Ibn-Sînâ gives further details on the relationship between the soul and the body:

Man does not have one single meaning (ma`nâ), but he is composed of two substances: one is the soul and the other the body. The soul has the role of a subject, and the body, with all its members, is like the instrument which the soul uses for its different operations. The surprising thing is that the body is not an extrinsic instrument, like a sword... but the body is an instrument that the soul joins to itself by preserving its shape and using it as it needs sit.⁽⁵⁸⁾

Nevertheless, in holding that the soul and the body are two distinct substances, with an accidental relationship with one another, Ibn-Sînâ does not see the consequence that, if the soul is not the form of the body, the body must have another form which is not the soul.⁽⁵⁹⁾

As for the mode of governing the body, Ibn-Sînâ says that the soul acts through the intermediacy of the heart, and the heart regulates the sensitive and vegetative powers, each in its own organ, through the intermediacy of physical “spirits”.⁽⁶⁰⁾

Earlier, Qustâ ibn-Lûqâ had postulated an “animal spirit” (ar-rûh al-hayawânî) which serves as the soul’s intermediary in giving life to the body, while the “psychic spirit” (ar-rûh an-nafsânî) in the brain serves as an intermediary for sensation and the movement of the body.⁽⁶¹⁾ This idea was retained by Ibn-Sînâ in his al-`Ilm al-ladunî,⁽⁶²⁾ but in his ar-Ru’yâ wa-t-ta`bîr,⁽⁶³⁾ he says that there are three spirits: a vegetative one in the liver, an animal one in the heart, and a psychic one in the brain. And he even goes as far as saying that there are three corresponding souls which are the forms of these spirits. This position, contrary to his position expressed elsewhere, raises the question of the authenticity of this work but, as we have seen, a multiplicity of substantial forms is in accord with the Ibn-Sînâ’s dualism. The three spirits with their proper organs are found also in his Risâla as-salât, where the three spirits seem to imply three souls, of which only the rational soul is immortal.⁽⁶⁴⁾

The senses

Ibn-Sînâ, like Aristotle, distinguishes five external senses.⁽⁶⁵⁾ But for the internal senses, he presents a slightly different scheme [Ibn-Rushd will be more accurate]: (1) the common sense (al-mushtarak), (2) the imagination (al-khayyâl/ al-mutasawwira) which retains sensible images, (3) the estimative power (al-mutawahhima) which judges the particular good or evil of sensible things, (4) the estimative memory (al-mutakhayyila), or cogitative power (al-mufakkira) in the case of men, to retain what the estimative power presents, and (5) memory (al-hâfiza/ adh-dhâkira) which retains all sensible images and their meanings (ma`ânî, whether of good or of evil) in general.⁽⁶⁶⁾ Reasoning, he observes, takes time because it uses the imagination.⁽⁶⁷⁾

In spite of the radical distinction that Ibn-Sînâ makes between the soul and the body, he holds that the exterior and interior senses serve the soul as a source of knowledge. Especially in geometry and astronomy, diagrams and graphic representations are necessary.⁽⁶⁸⁾ On the other hand, the senses can be an obstacle to abstract reasoning, because the senses do not want to be left idle during an intense activity of the intellect.⁽⁶⁹⁾

The four intellects

In ash-Shifâ’ Ibn-Sînâ follows al-Fârâbî in the division of intellects, with the addition of the habitual intellect.⁽⁷⁰⁾ The first, called the “material intellect” because of its resemblance to prime matter empty of all forms, is also the “passive intellect” in relationship to the Agent Intellect.⁽⁷¹⁾. The second is the intellect in act when it makes a judgement. The third is the habitual intellect which knows self-evident first principles and what derives from these principles. The fourth is the perfected or acquired (mustafâd) intellect. The fifth is the Agent Intellect.

The Risâla fî l-hudûd⁽⁷²⁾ and the Risâla fî l-`uqûl⁽⁷³⁾ present the same five intellects, but in these treatises the intellect in act precedes the acquired intellect, and there are many agent intellects which are identified with the angels. The Risâla fî l-hudûd goes on to explain other terms, such as “the intellect of all” (`aql al-kull), which can be understood as the intellect which governs the highest sphere, from which the motion of the whole universe flows, or as all the intermediate intellects; the last of these is the Agent Intellect for all human souls. Likewise, the “soul of all” (nafs al-kull) is all the soul of the heavenly bodies. The relationship between these souls and the corresponding intellects is the same as between our souls and the Agent Intellect. The soul [of the moon] is the proximate cause of the existence of sub-lunar things, and it derives its existence from the intellect which corresponds to it. In this work Ibn-Sînâ explains that the variant terms, “the universal soul”/ “the universal intellect” (an-nafs al-kullî/ al-`aql al-kulli) only mean a universal concept which includes all the heavenly souls or intellects, but elsewhere he speaks differently: The Intellect which is the first creation and which directs all creation which follows is sometimes called “the universal soul” (an-nafs al-kullî) or, in religious and non-philosophical language, “the universal spirit” (ar-rûh al-kullî).⁽⁷⁴⁾

In a noteworthy passage of his an-Nukat wa-l-fawâ’id fî l-`ilm at-tabî`î, Ibn-Sînâ compares the five intellects with the elements mentioned in Qur’ân 24:35:

God is the light of the heavens and the earth. His light is like a niche where there is a lamp; the lamp is inside a glass which is like a shining star. The lamp is lighted because of a blessed tree, an olive tree neither from the east nor from the west, whose oil would give light even if fire never touched it. Light upon light! God directs to his light anyone he wishes.

The material intellect is the niche. The reasoning by which the habitual intellect looks for the middle term of a demonstration is the olive tree; the rapid grasp of this middle term is the oil; the habitual intellect (`aql bi-l-malaka), if it is weak, is the glass; if it is strong it is the holy power whose oil would give light even if no fire touched it. The acquired intellect (al-`aql al-mustafâd), which actually knows first principles and what derives from them is the light upon light. When it can easily turn to intelligible things, putting itself in front of the rays of holy lights, it is the intellect in act (al-`aql bi-l-fi`l), or the lamp. The Agent Intellect which gives existence and knowledge to the soul is the fire.⁽⁷⁵⁾

The Risâla fî ithbât an-nabuwwât gives a variant interpretation of this Qur’ân verse:

God is the light; the material intellect is the niche; the acquired intellect is the lamp; an intermediate state between these intellects [i.e. the habitual intellect] is the glass. But the olive tree is the cogitative power (al-quwwa al-fikriyya), the interior sense that is between the intellect (the east from which the light comes) and the purely animal senses (the west where the light disappears). The Agent Intellect, finally, is the fire.⁽⁷⁶⁾

In passing, we can note that in his Tafsîr âya an-nûr, Ibn-Sînâ makes all the images of this verse refer to Muammad, who enlightens the world; the same holds for Risâla al-fi`l wa-l-infi`âl.⁽⁷⁷⁾ In al-`Ilm al-ladunî Ibn-Sînâ makes the animal spirit the lamp, the heart the glass, life its brilliance, the blood the oil; sensation and movement are the light; the concupiscible is its heat, and the irascible its smoke.⁽⁷⁸⁾

In summary, the division of the intellects in ash-Shifâ’, which follows al-Fârâbî, more or less, was revised in his other works. The Risâla fî l-hudûd⁽⁷⁹⁾ and the Risâla fî l-`uqûl ⁽⁸⁰⁾ change the order, and an-Nukat makes another change. Then Awâl an-nafs,⁽⁸¹⁾ `Uyûn al-masâ’il,⁽⁸²⁾ `Uyûn al-hikma⁽⁸³⁾ and Risâla fî ithbât an-nabuwwât⁽⁸⁴⁾ reduce the intellects to four, just as they were presented by al-Kindî.

Ash-Shifâ’: R. fî l-udûd/`uqûl: An-Nukat: The others:

Material intellect material material material

intellect in act habitual habitual habitual

habitual intellect in act acquired in act

acquired/holy intellect acquired in act

agent intellect multiple agents agent agent

The Risâla fî l-`uqûl clarifies that the different intellects of man (except for the agent intellect) are only different states (ahwâl) of the speculative intellect.⁽⁸⁵⁾

The intellect in act

Although Ibn-Sînâ describes knowledge of material things as a process of abstraction from the senses,⁽⁸⁶⁾ he insists that first principles, such as “the whole is greater than any of its parts” etc. cannot come from sensible experience, because they are too certain and universal; so they must come from a “divine emanation”.⁽⁸⁷⁾

In ash-Shifâ’ Ibn-Sînâ explains that intelligible forms are not in the intellect when it does not actually think of them. The intellect has no habitual knowledge, but only the proximate preparation to receive forms anew from the Agent Intellect. The intellect thus prepared is “a kind of intellect in act” (al-`aql bi-l-fi`l), but when it actually knows it is “the acquired intellect” (al-`aql al-mustafâd).⁽⁸⁸⁾ Thus Ibn-Sînâ adopts Aristotle’s terminology of habitual knowledge, but he empties it of meaning by situating it in a neo-Platonic context where all knowledge comes by infusion from on high.

In an-Nukat it is not clear whether Ibn-Sînâ denies habitual knowlege, as he does in ash-Shifâ’. Nevertheless he says: “If it happens that the soul has acts of understanding in a stable way, and these acts are present by actual consideration, it is in fact in contact with the Agent Intellect.”⁽⁸⁹⁾

The intellect cannot be fully in act in this life, but after death it will, being in continual contact with the Agent Intellect⁽⁹⁰⁾ Likewise, the human intellect in this life can know the existence of separated substances and some of their essential properties (lawâzim), but it cannot know their very essence (haqîqa), nor the essence of sensible things in this world, but only their properties and accidents.⁽⁹¹⁾

The Agent Intellect

The Agent Intellect, as with al-Fârâbî, is not part of man, but is separated from him. But Ibn-Sînâ goes much father than al-Fârâbî. For Ibn-Sînâ, the Agent Intellect gives existence to human intellects, to all souls and (with the dispositive action of heavenly bodies)⁽⁹²⁾ to the four natural elements.⁽⁹³⁾ Thus it possess all intelligible forms,⁽⁹⁴⁾ and impresses them in the human intellect “by a divine emanation”, according to the disposition of the intellect to receive this emanation.⁽⁹⁵⁾ It is not God, because it produces multiple effects, whereas God, the One, can only produce one effect, the first created intellect.⁽⁹⁶⁾

Above the Agent Intellect there is a whole hierarchy of other superior intellects: the souls of the heavenly bodiessince Ibn-Sînâ insists that these are animated, endowed with intelligence et imagination to regulate their movement⁽⁹⁷⁾then intellects completely separated from matter, and above all of them the First Principle which gives existence to all.⁽⁹⁸⁾

We should note that in his different works Ibn-Sînâ identifies the Agent Intellect with different heavenly spirits:

(1) Most strictly, it is the separated intellect corresponding to the lunar sphere, as the following passage says:

This tenth [intellect, that of the sphere of the moon] the philosophers call the Agent Intellect. It is the spirit of holiness, which gives necessity to our souls and perfects them. Its relation with our souls (kalimât) is like the relation of the sun to the eyes. He it is who greeted Mary saying, “I am only the messenger of your Lord, so that I may give you a pure boy” (Qur’ân 19:19).⁽⁹⁹⁾

In the Risâla fî bayân al-mu`jizât wa-l-karâmât wa-l-a`âjîb, Ibn-Sînâ identifies this Agent Intellect with the “preserved table” (lawh mafûz) of Qur’ân 85:22.

(2) Elsewhere he speaks of inspiration not only from the Agent Intellect but also from separated substances in general.⁽¹⁰⁰⁾ In his Risâla az-ziyâra wa-d-du`â’ Ibn-Sînâ explains that the eight separated intellects corresponding to the heavenly spheres are all called by the philosophers as agent intellects.⁽¹⁰¹⁾ The Risâla fî l-`uqûl identifies them with the angels.⁽¹⁰²⁾

(3) Lastly, sometimes he identifies the agent intellect with the first intellect, which God creates without any intermediary.⁽¹⁰³⁾

In his Risâla fî ithbât an-nubuwwa, Ibn-Sînâ explains that the Agent Intellect gives first intelligible principles directly, but further knowledge comes by way or reasoning.⁽¹⁰⁴⁾ Yet elsewhere Ibn-Sînâ gives the Agent Intellect a much wider role.

In sleep, the Agent Intellect acts directly on the human intellect, and through it acts on the imagination (at-takhayyul). But in wakefulness it is the opposite: the Agent Intellect acts directly on the imagination, and through it on the intellect.⁽¹⁰⁵⁾ Thus dreams can come from: (1) sensations that one had before sleeping, (2) from what thought of before sleeping, (3) from the psychic condition of the spirit of the brain, which depends on physical conditions, and lastly (4) from the Agent Intellect, which gives fore-knowledge of future things.⁽¹⁰⁶⁾ Ibn-Sînâ explains that the Agent Intellect fills the universe by its operation without being mixed with it, but only watching over it by its providence.

This is what the ancient Sâbi’ens called “the Immediate Director” (al-mudabbir al-aqrab), the other Greek philosophers “The Divine Infusion” (al-fayd al-ilâhî), the Syrians “the Word” (al-kalima), the Jews “Shakîna” and “Spirit of Holiness”, the Persians “Shayd Shaydân” (Light of Lights), the Manichaeans “the good spirits”, the Arabs “the Angels” and the Divine Determination (at-ta’yîd al-ilâhî), and Aristotle the “Agent Intellect”.

This intellect is concerned with the welfare of the whole universe, but especially the welfare of men. The highest degree of inspiration coming from him is prophecy; after that his providence extends especially to kings and philosophers (hukamâ’), who direct others.⁽¹⁰⁷⁾

In his ar-Risâla al-ahdawiyya fî l-ma`âd, Ibn-Sînâ discusses the opinion that separated souls can act on living men for good or for evil, according to the state of these separated souls. Some people say that unpurified souls retain their interior estimative sense, by which they act on corporal beings. They also say that good souls are the jinn, while the bad are the shayâtîn, or demons.⁽¹⁰⁸⁾ But we have seen above that, for Ibn-Sînâ, all the senses corrupt at death, and the jinn are only the interior senses.

Intellect-soul

If the intellect is a substance, it cannot be a power of the soul. In denying that the intellect uses and organ, Ibn-Sînâ says that this power “knows by its essence”.⁽¹⁰⁹⁾ We see the same confusion in ar-Risâla al-`arshiyya, where Ibn-Sînâ compares God’s knowledge of himself with the soul’s knowledge of itself.⁽¹¹⁰⁾ In Risâla fî s-sa`âda, Ibn-Sînâ argues that the intellective power is a substance distinct from the body.

The acts of this power come from it essentially, and not by something extrinsic to its essence. And anything whose act comes from it essentially and not from something extrinsic to its essence is a substance subsisting by its essence. Otherwise the intellect would be more noble than the substance and the essence.⁽¹¹¹⁾

On the other hand, he presents the rational soul as having two powers, the one speculative or cognitive which looks at the intelligible universe from on high, the other practical which looks from below at what it must do in particular things.⁽¹¹²⁾

Immortality

As for the immortality of the soul, Ibn-Sînâ rejects the exclusivism of al-Fârâbî and, before him, of Alexander of Aphrodisias, who said that the intellect becomes immaterial by taking on intelligible forms and that ignorant souls will be annihilated. Opting for the opinion of Themistius, he simply says that the intellect of man survives death. “The soul without the body is the true man.”⁽¹¹³⁾ “Death is only the soul abandoning its instruments.”⁽¹¹⁴⁾

Ibn-Sînâ presents two arguments to show that everyone has an immortal soul. The first is the soul’s experience of its own activity as being different from that of the body. Ibn-Sînâ supposes that if someone were in a void without any exterior sensation, his soul would nevertheless be conscious of itself. (He does not think here of the activity of the internal senses and the impossibility of self-consciousness without consciousness of something intelligible, normally through sensation.) Thus he concludes that the soul is a substance complete in itself, independent of the body, but which influences the body, especially by its emotions, much more than the body influences the soul.⁽¹¹⁵⁾

The second argument is that the intellect, as a receptacle of intelligible forms, should itself be immaterial and immortal.⁽¹¹⁶⁾ Since it does not use the body as an organ, the intellect is independent of it and can be separated from it. This is the classic argument of Aristotle and the scholastics. The principle of this argument is that, besides our knowledge of sensible singulars, we know the essences of things in an intelligible and universal way. The intelligibility of things in our knowledge is not individualized by matter, but is spiritual. This spiritual object is the actualization of the intellect either in a habitual way (like memory) or in an actual way. But act corresponds with potency. If the act is spiritual, the potency likewise must be spiritual. The human intellect and soul are therefore spiritual and by that fact immortal.

A sign of that is, as Aristotle said, that the intellect does not get weak by old age, nor does it suffer by knowing what is exceedingly intelligible, as the senses suffer from objects that are too strong.⁽¹¹⁷⁾ But, for Ibn-Sînâ this argument has the weakness of a dualistic context, where the soul is presented as a complete substance apart from the body.⁽¹¹⁸⁾

The soul, then, although “possible” or contingent from the point of view of its existence and its temporal beginning, from the point of view of its lack of composition of form and matter in its essence it cannot cease to exist.⁽¹¹⁹⁾

The soul’s origin with the body

On the other hand, the soul has no pre-existence, because humanity is one, and can only be multiplied by matter. When elements are put in the right shape and mixture to receive the soul, the soul is created and joined to the body.⁽¹²⁰⁾ The body is necessary for the beginning of the soul, but not for its continuation in existence.⁽¹²¹⁾

Thus the soul was created with the body and is individuated in relation to it.⁽¹²²⁾ Exactly what does this individuation consist in? Ibn-Sînâ rejects “the impression of the soul in the body”, and thus the “matter designated by quantity” of Thomas Aquinas. Ibn-Sînâ says that this individuation should be an order or configuration (hay’a) of the soul or else a power or a spiritual accident or a combination of these. It could also be a difference in intellectual knowledge or self-knowledge, or a difference of bodily powers or other things, even though we do not know which.⁽¹²³⁾ In the Ta`lîqât, speaking of individuation (tashakhkhu) in general, he says that it consists in position and time.⁽¹²⁴⁾ In any case, there will be no fusion of soul into a single soul or a fusion with God.⁽¹²⁵⁾

No reincarnation/ resurrection

Thus the soul cannot take on any other body but its own; this excludes the possibility of reincarnation or transmigration of souls.⁽¹²⁶⁾ As for those who hold for reincarnation, Ibn-Sînâ has in mind (1) the representatives of oriental traditions (such as Hinduism) to whom he alludes in quoting “Buzurgmihr”,⁽¹²⁷⁾ (2) Greek philosophers such as Plato and Pythagoras, whom he excuses, saying that they were speaking metaphorically,⁽¹²⁸⁾ (3) those who believe that the soul rejoins the body at the resurrection.⁽¹²⁹⁾ Ibn-Sînâ rejects reincarnation, taking more or less the same line of argumentation that Saint Thomas would later take, but without all the latter’s distinctions.

All that Ibn-Sînâ says implies that after death there will be no bodily resurrection. He expresses his though explicitly in his Risâla as-salât, where he denies the possibility of the resurrection or of the immortality of the vegetative and animal spirit (or soul), but he affirms it for the rational soul.

This will have a resurrection after death. “By death I mean separation from the body; by resurrection I mean its joining spiritual substances and its consequent reward and happiness.”⁽¹³⁰⁾

Maybe out of fear of the consequences of this position, at the end of this work Ibn-Sînâ admonishes the reader not to divulge his secret, so as to keep him out of trouble.⁽¹³¹⁾

In his Kalimât as-sûfiyya, Ibn-Sînâ quotes Qur’ânic verses (89:27-28; 70:4; 54:55; 33:44; 22:48; 75:30, 12; 53:8) to support his position that it is the soul without the body that will appear before God.⁽¹³²⁾

Nevertheless, we see in the sûfic work, al-`Ilm al-ladunî, the statement: “The rational soul... awaits its return to the body on the day of resurrection, as revelation says.”⁽¹³³⁾ Is he here speaking metaphorically or out of consideration for his hearers? In the same work he insists that the soul is a complete substance, independent of the body.⁽¹³⁴⁾ The Risâla fî l-hudûd says that it is only by revelation (shar`) that we know that there will be a bodily happiness,⁽¹³⁵⁾ but this treatise does not try to interpret what this happiness will be.

The most definitive treatment of this question is in the late work, ar-Risâla al-ahdawiyya fî l-ma`âd. First he rejects the opinion based on many Qur’ânic verses that man is a body having life as an accident; at death the body is reduced to dust and life disappears; the resurrection is a re-creation. In that case the raised man is not the same as the one who died, because the form of the body is not numerically the same.⁽¹³⁶⁾

Then he rejects the most common opinion among Muslims, that the resurrection is the reunion of the soul with a reconstituted body. If we suppose, with Ibn-Sînâ, the eternity of the world, that is impossible, because the whole earth would be insufficient for the formation of an infinitude of men. And if the true happiness of man is spiritual, it would be a punishment to make him go back to the body where compete happiness is impossible. Besides, what is the difference between resurrection and reincarnation, which is another impossibility? One cannot escape from this problem by saying that it is the same body with the dame matter that will be raised, because the body may have undergone mutilation; also, by the process of metabolism matter is continually and inevitably changing, and through natural cycles or by cannibalism the same matter is shared by many human bodies.⁽¹³⁷⁾

In particular, Ibn-Sînâ attacks the Christian teaching of the resurrection, because Christians hold for the resurrection of the body but reject bodily pleasures in Paradise. For Ibn-Sînâ, all these pleasures promised in the Qur’ân are metaphoric descriptions of the vision of God and of the communion of angels and saints. But he is convinced that preaching bodily rewards is necessary to motivate ordinary people, and that Christian preaching lacks all moral force.⁽¹³⁸⁾

4.10 Ibn-Gabirol

For Ibn-Gabirol, the soul is attached to the body without touching it;⁽¹³⁹⁾ it does so through the intermediacy of a [physical] spirit.⁽¹⁴⁰⁾ In the hierarchical gradation of the universe, the soul is intermediary between the [separate] intellect and the senses.⁽¹⁴¹⁾ There are three souls in man: the vital one (ha-hayônîth), the vegetative one (ha-hômêah), and the rational soul (ha-madbarath).⁽¹⁴²⁾

Ibn-Gabirol distinguishes between the universal intellect and particular intellects.⁽¹⁴³⁾ Presumably the first is the separate one posited by the other philosophers of the Arab world, and the second is the rational soul. Ibn-Gabirol opts for Plato’s theory of innate knowledge which is obscured by matter; so that learning is a process of remembering.⁽¹⁴⁴⁾

4.11 Ibn-Bâjja

Ibn-Bâjja’s Risâla al-ittisâl follows al-Fârâbî’s tradition on the different classes of men. It distinguishes: (1) the majority (jumhûr) who, like Plato’s people of the cave, have only sensible or material knowledge, (2) the scientists of nature (tabî`iyûn) who know intelligible forms abstracted from sensible things, and (3) those who know the Agent Intellect directly; these are in contact with the Agent Intellect through divine science (metaphysics) and not by the deceptive imagination of the Sûfîs; this criticism of the Sûfîs, taken up by Ibn-Rushd, is a frequent them with Ibn-Bâjja.⁽¹⁴⁵⁾ The intellect of the third type is numerically one and the object of their knowledge (al-ma`qûl) is likewise one. Their destiny is eternal happiness, but without any individuality, whereas the masses have nothing to look forward to.

The acquired intellect (al-`aql al-mustafâd) is the human intellect perfected by certain knowledge and always in act, so that the intellect and the object of its knowledge are one.⁽¹⁴⁶⁾

Ibn-Bâjja, perhaps without knowing Miskawayh’s opinion, preached the unicity of the intellect which Ibn-Rushd adopted.

The first mover of man is the intellect in act, and that is the intelligible in act, since the intellect in act is the intelligible in act... The intellect in act is an active power... This intellect then is numerically one in each man. It is clear from the above that all men, present past and absent are numerically one. But this idea is repugnant and maybe impossible. But if all existing, past and absent men are not numerically one, this intellect is not one. In a word, if this intellect is numerically one, the persons who have such an intellect are all numerically one.⁽¹⁴⁷⁾ He explains that the apparent multiplicity of this intellect comes from its multiple relationships with different material subjects. We can observe that, like Ibn-Rushd, in his Middle Commentary on De anima, the intellect in act and the Agent Intellect are identified, and there is no place for the possible intellect, except for the imagination which is called the “material intellect”.

4.12 Ibn-Tufayl

Hayy ibn-Yaqzân begins his speculation on the soul by making an autopsy of his step-mother, the gazelle, and by the vivisection of other animals. He discovers that the principle of life is a physical spirit in the left ventricle of the heart.⁽¹⁴⁸⁾ Then he embarks on a monist theory that this spirit is really one, but multiple by accident.⁽¹⁴⁹⁾ Then he extends this monism to plants, minerals and all things, saying that all the things that we observe in this world are unequal manifestations of a single reality. He concludes this meditation by explaining how the animal spirit is composed of a form, which is the soul, and prime matter.⁽¹⁵⁰⁾

Man is distinct and superior to all animals.⁽¹⁵¹⁾ The intellect is its essence, and it is independent of the body.⁽¹⁵²⁾ In this passage Ibn-Tufayl does not apply monism to the human intellect, because Hayy ibn-Yaqzân has not yet learned of the existence of other men. But at the end he affirms the unicity of all human souls, as Ibn-Rushd will later propose, and he denies individual survival:

If separated essences had a body which always exists and never corrupts, like the heavenly spheres, they would exist forever. But if they belong to a body which goes back to corruption, like the rational animal, they would corrupt, disappear and be annihilates, like reflected rays. For their form has no more stability than what is in a mirror; if the mirror corrupts, the form also corrupts and disappears.⁽¹⁵³⁾

Ibn-Tufayl also speaks of “the spirit or the intellect which always emanates from God and is like the light of the sun which always shines on the world.”⁽¹⁵⁴⁾ One might think here of the “Agent Intellect” of the other philosophers, but in the monist system of Ibn-Tufayl it is rather the single intellect of angels and men.

4.13 Ibn-Rushd

Ibn-Rushd preserved the whole system of his predecessors on the existence of separated intellects corresponding to the heavenly spheres, and the opinion that the heavenly bodies are animated. Since these bodies are of themselves incorruptible, they are not necessarily animated, but they are because they should possess the best possible condition.⁽¹⁵⁵⁾ But as for Ibn-Sînâ (and al-Fârâbî’s) idea of the Agent Intellect as a “giver of forms” in the physical world, Ibn-Rushd rejects this. He holds the simple position of Aristotle that everything begets its like, either in the same species or in the same genus, according to the idea that the heavenly bodies can cause generation –an idea which Ibn-Rushd says has “no evident proof” (ghayr al-mushâhada),”⁽¹⁵⁶⁾ but which Thomas Aquinas accepts without question. Later Ibn-Rushd explains that the partisans of the hypothesis of the “giver of forms” do not deny that natural causality disposes matter for the reception of a substantial form.⁽¹⁵⁷⁾

Sensitive powers

As for sensitive powers, in his small commentary, Jawâmi` Kitâb an-nafs, Ibn-Rushd repeats Aristotle’s division of the five exterior senses, but he gives only two internal senses: common sense (mushtarak) and the imagination (takhayyul). The latter, conserving sensible images in the absence of sensible objects, includes the function of the memory.⁽¹⁵⁸⁾ In the Tahâfut at-Tahâfut he says that the imagination estimates the convenience or inconvenience of sensible things, and that there is no need to suppose another power, the estimative (wahmiyya) as Ibn-Sînâ did.⁽¹⁵⁹⁾

In the Commentarium magnum Ibn-Rushd accepts all the four interior senses mentioned by Aristotle, against his former opinion that accepted only the common sense and the imagination.⁽¹⁶⁰⁾ As for the first principles of reason, he hesitates to pronounce from where they come, and seems to lean towards the opinion of Ibn-Sînâ that they are directly infused by the Agent Intellect.⁽¹⁶¹⁾ Ibn-Rushd also raises the question whether the material intellect can know separated substances. After a long discussion of opinions, he accepts the principle that the material intellect can know all that is intelligible, and that this can be realized by contact with the Agent Intellect.⁽¹⁶²⁾

The intellect

Regarding questions about the intellect, we can distinguish three stages in the evolution Ibn-Rushd’s thought. First, in his little commentary he insists that the intelligible, in so far as intelligible, is eternal and incorruptible, but he rejects the theory of Plato that these intelligibles pre-exist in us and that learning is nothing but remembering. All science comes through sensitive experience.

Ibn-Rushd asks how intelligible things can be received by a corruptible man and be multiplied according to the multitude of men. He answers that intelligible forms have a formal aspect, which is unique and eternal, and a material aspect, by which they can be received by many men. What is the precise aspect of man which permits him to receive these intelligible forms? It is not the body, which can only receive a bodily form; nor can it be an intellect, because an intellect as intellect must be in act; therefore it must be the soul, and among the powers of the soul, precisely imaginary forms. This preparation (isti`dâd) of the imagination is the “material intellect”, in its existence (wujûd), but not in is receptiveness; for if the material intellect receives intelligible forms it must be empty.

By receiving intelligible forms the material intellect becomes the “habitual intellect” (al-`aql bi-l-malaka), which becomes “the intellect in act” when man is conscious of intelligible forms. The “Agent Intellect” actualizes the material intellect; it is also called the “acquired intellect” (al-`aql al-mustafâd) when the material intellect is in union (ittihâd) or contact (ittisâl) with it. The word mustafâd is used because we take advantage (nastafîd-hu) of it.⁽¹⁶³⁾

The second stage was the Commentarium magnum. Ibn-Rushd rejects the opinion, attributed to Alexander of Aphrodisias and which he had adopted in his small commentary, that the material intellect is a disposition of the imagination.⁽¹⁶⁴⁾ He says that the Agent Intellect and the material intellect are both eternal, incorruptible and unique for all of humanity. The two come into contact with each man through the phantasies of the imagination which the Agent Intellect actualizes in the material intellect. The Agent Intellect, through phantasies made intelligible, also has the relationship of form to the material intellect. It is in this way that the material intellect somehow multiplies in humanity and that each individual has his own knowledge and learns little by little. But since the imagination is corruptible, the acquired or speculative intellect is corruptible, with all its individual knowledge. The material intellect nevertheless continues to be actualized by the Agent Intellect in other individuals, since the human race exists always.⁽¹⁶⁵⁾

After this large commentary Ibn-Rushd wrote an appendix to his little commentary, referring the reader to the large commentary and correcting his adoption of the opinion of Alexander of Aphrodisias that the material intellect is the preparation of the imagination, and says that he was deceived by Ibn-Bâjja in following this opinion. He affirms rather that the material intellect is an eternal substance, and the imagination only furnishes the objects of knowledge.⁽¹⁶⁶⁾

The third stage appears in the middle commentary, Talkhîs kitâb an-nafs, which is the latest. Ibn-Rushd explains that the material intellect has no physical passivity (infi`âl), but that it can receive (qubûl) intelligible forms.⁽¹⁶⁷⁾ He rejects the opinion of Alexander that this intellect or preparation to receive (isti`dâd) exists in the human soul, and he says that it should be in a subject of the same genus as the intelligible forms, that is, in a separated substance. But, as other commentators say, a separated substance is not in itself of the same nature as this preparation, but it is in so far as it is in contact (ittiâl) with man.

It is clear then that the material intellect is something composed of this preparation in us and of the intellect which is in contact with this preparation. In so far as it is in contact with it, it is the prepared (musta`add) intellect and not an intellect in act. It is an intellect in act in so far as it is not in contact with this preparation. And this intellect is exactly the Agent Intellect.⁽¹⁶⁸⁾ Thus, following Ibn-Bâjja, there is no need to posit a passive or material intellect distinct from the Agent Intellect which is unique for all of humanity.

The same idea is also supposed in the large commentary on the Metaphysics (later than the large commentary on the De anima), where Ibn-Rushd explicitly says that the material intellect is corruptible (it is then the imagination), as well as the habitual intellect. The Agent Intellect is distinct from the material intellect, but it comes in contact with it. By an act that is distinct from its essence, the Agent Intellect makes sensible forms intelligible, and thus an eternal intellect knows corruptible things. But when man comes to perfection he loses all that is potential and has no other act than that of the Agent Intellect. “That is ultimate happiness.”⁽¹⁶⁹⁾

Knowledge and appetite

All knowledge comes from the Agent Intellect through the imagination, even first principles, contrary to Ibn-Sînâ.⁽¹⁷⁰⁾ On self-knowledge, Ibn-Rushd says:

Speculative knowledge and what is known are exactly the same thing... But that is only fully true in things separated from matter, that is, that the intellect and the intelligible are one thing in ever respect. But in the case of our intellect they are one only by accident. That is, since is nothing but the knowledge of what exists outside itself, it knows its existence by accident when it knows things extrinsic to its essence. That is because its essence is nothing more than the understanding of things exterior to its essence, as opposed to separated substances which know external things through their essence.⁽¹⁷¹⁾

Intellection takes place in us when the Agent Intellect enlightens the phantasms of the imagination, making them intelligibles in act. The Agent Intellect produces in us “a likeness (shabîh) of what is in its substance,” giving us the habit (malaka) actually to consider whenever we want. This Agent Intellect, which is our last form, does not understand and exist from time to time, but has always existed and will always exist. If it goes out of the body it cannot die. It is precisely itself which knows (ya`qul) intelligible forms here when it is joined (`ind indimâmi-hi) to the material intellect. But if the material intellect leaves [the body] it can know nothing of what is here. Therefore after death we remember nothing of what we knew when it was in contact with the body. When it is in contact with us it knows intelligible forms that are here, but if it leaves us it knows its own essence. But if it can know its own essence while it is in contact with us is another question.

We should know that Themistius and most of the commentators are of the opinion that the intellect which is in us is composed of the intellect which is in potency and the intellect which is in act, that is the Agent Intellect. In so far as it is composed, it does not know its own essence, but it knows things that are here when it is joined to imaginative meanings (ma`ânî). But when these meanings corrupt, it happens accidentally (ya`rud) that intelligible forms corrupt and forgetfulness and error ensue.⁽¹⁷²⁾

The appetitive power (al-quwwa an-nuzû`iyya) is moved by the imagination, and it itself moves the natural heat which moves the members to cause motion in each animal.⁽¹⁷³⁾ In Talkhîs kitâb an-nafs Ibn-Rushd also speaks of good (khayr) and evil (sharr) known by the practical intellect as causes of movement. But he never speaks of the rational will as a special power.⁽¹⁷⁴⁾

The unicity of substantial form

As for the question of the unicity or multiplicity of substantial forms in an individual, Ibn-Rushd always supposes unicity. He affirms this explicitly when he says that elements exist only in potency in complex bodies.⁽¹⁷⁵⁾ But when he says that the soul is the form of a living body, he does not explain how one can have a “rational soul” and an intellect that is separable from this soul.

4.14 Moshe ben Maimon

By his intellect man is the image of God.⁽¹⁷⁶⁾ Moshe ben Maimon agrees that the soul is immortal, but in answering an objection to the hypothesis of an eternal world that this would entail an infinite number of separated souls, he answers by quoting Ibn-Bâjja that separated souls have no bodies to distinguish them and they are therefore all one.⁽¹⁷⁷⁾

Like Ibn-Sînâ, he holds that the human race is diversified by different levels of intelligence: (1) unbelievers, (2) heretics, (3) ordinary believers, (4) the jurists, who discuss the practices of religion, (5) those who venture into speculation on the fundamental principles of religion [theologians], (6) those who have demonstrative knowledge of natural science, (7) those who understand metaphysics, and (8) the prophets, some who see nearby things, others see afar.⁽¹⁷⁸⁾

Moshe ben Maimon wrote a Letter on the resurrection of the dead, replying to Samuel ben Eli who accused him of denying it. In this he held the immortality of the soul, but did not state clearly whether it would be individual or unique. He admitted nevertheless the possibility of a bodily resurrection.

4.15 Thomas Aquinas

The problem that Thomas Aquinas faced was to reconcile two facts: (1) that the human soul is the substantial form of man, and (2) that the act of intellection transcends matter and the subject of this act can survive without the body. Since act must correspond to potency, according to the first fact the soul should be a material form, but according to the second fact the act of intelligence requires an immaterial subject.

First of all, Thomas did not identify the rational soul with the intellect, as the Arab philosophers did, but distinguished the substance of the soul from its powers, as he distinguished these powers from their habits and acts. For him a single soul is the substantial form of the body. By its vegetative powers it is the source of the vital functions of the body; by its sensitive knowing and appetitive powers it is the source of its animal functions, and by the passive and active intellects and the will it exercises properly human activities.

Thus the soul has some activities that are purely material and others that are spiritual. Against Ibn-Sînâ, man is essentially soul and body; there is no room for dualism. To solve the problem how the form of matter can have an operation which transcends matter and can exist without matter, Thomas makes an exception to his general teaching that the act of existence is the act of the composite of matter and form. In the case of man, he says that the act of existence is attached first and directly to the human soul, and through the soul to the body which participates in it, being animated by the soul. Thus at death the soul retains its existence apart from the body.⁽¹⁷⁹⁾

Another point of sharp difference between Thomas and the Arab philosophers was his position that the intellect, whether passive or active, is a personal power of every man.⁽¹⁸⁰⁾ Instead of Ibn-Sînâ’s theory of continual dependence on an exterior agent intellect, Thomas holds that man retains a habitual knowledge; nevertheless he admits that man, apart from his normal knowledge acquired from sense experience, can receive angelic inspiration.

As for the origin of the human soul, Thomas is in agreement with Ibn-Sînâ that it is created with the body.⁽¹⁸¹⁾

As for heavenly spirits, Thomas holds that there are incorporeal intellectual creatures, each unique in its own species, whose number is not limited to the movers of the heavenly bodies.⁽¹⁸²⁾

1. ¹Risâla fî anna-hu jawâhir lâ ajsâm; Risâla fî l-qawl fî n-nafs al-mukhtasar min kitâb Aristû wa-Flâtun wa-sâ’ir al-falâsifa; Kalâm fî n-nafs mukhtasar wajîz.

2. Risâla fî mâhiyya an-nawm wa-r-ru’yâ, p. 297.

3. For a detailed analysis of this work, see Jean Jolivet, L’Intellect selon al-Kindî.

4. At-tibb ar-rûhânî, section 5.

5. ⁵Al-`ilm al-ilâhî, 4; Amad ibn-`Abdallâh al-Kirmânî, Kitâb al-aqwâl adh-dhahabiyya fî t-tibb an-nafsânî, section 5.

6. Risâla al-i`tibâr, pp. 67-69; Khawâss al-hurûf, p. 80.

7. Khawâss al-hurûf, pp. 87-91.

8. Ibid., 91, 97, 104.

9. Ibid., p. 101; cf. p. 108.

10. Ibid., p. 108.

11. ¹¹P. 166.

12. ¹²P. 169.

13. ¹³Kitâb al-farq bayn ar-rûh wa-n-nafs wa-quwâ n-nafs wa-mâhiyya an-nafs, in Rasâ’il Ibn-Sînâ, 2, p. 88, 93

14. Liber de definitionibus, pp. 311, 332.

15. Ibid., p. 312.

16. Ibid., p. 318.

17. Ibid., p. 320.

18. ¹⁸Mabâdi’ ârâ’, 16, 19 (p. 33).

19.

20. ²⁰Ibid., 21.

21. ²¹Ibid., 27, p. 58.

22. ²²Nos. 75-76.

23. ²³On the whole question of intellects, cf. Mabâdi’ ârâ’ 22 & 27 (p. 58); as-Siyâsa al-madaniyya, 32:6, 36:1, 55:5, 79:9 ff.;

Risâla fî l-`aql, nn. 17, 18, 31, 32-40

24. ²⁴Nos. 90-93.

25. ²⁵Cf. Falsafa Aristûtâlîs, 98.

26. ²⁶Jawâb masâ’il su’il `an-hâ, n. 28.

27. ²⁷Ta`lîqât, n. 52; cf. Ihsâ’ al-`ulûm, ch. 3, p. 103, on “practical astrology”.

28. ²⁸Ta`lîqât, n. 53.

29. ²⁹Ta`lîqât, n. 78.

30. ³⁰Ibid., n. 2.

31. ³¹Jawâb masâ’il su’il `an-hâ, n. 28.

32.

33. ³³Risâla fî l-`aql, n. 49.

34. ³⁴N. 99.

35. C. 3.

36. ³⁶N. 37.

37. Maqâla fî n-nafs wa-l-`aql, pp. 50, 21-20; al-Fawz al-asghar, p. 64.

38. Fasl âkhar min kalâm-hi, p. 195.

39. Al-Fawz al-asghar, 75-81.

40. ⁴⁰Risâla fî jawhar an-nafs, p. 197

41. Fî ithbât as-suwar ar-rûhâniyya, p. 200.

42. ⁴²Fî ithbât dhâlika ayan, p. 201

43. Maqâla fî n-nafs wa-l-`aql, 62-61.

44. Al-Fawz al-asghar, p. 87.

45. Risâla fî l-ladhdhât wa-l-âlâm, p. 68.

46. Al-Fawz al-asghar, p. 101.

47. Maqâla fî n-nafs wa-l-`aql, pp. 64, 49; al-Fawz al-asghar, p. 126.

48. ⁴⁸Risâla fî n-nafs wa-l-`aql, pp. 55-54

49. P. 105.

50. ⁵⁰Ch. 1.

51. ⁵¹Risâla fî l-kalâm `alâ n-nafs an-nâtiqa, one of the late works of Ibn-Sînâ, which summarizes ash-Shifâ’, an-nafs, maqâla 5.

fasl 1-2; cf. Kalimât as-sufiyya, 158-160; Risâla fî bayân al-mu`jizât wa-l-karâmât wa-l-a`âjîb, p. 404

52. ⁵²Ash-Shifâ’, an-nafs, maqâla 5. fasl 2, p. 196.

53. ⁵³Mabhath `an al-quwâ n-nafsâniyya, ch. 2.

54. ⁵⁴Ar-Risâla al-ahdawiyya fî l-ma`âd, 141-151.

55. ⁵⁵Ash-Shifâ’, an-nafs, maqâla 1, fasl 3; maqâla 5, fasl 7.

56. ⁵⁶Ahwâl an-nafs, ch. 11.

57. Ash-Shifâ’: al-Kawn wa-l-fasâd, fasl 7.

58. ⁵⁸Al-fasl alaf, p. 274; cf. also al-`Ilm al-ladunî, p. 187-188.

59. ⁵⁹Ibn-Sînâ discusses the relationship of the soul to the body in ash-Shifâ’, an-nafs, maqâla 5, fasl 4 = Awâl an-nafs, ch. 9; cf. An-nukat wa-l-fawâ’id fî `ilm at-tabî`î, pp. 158-161.

60. ⁶⁰Ash-Shifâ’, an-nafs, maqâla 5, fasl 8; an-Nukat wa-l-fawâ’id fî l-`ilm at-tabî`î, pp. 155-156.

61. ⁶¹Kitâb al-farq bayn ar-rûh wa-n-nafs wa-quwâ n-nafs wa-mâhiyya an-nafs, in Rasâ’il Ibn-Sînâ, 2, p. 88, 93.

62. ⁶²P. 187-188.

63. ⁶³P. 275.

64. ⁶⁴Pp. 3-7.

65. ⁶⁵An-Nukat wa-l-fawâ’id fî l-`ulûm at-tabî`î, p. 152.

66. ⁶⁶Ibid., pp. 154-155; ash-Shifâ’, an-nafs, pp. 145-171; Risâla fî bayân al-mu`jizât wa-l-karâmât wa-l-a`âjîb, pp. 401-403.

67. ⁶⁷Ta`lîqât, p. 109.

68. ⁶⁸Ahwâl an-nafs, ch. 6; Mabhath `an al-quwâ n-nafsâniyya, ch. 8; ash-Shifâ’, an-nafs, maqâla 5. fasl 3; An-Nukat wa-l-fawâ’id fî l-`ilm at-tabî`î, pp. 156-157, 161-162, 167-169; Ta`lîqât, pp. 83-84

69. ⁶⁹An-Nukat wa-l-fawâ’id fî l-`ilm at-tabî`î, pp. 164-165, 168-169; Risâla fî bayân al-mu`jizât wa-l-karâmât wa-l-a`âjîb, p. 405

70. ⁷⁰Maqâla 5, fasl 6, pp. 212-220.

71. ⁷¹Ahwâl an-nafs, ch. 12.

72. ⁷²Pp. 68-70.

73. P. 416.

74. ⁷⁴Risâla ajwiba `an `ashar masâ’il, al-mas’ala ath-thâlitha, p. 78.

75. ⁷⁵Pp. 162-163, 167.

76. ⁷⁶Pp. 49-52.

77. f⁷⁷P. 4

78. ⁷⁸P. 188.

79. Pp. 68-70.

80. P. 416.

81. Ch. 2.

82. P. 21.

83. P. 37-38.

84. Pp. 43-44.

85. ⁸⁵P. 416.

86. ⁸⁶Ahwâl an-nafs, ch. 3.

87. ⁸⁷Mabhath `an al-quwâ n-nafsâniyya, ch. 10; cf. an-Nukat wa-l-fawâ’id fî l-`ilm at-tabî`î, 163-165; ar-Risâla fî s-sa`âda, p. 13; Ta`lîqât, p. 23.

88. Pp. 212-220; cfr. an-Nukat wa-l-fawâ’id fî l-`ilm at-tabî`î, 167.

89. ⁸⁹An-nukat, p. 172.

90. ⁹⁰Ash-Shifâ’: an-nafs, maqâla 5, fasl 6.

91. ⁹¹An-Nukat wa-l-fawâ’id fî l-`ilm at-tabî`î, 165-166; Ta`lîqât, p. 34-35, 82.

92. ⁹²See also Ta`lîqât, p. 41.

93. ⁹³`Uyûn al-masâ’il, 9; Mabath `an al-quwâ n-nafsâniyya, ch. 3, says that all souls (of all kinds) come “from without”.

94. ⁹⁴Ahwâl an-nafs, ch. 12; Mabhath `an al-quwâ n-nafsâniyya, ch. 10.

95. ⁹⁵Ibid., 39.

96. ⁹⁶An-Nukat wa-l-fawâ’id fî l-`ilm at-tabî`î, 166-167.

97. ⁹⁷Cf., for example, Risâla fî s-sa`âda, pp. 13-15; Ta`lîqât, 62, 101-108, 128-130, 166.

98. ⁹⁸Cf. also the opusculum Masâ’il `an ahwâl ar-rûh.

99. ⁹⁹Kalimât as-sufiyya, p. 165; the word kalima is often used in this sûfic work for the human soul.

100. ¹⁰⁰For example, an-Nukat wa-l-fawâ’id fî l-`ilm at-tabî`î, 167.

101. ¹⁰¹Jâmi` al-badâ’i`, p. 33; `Âsî, p. 284.

102. ¹⁰²P. 418.

103. ¹⁰³In Risâla fî mâhiyya al-`ishq, p. 26; Ta`lîqât, p. 100.

104. ¹⁰⁴P. 44.

105. ¹⁰⁵Ibid., pp. 167-168; Ta`lîqât, p. 83.

106. ¹⁰⁶Ar-Ru’yâ wa-t-ta`bîr, al-fasl hâ, wâ, pp. 283-288.

107. f¹⁰⁷Ibid., fasl jâ, pp. 290-294

108. ¹⁰⁸Pp. 215-223.

109. ¹⁰⁹Ahwâl an-nafs, ch. 7; `Uyûn al-ikma, pp. 35, 38; ar-Risâla al-ahdawiyya fî l-ma`âd, pp. 167, 175

110. ¹¹⁰P. 8.

111. ¹¹¹P. 12.

112. ¹¹²An-Nukat wa-l-fawâ’id fî l-`ilm at-tabî`î, pp. 156 et 162, Risâla fî bayân al-mu`jizât wa-l-karâmât wa-l-a`âjîb, p. 404, Risâla fî l-`uqûl, p. 416-417, and in the other works of Ibn-Sînâ.

113. ¹¹³`Uyûn al-masâ’il, 21; cf. Risâla fî s-sa`âda, p. 15; ar-Risâla al-ahdawiyya, p. 213

114. Risâla fî l-mawt, p. 379.

115. Al-Ishârât, nama 3, fasl 1-4; ash-Shifâ’: an-nafs, maqâla 1, fasl 1; there is a similar argument in the opusculum Masâ’il `an ahwâl ar-rûh.

116. ¹¹⁶Ahwâl an-nafs, ch. 4 & 9; Mabhath `an al-quwâ n-nafsâniyya, ch. 9.

117. ¹¹⁷Al-Ishârât, loc. cit.; ar-Risâla al-ahdawiyya fî l-ma`âd, 153-183.

118. ¹¹⁸Cf., for example, ar-Risâla fî s-sa`âda, pp. 12-13.

119. ¹¹⁹Cf. Risâla ilâ Abî `Ubayd al-Jûzjânî.. fî amr an-nafs; an-Nukat wa-l-fawâ’id fî l-`ilm at-tabî`î, p. 177-178; Kalimât as-sûfiyya, p. 166; ar-Risâla al-ahdawiyya fî l-ma`âd, 185-189.

120. Ta`lîqât, pp. 63-64, 110.

121. ¹²¹Ta`lîqât, p. 81.

122. ¹²²Ibid., ch. 8; an-Nukat wa-l-fawâ’id fî l-`ilm at-tabî`î, p. 177-178; Kalimât as-sufiyya, 159; ar-Risâla al-ahdawiyya fî l-ma`âd, 125-133

123. ¹²³Ash-Shifâ’, an-nafs, maqâla 5, fasl 3; cf. Ta`lîqât, 65.

124. ¹²⁴P. 107; cf. p. 145.

125. ¹²⁵Cf. Kalimât as-sûfiyya, p. 178.

126. ¹²⁶Awâl an-nafs, ch. 10; ash-Shifâ’, an-nafs, maqâla 5, fasl 4; Kalimât as-sûfiyya, p. 167; ar-Risâla al-ahdawiyya fî l-ma`âd, 99-139; Ta`lîqât, pp. 65, 67

127. ¹²⁷P. 139

128. ¹²⁸Pp. 135, 207.

129. ¹²⁹In ar-Risâla al-ahdawiyya Ibn-Sînâ restricts himself to answering this third category.

130. ¹³⁰P. 7.

131. ¹³¹P. 14.

132. ¹³²P. 159.

133. ¹³³P. 189.

134. ¹³⁴Pp. 189-190.

135. ¹³⁵P. 91.

136. ¹³⁶Pp. 41-43, 63-65.

137. ¹³⁷Pp. 29-31, 67-85, 107, 205.

138. ¹³⁸Pp. 85-97; for the communion of separated souls, see p. 215.

139. Maqôr hayyîm, 2:29-30.

140. Ibid., 3:3.

141. Ibid., 3:24.

142. Ibid., 3:28-30.

143. Ibid., 4:6; cf. 4:19.

144. Ibid., 5:65.

145. Risâla al-wadâ`, pp. 121 ff. which criticizes the Munqidh of al-Ghazâlî, and Ittisâl al-`aql bi-l-insân, pp. 166-167, 171.

146. ¹⁴⁶Ittiâl al `aql bi-l-insân, pp. 130-131

147.

148. Pp. 138-148.

149. Pp. 149-150.

150. ¹⁵⁰Pp. 150-162

151. Pp. 188-189.

152. Pp. 178-180.

153. P. 215.

154. P. 124.

155. ¹⁵⁵Tahâfut, II, p. 438.

156. ¹⁵⁶ Tahâfut, II, p. 622; Tafsîr mâ ba`d at-tabî`a, pp. 1497 ff

157. ¹⁵⁷ Tahâfut, II, p. 790

158. Jawâmi` Kitâb an-nafs, pp. 54-65; the same restriction of the interior senses is found in Talkihîs kitâb an-nafs, pp. 106-120.

159. ¹⁵⁹II, pp. 818-819; cf. Talkhî kitâb an-nafs, p. 120.

160. ¹⁶⁰Pp. 419, 449; these senses are also recognized in The epistle on the possibility of conjunction with the active intellect, p. 27.

161. ¹⁶¹Pp. 407, 496, 506.

162. ¹⁶²Pp. 488 ff.

163. Jawâmi` kitâb an-nafs, pp. 66-90.

164. P. 396-397; the same position is found in Tractatus de animae beatitudine et Epistula de connexione intellectus abstracti cum homine.

165. J¹⁶⁵Pp. 999-412, 448-500

166. P. 90.

167. Pp. 121, 128.

168. ¹⁶⁸P. 124.

169. Tafsîr mâ ba`d at-tabî`a, pp. 1489-1490.

170. ¹⁷⁰Talkhîs kitâb an-nafs, p. 137.

171. ¹⁷¹Pp. 128-129; the same is said in the Commentarium magnum de Anima, p. 420.

172. ¹⁷²P. 130-131.

173. ¹⁷³Kitâb an-nafs, pp. 87-93; cf. Talkhîs kitâb an-nafs, p. 145

174. Pp. 134, 138-145.

175. Talkhîs as-Samâ’ wa-l-`âlam, pp. 306-307.

176. Dalâ’il al-hâ’irîn, pp. 26-28.

177. Dalâ’il al-hâ’irîn, pp. 223-224.

178. Ibid., pp. 718 ff.

179. Cf. Contra gentiles, II, n. 69-72.

180. Ibid., II, nos. 59, 69, 73-78; De unitate intellectus contra Averroistas.

181. Contra gentiles, II, nos. 83-90.

182. Ibid., II, nos. 91-101.