CHAPTER 4
THE HUMAN SOUL


4.1 Al-Kindī
4.2 Ar-Rāzī
4.3 Ibn-Masarra
4.4 Isḥāq ibn-Ḥunayn
4.5 Qusṭā ibn-Lūqā
4.6 Isḥāq ibn-Sulaymān al-Isrā’īlī
4.7 Al-Fārābī
4.8 Miskawayh
4.9 Ibn-Sīnā

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-Bājja
4.12 Ibn-Ṭufayl
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-Kindī

The problem that al-Kindī 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-Kindī 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-Kindī, the brain is “the seat of all psychic power”. (2)

In his Risāla fī l-`aql al-Kindī distinguishes four intellects:

  1. the intellect which is always in act; this is eternal, and al-Kindī lets the reader suppose that this intellect is God, but he does not call it God later al-Fārābī 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-Fārābī denies a distinction between the soul and its sensitive or intellective powers;
  3. the intellect that has passed from potency to act, having acquired (mustafād), through the influence of the first intellect, intelligible forms and having identified with them; this refers to habitual knowledge;
  4. the manifest intellect (ẓāhir), that is, the soul actually considering what it knows. (3)

4.2 Ar-Rāzī

For ar-Rāzī, 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-kubrā) 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 Isḥāq ibn-Hunayn

To this translator of Greek works into Arabic is attributed a Kitāb 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 Qusṭā ibn-Lūqā

From this translator and author one work has survived, al-Firq bayn an-nafs wa-r-rūh, on the difference in man between the spirit and the soul. “The animal spirit” (ar-rūḥ al-ḥayawānī) 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-rūḥ an-nafsānī) in the brain serves as an intermediary for sensation and moving the body. (13)

4.6 Isḥāq ibn-Sulaymān al-Isrā’īlī

In the course of defining a wide range of philosophical terms, Isḥāq ibn-Sulaymān 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; Isḥāq offers various definitions of “nature”, none of which is Aristotelian. (17)

4.7 Al-Fārābī

Al-Fārābī 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-Fārābī 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-Fārābī 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`āwī al-qalbiyya, he says that man has only one soul, in his Falsafa Arisṭūṭālīs he takes a very clear position for the multiplicity of forms or of souls in an individual. (22)

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

  1. man is born with an intellect that is rational (nātiqa) in potency (the possible intellect of Aristotle); this intellect is also called the material intellect (hayūlānī).
  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 (mustafād); in this way it becomes “divine” (ilāhī), because it is in contact with God through the world of spirits separated from matter. (23) In his Falsafa Arisūālīs, al-Fārābī goes so far as to say that the different stages of the intellect make a distinction in nature (abī`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-Fārābī accepted this idea and identified this intellect with the “faithful spirit” (ar-rūh al-amīn) and “the holy spirit” (rūh al-qudus) of the Qur’ān, which Muslims understand as being the angel Gabriel.

The job of the Agent Intellect, according to al-Fārābī, 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-Fārābī 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`līqāt al-Fārābī 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 Risāla fī ithbāt al-mufāraqāt.

Does the Agent Intellect have as cosmic function for al-Fārābī, as it does for Ibn-Sīnā? In his large treatises on siyāsa 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 (Risāla fī 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 Arisūālīs, 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 Zaynūn al-kabīr al-yūnānī 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 Risāla fī l-`aql al-Fārābī 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 Kitāb maqālāt ar-rafī`a fī uṣūl `ilm aṭ-ṭabī`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-aṣghar, 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-Sīnā

What is the soul?

As for Ibn-Sīnā, in his Aḥwāl 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-Shifā’:

The soul is not impressed in the body nor does it subsist in it, but its special relationship (ikhtiṣāṣ) 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-Sīnā 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-Shifā’, Ibn-Sīnā holds that every soul, even that of plants, is a substance (jawhar) and not an accident (`araḍ); 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-Sīnā 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-Sīnā says that on this point he differs from Plato (and implicitly from al-Fārābī). (56)

But we should not forget that when he writes about chemistry, Ibn-Sīnā 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’yā wa-t-ta`bīr, Ibn-Sīnā gives further details on the relationship between the soul and the body:

Man does not have one single meaning (ma`nā), 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-Sīnā 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-Sīnā 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, Qusṭā ibn-Lūqā had postulated an “animal spirit” (ar-rūḥ al-ḥayawānī) which serves as the soul’s intermediary in giving life to the body, while the “psychic spirit” (ar-rūḥ an-nafsānī) in the brain serves as an intermediary for sensation and the movement of the body. (61) This idea was retained by Ibn-Sīnā in his al-`Ilm al-ladunī, (62) but in his ar-Ru’yā wa-t-ta`bīr, (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-Sīnā’s dualism. The three spirits with their proper organs are found also in his Risāla aṣ-ṣalāt, where the three spirits seem to imply three souls, of which only the rational soul is immortal. (64)

The senses

Ibn-Sīnā, 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-khayyāl/ 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-ḥāfiẓa/ adh-dhākira) which retains all sensible images and their meanings (ma`ānī, 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-Sīnā 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-Shifā’ Ibn-Sīnā follows al-Fārābī 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 (mustafād) intellect. The fifth is the Agent Intellect.

The Risāla fī l-ḥudūd (72) and the Risāla fī l-`uqūl (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 Risāla fī l-hudūd 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 souls 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-Sīnā explains that the variant terms, “the universal soul”/ “the universal intellect” (an-nafs al-kullī/ 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-kullī) or, in religious and non-philosophical language, “the universal spirit” (ar-rūḥ al-kullī). (74)

The Risāla fī ithbāt an-nabuwwāt Ibn-Sīnā compares the five intellects with the elements mentioned in Qur’ān 24:35: (75)

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.

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 Tafsīr āya an-nūr, Ibn-Sīnā makes all the images of this verse refer to Muḥammad, who enlightens the world; the same holds for Risāla al-fi`l wa-l-infi`āl. (77) In al-`Ilm al-ladunī Ibn-Sīnā 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-Shifā’, which follows al-Fārābī, more or less, was revised in his other works. The Risāla fī l-ḥudūd (79) and the Risāla fī l-`uqūl (80) multiply the agent intellects. Then Aḥwāl an-nafs, (81) `Uyūn al-masā’il, (82) `Uyūn al-ḥikma (83) and Risāla fī ithbāt an-nabuwwāt (84) reduce the intellects to four, just as they were presented by al-Kindī.

  Ash-Shifā’:  R. fī l-ḥudūd/`uqūl:  The others:
  Material intellect  material  material
  habitual intellect  habitual  habitual
  intellect in act  in act  in act
  acquired/holy intellect  acquired   —
  agent intellect  multiple agents  agent

The Risāla fī l-`uqūl clarifies that the different intellects of man (except for the agent intellect) are only different states (aḥwāl) of the speculative intellect. (85)

The intellect in act

Although Ibn-Sīnā 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-Shifā’ Ibn-Sīnā 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-mustafād). (88) Thus Ibn-Sīnā 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. (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 (lawāzim), but it cannot know their very essence (haqīqa), 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-Fārābī, is not part of man, but is separated from him. But Ibn-Sīnā goes much father than al-Fārābī. For Ibn-Sīnā, 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 bodies —since Ibn-Sīnā insists that these are animated, endowed with intelligence and 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-Sīnā 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 (kalimāt) 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’ān 19:19). (99)

    In the Risāla fī bayān al-mu`jizāt wa-l-karāmāt wa-l-a`ājīb, Ibn-Sīnā identifies this Agent Intellect with the “preserved table” (lawḥ mafūẓ) of Qur’ān 85:22.

  2. Elsewhere he speaks of inspiration not only from the Agent Intellect but also from separated substances in general. (100) In his Risāla az-ziyāra wa-d-du`ā’ Ibn-Sīnā explains that the eight separated intellects corresponding to the heavenly spheres are all called by the philosophers as agent intellects. (101) The Risāla fī l-`uqūl 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 Risāla fī ithbāt an-nubuwwa, Ibn-Sīnā explains that the Agent Intellect gives first intelligible principles directly, but further knowledge comes by way or reasoning. (104) Yet elsewhere Ibn-Sīnā 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-Sīnā 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 Sābi’ens called “the Immediate Director” (al-mudabbir al-aqrab), the other Greek philosophers “The Divine Infusion” (al-fayd al-ilāhī), the Syrians “the Word” (al-kalima), the Jews “Shakīna” and “Spirit of Holiness”, the Persians “Shayd Shaydān” (Light of Lights), the Manichaeans “the good spirits”, the Arabs “the Angels” and the Divine Determination (at-ta’yīd al-ilāhī), 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 (hukamā’), who direct others. (107)

In his ar-Risāla al-aḥḍawiyya fī l-ma`ād, Ibn-Sīnā 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 shayātīn, or demons. (108) But we have seen above that, for Ibn-Sīnā, 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 an organ, Ibn-Sīnā says that this power “knows by its essence”. (109) We see the same confusion in ar-Risāla al-`arshiyya, where Ibn-Sīnā compares God’s knowledge of himself with the soul’s knowledge of itself. (110) In Risāla fī s-sa`āda, Ibn-Sīnā 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-Sīnā rejects the exclusivism of al-Fārābī 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-Sīnā 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-Sīnā 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-Sīnā 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-Sīnā rejects “the impression of the soul in the body”, and thus the “matter designated by quantity” of Thomas Aquinas. Ibn-Sīnā 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`līqāt, 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-Sīnā 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-Sīnā 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-Sīnā says implies that after death there will be no bodily resurrection. He expresses his though explicitly in his Risāla as-salāt, 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-Sīnā admonishes the reader not to divulge his secret, so as to keep him out of trouble. (131)

In his Kalimāt aṣ-ṣūfiyya, Ibn-Sīnā quotes Qur’ānic 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 sūfic work, al-`Ilm al-ladunī, 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 Risāla fī l-hudūd 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-Risāla al-aḥḍawiyya fī l-ma`ād. First he rejects the opinion based on many Qur’ānic 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-Sīnā, 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 same 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-Sīnā attacks the Christian teaching of the resurrection, because Christians hold for the resurrection of the body but reject bodily pleasures in Paradise. For Ibn-Sīnā, all these pleasures promised in the Qur’ān 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-ḥayônīth), the vegetative one (ha-ṣômêḥah), 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-Bājja

Ibn-Bājja’s Risāla al-ittiṣāl follows al-Fārābī’s tradition on the different classes of men. It distinguishes: (1) the majority (jumhūr) who, like Plato’s people of the cave, have only sensible or material knowledge, (2) the scientists of nature (ṭabī`iyūn) 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 Ṣūfīs; this criticism of the Ṣūfīs, taken up by Ibn-Rushd, is a frequent them with Ibn-Bājja. (145) The intellect of the third type is numerically one and the object of their knowledge (al-ma`qūl) 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-mustafād) 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-Bājja, 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-Ṭufayl

Ḥayy ibn-Yaqẓān 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-Ṭufayl does not apply monism to the human intellect, because Ḥayy ibn-Yaqẓān 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-Ṭufayl 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-Ṭufayl 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-Sīnā (and al-Fārābī’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-mushāhada),” (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, Jawāmi` Kitāb 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 Tahāfut at-Tahāfut 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-Sīnā 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-Sīnā 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`dād) of the imagination is the “material intellect” in its existence (wujūd), but not in its 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-mustafād) when the material intellect is in union (ittiḥād) or contact (ittiṣāl) with it. The word mustafād is used because we take advantage (nastafīd-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-Bājja 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, Talkhīṣ kitāb an-nafs, which is the latest. Ibn-Rushd explains that the material intellect has no physical passivity (infi`āl), but that it can receive (qubūl) intelligible forms. (167) He rejects the opinion of Alexander that this intellect or preparation to receive (isti`dād) 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 (ittiṣāl) 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-Bājja, 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-Sīnā. (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 (shabīh) 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 inḍimāmi-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`ānī). But when these meanings corrupt, it happens accidentally (ya`ruḍ) that intelligible forms corrupt and forgetfulness and error ensue. (172)

The appetitive power (al-quwwa an-nuzū`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 Talkhīs kitāb 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-Bājja that separated souls have no bodies to distinguish them and they are therefore all one. (177)

Like Ibn-Sīnā, 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 and have perfect knowledge of natural science, (6) those who understand metaphysics, and (7) 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-Sīnā, 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-Sīnā’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-Sīnā 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. Risāla fī anna-hu jawāhir lā ajsām; Risāla fī l-qawl fī n-nafs al-mukhtasar min kitāb Aristū wa-Flātun wa-sā’ir al-falāsifa; Kalām fī n-nafs mukhtasar wajīz.

2. Risāla fī māhiyya an-nawm wa-r-ru’yā, p. 297.

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

4. Aṭ-ṭibb ar-rūḥānī, section 2.

5. Al-`ilm al-ilāhī, 4; Aḥmad ibn-`Abdallāh al-Kirmānī, Kitāb al-aqwāl adh-dhahabiyya fī ṭ-ṭibb an-nafsānī, section 5.

6. Risāla al-i`tibār, pp. 67-69; Khawāṣṣ al-ḥurūf, p. 80.

7. Khawāṣṣ al-ḥurūf, pp. 87-91.

8. Ibid., 91, 97, 104.

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

10. Ibid., p. 108.

11. P. 166.

12. P. 169.

13. Kitāb al-farq bayn ar-rūḥ wa-n-nafs wa-quwā n-nafs wa-māhiyya an-nafs, in Rasā'il Ibn-Sīnā, 2, p. 88, 93.

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

15. Ibid., p. 312.

16. Ibid., p. 318.

17. Ibid., p. 320.

18. Mabādi' ārā', #16, 19.

19. Ibid., #19.

20. Ibid., #21.

21. Ibid., 27, p. 58.

22. Nos. 75-76.

23. On the whole question of intellects, cf. Mabādi’ ārā’ 22 & 27; as-Siyāsa al-madaniyya, 32:6, 36:1, 55:5, 79:9 ff.; Risāla fī l-`aql, nn. 17, 18, 31, 32-40.

24. Nos. 90-93.

25. Cf. Falsafa Arisṭūṭālīs, 98.

26. Jawāb masā’il su’il `an-hā, n. 28.

27. Ta`līqāt, n. 52; cf. Ihsā’ al-`ulūm, ch. 3, p. 103, on “practical astrology”.

28. Ta`līqāt, n. 53.

29. Ta`līqāt, n. 78.

30. Ibid., n. 2.

31. Jawāb masā’il su’il `an-hā, n. 28.

32. N. 38, 42.

33. Risāla fī l-`aql, n. 49.

34. N. 99.

35. C. 3.

36. N. 37.

37. Maqāla fī n-nafs wa-l-`aql, pp. 50, 21-20; al-Fawz al-aṣghar, p. 64.

38. Fasl ākhar min kalām-hi, p. 195.

39. Al-Fawz al-aṣghar, 75-81.

40. Risāla fī jawhar an-nafs, p. 197.

41. Fī ithbāt aṣ-ṣuwar ar-rūḥāniyya, p. 200.

42. Fī ithbāt dhālika ayan, p. 201.

43. Maqāla fī n-nafs wa-l-`aql, 62-61.

44. Al-Fawz al-aṣghar, p. 87.

45. Risāla fī l-ladhdhāt wa-l-ālām, p. 68.

46. Al-Fawz al-aṣghar, p. 101.

47. Maqāla fī n-nafs wa-l-`aql, pp. 64, 49; al-Fawz al-aṣghar, p. 126.

48. Risāla fī n-nafs wa-l-`aql, pp. 55-54.

49. P. 105.

50. Ch. 1.

51. Risāla fī l-kalām `alā n-nafs an-nāṭiqa, un des ouvrages tardifs d'Ibn-Sīnā, qui récapitule ash-Shifā', an-nafs, maqāla 5. faṣl 1-2; cf. Kalimāt aṣ-ṣufiyya, 158-160; Risāla fī bayān al-mu`jizāt wa-l-karāmāt wa-l-a`ājīb, p. 404.

52. Ash-Shifā', an-nafs, maqāla 5. faṣl 2, p. 196.

53. Mabḥath `an al-quwā n-nafsāniyya, ch. 2.

54. Ar-Risāla al-aḥḍawiyya fī l-ma`ād, 141-151.

55. Ash-Shifā', an-nafs, maqāla 1, faṣl 3; maqāla 5, faṣl 7.

56. Aḥwāl an-nafs, ch. 11.

57. Ash-Shifā': al-Kawn wa-l-fasād, faṣl 7.

58. Al-faṣl alaf, p. 274; see also al-`Ilm al-ladunī, p. 187-188.

59. Ibn-Sīnā discusses the relation between the soul and the body in ash-Shifā', an-nafs, maqāla 5, faṣl 4 = Aḥwāl an-nafs, ch. 9. fī `ilm aṭ-ṭabī`ī, pp. 158-161.

60. Ash-Shifā', an-nafs, maqāla 5, faṣl 8. See also the spurious work, an-Nukat wa-l-fawā'id fī l-`ilm aṭ-ṭabī`ī, pp. 155-156.

61. Kitāb al-farq bayn ar-rūḥ wa-n-nafs wa-quwā n-nafs wa-māhiyya an-nafs, in Rasā'il Ibn-Sīnā, 2, p. 88, 93.

62. P. 187-188.

63. P. 275.

64. Pp. 3-7.

65. Ash-Shifā', an-nafs, maqāla 2, faṣl 5 (pp. 32 ff.) enumerates the powers of the soul.

66. Ibid., pp. 154-155; ash-Shifā', an-nafs, pp. 145-171; Risāla fī bayān al-mu`jizāt wa-l-karāmāt wa-l-a`ājīb, pp. 401-403.

67. Ta`līqāt, p. 109.

68. Aḥwāl an-nafs, ch. 6; Mabḥath `an al-quwā n-nafsāniyya, ch. 8; ash-Shifā', an-nafs, maqāla 5. faṣl 3; Ta`līqāt, pp. 83-84.

69. Risāla fī bayān al-mu`jizāt wa-l-karāmāt wa-l-a`ājīb, p. 405.

70. Maqāla 5, faṣl 6, pp. 212-220.

71. Aḥwāl an-nafs, ch. 12.

72. Pp. 68-70.

73. P. 416.

74. Risāla ajwiba `an `ashar masā’il, al-mas’ala ath-thālitha, p. 78.

75. Pp. 49-52.

76. In the first edition of this work, at this point I cited an-Nukat wa-l-fawā'id fī l-`ilm aṭ-ṭabī`ī, pp. 162-163, 167. I learned later that this is not an authentic work of Ibn-Sīnā.

77. P. 4.

78. P. 188.

79. Pp. 68-70.

80. P. 416.

81. Ch. 2.

82. P. 21.

83. P. 37-38.

84. Pp. 43-44.

85. P. 416.

86. Aḥwāl an-nafs, ch. 3.

87. Mabḥath `an al-quwā n-nafsāniyya, ch. 10; cf. ar-Risāla fī s-sa`āda, p. 13; Ta`līqāt, p. 23.

88. Pp. 212-220.

89. The spurious work, an-Nukat wa-l-fawā’id fī l-`ilm at-tabī`ī, does not clearly deny habitual knowlege, as Ibn-Sīnā does in ash-Shifā’. Nevertheless it 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” (p. 167; cf. p. 172).

90. Ash-Shifā’: an-nafs, maqāla 5, fasl 6.

91. Ta`līqāt, p. 34-35, 82.

92. See also Ta`līqāt, p. 41.

93. `Uyūn al-masā’il, 9; Mabḥath `an al-quwā n-nafsāniyya, ch. 3, says that all souls (of all kinds) come “from without”.

94. Aḥwāl an-nafs, ch. 12; Mabḥath `an al-quwā n-nafsāniyya, ch. 10.

95. Ibid., 39.

96. Cf. `Uyūn al-masā’il, 7; Kalimāt as-sūfiyya, 163-164; ar-Risāla al-`arshiyya, p. 15.

97. Cf., for example, Risāla fī s-sa`āda, pp. 13-15; Ta`līqāt, 62, 101-108, 128-130, 166.

98. Cf. also the opusculum Masā’il `an ahwāl ar-rūh.

99. Kalimāt aṣ-ṣufiyya, p. 165; the word kalima is often used in this sūfic work for the human soul.

100. The explicit statement in the spurious work, an-Nukat wa-l-fawā'id fī l-`ilm aṭ-ṭabī`ī, 167, is in tune with the genuine works in the following citations.

101. Jāmi` al-badā'i`, p. 33; `āṣī, p. 284.

102. P. 418.

103. In Risāla fī māhiyya al-`ishq, p. 26; Ta`līqāt, p. 100.

104. P. 44.

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

106. Ar-Ru'yā wa-t-ta`bīr, al-faṣl hā, wā, pp. 283-288.

107. Ibid., faṣl jā, pp. 290-294.

108. Pp. 215-223.

109. Aḥwāl an-nafs, ch. 7; `Uyūn al-ḥikma, pp. 35, 38; ar-Risāla al-aḥḍawiyya fī l-ma`ād, pp. 167, 175.

110. P. 8.

111. P. 12.

112. Risāla fī bayān al-mu`jizāt wa-l-karāmāt wa-l-a`ājīb, p. 404, Risāla fī l-`uqūl, p. 416-417, and in other works of Ibn-Sīnā.

106. Ar-Ru'yā wa-t-ta`bīr, al-faṣl hā, wā, pp. 283-288.

107. Ibid., faṣl jā, pp. 290-294.

108. Pp. 215-223.

109. Aḥwāl an-nafs, ch. 7; `Uyūn al-ḥikma, pp. 35, 38; ar-Risāla al-aḥḍawiyya fī l-ma`ād, pp. 167, 175.

110. P. 8.

111. P. 12.

112. Risāla fī bayān al-mu`jizāt wa-l-karāmāt wa-l-a`ājīb, p. 404, Risāla fī l-`uqūl, p. 416-417, and in other works of Ibn-Sīnā.

114. Risāla fī l-mawt, p. 379.

115. Al-Ishārāt, nama 3, fasl 1-4; ash-Shifā’: an-nafs, maqāla 1, fasl 1; there is a similar argument in the opusculum Masā'il `an aḥwāl ar-rūḥ.

116. Aḥwāl an-nafs, ch. 4 & 9; Mabḥath `an al-quwā n-nafsāniyya, ch. 9.

117. Al-Ishārāt, loc. cit.; ar-Risāla al-aḥḍawiyya fī l-ma`ād, 153-183.

118. See, for example, ar-Risāla fī s-sa`āda, pp. 12-13.

119. Cf. Risāla ilā Abī `Ubayd al-Jūzjānī.. fī amr an-nafs; Kalimāt aṣ-ṣūfiyya, p. 166; ar-Risāla al-aḥḍawiyya fī l-ma`ād, 185-189.

120. Ta`līqāt, pp. 63-64, 110.

121. Ta`līqāt, p. 81.

122. Ibid., ch. 8; Kalimāt aṣ-ṣufiyya, 159; ar-Risāla al-aḥḍawiyya fī l-ma`ād, 125-133.

123. Ash-Shifā', an-nafs, maqāla 5, faṣl 3; cf. Ta`līqāt, 65.

124. P. 107; cf. p. 145.

125. Cf. Kalimāt aṣ-ṣūfiyya, p. 178.

126. Aḥwāl an-nafs, ch. 10; ash-Shifā', an-nafs, maqāla 5, faṣl 4; Kalimāt aṣ-ṣūfiyya, p. 167; ar-Risāla al-aḥḍawiyya fī l-ma`ād, 99-139; Ta`līqāt, pp. 65, 67.

127. P. 139.

128. Pp. 135, 207.

129. In ar-Risāla al-aḥḍawiyya Ibn-Sīnā restricts himself to answering this third category.

130. P. 7.

131. P. 14.

132. P. 159.

133. P. 189.

134. Pp. 189-190.

135. P. 91.

136. Pp. 41-43, 63-65.

137. Pp. 29-31, 67-85, 107, 205.

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

139. Maqôr ḥayyīm, 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. This criticism of ṣūfīs, which Ibn-Rushd picks up, is a frequent theme in IbnBājja; see Risāla al-wadā`, pp. 121 ff. which criticizes the Munqidh of al-Ghazālī, and Ittisāl al-`aql bi-l-insān, pp. 166-167, 171.

146. Al-wuqūf `alā l-`aql al-fa``āl, pp. 130-131.

147. Ittiṣāl al-`aql bi-l-insān, pp. 160-161; see also chapter 5, "Ibn-Bājja".

148. Pp. 138-148.

149. Pp. 149-150.

150. Pp. 150-162.

151. Pp. 188-189.

152. Pp. 178-180.

153. P. 215.

154. P. 124.

155. Tahāfut, II, p. 438.

156. Tahāfut, II, p. 622; Tafsīr mā ba`d at-ṭabī`a, pp. 1497 ff.

157. Tahāfut, II, p. 790.

158. Jawāmi` Kitāb an-nafs, pp. 54-65; the same restriction of the interior senses is found in Talkihīs kitāb an-nafs, pp. 106-120.

159. II, pp. 818-819; cf. Talkhī kitāb an-nafs, p. 120.

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

161. Pp. 407, 496, 506.

162. Pp. 488 ff.

163. Jawāmi` kitāb 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. Pp. 399-412, 448-500.

166. P. 90.

167. Pp. 121, 128.

168. P. 124.

169. Tafsīr mā ba`d at-ṭabī`a, pp. 1489-1490.

170. Talkhīs kitāb an-nafs, p. 137.

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

172. P. 130-131.

173. Kitāb an-nafs, pp. 87-93; cf. Talkhīs kitāb an-nafs, p. 145.

174. Pp. 134, 138-145.

175. Talkhīṣ as-Samā' wa-l-`ālam, pp. 306-307.

176. Dalāla al-ḥā'irīn, pp. 26-28.

177. Dalāla al-ḥā'irīn, 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.