- Length
- 260 pagesMarmura, parallel Arabic-English, 2nd ed. 2000
- Reading
- HardPresupposes texts it does not explain; a guide helps
- Availability
- In printA current standard edition is available
The Incoherence of the Philosophers
In 1095 the most respected teacher in Baghdad published a book arguing that the leading philosophers of his civilisation had failed to prove twenty of their central claims, and that three of them amounted to unbelief. He did not argue as a theologian shouting from outside. He argued as a philosopher, using their own logic, having first written a separate volume summarising their positions so accurately that Latin Europe later mistook it for his own philosophy. The Incoherence of the Philosophers is the most formidable attack on philosophy ever written by someone who had mastered it, and it drew the most literal reply in the history of the subject.
- Date
- 1095
- Author
- al-Ghazali
- Region
- Baghdad; Khurasan
- Language
- Arabic
- 1328 Latin, Calo Calonymos Reached Latin embedded inside Ibn Rushd's reply rather than on its own Consensus
- 1958 English, Sabih Ahmad Kamali First complete English version Attested
- 1997 English, Michael E. Marmura Standard parallel Arabic-English edition; in copyright Attested
Where it stands in the argument
- Position
- Exchange — Both: answers an earlier work and drew a later one
- Form
- Treatise
- Method
- Demonstration — Proof from premises the opponent already grants
- Transmission
- Translated — Reached its later readers in another language
- Standing
- Live — Still argued in current philosophical work
- Years to the reply
- 85 years
- Years back to what it answers
- 68 years
Still argued over, and not only by historians: the seventeenth discussion is a standing reference point in modern debates about causation and occasionalism.
What the book says
The book is organised as twenty separate disputes, each one taking a doctrine the philosophers held and asking whether they have actually proved it. Al-Ghazali states each position fairly first - he had already written a whole companion volume doing nothing but that - and then argues that the demonstration falls short. Some of the disputes are technical: whether the heavens have a soul, whether the world could have begun. Three he treats as far more serious, because on those the philosophers contradict scripture outright: that the universe is eternal and had no beginning, that God knows only general truths and not particular events, and that what survives death is the soul without the body. The most famous chapter is the seventeenth, on cause and effect. Put cotton to a flame and the cotton burns. We see the flame, then we see the burning; what we never see is any necessary link between the two. Al-Ghazali's point is not that fire does not burn, but that nobody has shown why it must - the connection is a habit of expectation, and the actual cause of every event is God acting directly. The book ends by naming the three doctrines that in his judgement place their holders outside the faith, which is why it is remembered as an attack rather than as the piece of technical logic most of it actually is.
What it argues
Al-Ghazali takes twenty propositions held by the falasifa and argues that in each case the demonstration fails. The philosophers claim the world is eternal, that God knows only universals and not particular events, and that resurrection is of the soul alone and not the body. On these three, al-Ghazali holds, they contradict revelation and their arguments do not carry the weight required. On the remaining seventeen his charge is narrower and more damaging: not that the conclusions are false, but that the proofs are not proofs. The most consequential is the seventeenth discussion, on causation. When cotton is brought to fire and burns, we observe the fire, then the burning. We do not observe any necessary connection between them. What we call a causal law is a habit of expectation about the customary order of things, and God is the direct agent of every event.
What it answered
The Book of Healing c. 1020-1027Ibn Sina
The target is the philosophical system Ibn Sina had built, and behind him al-Farabi: a fully worked account of God, the intellect, the soul and the eternal cosmos assembled out of Aristotle and the Neoplatonists and presented as demonstrative science. Al-Ghazali had studied it thoroughly enough to summarise it without distortion in the Maqasid al-Falasifa, which he wrote as the first half of the same project. That is what makes the attack unusual. Most refutations begin by misdescribing the position; this one begins by stating it better than its defenders had.
What answered it
The Incoherence of the Incoherence c. 1180Ibn Rushd
Ibn Rushd replied around 1180, eighty-five years later and at the far western end of the Islamic world, with The Incoherence of the Incoherence. The reply is unusually literal: he prints al-Ghazali's text, keeps the twenty discussions in order, and answers each in place, so the book cannot be read without its opponent. His central move is to defend the reality of secondary causation, arguing that a world in which fire does not burn by its own nature is a world in which nothing has a nature, and in which knowledge of anything becomes impossible. The exchange was not settled. Both books continued to be read, and the argument about whether causal necessity is in the world or in the mind was still live when Hume restated the observational half of it six centuries later, without any evidence of having read either.
How it argues
The form is the argument. Al-Ghazali does not appeal to scripture to settle a philosophical question, because that would concede that philosophy and revelation are separate courts. He works entirely inside demonstrative logic and shows that the philosophers' own instrument does not reach their own conclusions. He also declines to assert a rival cosmology: the book's stance is that the proofs fail, not that the opposite has been established. That restraint is why the argument survived its context. A reader who accepts none of al-Ghazali's theology can still follow the seventeenth discussion and find it hard to answer.
The moment
Al-Ghazali was appointed to the Nizamiyya madrasa in Baghdad in 1091, at the intellectual centre of the Seljuk world, and was among the most powerful academic figures of his time. The Incoherence belongs to the end of that period. In 1095 he suffered the crisis he later described in his autobiography, abandoned his post and left the city for eleven years of withdrawal. The book therefore sits at the hinge of his life, written by the establishment scholar immediately before he stopped being one.
How it travelled
The route into Europe is the strangest thing about this book, and it produced a three-century misunderstanding. In Toledo in the later twelfth century, Dominicus Gundissalinus and a Jewish collaborator identified as Avendauth translated not the Incoherence but its companion volume, the Maqasid al-Falasifa. They omitted the short introduction and closing note in which al-Ghazali states that the work is an uncommitted report of the philosophers' teachings, to be demolished in the sequel. Latin scholastics therefore read Algazel as a straightforward Avicennan philosopher, and the figure they cite bears almost no resemblance to the Ash'arite jurist known in Arabic. Ibn Rushd's reply reached Latin much later and carried al-Ghazali's text embedded inside it, which meant Europe eventually met the attack in the form of its refutation.
The strongest objection
The strongest case against the book is Ibn Rushd's and it has not been dissolved. If no event has genuine causal power of its own, then nothing has a stable nature, and the natural sciences describe nothing more than a reliable divine habit. Al-Ghazali is prepared to accept this; most readers since have found the price too high. There is a second objection, subtler: by refusing to assert an alternative and arguing only that the proofs fail, the book adopts a position that cannot itself be refuted in the same way. Some readers find that rigour. Others find it a stance that wins by declining to stand anywhere.
Why read it
Because it is the rare case of a first-rate mind attacking a position it has fully understood, and because the seventeenth discussion is one of the great arguments about causation, made six hundred years before the argument it is usually credited to. It is also the clearest available demonstration of what this section is for: a book, and the book written to destroy it, both still in print, still argued over, and unintelligible apart from each other.
- First printed
- 1303
- First in English
- 1958
- Digitised
- Partial
Circulated in manuscript across the Islamic world from the twelfth century; printed in Cairo from the nineteenth.
The standard English is Michael Marmura's parallel Arabic-English edition (Brigham Young University Press, 1997; second edition 2000), which is in copyright.
Where it stands
The Incoherence remains a working text in Islamic thought rather than a historical monument, and the seventeenth discussion has had a second life in Western philosophy of religion and metaphysics, where occasionalism is a position with living defenders. Its wider reputation is a different matter, and contested: a popular account holds that this book ended philosophical enquiry in Islam, which is discussed below.
On quoting this book
Arabic text is public domain; every usable English translation is in copyright, and the older partial versions are unreliable. No passage is quoted.
Contested
The claim that this book caused the decline of science and philosophy in the Islamic world is widely repeated and rejected by most specialists. Philosophical work continued for centuries after it: Ibn Rushd himself is later, Suhrawardi founded a new school within a hundred years, and the Persian tradition through Mulla Sadra runs to the seventeenth century. The date of composition is given as 1095 by most authorities but the Maqasid is sometimes dated 1094 and the pair may have been drafted together over several years. The exact number of positions declared unbelief is not in dispute at three, but which philosophical schools al-Ghazali intended to include under falasifa is.