Arabic philosophy

32 See H. Bellosta, “Cinematica,” Storia della scienza, vol. III: La civilta`

islamica (Rome: 2002), 642–6.

33 See M. Rashed, “Dinamica,” Storia della scienza, vol. III: La civilta`

islamica (Rome: 2002), 624–42.

34 See Hasnawi [194], with further bibliography.

35 See M. Wolff, Fallgesetz und Massbegriff (Berlin: 1971), and M. Wolff,

“Philoponus and the Rise of Preclassical Dynamics,” in Philoponus and

the Rejection of Aristotelian Science, ed. R. Sorabji (London: 1987).

36 See Ibn Mattawayh, Tadhkira, 488.9–11 (cf. 473.9–11): “The reason why

the fall of the light body differs from the fall of the heavy body is the air

that is in the atmosphere. Because otherwise, if we threw a stone and a

feather, they would fall in the same time. But the air prevents the light

body from falling, whereas the heavy body cuts through it.”

37 For more details on this issue, see also A. Sayili, “Ibn S¯ın¯a and Buridan

on the Dynamics of Projectile Motion,” in Ibn Sı¯na¯ : O¨ lu¨mu¨ n bininci

yılı Armaflani 1984’ten ayribasim (Ankara: 1984).

Cambridge Companions Online © Cambridge University Press, 2006

Cambridge Companions Online © Cambridge University Press, 2006

Natural philosophy 307

38 The general equivalence between the notion of mayl and i‘tima¯d was

accepted by the ancient scholars themselves (cf. Naz. ı¯f, “A¯ ra¯ ’,” 51).

39 Ibn Mattawayh, Tadhkira, 596.19–597.13.

40 Avicenna, al-Shifa¯ ’: al-t.abı¯‘iyya¯ t [Physics], vol. I, Al-sama¯ ‘ al-t.abı¯‘ı¯, ed.

S. Z¯ayid (Cairo: 1983), 325.19–326.1.

41 Avicenna, Shifa¯ ’: Physics, 212: “We say . . . that it is impossible, in

things counted and endowed with a natural or positional order (la-ha¯

tart¯ıbun f¯ı al-t.ab‘ aw f¯ı al-wad.

‘), that there be a magnitude or a number

existing that is actually infinite.”

42 Avicenna, Ta‘lı¯qa¯ t, ed. ‘A. Badawı¯ (Bengazi: 1972), 101–14, 105.6–13 in

part.

43 More on this criterion in Ibn Sı¯na¯ [Avicenna], Risa¯ la ila¯ al-wazı¯r Abı¯

Sa‘d, ed. and French trans. Y. Michot (Beirut: 2000), 32–3.

44 See A. Maier, Zwischen Philosophie und Mechanik (Rome: 1958),

12–20, and Hasnawi [195].

45 Because every instant of movement is characterized by a mayl-2, it is

useful and necessary to reform Aristotle’s doctrine and to introduce an

instantaneous movement, “the thing of which we have shown that it

is really the motion,” as Avicenna calls it (see the numerous references

collected in Hasnawi [195], 236 n. 44).

46 See Avicenna, Ta‘l¯ıq¯ at 105.14–15: wa laysa sababu istih.

a¯ latihi

awd. a¯ ‘ahu bal tawahhumahu wa ira¯datahu al-mutajaddidata tawahhuman

ba‘da tawahhumin.

47 Which explains why the criticisms of the continuists now focus on the

alleged finitism of their adversaries.

48 As it was in the Aristotelian tradition. Cf. Physics, VI, De Caelo, III.4,

303a20–4, III.7, 306a26–b2.

49 For Latin mathematical atomism, probably influenced by the

mutakallimu¯ n through the refutations of Avicenna, Averroes, and

Maimonides, see B. Pabst, Atomtheorien des lateinischen Mittelalters

(Darmstadt: 1994), 276–85 with further references.

Cambridge Companions Online © Cambridge University Press, 2006

Cambridge Companions Online © Cambridge University Press, 2006

deborah l. black

15 Psychology: soul and intellect

Most Arabic philosophers took the general inspiration for their discussions

of soul (al-nafs) and intellect (al-‘aql) from the Arabic translations

of Aristotle’s De Anima and Parva Naturalia and later Greek

commentaries on Aristotle, although a few philosophers, such as

al-R¯az¯ı, were of a more Platonic bent.1 In addition to assimilating

Greek sources into their own philosophical psychology, Arabic

philosophers were also sensitive to the need to address the competing

views of the Islamic theologians (mutakallimu¯ n), who upheld an

atomistic metaphysics in which all created beings were understood

to be mere aggregates of atoms and accidents held together by God’s

absolute power. This yielded a bundle theory of personal identity

which left no room for an immaterial soul. Such a view of human

nature was vehemently denied by the philosophers, although it was

attractive to the theologians since it allowed them to offer an account

of the revealed doctrine of the resurrection of the body.2

the nature of the soul and its relation

to the body

Unlike their theological adversaries, all the Arabic philosophers

accepted some conception of the soul derived from the Greek tradition.

In most cases it was Aristotle’s definition of the soul in De

Anima, II.1, as the first “form” or “actuality” of a body which is

potentially alive, that held sway. Under this conception, the soul is

simply the animating and organizing principle of a body and is therefore

“inseparable from the body.”3 Most of the Arabic philosophers

also accepted Aristotle’s division of the parts and powers of the soul,

according to which “soul” is an ordered genus divided into three

308

Cambridge Companions Online © Cambridge University Press, 2006

Cambridge Companions Online © Cambridge University Press, 2006

Psychology 309

species, corresponding to the division of living things into plants,

animals, and humans. The lowest power of the soul is the nutritive

or vegetative, which is common to all living bodies – plants, animals,

and humans alike; next is the sensitive soul, which belongs to animals

as well as humans; and finally the intellective or rational soul,

which is unique to human beings.

While this Aristotelian account of the soul was accepted by most

philosophers in the Arabic tradition, both al-R¯az¯ı and Avicenna took

exception to it in some way. In the case of al-R¯az¯ı, the entire Aristotelian

view of the soul and its powers was rejected in favor of

an account based in large part on Plato’s Timaeus.4 Al-R¯az¯ı accepts

Plato’s tripartite division of the soul into the desiderative, the spirited,

and the rational, and he upholds a belief in the transmigration

of souls which greatly downplays the divide between humans and

other animals. Al-R¯az¯ı also subscribes to the Timaeus’ conception of

aWorld Soul, from which all animal and human souls in the present

world have fallen, a Fall which he recounts in mythic form.5

Unlike al-R¯az¯ı, Avicenna does not reject the Aristotelian conception

of the soul outright, but he upholds a formof soul–body dualism

that is foreign to Aristotle. While Aristotle and most of his Arabic

followers allow for the possibility that the human intellect is separable

from the body, this holds for them only to the extent that the

intellect is separable from the rest of the soul as well. For Avicenna,

by contrast, the individual human soul is more than a physical entity

and organizing principle for the body. It is a subsistent being in its

own right, and a complete substance independent of any relation it

has to the body.6

This dualistic perspective on human nature is evident in many

places in Avicenna’s psychology, but the best-known of these is a

thought experiment that has come to be known as the “flying man,”

a precursor ofDescartes’ famous cogito, ergo sum argument inwhich

Avicenna attempts to show that human self-awareness is entirely

non-sensory.7 To conduct the experiment, the reader is asked to

imagine herself in a state in which all forms of sensory perception

are impossible. This means that one must bracket (1) all previously

acquired sense knowledge; and (2) all occurrent sensation. The first

is done by imagining oneself as newly created, but as a mature adult

with full rational capacities. The second is accomplished by imagining

oneself suspended in a void in such a way that one’s limbs

Cambridge Companions Online © Cambridge University Press, 2006

Cambridge Companions Online © Cambridge University Press, 2006

310 deborah l. black

do not touch each other, thereby cutting oneself off from sensing

both external objects and one’s own body (hence, the label “flying

man”). Avicenna claims that even under these conditions, each of us

would undoubtedly affirm her own existence. But that affirmation

can in no way depend upon the experience of having a body, for the

very state hypothesized in the thought experiment abstracts from all

bodily experience.8

Despite his dualism, Avicenna recognizes that there are close ties

between the soul and the body. The body serves as an instrument for

the soul, and it is a necessary condition for its creation and individuation.

While this may seem to conflict with Avicenna’s claim that

the soul is subsistent, Avicenna is forced to uphold this position

on metaphysical grounds. Unlike the separate or angelic intelligences,

each individual of which constitutes a species unto itself,

“humanity” is a single species common to many individuals, and

numerical multiplicity within a species is a function of matter.

Avicenna places the creation of human souls within the framework

of his theory of emanation. Whenever the appropriate material conditions

are present in the sublunar world (that is, whenever a human

embryo is conceived), the agent intellect concomitantly creates a

human soul to inform that body. According to this picture, then, the

true cause of the existence of the individual human soul is the agent

intellect itself, and the parents merely serve to prepare a material

body appropriate for receiving it. The soul and the body are thus made

for each other, and the soul has a special attraction to its own body,

which aids it in the performance of many of its operations. This,

Avicenna argues, also refutes theories advocating the pre-existence

of a single World Soul and transmigration, such as those upheld by

al-R¯az¯ı.

Despite the soul’s dependence upon the body for its initial creation,

Avicenna denies that the soul requires the body for its continued

existence. Upon the death of the body, the soul retains its individuality

in virtue of its own intrinsic substantiality, and because

of the persistence of individuating characteristics that defined its

embodied life. The very fact of having been born with a particular

body and having uniquely individual experiences while in that body

affects the soul itself. Different souls thus achieve different levels

of perfection through the use they make of their individual bodies,

and those differences will remain after death.9 Thus, Avicenna alone

Cambridge Companions Online © Cambridge University Press, 2006

Cambridge Companions Online © Cambridge University Press, 2006

Psychology 311

among the fala¯ sifa upholds the personal immortality of the individual

human soul.

soul as a principle of cognition

One of the most important functions of the soul is to serve as the

principle of cognition, both sensitive and intellectual. In the Arabic

tradition, the divide between the senses and the intellect was a fundamental

assumption of all cognitive psychology, and the contribution

of the senses to human knowledge was always subordinated to that of

the intellect, on the grounds that sensation is always of the particular

and operates through a bodily organ, whereas true knowledge is of the

universal. Despite their professed devaluation of sense-knowledge,

however, some of the most original developments in Arabic philosophy

arise from the efforts of Arabic philosophers to explain the nature

and mechanics of sense-perception.

Moreover, while a deep chasm is posited between sense and intellect

in terms of their cognitive value, the Arabic philosophers offered

a general theory of the nature of cognition that was applicable to

both sensation and intellection. The ultimate foundation of their

theory was Aristotle’s description of cognition as the reception of

the form of the perceived object without its matter.10 The result

of their attempts to explain and expand upon this remark was the

theory that intentionality is the mark of cognition.

“Intentionality” is a concept that continues to influence contemporary

philosophy of mind, where it refers to the directedness of

mental states toward objects, and it has a similar meaning in its original

usage in Arabic philosophy. In the technical terminology of the

Arabic philosophers, an “intention” (ma‘nan) – literally a “meaning”

or an “idea” – is a formor essence insofar as it is apprehended by any

cognitive faculty and serves as an object for that faculty. There are

thus different types of intentions corresponding to the various cognitive

faculties – color and sound are sensible intentions, for example;

images are intentions in the faculty of imagination; and universal

concepts are intelligible or understood intentions. The exact origins

of the philosophers’ concept of intentionality are unclear, and no

completely satisfactory explanation has been offered. One important

precedent comes from the Islamic mutakallimu¯ n, for whom

ma‘nan was one of the technical terms for accidents.11 As for the

Cambridge Companions Online © Cambridge University Press, 2006

Cambridge Companions Online © Cambridge University Press, 2006

312 deborah l. black

English term “intention,” it came to be applied to the Arabic concept

through the use of intentio as the medieval Latin translation of

ma‘nan. While not a literal rendition of the Arabic, the term nicely

reflects one of the few explicit definitions of intentionality offered by

Avicenna inhis Interpretation. According to this definition,ma‘a¯nin

are “what is intended by the soul” (maqa¯ s. ida li-al-nafs), that is, they

are the things that linguistic expressions are meant to signify.12 For

Avicenna intentionality is interpreted as the mental existence of the

formor quiddity that is perceived in the soul of the perceiver, and it is

closely connected to his metaphysical distinction between essence

and existence.13 While Averroes rejects the metaphysical basis for

Avicenna’s understanding of intentions, he too upholds the thesis

that as sensible, imagined, or intelligible intentions, the forms of

the objects that we know can be said to exist in some way in our

souls, so that all cognized forms have two “subjects.” One subject,

the “subject of truth,” is the object to which the cognitive act refers,

and by which its truth or falsity is determined, ultimately, the extramental

thing itself. The other subject, the “subject of existence,” is

the faculty inwhich the form exists as an intention, be it the senses,

the imagination, or the intellect.14

In addition to providing the foundation for the Arabic theory of

intentionality, the claim that cognition involves the reception of

form apart from matter also led the Arabic philosophers to interpret

not only intellectual cognition, but also sensation, as a type of

abstraction (tajr¯ıd). Hence all cognition came to be viewed as a hierarchy

of grades of abstraction beginning with the senses and reaching

its apex in the intellect. The abstractive hierarchy receives its

first explicit formulation with Avicenna, who defines “perception”

(idra¯k) as the “grasping (akhdh) of the formof the thing apprehended

in some way,” adding that “the kinds of abstraction vary and differ in

degree.”15 Avicenna identifies four grades of abstraction, with sensation

the lowest, intellection the highest, and the two middle grades

occupied by the faculties which were known in the Arabic tradition

as “the internal senses” (al-h. aw¯ ass al-b¯ at.

ina).16

The doctrine of the internal senses is an attempt to expand and systematize

Aristotle’s account of the pre-intellectual capacities of the

soul that could not simply be explained as functions of the five external

senses of vision, hearing, smell, taste, and touch. Among these

capacities were the common sense (koinˆe aisthˆesis), the imagination

Cambridge Companions Online © Cambridge University Press, 2006

Cambridge Companions Online © Cambridge University Press, 2006

Psychology 313

(phantasia), and memory. The doctrine of the internal senses also

drew upon later Greek developments in physiology stemming from

the physician Galen. Like the external senses, the internal senses

require a bodily organ to performtheir operations, usually identified

as the brain, following Galen, or less frequently the heart, following

Aristotle.

The theory of the internal senses is not yet evident in al-F ¯ar¯ab¯ı’s

writings of undisputed authenticity.17 Al-F¯ar¯ab¯ı presents instead a

sparse Aristotelian scheme that includes the common sense power,

which is assigned the task of collecting and collating the information

provided by the five senses, and the imagination, both of which are

localized in the heart rather than the brain. Initially, al-F ¯ar¯ab¯ı assigns

two functions to the imagination, the capacity to retain sensible

impressions when the external object itself is absent, and the ability

to compose and divide these retained impressions into combinations

that may or may not represent real objects in the external world. To

these two he later adds a third function, “imitation” (muh. a¯ka¯ t), by

which he seems to mean the depiction of an object by means of

an image other than its own. To imitate x, then, is to imagine x by

depicting it under sensible qualities that do not describe its own sensible

appearance. Through imitation, the imagination can represent

not only sensible bodies, but also bodily temperaments, emotions,

and even abstract universals, as happens when evil, for example, is

symbolized by the image of darkness.18 The imitative capacities of

imagination are also the foundation for al-F ¯ar¯ab¯ı’s characterization

of the prophet, that is, the founder of a religion. In virtue of possessing

a strong imaginative faculty, the prophet is able to receive an

“overflow” of intelligibles into his imagination, where they become

subject to symbolic imitation. Through these symbols and images,

the prophet can communicate abstract truths in concrete terms that

can be understood by simple believers.

The full spectrum of internal sense powers makes its first appearance

in the works of Avicenna, who posits five internal sense powers,

each assigned to its own location within the ventricles of the brain.

Avicenna justifies his positing of each of these sense powers by a set

of principles for differentiating psychological faculties. Of these principles,

two are fundamental. The first is the claimthat the reception

and retention of sensibles must be functions of distinct faculties, a

principle supported by the observation that in the physical world

Cambridge Companions Online © Cambridge University Press, 2006

Cambridge Companions Online © Cambridge University Press, 2006

314 deborah l. black

what receives an imprint easily, for example, water, does not retain

that imprint well. The second is the claim that a diversity of objects

diversifies faculties. The most innovative and influential part of

Avicenna’s theory of the internal senses is his assertion that perceptual

objects are of two types. One sort of perceptual object is a

sensible form, that is, an image of one of the five proper sensibles

of color, sound, taste, smell, and texture, or an image of one of the

common sensibles, objects perceptible by two or more senses, such

as motion, magnitude, and shape. The other sort of object is one that

Avicenna calls an “intention” (ma‘nan), using the same term that

Arabic philosophers had adopted to signify the object of any cognitive

faculty.

In the context of the internal senses, Avicenna defines an “intention”

as a property which is not essentially material or sensible, but

which in some way accompanies a sensible form. Avicenna often

illustrates this with the example of the sheep’s instinctive perception

of hostility in the wolf. “Hostility” is not itself a sensible form

like color or motion, but it must still be an object of sense perception

in some way, for animals perceive intentions of this sort. Indeed, it

is our observation of animal behavior and the underlying perceptual

capacities that such behavior presupposes that requires the positing

of an internal sense faculty for grasping intentions, since animals do

not have reason or intellect. Avicenna calls the faculty which grasps

intentions “estimation” (wahm).19 Nonetheless, Avicenna does not

confine estimation to animals, and humans too have an estimative

faculty. Nor does Avicenna limit estimative intentions to affective

properties such as hostility and friendliness. Rather, the estimative

faculty ultimately functions as the animal analogue to the intellect,

directing and controlling all the judgments of the sensitive soul and

allowing it to associate sensible descriptionswith individual objects,

a capacitywhich Aristotle calls “incidental” perception, for example,

my perception of the white thing as Diares’ son.20

From the principles we have examined, Avicenna deduces four of

the five internal sense faculties: the common sense receives, distinguishes,

and collates sensible forms from the external senses,

and they are then stored in the retentive imagination (al-khaya¯ l),

sometimes called the formative faculty (al-mus.

awwira); estimation

receives non-sensible intentions, and they are retained in the memorative

faculty. Avicenna also posts a fifth internal sense power, the

Cambridge Companions Online © Cambridge University Press, 2006

Cambridge Companions Online © Cambridge University Press, 2006

Psychology 315

compositive imagination (al-mutakhayyila), which is the ability to

manipulate images and intentions rather than receive them passively