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WorkAvicenna

Kitāb al-Nafs

(lit.: The Book of the Soul)

Asks what a man created in empty air, seeing and touching nothing, would still know, and answers that he would know he exists.

by Avicenna192 passages held

  • Arabic, the original language
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Overview

In the twelfth century this book was translated into Latin as the Liber de anima, and it went on to shape how scholastic philosophers, William of Auvergne and Albertus Magnus among them, described the powers of the soul. In Arabic it is Kitāb al-Nafs, the sixth part of the physics of al-Shifāʾ (The Healing). Avicenna begins where Aristotle did, treating the soul as a subject of natural science: the form that makes a body alive. He then argues that the human soul is more than that. The first chapter asks the reader to imagine a man created all at once and fully formed, his sight veiled, falling through air or empty space so that his limbs touch nothing and nothing touches them. Such a man, Avicenna argues, would affirm that he exists while affirming nothing about his body, so the self he affirms cannot be the body. Later readers called this the floating man, and modern readers have set it beside Descartes, though scholars disagree about how deep the likeness goes. The book also adds a power of its own to the inner senses of Aristotle's tradition. Avicenna calls it wahm, estimation: it lets a sheep grasp, in the shape and colour of a wolf, an enmity its eyes cannot see. No earlier philosopher, Greek or Arabic, seems to have described it, and Latin readers took it over as estimatio. The last treatise argues that the rational soul thinks without any bodily organ, and that it therefore survives the death of the body. Fazlur Rahman's edition of the Arabic, printed at Oxford in 1959, is the text scholars cite; no complete English translation of the Arabic has been made.

Key concepts

What does it mean to call the soul a body's first perfection?

It means the soul is what makes a body the living kind of thing it is, before it does anything. Avicenna's example is the sword: its shape makes it a sword, its cutting is a second perfection that follows. So the soul is defined by what it does for a body, which says nothing yet about whether it could exist without one.

What are the inner senses?

They are five powers inside the head that work on what the outer senses deliver. The common sense gathers sight, sound and touch into one experience; imagination keeps the images; a further power combines and separates them; estimation grasps meanings no sense delivers, such as danger or affection; and memory stores those meanings. Each has its own place in the brain.

Why can thinking not happen in a bodily organ?

Because what the mind grasps cannot be divided, and everything in a body can. Whatever sits in a body can be split into parts, as the body can. An understood idea, such as what a triangle is, has no halves, so it cannot sit in a body. The power that holds it must therefore be something that is not a body.

What does transparency have to do with seeing?

Seeing needs a transparent medium between the eye and its object, such as air or water. The medium is seen through and never itself seen; when light is present, it carries the form of a coloured thing to the eye. Darkness is not a dark substance in the way but the absence of anything visible, so a lit fire is seen across dark air.

Themes of the book

What this book returns to, gathered into themes and ordered by how much of the text each one occupies.

A Self the Body Cannot Hold

If the soul is what makes a body alive, how can a human soul be anything more than the life of its body? The answer decides whether a person can outlast their death.

Avicenna starts as a natural scientist: the soul is the first perfection of an organic body, as its shape is the perfection of a sword. Then he shows that this names what the soul does, not what it is. A man created in empty air, touching nothing, would affirm himself without affirming any body. Thought needs no organ, since what it grasps cannot be divided as a body can, and the power to understand often grows after forty while the body declines. Each soul begins with its own body, and none passes into another.

  • soul
  • intellect
  • embodiment
  • soul-body relation
  • causation

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The Senses Within

Between the eye that sees a wolf and the leap of a sheep that flees it, something inside judges. What are these hidden powers, and how far do they reach?

Behind the five outer senses Avicenna places a row of inner ones, each with its own job and its own seat in the brain: a common sense that gathers what the outer senses deliver, an imagination that keeps the images, a power that combines and separates them, estimation, which grasps meanings no sense delivers, such as danger or affection, and a memory that stores those meanings. Estimation is his addition to the tradition. The same powers, working undisturbed in sleep or in a rare soul, account for dreams and for prophecy.

  • perception
  • imagination
  • memory
  • mental representation
  • psychic faculties
  • sensation
  • dreams

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How Seeing Happens

Does the eye reach out to things, or do things reach the eye? Settling it takes Avicenna through light, colour, transparent air and mirrors, and on to why one thing is sometimes seen as two.

A whole treatise is given to sight. Against those who held that rays leave the eye and touch their objects, Avicenna argues that the eye only receives: the form of a lit, coloured thing is carried through a transparent medium such as air or water, which is seen through and never seen. Darkness is not a thing standing in the way but the absence of anything to see, so a fire far off in the night is seen across the dark air. Reflections in mirrors and water get long, careful treatment.

  • optics
  • vision
  • visual perception
  • light
  • color
  • reflection
  • theories of vision
  • transparency

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Within this work

passages held
192
distinct concepts
238
by passages held, corpus-wide
#365

What this book thinks together

The wheel takes this book’s leading concepts and shows how often they come up together. The wider the band between two, the more of its passages speak of both. Among them, most often together: “imagination” and “perception”.
Concept co-occurrence, strongest first 8 concepts, joined by 18 pairings. 86 pairings reach beyond these concepts and are not drawn.
ConceptPaired conceptShared passages
imaginationperception12
causationperception11
opticsvisual perception10
perceptionvision10
opticsvision9
causationsoul8
causationvision8
causationoptics7
intellectsoul7
opticsperception7
imaginationintellect6
intellectperception5
perceptionsoul5
perceptionvisual perception4
causationimagination2
imaginationvision2
imaginationvisual perception2
visionvisual perception1

Works held

The author's work in order, this book marked in place. Your-language title first, the original beneath it where the two differ; side chips show which full texts are held.

  1. A Compendium on the Soul (Kitāb fī al-nafs ʿalā sunnat al-ikhtiṣār)

    The earliest of his books, written for the Sāmānid court at Bukhara before any of the summaries of philosophy that made his name.

     EN
  2. A Treatise on Love (Risāla fī māhiyyat al-ʿishq)

    Written at the request of a jurist, Abū ʿAbd Allāh al-Maʿṣūmī, and set out in seven short sections.

     AR
  3. al-Najāt

    Between the vast al-Shifāʾ and the allusive Ishārāt in both length and manner, and the usual way into his logic.

     AR
  4. al-Taʿlīqāt

    A classroom companion to his metaphysics: short notes on its key terms, read today beside al-Shifāʾ.

     AR
  5. Commentary on the Poetics of Aristotle (Fann al-Shiʿr)

    Filed under logic, as the Arabic tradition filed Aristotle's Poetics, it closes the nine logical books of al-Shifāʾ.

     AR
  6. Kitāb al-Nafs you are here AR
  7. Kitāb al-Siyāsa

    The household branch of practical philosophy, set out for a man, his family and his servants, in a short Arabic treatise.

     AR
  8. Remarks and Admonitions (al-Ishārāt wa-l-tanbīhāt)

    Shorter than al-Najāt and far shorter than al-Shifāʾ, though written after both, as a statement of his mature philosophy.

     AR
  9. Risāla fī maʿrifat al-nafs al-nāṭiqa wa-aḥwālihā

    A short epistle in three chapters and an epilogue, one of several treatises on the soul that circulate under his name.

     AR
  10. The Healing, Logic: Isagoge (al-Madkhal)

    The first of the nine books of logic in al-Shifāʾ, and the place where the prologue to the whole encyclopedia stands.

     AR
  11. The Metaphysics of The Healing (al-Ilāhiyyāt)

    His fullest metaphysics, known to Latin readers as the Liber de philosophia prima; it closes al-Shifāʾ after the logic, the physics and the mathematics.

     AR
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