Like his metaphysics, Avicenna’s psychology or doctrine of the soul has an Aristotelian base with a strong Neoplatonic superstructure. This we can see already in his definition of the soul. While Aristotle defines the soul as an entelechy or form of an organized natural body, Avicenna interprets the term entelechy in the sense in which a pilot is the entelechy of the ship (De anima, Ar. text, p. 6.13ff.). This example we find already in Aristotle but Aristotle does not offer it as his doctrine.
Avicenna gives a proof for the substantiality of the soul that renders it capable of existing by itself apart from the body. This proof was famous in medieval times, in Europe also, and is called the “proof of the suspended man.” Avicenna asks us to suppose a person to be born adult and suspended in a vacuum where there is no air to resist him and, finally, to suppose that the parts of his body are so situated vis-à-vis each other that no part can touch others, then in that case such a person will not affirm the existence of anything external to him nor yet of his own body but he will still say, “I am.” This assertion of self-consciousness apart from the body is the basis upon which the existence of the soul as a purely spiritual being is established (ibid., p. 15.12ff.). The striking affinity of this proof with the Cartesian proof is unmistakable.
Avicenna’s theory of knowledge exhibits the same character, namely an Aristotelian starting point and a highly neoplatonized superstructure. His theory of sense-perception, imagination, and intellect have all an Aristotelian point of departure. First of all, Avicenna elaborates on the basis of Aristotelian suggestions that knowledge comes about by abstraction (Rahman, Avicenna’s Psychology, pp. 38ff.). In sense-perception, for example, the matter of the perceived object is left out, but the form of the object is perceived. The next step in abstraction is reached in imagination because imagination can preserve an image which is free from matter. Although perception is not free from material attachments, imagination is free even from material relationships and attachments. The final stage of abstraction is reached in conception because a concept applies indifferently to all the members of a species: It is completely abstracted from the particulars of that species and is therefore universal. Just as there are five external senses—vision, audition, touch, taste, and smell—so there are five internal senses. Avicenna seems to be the originator of this theory. The first of the internal senses is the sensuscommunis which fuses information coming from different external senses into an object or a percept. The second internal sense is what he calls imagination or, rather, the memory-image (ḵayāl). This is the faculty which contains the image of the object perceived after that object is removed from direct perception. Next comes the faculty which Avicenna calls taḵayyol, which literally means “imagining” as a verb. The function of this faculty is to combine images retained in the memory and to separate them from one another. Thanks to this faculty, fantastic images can be formed, for example, that of a golden mountain by combining that of gold with that of mountain. While much of the activity of this faculty, as we shall presently see, is non-rational and, in fact, recalcitrant to the control of reason, it plays a fundamental role in rational activity because thinking never comes about without the interplay of images.
The fourth faculty among the internal senses appears to be an innovation of Avicenna’s because it is not found in any other earlier philosopher, either Greek, Christian, or Muslim. This faculty he terms wahm (ibid., p. 31.13ff.; De anima, pp. 166ff.) which is translated into Latin by the term estimatio. While the external perception perceives the physical form of the thing, its inner meaning is perceived by an internal sense; for example, when a sheep sees a wolf for the first time, it runs away in fear. Now the external perception of the sheep only perceives the form and the shape of the wolf. That the wolf is dangerous is conveyed to the sheep not by external perceptions but by an inner faculty.
Lastly, the fifth internal sense consists of a faculty which retains not the forms of perceived things, but their meanings and ideas as perceived by the faculty of wahm. This faculty, which is a storehouse of ideas and meanings rather than that of externally perceived forms must be clearly noted because it retains individual meanings, just as the faculty of memory preserves individual forms.
In his doctrine of intellection, Avicenna again starts from the Aristotelian distinction between the active and the passive intellect. The human intellect is at first only potential and is gradually actualized by the operations of the faculties of perception and particularly imagination. The faculty of imagination helps intellection in that the intellect compares and contrasts the images stored in the mind. Through this exercise of comparing and contrasting, the universal emerges from those particular images. This emergence of the universal from particular images is thanks to the action upon the human mind of the Active Intellect, which is the lowest in the series of ten incorporeal and cosmic intelligences below God. Avicenna emphasizes that the universal does not emerge from the images, but that due to the activity of comparing and contrasting the images and combining them also with the meanings that are retained in the mind, the universal emerges into the human mind from the Active Intellect. Thus the mind’s activity of comparing and contrasting the images is an exercise which prepares the soul for the reception of the universal intelligence from the cosmic intelligence. It is in this connection that Avicenna asserts that the mind has no storehouse or memory for the universal or abstract ideas as it has for particular forms and meanings. Therefore when the human mind wants to remember or recall universals, it reestablishes a contact with this universal Active Intelligence and receives the intelligible afresh, but whereas in the first instance it had to go through the whole exercise of comparing and contrasting images, this time it does not have to rehearse all the activity; its mere attention to the Active Intelligence is sufficient (ibid., pp. 116ff.)
Avicenna is also the author of a famous doctrine about the intellect, according to which the human mind, when it contacts the Active Intelligence, receives from the latter a power which he calls “simple knowledge” (known in the medieval Latin West as scientiasimplex; De anima, p. 243.9ff.). This doctrine asserts that a person may be asked a question about a matter he had never thought of before in detail, yet he is sure that he possesses the ability to answer the question. This assurance that the person has that he can definitely answer the question in detail means that he knows the answer already—this is simple knowledge. But as he begins to answer the question of the questioner in detail, he comes to know it in a different way than in a simple unanalyzed form. The first kind of knowledge is the creative simple knowledge on the pattern of God’s knowledge, while the second form of knowledge is termed by Avicenna “psychic knowledge” or discursive knowledge. This doctrine of the simple intellect exercised a good deal of influence on the development of Islamic mysticism as well.
Avicenna also strenuously denied the transmigration of souls (Psychology, chap. 14 with notes) because the soul, through its association and experiences with a certain given body, becomes permanently individuated. Hence, it can not pass into another body. Indeed, according to Avicenna, a particular soul comes into existence at a time when a certain body with a particular temperament comes into existence and is prepared to receive this soul. Therefore, there is an initial reciprocity that is further strengthened by individual experiences and, hence, any talk of one soul entering another new body, whether human or non-human, is absurd. But for Avicenna there is no survival of the body after its death at the end of this life (Rahman, Prophecy, pp. 42-44). He believed that the soul survives by itself. Those souls which have become intellectually developed do not need the body at all and therefore do not need to seek physical survival or indeed revival on the day of resurrection. Such intellectually developed souls form a kind of paradise wherein they enjoy each. other. As for those human souls which have not become intellectually fully developed and still need some sort of physical support, they will survive through their imagination because they are unable to go beyond the level of imagination. Such souls experience in the future life physical pleasures and pains just as described graphically in the Koran—the tortures of the fire of hell and the enjoyment of a physical paradise. Whether such souls have the opportunity of further development in the afterlife, Avicenna does not discuss.
Avicenna also formulated a comprehensive and elaborate theory of prophethood and prophetic revelation, several elements of which were taken from Greek thought and which had earlier been welded in some form by the philosopher Fārābī. (On the forms of prophethood see ibid., chaps. 1 and 2; Gardet, La pensée, chap. 4) Avicenna’s prophetic faculty or power has three aspects: intellectual, imaginative, and practical. Whereas by the first, the prophet receives intellective revelation or wisdom, this results in the verbal revelation (for example, the Koran) thanks to the strong prophetic power of imagination which transforms intellective knowledge into moving images. Whereas the prophet shares the first with the philosopher, he is distinguished from the philosopher by the power of imagination. The third aspect of prophethood concerns the production of miracles, on the one hand, and the founding of the state and giving the law on the other.
Avicenna, De anima (Ar. text), ed. F. Rahman, Oxford, 1959.
F. Rahman, Avicenna’s Psychology, Oxford, 1952, repr. Westport, Conn., 1981.
Idem, Prophecy in Islam—Philosophy and Orthodoxy, repr. Chicago, 1979.
L. Gardet, La pensée religieuse d’Avicenne, Paris, 1951.
Works in Arabic: F. Ḵolayf, Ebn Sīnā wa maḏhaboho fi’l-nafs (Avicenna on psychology), Beirut, 1974.
A. Nadir, al-Nafs al-bašarīya ʿenda Ebn Sīnā, Beirut, 1968 (an anthology of Arabic texts on the human soul by Avicenna).
Originally Published: December 15, 1987
Last Updated: August 17, 2011
This article is available in print.
Vol. III, Fasc. 1, pp. 83-84