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WorkAl-Ghazali

The Incoherence of the Philosophers

Twenty teachings of Avicenna's school, held to the philosophers' own standard of proof and found unproven; Averroes answered with a whole book.

by Al-Ghazali247 passages held

  • Arabic, the original language
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Original title
تهافت الفلاسفة
Original language
Arabic

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Overview

A manuscript in Istanbul records that this book was finished on 21 January 1095, while Abū Ḥāmid al-Ghazālī was teaching at the Niẓāmiyya in Baghdad, the prestigious college to which the Seljuq vizier Niẓām al-Mulk had appointed him in 1091. It is a refutation, and its target is the falāsifa, the Muslim followers of Aristotle, above all the Persian philosopher Avicenna (Ibn Sīnā), who held that their demonstrations gave surer knowledge of God and the world than any theology drawn from revelation. Al-Ghazālī took twenty of their teachings, sixteen from their metaphysics and four from their natural science, and argued that none of them met the philosophers' own standard of proof: each rested on premises inherited from the founders of the school and never established. Some positions he rejected here he accepted in later books; what he denied was that they had been demonstrated. The first and longest discussion attacks the claim that the world has no beginning, with arguments against an infinite past that go back to John Philoponus, a sixth-century Christian scholar of Alexandria. The seventeenth takes fire touching cotton and holds that God, directly or through the angels, makes the cotton burn, with no necessary link between the fire and the burning. At the close, writing as a jurist, al-Ghazālī ruled that three teachings amount to unbelief when taught in public: that the world has no beginning, that God knows only universals and not particular things, and that after death souls never return to bodies. In the late twelfth century the Andalusian philosopher Averroes answered him in The Incoherence of the Incoherence, which quotes his arguments passage by passage before answering them; for centuries Western readers knew the book mainly through that reply.

Key concepts

What is emanation, and why does the book attack it?

Emanation is the philosophers’ account of how a world of many things comes from a God who is perfectly one. Since one, they say, can produce only one, God produces a single first intellect; from it come a second intellect, a soul and a heavenly sphere, and so on down through the spheres of the planets, Saturn’s among them, to our world. Al-Ghazālī reports the whole ladder in order to show that none of its steps is proved.

What does al-Ghazālī mean by the “habit” of nature?

A habit, here, is the customary order God keeps in creating things one after another, so that burning follows touching fire and fullness follows eating. Because God keeps it, people can rely on it in daily life. Because it is a habit and not a necessity, God can depart from it, which is how al-Ghazālī makes room for miracles. The regularities are real, but what brings each event about is God, not the things themselves.

What is the difference between knowing universals and knowing particulars?

Universal knowledge grasps kinds and laws, such as how and when eclipses happen; particular knowledge grasps this event, at this time. Avicenna said God knows particulars only in a universal way, so that his knowledge never changes as events come and go. Al-Ghazālī replies that this leaves God unaware of what is happening now, and so of what any individual person believes or does.

Which of the philosophers’ teachings does the book call unbelief?

Of the twenty teachings, al-Ghazālī judges three to be unbelief: that the world has no beginning, that God does not know particular events, and that bodies are not raised after death. These three, he says, imply that the prophets spoke falsely. The other seventeen he calls errors or innovations, positions resembling those held in some Muslim schools, which a person can hold and remain a Muslim.

What is a demonstration, and why does it matter so much here?

A demonstration is a proof from premises that are certain, so its conclusion is certain too. The philosophers claimed that their metaphysics met this standard, the same one their logic and mathematics meet. The book does not set out to prove the opposite of each teaching. It shows, discussion by discussion, that the premises behind it are borrowed from earlier philosophers and never established, so the claim to certainty fails on its own terms.

Themes of the book

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

Did the World Begin?

Could the world have had no beginning? The book's opening argument stakes everything on whether a choice needs a reason to fall where it does.

The philosophers argued that an eternal God with an unchanging will could not have created the world at one moment rather than another, so the world must be as old as he is. The first and longest discussion turns the argument around. A will, al-Ghazālī replies, is exactly the power to pick one of two equal options, as a hungry man takes one of two identical dates. And an infinite past is itself absurd: Saturn turns once for every thirty turns of the sun, yet both counts would be infinite and so equal.

  • eternity of the world
  • eternity
  • time
  • creation
  • divine will
  • infinite regress
  • possibility
  • celestial motion

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Fire Touching Cotton

Does fire burn, or does it only come before burning? The seventeenth discussion asks what anyone actually sees when one event follows another.

When fire touches cotton, the cotton burns, and everyone concludes that the fire burned it. Al-Ghazālī holds that observation shows only that the burning happens with the touching, never that it happens through it. God, directly or through angels, creates the burning, and the regular sequence is a habit he keeps, not a necessity. This is what lets Abraham stand in the fire unharmed. Against the charge that anything could then become anything, he answers that God creates in us the knowledge that he will not make such things happen.

  • causation
  • causality
  • divine power
  • prophecy
  • perception

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Knowing Without Changing

Can a God who never changes know what is happening now? Many discussions ask whether the philosophers' simple God can still know and act at all.

The philosophers' God is one and simple, and from one, they say, only one thing can come, so the world flows from him through a ladder of intellects and heavenly spheres. To keep him unchanging, Avicenna held that he knows particular things only in a universal way: he knows every feature of an eclipse, but not that it is happening now. Al-Ghazālī presses both points, arguing that the chain of intellects explains nothing and that a God ignorant of present events could not know what any individual person does.

  • divine knowledge
  • divine attributes
  • divine simplicity
  • divine unity
  • universals
  • emanation
  • necessary existence
  • intellect
  • cosmology

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A Soul That Returns

Must a surviving soul stay bodiless? The last discussions ask what makes the person who rises the same person who died.

The philosophers taught that the soul survives death and finds pleasure or pain according to its knowledge and purity, but that bodies do not rise again. Al-Ghazālī accepts the soul's survival and denies that it rules out a bodily return. If the person is the surviving soul, it can be given a body made of the same matter or of new matter and still be that person. Promises of paradise and hell, unlike talk of God having a place, contain nothing reason finds impossible, so they are to be taken as stated.

  • soul
  • bodily resurrection
  • personal identity
  • philosophy of mind
  • afterlife
  • imagination

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Within this work

passages held
247
distinct concepts
249
by passages held, corpus-wide
#303

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: “causation” and “divine will”.
Concept co-occurrence, strongest first 8 concepts, joined by 23 pairings. 90 pairings reach beyond these concepts and are not drawn.
ConceptPaired conceptShared passages
causationdivine will13
causationcreation9
causationdivine knowledge9
causationcosmology8
causationdivine attributes5
causationmetaphysics4
cosmologycreation4
divine attributesdivine knowledge4
causationsoul3
creationmetaphysics3
divine knowledgedivine will3
cosmologydivine will2
cosmologymetaphysics2
creationdivine will2
divine attributesdivine will2
divine knowledgemetaphysics2
metaphysicssoul2
cosmologydivine attributes1
cosmologydivine knowledge1
cosmologysoul1
creationdivine knowledge1
creationsoul1
divine attributesmetaphysics1

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. Deliverance from Error (المنقذ من الضلال)

    An intellectual autobiography, written at Nishapur after his return to teaching in 1106; Claud Field's Confessions of Al Ghazzali first brought it into English in 1909.

     EN
  2. The Alchemy of Happiness (Kīmiyā-yi Saʿādat)

    His major work in Persian, written around 1105 for readers without Arabic, and a shorter companion to the Revival of the Religious Sciences.

     EN
  3. The Incoherence of the Philosophers (تهافت الفلاسفة) you are here AR
  4. The Just Balance (القسطاس المستقيم)

    One of several answers to the Ismāʿīlīs, this one cast as a dialogue on the road; his autobiography points readers to it instead of repeating its case.

     AR
  5. The Marvels of the Heart (كتاب شرح عجائب القلب)

    The twenty-first of the forty books of the Revival of the Religious Sciences, and the ground for the books on vices and virtues that follow it.

     AR
  6. The Niche of Lights (مشكاة الأنوار)

    Among his late works, and the one in which his thought comes closest to the mystics: three chapters on a single verse of the Qurʾān and a single saying of the Prophet.

     AR
  7. The Standard of Knowledge (معيار العلم في فن المنطق)

    Written after The Incoherence of the Philosophers to explain the philosophers' technical vocabulary to its readers, and to give jurists and theologians a test for their own arguments.

     AR
  8. مقاصد الفلاسفة

    A report before a refutation: Avicenna's system set out without a word of objection, then framed by a short preface and ending that point ahead to The Incoherence of the Philosophers.

     AR
  9. ميزان العمل

    The second half of a pair: having set a standard for knowing in The Standard of Knowledge, he set one here for acting, still in Baghdad, around 1095.

     AR
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