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Chapter Six: Ibn Sina

Life and Works

Ibn Sina, Avicenna (370/980-429/1037), also known as al-Ra’ is (“Master and Head”) is among the very few medieval Muslim thinkers to have written an autobiography, which was completed by his student Abu Ubayd al-Juzjani.² This autobiography was later transmitted by a number of biographers, including al-Bayhaqi (d. 565/1170), al-Qifti (d. 646/1248), Ibn Abi Usaybiah (d. 669/1270) and Ibn Khallikan (d.680/1282).

Ibn Sina was born in Afshanah (a small village neighbouring Bukhara, the capital of the Samanid dynasty), where his farther ‘Abd Allah, originally from Balkh, met and married Sitarah. They had three sons, ‘Ali, al-Husayn (Ibn Sina) and Mahmud. When Ibn Sina was about five years of age, the family moved to Bukhara. There the farther was appointed governor of Kharmayathnah, a village in the suburbs of Bukhara.

The rest of the story of Ibn Sina’s life, education and career is well known, and there is no need to recount it here in detail. Suffice it to say that the most striking features of this story, as he and al-Juzjani tell it, are (1) his completing the study of the Qur’an and Islamic literature by the age of ten and the rest of the sciences, including Islamic law, astronomy, medicine, logic and philosophy, by the age of eighteen, and (2) his enormous productivity in spite of the unstable political conditions under which he lived that forced him at times to flee from one territory to another, to move in disguise and even to be imprisoned. His great achievement in the various branches of learning seems to have resulted from a rare memory that enabled him to retain by heart, for example, the Qur’an and Aristotle’s Metaphysics; a high intellectual curiosity that helped him consider and solve difficult problems even in his sleep; and an inner determination that generated extraordinary physical and intellectual energy. The number of works he wrote (estimated to be between 100 and 250), the quality of his work and his involvement in medical practice, teaching and politics all reveal an unusual level of competence.

At a very early age, Ibn Sina was introduced to various religious, philosophical and scientific teachings. For example, he was introduced to the Epistles of the Brethren of Purity and Isma’ilism by his father, who was a member of this sect. He was also exposed to the Sunni doctrine, as his fiqh teacher Ismail al-Zahid, was a Sunni, and to Twelve-

Imam Shi’ism. In addition, he was given some background in logic, geometry and astronomy by his other teacher, al-Natili. He exercised his independence of though very quickly, however. First, he dispensed with reaches, continuing his education on his own; and second, he did not adhere to any of the doctrines to which he was exposed.

Rather, he drew on various sources, selecting only what he considered convincing. Thus, we see in his system traces of Platonism, Aristotelians tendency, is not purely Aristotelian, as it is usually considered. The theory of creation, for example, which is basically Neo-Platonism, and that of prophecy, which is Islamic in essence, they are but two examples of its many non-Aristotelian teachings. Al-Juzjani confirms the uniqueness of this work and asserts that it is nothing but the product of Ibn Sina’s own thought.6 Ibn SIna himself makes a similar point, stressing his originality in this work, especially, in the Logic and Physics.7

The most important of Ibn Sina’s books are al-Qanun fi’l-tibb (“The Canon of Medicine”), al-shifa’ (“Healing”), al-Najah (“Deliverance”), ‘Uyun al-hikmah (“Sources of Wisdom”), Danishmama-yi- ‘ala’i (“the book of Science Dedicated to ‘Ala’ al-Dawlah”) and al-Isharat wa’l-tanbihat (“Remarks and Admonitions”). Al-Qanun fi’ltibb consists of five parts. Translated into Latin a number of times, it was considered the most important medical source both in the East and in the West for about five centuries (i.e., until the beginning of the eleventh/seventh century) and continues to be the primary source of Islamic medicine wherever it is practiced to this day, such as the Indo-Pakistani subcontinent. The enormous amount of material in al-Shifa’, which is the most detailed philosophical work of Ibn Sina, is grouped under four main topics: Logic, Physic into eight, and Mathematics into four. Physics (with the exception of the two parts dealing with animals and plants, which were completed after Mathematics) was the first to be written, followed by Metaphysics, then Logic, and finally Mathematics. Al-Najah, which is a summary of al-Shifa’, also consists of four parts. The Logic, physics and Metaphysics of this work were prepared by Ibn Sina and the Mathematics by al-Juzjani. ‘Uyun al-hikmah, known also as al-Mujaz (“Epitome”). Seems to have been intended for class instruction in Logic, physics and metaphysics. This is evident from the simplicity, clarity and drevity with which the work is presented. Danishmama-yi ‘alai also consists of four parts and is particularly significant in that it is the first work of Islamic Peripatetic philosophy in the Persian language. Al-Isharat wa’l-tanbihat, which is the most mature and most comprehensive philosophical work of Ibn Sina, also consists of Logic, Physics and Metaphysics. It closes with a treatment of mysticism, a treatment in its Sufi sense than metaphysics. In addition, Ibn SIna left a number of essays and poems. Some of his most important essays are Hayy ibn Yaqzan (“The Living Son of the Vigilant”), Risalat al-tayr (“the Epistle of the Bird”). His most important poems are al-Urjuzah fi’l-tibb (an iambic poem on medicine),8 al-Qasidat al-muzdawijah (anode in couples)9, and al-Qasidat al-‘dat al-ayniyyah (an ode whose verses end with the letter’).10 He also wrote a number of Persian Poems.

Division of sciences

Ibn SIna understands “the purpose of philosophy to be the determination of the realities of all things, inasmuch as that is possible for a human being”. There are two types of philosophy, theoretical and practical. The former seeks knowledge of the truth; the latter of the good. 12 The purpose of theoretical philosophy is to perfect the soul through knowledge alone.

The purpose of practical philosophy is knowledge of what must be done; so that the soul acts in accordance with this knowledge 13 Theoretical philosophy is knowledge of things that exist not owing to our choice and action. Practical philosophy is knowledge of things that exist on account of our choice and action.

The individual subjects of theoretical knowledge are of two main types: those to which movement can be attached, such as humanity, queerness and unity and those to which movement cannot be attached, such as God and the intellect. The former are again divided into those that cannot exist unless movement is attached to them, such as humanity and sugariness; and those that can exist without any movement being attached to them, such as unity and multiplicity. The former of the last two types is either such that it cannot be free movement either in reality or in though (e.g., humanity and horsiness), or such that it can be fore from movement in thought but not in reality (e.g., sugariness). 14

There are, therefore three branches of theoretical philosophy: that which deals with things inasmuch as movement is attached to them both in reality and in thought; that which deals with things inasmuch as movement is attached to them in reality but not in thought; and that which deals with things inasmuch as movement is attached to them neither in reality nor in though, regardless of whether movement can be attached to them, as in the case of unity, or cannot be attached to them, as in the case of God. The first is physics, the second is pure mathematics and the third is metaphysics. 15

Practical philosophy, on the other hand, is concerned with learning one of the following: (1) the principles on which pubic sharing among people is based, (2) the principles on which personal sharing among peoples is based, or (3) the principles on which the affairs of the individual are based. The first is the management; 16 and the third is management of the individual, referred to as ethics.17The principles of practical philosophy are derived from the divine shari ah, and its complete definitions are made clear by the divine Shari’ah.18

The benefit of the science of management of the city is to make known the manner in which sharing among people accurse for the purpose of the well-being of the human body and of the preservation of humanity.

The benefit of the science of home management is to make known the type of sharing that must take place among the members of the same home in order to ensure their well-being. Such sharing occurs between husband and wife, and child, and master and slave. The science of management of the individual yields a twofold benefit-tomakeknown the virtues and the manner of acquiring them in order to refine the soul, and to make known the vices and the manner of avoiding them in order to purify the soul.19

Only an outline of the most important aspects of Ibn SIna’s philosophy can be provided here. The most essential elements of this logic, which he considers the introductory part to philosophy, 20 are discussed in Chapter 48 below. Only a sketch of his general logical scheme will be given in this chapter.

Logic

Ibn Sina considers logic as the key to philosophy, whose pursuit (knowledge) is the key to human happiness. Logic performs this function by helping to derive unknown concepts and judgments from known ones, thus increasing our degree of knowledge (concepts are mental objects with no affirmation or negation; judgments are mental objects with affirmation or negation). Logic does this by acting as a set of rules for distinguishing the valid from the invalid explanatory phrases, which embody concepts and are the instruments for moving from known concepts to unknown ones, and proofs, which embody judgment and are the instruments for moving from known judgments to unknown ones. Since the valid leads to certitude and the invalid to falsehood, knowledge is attained only through the use of logic, except when, on rare occasions, God provides this knowledge without any human effort. 21

While the logician’s function is to open the way for the knowledge of the natures of things, he or she is not concerned with such natures in themselves or as they exist externally or in the mind but only with concepts, representing these natures under the aspect of being subject or predicate, individual or universal, essential or particular. 22 Only when the concepts, of the natures of things are considered inasmuch as they have certain states and a certain relationship to each other can they help to move though from the known to the unknown. Even though the primary concern of the logician is concepts inasmuch as they are arranged in a certain manner, the logician must deal with expressions, as arranged in a certain manner; the logician must deal with expressions, as they are the only way to reason about or to communicate concepts. 23 With this in mind, Ibn Sina opens his logical treatises with discussions, of expressions, beginning with single expressions, the smallest elements of the explanatory phrase and proof.

As the ultimate goal of the logician is to pave the way for knowledge of the natures of things, universal expressions that mirror universal concepts, which in turn mirror these natures, must be his or her concern.

That is why most of the discussion of the single expression focuses on the study of universal terms (the five periodical): genus, species, difference, property and common accident. The main types of the explanatory phrase, of a genus and a differences, is said to be the most reliable form of the explanatory phrase.

The proof, which utilizes explanatory phrase as its parts these are the propositions or premises - is of three types: syllogism, induction and analogy. The conjunctive, the conditional and the exceptive. The propositions that form the premises of the various types of the syllogism fall into nine categories. Each of these categories derives its assent or judgment from a different source, which will be indicated here in parentheses following the name of the category of propositions: sensible (from the external senses only); experiential or observational (from memory of repeated sense experience); based on unanimous traditions (from multiple testimonies); received (from scholars or respected religious leaders); estimative (from the estimative power); widespread (from being widely known); presumed (from the realization that the opposite is possible); imagined (from resemblance to propositions involving assent); primary (from the clarity of reason). 24

Demonstrations is the most reliable form of the syllogism composed of propositions characterized by certainty, it leads to a conclusion with certainty. Such propositions are primary, experiential, sensible or widely known. A demonstration requires three elements: those principles with which the demonstration is made (the premises), those issues that are the object of demonstration (the problems), and those subjects in which demonstration is made.

Ibn Sina usually closes his logical discussions with a study of ambiguities, whether in expression or in meaning.

Physics

Physic is concerned with the study of certain principles and of the things that are attached to natural bodies. These intellect is considered a natural principle inasmuch as it is the cause of holding matter and form together and, as such, is the relation to the physics realm is the agent intellect discussed in physics, and not inasmuch as it has such and such a nature or such and such a relation to separate principles or intelligible. The things that are attached to natural bodies include motion, rest, time, place, void, the finite and so forth.

For example, every natural body is said to have a natural place and a natural shape. All natural motions lead to a creative, circular motion belongs to the heavenly bodies, which are followed by the bodies that are subject to generation and corruption. This first of the latter type of bodies in existence is the four elements: water, air, fire and earth. These elements are subject to the celestial influences. 26 When the four elements come together, their mixtures vary in temperament owing to the influence of the celestial powers. This variation in temperament results in the composition of these elements: minerals, plants and animals (the last and highest of whom are human beings). The closer their temperament is to equilibrium, the higher the form of the natural body. For this reason, there is a gradation in being from minerals to plants to animals, as well as a gradation of the various kinds subsumed under every level of these three types of being. The closest temperament to equilibrium causes the existence of human bodies, which have the highest form in the terrestrial sphere -this form being the human soul. This kind of soul is defined as “a primary perfection of an organic, natural body to which it belongs to perform acts of life”. 27Primary perfection is what gives actuality to the species of a thing, as shape gives actuality to the sword. This is to be contrasted with secondary perfection, which is what gives actuality to the actions and reactions that follow upon the species, as does cutting for the sword. 28 The discussion of the soul takes up a large portion of Ibn Sina’s Physic. We are told that if the function of the soul is limited to nutrition, growth and reproduction, it is a mere plant soul. 29 If sensation and movement are added to these, then it is a mere animal soul. 30 The soul of a human being includes these, but has a practical and the theoretical faculties or intellects. 31 When this rational part occurs to a being, that being becomes a human being. 32 Through conjunction with the agent intellect that contains the intelligible, the theoretical part of the rational soul receives its proper perfection, the perfection that makes it what it is. This perfection is the best thing a human being can achieve; at it is the best thing for any being to achieve is proper perfection, which completes its nature.

A brief discussion of the animal and rational souls is now in order, given the important role that they play in achieving this perfection. As mentioned, the animal soul has sensation and movement. The sensitive part consists of the external and the internal senses. The external senses are, in order of necessity for animals, touch, taste, smell, hearing and sight. The internal ones are common sense, representational faculty, imagination, estimative faculty and memory. The common sense is the faculty in which external sensations or forms of external objects collect. It is the faculty that enables us to judge, for example, the honey is sweet when we perceive honey visually, without the gustatory sensation that it is sweet. The reason is that the faculty of common sense simultaneously receives from the different external senses the different sensations of the one external object, which we call honey. This makes it possible for us to distinguish between the yellow colour and the sweet taste of honey, while realizing at the same time that they belong to the same object. The representational faculty retains the forms that the common sense receives from the outside. The objects In contrast, the objects of the common sense are present only when the external objects are there - except in rare cases when they are poured into the common sense from the internal senses, which either manufacture them or receive them from the divine world. 33 The estimative faculty is said to grasp sense notions that are different from the sense forms grasped by the common sense. These notions are exemplified by the lamb’s fear of the wolf. The memory retains the notions of the estimative faculty, as the representational faculty retains the sense forms. Finally, the imagination combines some objects of the representational faculty and of memory with each other, while separating the rest from each other. It must be mentioned that this faculty is called imagination, but only if employed by the estimative faculty. If it is employed by the intellect, it is called cognition. 34The locomotive part of the soul is responsible for the motion of the organs by means of the nerves and muscles due to the will. This motion is assisted by primary and secondary instruments. The primary ones, which concern us here, are either the imagination or the rational soul. These cause inclination either in the direction of or away from a perceived object. Inclination in the direction of an object is for an object that is imagined or presumed to be useful.

When a power expresses such an inclination, it is called appetitive, which the inclination itself is called a petition.

Inclination away from an object is for an object that is imagined or presumed harmful. When a power expresses such an inclinations. It is called irascible, while the inclination itself is called anger. Both intellection and motion are affected by the condition of their instruments. If, for example, the instrument of sight is diseased or has aged, then sight declines or disintegrates totally. 35 The human or rational soul performs either bodily actions and reactions, or purely intellective actions. The former do not belong to it and proceed from it and the body, whereas the latter belong to it and proceed from its essence.

The actions that the rational soul performs in conjunction with the body are exemplified by consideration of the particular matters that must be done or avoided voluntarily, including the practical crafts such as carpentry, farming and animal husbandry. Reactions, on the other hand, are states consequent upon the preparations of the body and the rational soul, such as the preparation for crying or shyness. The purely intellective acts, which are performed by the rational soul, consist of grasping the quiddities or natures of things as universal concepts, such as “humanity” and “horsiness”. Such concepts cannot be grasped by any of the external or internal powers, for these powers belong to the animal world and thus whatever they grasp must be to some degree material and particular. 36 Contrary to the animal powers, the rational soul can grasp the quiddities or natures of things apart from matter and particularity. From such universal concepts, it composes judgments possessing certainty.

As mentioned, the rational soul has two parts, one with a capacity for action and the other with a capacity for action and the other with a capacity for knowledge. The former, called the practical intellect, is directed towards the body. With it, one can distinguish between what must and what must not be done, as well as between good and bad particular things. This intellect is perfected through habits and experiences. The latter, called the theoretical intellect, is directed towards the divine world and enables one to receive the intelligible. 37

The theoretical intellect passes through four stages. Firstly, it is in potentiality and has not yet formed any concepts or grasped any intelligible. This is the potential or material (al-aql al-hayulani). This intellect is called material, not because it is material in nature but because it has the capacity for receiving intelligible forms as matter has the capacity for receiving material forms.

Secondly, it is this potentiality actualized by the occurring of primary intelligibles in it.

This is the habitual intellect (al-aql bi’lmalakah).

Thirdly, it is the acquisition of the intelligibles made constant. This is the actual intellect (al-aql bi’l-fi’l). Fourthly, it is these intelligibles themselves. This is the acquired intellect (al-aql al-mustafad). 38

For a thing to move from potentiality to actuality, another thing, which is already in actuality, must give it the form that actualizes it. What body, because it must already possess the intelligible forms, which are non-material and which it gives to our theoretical intellect. Therefore it must be an intellect-this intellect being the agent intellect. The agent intellect sheds its light on the objects of our imagination, which have been received originally from the external world, thus making them visible to our theoretical intellect, as the sun sheds its light on the external things, thus making them visible to our sight. When the light of the agent intellect reaches the objects of the imagination, it renders them intelligible to our theoretical intellect by abstracting them from matter. 39

Since the rational soul can receive the intelligible forms, it must be in its substance of the nature of these forms. If what receives the intelligible forms were a body or a power in a body, these forms would be divisible, and a simple form could not be intelligible. Arguments are advanced to show that the idea that the rational soul is immaterial. 40 It follows that the rational soul is simple, for multiplicity lies in materiality. Because it is simple, it is indestructible. Contrary to Alexander of Aphrodisias and al-Farabi, who believe that the only human soul assured of indestructibility is that which knows at least some realities -that which is completely deficient in such knowledge is eventually destroyed-Ibn SIna considers all human or rational souls to be indestructible? To him, knowledge of the realities of things is necessary only for happiness but not for existence after death.

Metaphysics

Metaphysics 41is the science that provides knowledge of the principles of theoretical philosophy. This it does by demonstrating through the intellect the complete acquisition of these principles.42 Metaphysics deals with the existent inasmuch as it exists, that is, with the general or absolute existent and what is attached to it. In other words, the subject of metaphysics is the existent, not inasmuch as it applies to some things and inasmuch as something particular is attached to it, as in physics and mathematics (such as quantity and quality, action and reaction, which are attached to the objects of physics) but inasmuch as it applies to the principle of existence and inasmuch as something universal is attached to it (such as unity and multicity, potentiality and actuality, eternity and coming into being, cause and effect, universality and particularity, completeness and incompleteness, necessity and possibility). 43 These qualities are essential accidents of the particular existent. We understand from Ibn Sina’s logic that an essential accident is one that does not constitute or enter into the essence of a thing, yet necessarily accompanies it, as “laughter” for “human being”. A nonessential accident neither constitutes the essence of a thing nor necessarily accompanies it; however, it resides in it, as “white” may reside in “human being”.

The existent is either substance or accident. A substance is anything that is not in a subject, whether or not it is in matter. Thus substance is of two main types: (1) that which is in matter, and (2) that which is not in matter. The latter category is broken down into three types (2a) matter, (2b) that which is accompanied by matter, and (2c) that which is neither matter nor accompanied by matter. This scheme means that substance is of four types: (1) form in matter, as the soul is in the body (2a) matter with no form-this is absolute matter, which has no existence in actuality but only in conception; (2b) the composite of form and matter, as the human being is a composite of soul and body, (2c) form separate from matter, as God or any intellect is neither matter nor in contact with matter. 44Accident on the other hand, is in a subject and is divided into nine types: quality, quantity, relation, time, place, position, condition, action and reaction.

The existence of a thing is either necessary or possible (contingent). Necessary existence is such that if the thing to which it belongs is assumed to be non-existent, impossibility arises. Possible existence is such that if the thing to which it belongs is assumed to be non-existent or existent, no impossibility arises. 45Ibn Sina mentions that in other contexts “possible, existence” could also be used in the sense of “being in potentiality”. 46Necessary existencesare either that which always belongs to a thing through that thing itself, or that which always belongs to it through another. For example, the existence of burning is necessary, not because of the burning itself, but because of the meeting of two things, one naturally capable of burning and the other naturally capable of being burnt. 57 What is necessary through itself cannot be necessary through another and conversely. For example, if the existence of A is necessary through A, itself, this existence cannot be necessary through B.

Similarly, if it is necessary through B, it cannot be necessary through A, itself. This is to say that if, is the second case, one considers A in itself, one finds its existence non-necessary, or possible in itself. If this is not the case, its existence would be either necessary in itself, but this has been denied, or impossible without another. Its existence through another is other than its existence without another. By the former, it is necessary; by the latter, it is possible. 48

The existence of a being necessary in itself is determined on the basis of two principles: first, the chain of possible beings at any time cannot be infinite, thus, it must lead to a necessary cause external to this chain - this cause being the Necessary Existent or Being, otherwise known as God.

Being eternally prior in existence to everything and the source of the existence of everything, this Existent is said to be the first cause. 50 It is free from matter, one and simple in all respects. 51 Thus it has no genus or difference, the two necessary elements of a definition. Therefore there is no definition of it, but only a name. Being immaterial, it is purely good, for only in matter, the source of privation, does evil lie.52 Owing to its immateriality, it is also an intellect, and, owing to its simplicity, the intellect and the intelligible in it are one.53 In itself, it is the Beloved and the Lover, the pleasurable and the pleased. It is the Beloved because it is the highest Beauty. It is the highest beauty because there is no highest beauty than that of being a pure intellect, above all manner of deficiency, and one in all respects. Suitable and apprehended beauty or goodness is desired and beloved. The more the apprehended is beautiful, the more the power of apprehension loves it and finds pleasure in it. 54

Thus the Necessary Being, who is most beautiful, perfect, and best, who apprehends itself at this ultimate beauty and goodness and in the most complete manner of apprehension, and who apprehends the apprehender and the apprehended as one in reality is in essence, and by its essence, the greatest lover and beloved and the greatest thing pleased and pleasurable.

From this Necessary Being the rest of the existing things overflow through the process of emanation. The first things that emanate are the celestial intellects, followed by the celestial souls, the celestial bodies and finally terrestrial beings. All these things emanate from it in eternity; otherwise, a state would arise in it that was not there before. But this is impossible in a being whose existence is necessary in all respects. 56 This emanation is a necessary outcome of God’s Essence and cannot be linked to any intention external to His Essence. Firstly, there is nothing in Him external to His Essence-He is a total simplicity, but He can be considered from different points of view. It is only by virtue of such consideration that one can speak of His Attributes. Secondly, even if it were possible for Him to have among such Attributes any intention relating to the world. “The reason is that every intended.

This is because if a thing is for the sake of another, that other is more complete in existence than it.” 57 This is to say that whatever is more complete in existence then another cannot intend that other.

God, therefore, cannot intend the world or anything in the world, since He is more complete in existence than the world.

Even though neither God nor any other cause can be perfected essentially by its effects and therefore cannot intend its effects or anything for them, still it may lead accidentally to beneficial effects and, if it is divine, know and be pleased with these effects. Health, for example, is such “in substance and essence, not to benefit the sick; but it results in benefiting the sick”.

58Similar to health, superior causes are what they are in themselves, not to benefit anything else; but they do benefit other things accidentally. They differ from health, though, in that they know the things that exist. 59Still, providence is attributed to God, the first cause of all things. Providence must be understood, however, not in the sense of divine guidance of the world or concern about it. Rather, providence is defined as God’s knowledge of the order of existence and the emanation of this order inasmuch as that is possible, and His being pleased with it. 60

Ibn Sina’s thought had a clear and strong impact on the East and on the West, in science, literature and philosophy. The impact of his philosophical thought, which concerns us here, was exhibited in a large number of commentaries on his works and in other forms of writings it. The best known of such commentaries are thoseof Ibn Kammunah, Fakhr al-Din al-Razi and Nasir al-Din al-Tusi on al-Isharat, and Sadr al-Din al-Shirazi on part of al-Shifa’. Among the most prominent Eastern thinkers whose thought reflects that of Ibn Sina are al-Tusi, Suhrawardi, Qutb al-Din al-Shiraz, Mir Damad, Sadr al-Din al-Shirazi (Mulla Sadra) and the Syriac Christian Ibn al-Ibri.

Suhrawardi’s and al-Shirazi’s theories of illumination, for example, stem from Ibn Sina’s “Oriental philosophy”. Also, their discussions of being and essence were generated by Ibn Sina’s view on this subject.

Ibn al-Ibri too adheres closely to Ibn Sina’s analysis of God’s relationship to the world, the presence of evil, and the nature and unity of the human soul as well as the impossibility of the soul’s pre-existence and transmigration. 61

But, as mentioned, not all those who felt the effect of Ibn Sina’s thought responded to it positively. Ibn Sina had his strong critics, such as al-Ghazzali and al-

Shahrastani in the East, and William of Auvergne and Thomas Aquinas in the West.

These critics rejected primarily his ideas concerning God’s nature, knowledge of particulars and relationship to the world, as well as the eternity of the universe and the denial of the resurrection of the body. Also, Ibn Rushd, who in his major work, The Incoherence of Incoherence, seeks to defend philosophy as embodied primarily in Ibn Sina’s works, charges that Ibn Sina misunderstood and distorted Aristotle at times.

Such opposition to Ibn Sina’s ideas, however, did not prevent even these critics from borrowing heavily from him. Al-

Ghazzali’s logic and philosophical terminology, to give but two examples, are, for the most part, those of Ibn Sina. Also, the distinction Ibn Sina introduced in his theodicy, for example, between evil in itself and evil for another was borrowed by Aquinas and from him by Suarez. Because Ibn Sina’s works are not sufficiently know in the West, however, the credit for this distinction is given in the West to Aquinas.

Furthermore, two of Aquinas’s well-known proofs of God’s existence, that from efficiency and that from contingency, as well as his distinction between essence and existence, were also borrowed from Ibn Sina. The numerous references Aquinas gives to Ibn Sina in Being and Essence and elsewhere is sufficient to show the influence Ibn Sina had on his prominent Christian philosopher and theologian whose ideas dominated Western thought for so long. Gundissalinus, Albert the Great and Roger Bacon are also among the Western thinkers whose work reflected elements of Ibn Sina’s thought, especially with regard to the nature of the human soul. No doubt the following factors facilitated Ibn Sina’s influence on Latin philosophical circles; first, the translation parts of al-shifa’s as early as the twelfth and thirteenth Christian centuries; and, second, Ibn Sina’s efforts to synthesize Greek and Islamic though, an attempt in which the West found the seed for a synthesis between Greek Philosophy and Christianity.

Notes

1- His full name is Abu ‘Ali al-Husayn ibn ‘Abd Allah ibn ‘Ali ibn Sina - Abu ‘Ali being his nickname. Perhaps his titles, Master and Head, refer respectively to his prominent rank in learning and his high political position as a vizier (A. F. al- Ahwani, Ibn Sina (Cairo, 1958): 18). This would correspond to his other title, al-Hakim al-Wazir (Wise man and Vizier). He was also known as Hujjat al-Haqq (Proof of the truth).

2- He was one of Ibn SIna’s closest students, who accompanied during most of his later life. For a translation of his bibliography see W.E. Golham, The Life of Ibn Sina (Albany, 1974).

3- See Z.D. al-Bayhaqi, Tarikh hukama’ alislam, ed. M. K. ‘Ali (Damascus, 1976): 52-72; A.H. al-Qifti, Tarikh al-hukama. ed. J. Lippert (Leipzig, 1903): 413-26; I.A. Usaybi’ah, ‘Uyun al-anba’ fi tabaqat alatibba’, Part Three, ed. Samith al-Zayn (Beirut, 1987): 2-28; I. Khallikan, Wafayat al-a’yan wa anba’ abna’ alzaman, Part Two, ed. Ihsan ‘Abbas (Beirut, 1978): 157-62.

3- See Ibn Abi Usaybi’ah, ‘Uyun al-anba’: 5.

4- For a list of Ibn Sina’s works, see G.C. Qanawati (Anawati), Mu’allafat Ibn Sina (Cairo, 1955) and Y. Mahdavi, Fihrist-i musannafat-i Ibn Sina (Tehran, 1954).

5- Ibn Sina, al-Shifa, al MAntiq, al-Madkhal (hereafter al-Madkhal), ed. G. C.Anawati, M. al-Khudayri and A. F. al-Ahwani (Cairo, 1952): 2-4. Unless otherwise specified, all works referred to in the rest of this chapter are bi Ibn Sina.

5- Ibid: 10

6- This is Ibn Sina’s longest poem, consisting of around one thousand verses.

7- In this ode, which was written for al-Suhayli, Ibn Sina summarizes the study of logic in a poetic form so that his brother ‘Ali could remember it easily.

8- This poem on the soul is Ibn Sina’s best known.

9- Al-Madkhal: 12. Falsafah (philosophy) and hikmah (wisdom) are used by Ibn Sina interchangeably.

10- Al-Madkhal: 14

11- Ibid.: 12

12- Ibid.: 12-13

13- Ibid. 14. For the division of the sciences, see also al-Shifa’, al-Ilahiyyat (hereafter al-Ilahiyyat), I. ed. M. Y. Musa, S. Dunya and S. Zayid (Cairo, 1960): 3-4; Mantiq al-Mashriqiyyin (Cairo, 1910): 6-7; and ‘Uyun al-hikmah, ed. A. R. Badawi (Cairo, 1954): 17.

14- No specific name is given to the science of home management, but it may be referred to as social science; it corresponds to the Greek understanding of “economics”.

15- Al-Madkhal: 14

16- Uyun al-hikmah: 16

17- Ibid. For the division of the sciences, see also Ti’s rasa’il, ed. Hasan ‘ASI (Beirut, 1986): 83-5.

18- For a study of the relationship of logic to philosophy, see Shams Inati, Remarks and Admonitions, Part One (Toronto, 1984): 9-11.

19- Al-Madkhal: 19

20- Remarks and Admonitions, Part One: 11.

21- Ibid.: 12

22- Ibn SIna, al-Najah, ed. M. Fakhri (Beirut, 1985): 97-101; Remarks and Admonitions, Part One: 28-9 and 118-28.

23- The agent or active intellect (al-‘aql alfa”al) is, according to Islamic philosophy, the intelligence governing the Moon. This term seems to have been coined by al-Farabi, as al-Kindi before him seems unfamiliar with it. Al-Kindi calls thisintellect instead the first intellect. In any case, according to Ibn Sina, this intelligence is caused by intellectual emanation proceeding from God and ending with the human rational soul. The agent intellect is the last divine intelligence and is responsible for administering the sublunary world. Its primary function is to give corporeal form to matter and intellectual form to the rational soul, hence its name the giver of forms (wahib al-suwar). For a summary of Ibn Sina’s cosmology and natural philosophy see S.H. Nasr, An Introduction to Islamic Como logical Doctrines (Albany, 1993): 215ff

24- Uyun al-hikmah: 33

25- Al-Shifa’, al-Tabi’yyat, al-Nafs (hereafter al-Nafs), ed. F. Rahman (London, 1959):

26-.See also Tis’rasa’IL: 69, where the definition of the soul is given, but there the perfection is not described as primary, and the body is described as having “life in potentiality”.

27- Al-Nafs: 11. For the distinction between primary and secondary perfections, compare with Aristotle, De anima, 2,412A.

28- Tis’ rasa’il: 55 and ‘Uyun al-hikmah: 35.

29- Tis’ rasa’il: 55-6 and ‘Uyun al-hikmah: 35-7.

30- Al-Nafs: 45.

31- Tis’ rasa’il: 51.

32- Ibid. 59.

33- Al-Isharat wa’l-tanbihat, Part Two (published with Part Three and Part Four), ed. S. Dunya (Cairo, 1958): 382 and Tis’ rasa’il:57. For a list of the faculties of the three parts of the soul; 58ff. for an elaboration of the external senses; and 152-4 and 159ff. for an elaboration of the internal senses. For a brief of the internal senses, see ‘Uyun al-hikmah: 38-9.

34- Ibid. 39-40.

35- Tis’ rasa’il: 57-8

36- Ibid.: 68

37- Ibid. 68-9. For a discussion of the rational soul, see ‘Uyun al-hikmah: 42-3.

38- For the relation of the agent intellect to us, see Tis’ rasa’il: 69 and Uyun alhikmah: 43.

39- For the immateriality of the rational soul, see ibid. 44-46.

40- Ibn Sina also refers to this branch of philosophy as first philosophy, divine science or wisdom in an absolute sense (al-Ilahiyyat, 1: 5).

40- Ibid.: 17

41- Al-Najah: 235-6 and ‘Uyun al-hikmah: 47.

42- See al-Najah: 237: al-Ilahiyyat, 1: 93; and ‘Uyun al-hikmah: 48.

43- Al-Najah: 261.

44- Ibid.

45- Ibid.

46- Ibid. 262 and ‘Uyun al-hikmah: 55.

47- Al-Najah: 271-2.

48- Al-Ilahiyyat, 2: 342-3.

49- Al-Najah: 264-5.

50- For a detailed discussion of God’s Attributes, see al-Ilahiyyat, 1: 344-69.

51- Al-Najah: 280.

Chapter Three: The Relation between Science and Philosophy

In the last two chapters we learned that both the subject of science and philosophy and their research methodology are different and thus science can no more solve a philosophical problem than philosophy can solve scientificone. In short philosophy and science cannot replace each other.

However, this does not mean that the two disciplines are totally disconnected and have no influence on each other. The present chapter aims at explaining this point and is divided into three section 1The impact of science on philosophy 2 The impact of philosophy on science and 3. The priority of philosophy over science, which is the conclusion draw from the two previoussection.

The impact of science on Philosophy

Philosophy questions are divided into two groups the first group is not independent from science, in the sense that it is influenced by changes and development in scientific theories while the second group is independent for science. The first group is called philosophy after science and the second Philosophy before science lets us now consider these two types of philosophy issues.

Philosophy after Science

The reason why the change and development of scientific theories influences the outcome of the questions of ‘philosophy after science’ is that in this group of questions scientific theories, in different ways, are taken as presuppositions for philosophical questions. By a presupposition we mean a statement that in a certain field of learning is assumed to be true independent of any proof, for all or some of the questions in that are dependent upon it. The reason its validity is assumed independent of ay proof is either because it is self-evident, or it has been taken for another discipline where it validity has been proved already, or has been accepted with n evidence or reason whatsoever. In what follows we will discuss the different ways in which scientific theories are taken as presuppositions for philosophical questions.

The Scientific Theory raises a Philosophical Question

In some of the questions of ‘philosophy after science’, the philosophical question can e discussed essentially on the basis of a scientific presupposition. In such cases, science discovers a certain thing with characteristics that are either apparently contradictory to some philosophical laws so that the removal of this opposition would create some new issues for philosophy or, at the least, application of clear principles of philosophy to which will necessitate a new intellectual analysis. For example, the discovery of energy, the consequent appearance of the theory of the transformation of matter into energy and the emergence of particles of matter from condensed energy have the raised the questions in philosophy as to what the essence of energy is. Does it have mass or not? If it does, what differentiates it from ordinary bodies? If not, how can something possessing mass change into something that has no mass? In any case, a new material form that has not been discussed in philosophy heretofore has to be accounted for.

The Scientific Theory as a step to Philosophical Demonstration

In such cases the philosophical issue is discussed on the basis of tangible or intuitive issues or according to previous philosophical discussions, rather than on the basis of scientific presuppositions.

However, the philosopher in his attempt to prove the validity of the philosophical position must depend on the scientific theory as one the premises of his demonstration. On other words, in these cases the philosophical question has only a rational-experiment solution. For example, in the philosophy of Avicenna, in order to prove that the number of the abstract immaterial incorporeal existents is ten, the Ptolemaic geocentric theory is employed.

The Scientific Theory determines the Extensions of the Philosophical Theory

In these cases, in the premises used in proving a certain philosophical theory or in the philosophical theory itself the philosopher employs a concept that has a tangible extension, such as the concept of body, the concept of expansion and the concept of contraction, which in the old physics were called ‘penetration’ and ‘condensation’. The role of the scientific the scientific theory is to make the extension of that concept known to the philosopher. For example, the atomic theory, at the time of its advent, showed that the true extensions of the body in different philosophical precepts proved for body are not these observed bodies, but rather the electrons and nuclei. With the fission of the nucleus and the discovery of nuclear particles it has become clear that the true extensions of body are electrons and nuclear particles, and so on. In these cases, besides showing the extensions, the scientific theory often corrects mistakes made by philosophers.

It is clear that in the above cases any change or development in the scientific theory will result in a corresponding effect on the dependent philosophical question. However, it should be kept in mind that few philosophical questions fall within the category.

Philosophy before Science

It has already been said that ‘philosophy before science’ includes that group of philosophical questions that are independent from science and are therefore unaffected by any changes and developments that occur in scientific theories. This group in turn is divided into two further groups. One group does not take any scientific theory as a presupposition at all. Here, not only philosophical questions introduced independently from scientific theories but their solution also is purely rational. No scientific theory is used in proving them and the determination of the extension of the concept employed in them is not based on scientific concepts. The fundamentality of existence, proving the existence and attributes of God, the unity of divine essence and His attributes and actions, the possibility of resurrection predestination, freedom, and in general the most important philosophical questions are included in this group. The other group consists of those that have both a purely rational solution and also a rational-empirical solution that depend on the scientific theories and presupposes them. It is clear that this group is also independent of science, for if developments alter the scientific theory in question and invalidate the rationalempirical solution, it will not leave the question without a solution independent of all experimentation can always be relied upon; the issue of the immateriality of the soul, for example, is one such question.

The above issues, meanwhile, clearly show that the claim made in the last chapter to the effect that philosophical propositions are a priori is only applicable to ‘philosophy before science’ , which includes the main philosophical questions, rather than to ‘philosophy after science’. All the questions of ‘philosophy after science’ are of the posterior type, for the validity or invalidity of their presupposed scientific propositions can be determined only through experimentation. Thus, demonstrating either the truth or the falsity of these questions ultimately depends on experimentations as well.

The Impact of Philosophy on Science

In the last section we explained the different types of scientific propositions relied on in philosophy in order to investigate the way science influences philosophy. In this section, however, we shall explain the different types of philosophical presuppositions relied upon by science so as to show the manner in which philosophy influences it. For that purpose, we must first study the way in which the sciences are dependent on philosophy, for every need necessitates presupposition of particular philosophical law or laws.

The Dependence of Science on Philosophy in Proving a Subject

It was said in chapter one that every real field of learning, including every science, has a subject that in effect acts as an axis that gathers the different propositions of that discipline around itself and gives them the form peculiar to that particular field in such a way that all the propositions of that knowledge in one way or another deal with that particular subject; that is, they delineate it types and divisions, the relationship between these divisions and the laws governing each of them. It goes without saying that the subject of every field of learning must exist outside the mind; otherwise its study will be a kind of fancy rather than a scientific activity. Therefore, in every field of learning, before we begin our studies, we must make sure that its subject has objective existence.

If the existence of the subject of a certain field of learning is evident, it will not need proof; however, if it is not evident, we have to prove it or may even have to discuss its nature. Now, where can we deal this issue? Is it in the particular field of learning itself? No! For, every kind of knowledge begins with the assumption that its subject exists, and no scientist qua scientist needs to prove the existence of the subject of his study. Keeping in mind what was said in the first chapter, proving the existence of things and determining their nature are activities that belong only to the domain of philosophy and not to that of any other intellectual discipline.

Therefore, those fields of study the existence or nature of whose subject is not evident are dependent on philosophy.

Thus, the existence of the subject of these fields of learning and the nature of this existence is a presupposition taken from philosophy.

Dependence of Science on Philosophy in Ensuring the Universal and Necessity of its Laws

By law here we mean the genetic (takwini) laws employed in different fields of learning, including science, which describe phenomena and existents, rather than the conventional laws which are promulgated by the legislative bodies of different countries. The salient characteristic of every genetic law is its universality and necessity, in other words, every law is universal and necessary.

The universality of a law means that, firstly, its subject does not refer to a particular thing, or, technically speaking, it does not refer to an individual; that is, it is a universal rather than a particular concept. Accordingly, the terms used in a proposition indicating a certain law should be common names, such as man, electron, or metal rather than proper name such as Avicenna, Iran, or Rakhsh.

Therefore, the proposition ‘Avicenna is a scientist’ does not express a law, for the term, ‘Avicenna’ which is the subject of this proposition is a proper name and refers to only a particular person.

Secondly, the judgment and the predicate expressed in a law which admits no exceptions include all the extensions of the subject the law applies to, be they extensions that existed in the past, exist now, will exist in the future, or any other hypothetical extensions. Accordingly, a proposition indicating a law should be begin with a universal quantifier, for instance, a word like ‘every’ or ‘none’ or other synonymous words, but not with an existential quantifier, such as ‘some’ or its synonymies. Therefore, the proposition ‘Some metals are expanded by heat’ does not express a law, but the proposition ‘every number is either even or odd’ expresses a law. In logical terms, universal proposition can express a law rather than particular (existential) or personal propositions. In short, every law expresses a particular judgment that includes all the things the subject of the law is applicable to.

The necessity of a law means that once the condition is stated in the law are present that law will never be violated; that is. With the stated condition the subject of the law cannot exist without the judgment mentioned in the law.

Therefore, the fact that all the previous, present and future extensions of the subject possess this quality will not be enough for the law; rather, besides these, once the conditions are present, the law must not be violated. If we claim that the proposition ‘the freezing point of all types of pure water under one atmospheric pressure if 0°C’ is a law, this means that, firstly, this rule include all kinds of water in the past, present and future, and even covers everything that is supposed to be water. Secondly once the stated conditions are present, it will be impossible for any type of water not behave in that manner. The result is that in general, the universality and necessity of scientific laws indicate that in equal conditions similar natural elements would invariably behave in a similar fashion. In short, nature always behaves in a fixed and unchanging manner.

In order to understand the importance of the universality and necessity of scientific laws it will suffice to note that all the progress man has made in industry and technology and the great civilisation he possesses today is due to the discovery of these laws, and their whole importance is due to their predictability. With their help, especially when they put into mathematical terms, we can perceive the past, the present and the future behaviours, conditions and states of phenomena, such as calculating the age of the earth, perceiving the invisible symptoms of a disease on the basis of its visible symptoms, predicting the exact time of eclipses, predicting the exact time and place of landing of a missile fired from a certain station, and so on. Finally, the power of prediction of scientific laws is due to a number of factors that include their universality and necessity. For if a scientific law were not universal or necessary, even if we knew and provided all the necessary conditions for the application of that law, there would be the probability that the law would not be valid, and, therefore, in cases that are supposedly similar to those that have been already experienced, the law would not be applicable. There would also be the probability that even in cases where the law has been applicable up to now, though nothing has changed, the law would not be applicable any longer, and it is clear that with the existence of such probabilities prediction would be impossible. Therefore, because of the possibility of prediction according to scientific laws, we cannot deny the universality and necessity of these laws.

Now, on the one hand we know that the instruments of science are sense and experience and, on the other, according to what was said in the second chapter regarding the domain of those things that are understood directly or indirectly by the senses, the universality of a scientific law (continuous invariability in the behaviour of nature) and its necessity (the impossibility of alteration in the behaviour of nature) are not tangible objects, and according to all philosophers, including the philosophers of science, they cannot be experienced. Therefore, n science can possibly provide the required universality or necessity for its laws. It is here that the sciences once again show their dependence on philosophical presuppositions. For this purpose, they take as their presupposition the three philosophical laws, namely ‘the principle of casualty’, ‘the homogeneity of cause and effect’ and ‘casual necessity’.

Relying on these presuppositions, the scientist forms the scientific law in his mind in a process compromised of four stages. In the first he realizes that in general, on the basis of the principle of casualty, some natural phenomena have a causal relationship with others. In the second stage, he turns to nature and in the special samples selected for the experiment, by employing empirical methods, he discovers in detail which phenomenon is the exact cause of another phenomenon. For example, he discovers that in a few samples of tested metals, heat has been the cause of expansion. In the third stage, on the basis of the law of ‘the homogeneity of cause and effect’, he declares that the discovered relationship is universal (invariable and permanent); that is, in similar samples the same relationship always exist. Therefore, when heated, all other untested metals must also expand. Finally, in the fourth stage, on the basis of the law of ‘casual necessity’, he declares that the stated relationship is necessary and once these conditions are present it cannot be violated.

Of the above four stages, the second stage is not certain; that is, in the tested samples the scientist cannot be certain he has discovered the real causal relationship. For example, he cannot be certain that in those samples heating has been the only real cause of the expansion of the metal. In this stage, ancient scientists used to employ the philosophical presupposition, ‘something accidental cannot be persistent or nearly persistent’. The purport of this law is that two phenomena that always or often happen simultaneously, such as heating and metal expansion, would necessarily have a kind of causal relationship with each other, otherwise it would be impossible for them always o often to occur at the same time. Philosophers of science reject this law, and some famous philosophers, such as Avicenna, have also treated it with great caution. In other words, they have been hesitant to employ it. In any case, rejection of this law or hesitation over its use indicates that in the mentioned example it is possible that the cause of the expansion of the metal could be something other than heating. In that case, in the mentioned samples the coincidence of expansion and heating could be only accidental, and in some other metals that have not been tested such a thing may not happen, and, consequently, at the time of heating the metal may not expand. Therefore, we cannot be certain that in the second stage we have discovered a real causal relationship. Accordingly, though the other three stages are certain, the scientific law, which is the result of all four stages, is not certain and there will always be the possibility that certain new phenomena may be observed or new experiments may be carried out where the scientific law in question may not be applicable. In other words, a posterior proposition is falsifiable and could be invalidated, or, as was said in the previous chapter, exceptive. Therefore, this falsifibility and invalidability stem from the negation of the law, ‘something accidental cannot be persistent or nearly persistent’.

One must take note of the fact that the falsifibility and invalid ability of the scientific law stems from the negation of the law ‘something accidental cannot be persistent or nearly persistent’ (in the second stage) and does not negate the law of ‘casual necessity’ (in the fourth stage).

Therefore, though the scientific law is falsifiable and can be invalidated, it is necessary, otherwise it would necessitate that the scientific law which applied to a certain number of samples in certain conditions in the first test may not apply to the same samples in exactly the same conditions in another test, and this would be unacceptable, even by the scientists.

This is proved by the way scientist deal with invalidated scientific laws. Modern science admits the invalidity of the laws of Newtonian physics, nevertheless it still employs them in a certain domain of nature where physical bodies have normal dimensions and velocity - in technology and industry, for example - and on its basis it makes predictions and is certain of the accuracy of these predictions. What is the cause of this certainty? It is their belief in the law of ‘causal necessity’. The scientist unconsciously believes that though these laws are invalid and only by approximation - apply to the domain in question, rather than exactly and without approximation, nevertheless these laws, with this level of approximation, are necessarily always true in this domain.

We cannot say that sometimes they are true in this domain and sometimes they are not, or sometimes they are true with a certain level of approximation and at other times with another level, etc. This is nothing other than the application of the law of ‘causal necessity’.

We can conclude, then, that the principle of causality and the law of ‘the homogeneity of cause and effect’ and the law of ‘causal necessity’ are some of the necessary philosophical presuppositions of all sciences.

Dependence of Science on Other Philosophical Presuppositions

In addition to what has already been said, sciences are dependent on philosophy in other ways too and this indicates that sciences require other philosophical presuppositions. For example, each science studies its subject by describing it.

In fact, the goal of science is to understand the laws related to its subject.

Therefore, before starting any investigation, every science must assume that it is possible to know natural phenomena - including the phenomena considered as the subject of that science - otherwise its entire would be no more than an exercise in futility. Now, the question arises as to what kind of knowledge determines the validity or invalidity of this assumption or its limits and boundaries. The answer is that field of learning that examines the question of knowledge, namely the field of “epistemology” in philosophy. Therefore, the principle of ‘the know ability of the world for man’ is one of the philosophical presuppositions of all sciences. Moreover, all sciences employ the ‘principle of noncontradiction’ and we know that philosophy is the proper place for careful investigation of contradiction and for defining its conditions. Thus, this principles is one the philosophical presuppositions of all sciences. Moreover, all sciences, more or less, employ the principles of impossibility of contrary and the impossibility of circle and infinite regress, while proving these principles and solving problems with them belong to the domain of philosophy. Therefore, these three principles are also among the philosophical presupposition of sciences.

Besides the above mentioned philosophical principles, which are needed by all sciences and are among common philosophical presuppositions, there are other principles in philosophy which are needed only by certain sciences; in other words, they are philosophical presuppositions particular to those sciences, such as the principle of simplicity, the question of the existence or non-existence of natural movements’, the question of ‘the existence or nonexistence of absolute time’, the question of ‘the existence or non-existence of absolute space’’, which are used in nonhuman empirical sciences, and the question of ‘the existence or nonexistence of the whole as something independent of the parts’, the question of ‘determinism versus free will’, which are used in human empirical sciences.

However, here we do not intend to list all the philosophical presuppositions of sciences, and no doubt further investigation will reveal more presuppositions.

The Priority of Philosophy over Science

So far we have seen that philosophy is assisted by scientific presupposition and sciences are assisted by philosophical presuppositions, with the difference that scientific presuppositions re used only in some philosophical questions (philosophy after science) and there is no scientific presupposition on which all philosophical questions (philosophy before science) do not need the sciences all together.

However, all scientific questions use general philosophical presuppositions, such as ‘the principle of noncontradiction’, the principle of ‘the know ability of nature’, ‘the principle of causality’, the law of ‘the homogeneity of cause and effect’, the law of ‘causal necessity’, and so on, especially the first and the second principles. Consequently, all scientific questions without exception need philosophy. Thus, we can have philosophy without science but no science without philosophy. In other words, philosophy is not dependent on science, but science is dependent on philosophy.

Couched in philosophical terms, philosophy has priority over science. Moreover, the above distinction necessitates another difference related to the way presuppositions are used. In explanation, we can say that the general presuppositions on which all the questions of a science or a number of sciences are dependent are not used as “means”, but the presuppositions on which one or some questions of a particular field of learning depends on often are. When we speak of a presupposition being used as “means” we mean that it is used as a premise in demonstrating a statement or statements in a particular field of learning. This kind of presupposition is productive, because from its combination with other premise of demonstration a kind of deduction is formed, which in turn produces a conclusion, such as the principles of Euclidian geometry, which are used as the premise of the demonstrating for proving the propositions of that geometry. When we speak of a presupposition that is not used as a “means”, on the other hand, we mean that presupposition that is not used as a premise of a demonstration in any arguments; nevertheless, the truth if that presupposition must be accepted in any field of knowledge that includes it. As examples we can mention the rules of interference in logic, the ‘principle of noncontradiction’, the principle of ‘the know ability of the world’, the principle of causality, the law of ‘the homogeneity of cause and effect’, the law of ‘causal necessity’, ‘the principle of simplicity’, assuming the existence of the subject of a field of learning where the existence is not evident, and so on. The philosophical presuppositions of the sciences are often “non-means”, while the scientific presuppositions of philosophy are often “means”. Closer to Islam. It is because of his endeavours that today the philosophy of Avicenna is considered the most nature complete and important expression of Peripatetic Philosophy in the Islamic world. Thomas Aquinas the great medieval European philosopher is one of his book admits this with great respect and modesty.

At the end of his life Avicenna directed his attention to a philosophy he called ‘the philosophy of the select’ and common people. What this philosophy of the select is, is still most entirely clear for as it has already been motioned his Al-Hikmah al- Mashriqiyyah (Oriental Philosophy) that discussed this philosophy is not extant.

Nevertheless some philosopher in their study of the esoteric philosophy of Avicenna, have come to the conclusion that the philosophy of the select or the Oriental Philosophy is not purely demonstrative but rather a kind of philosophy whose ultimate end is resting man from the imperfect and limited either world and guiding him to the higher spiritual world and the pure light, For further explanation see.

1- Ibn Qifti Tarkh al-Hukama edited by bahin Daraie Tehram Tehran University press 137 pp 555 - 570

2- Hanry Corbin History of Islamic Philosophy Henry Thomas The great Philosophy M.Notahharii Collected works nol 13 pp 80-86

3- See Avicenna Al-shifa section of Al-

Mantiq (Logic) and Al-Burhan (Argument) Qon the Library of Ayat Allah Al-Masrashi al-Najafi 1404 AH 4 vols 3 pp 96 - 97

4- for further explanation se hastishenasi (Ontology) by the present author fifty edition Chapter 4 the Second Problem pp 58-64

5- The principle if the Knowability of the world and the principle of noncontradiction are both self-evident and therefore do not belong to the question of any particular discipline, however because they the law and precepts of the absolute existent and therefore, naturally, defining their exact purports, investigating the condition of their validity and refuting the objections made to them mainly belong to the domain of philosophy, they are counted among the question of philosophy. Perhaps in such cases using the term ‘question’ denotes a ‘statement’ that has to be proved.

Therefore it would be better to call such principle ‘philosophical statement “rather than” philosophical question ‘’

6- According to the principle of simplicity, nature performs its task in the simplest way possible. This principle is employed in cases where in order to explain a certain nature phenomenon there are two or more acceptable theories. In such cases according to the principle of simplicity the theory that provides the simpler explanation should be preferred. The preference which scientists given to non- Euclidian geometry concerning is very vast space is based on this principle.