al-Ghazali and the Apes of Unbelief

al-Ghazali was one of the greatest of the Islamic thinkers. Virtually single-handedly, al-Ghazali brought it about that Islam came to regard mathematics, science, and philosophy with suspicion and hostility. And this, arguably, was what was responsible for what has been called “the closing of the Islamic mind,” and the bringing of the Islamic Golden Age of intellectual inquiry (~950-1150) to its end.

Even today, the Islamic world remains on the whole very hostile to the very idea of science and philosophy—these things seem to be man attempting to fathom the ways of Allah, in a way which is blasphemous and impious, as well as absurd and ridiculous. What man can fathom the mind of God? What man would be so presumptuous?

The Muslim world likes technology—because these things may easily be regarded as gifts from Allah. Muslims tend to deny any strong causal link between developed theoretical science and technological development. If you assert that there is one, you will be told (correctly) that correlation does not entail causation. Muslims are, or tend to be, Humeans (or more precisely, Hume is a Ghazalite or Ash ̔arite, al-Ghazali following al Ash ̔ari on this crucial point) that

  1. Correlation does not establish causation.
  2. All attempts to establish causation do so by means of correlation.
  3. ∴ Causation can never be established.
  4. ∴ There is no evidence for causation.
  5. ∴ Natural cause and effect are fictions of the mind.

Hume taught that “cause and effect” was not a reality, but a mere psychological habit the human mind has of connecting things. It followed that all or most of human science was not grounded in reason, but it an irrational and unjustifiable psychological prejudice. So Hume ended up in a deep and almost total skepticism.

al Ghazali applies Ockham’s Razor centuries before Ockham and notes (correctly) that the most parsimonious explanation of seeming regularity in the world, or what some call “nature,” is simply a single cause: the omnipotent will of Allah. One cannot get more parsimonious than one and only one cause.

So it follows that there is simply no such thing as “nature.” There are no second-order causes that operate apart from the will of Allah. It is not the case that paper placed in fire will burn because the fire consumes it.  Fire has no power to cause anything, including burning—what happens is, when paper is place into fire, Allah may (or may not) cause the paper to be burnt. Every event, bar none, is caused directly by the will of Allah. The word “nature” is not the name of anything. There is no such thing as nature. The very idea of “nature” and therefore of “natural sciences” rests on a mistake, namely, that there is an order of causation that is independent of the will of Allah. But this cannot be so, so it is not so.

It is a strange argument for most Westerners, given their understanding that “nature” was the great discover of the Greeks that allows the very possibility of philosophy and science. But it isn’t entirely foreign to the Western tradition either. As I’ve already noted, William of Ockham taught just such a an occasionalism conception in which God is the single cause of all events; and David Hume took philosophers and scientists to task for believing their concept of “cause and effect” was a rational one, as opposed to a merely irrational habit of associating two things in the mind.


As new and radical as the insights of Ockham and Hume seemed in their own day, they were only following in the footsteps of al Ghazali. Here are some of his words.

As a thought experiment, when you read al-Ghazali’s words below, replace “mathematics” and “mathematician” with “science” and “scientist” respectively:

Mathematics comprises the knowledge of calculation, geometry, and cosmography: it has no connection with the religious sciences, and proves nothing for or against religion; it rests on a foundation of proofs which, once known and understood, cannot be refuted. Mathematics tend, however, to produce two bad results.

The first is this: Whoever studies this science admires the subtlety and clearness of proofs. His confidence in philosophy increases, and he thinks that all its departments are capable of of the same clearness and solidity of proof as mathematics. But when he hears people speak of the unbelief and impiety of mathematicians, of their professed disregard for the Divine Law, which is notorious … he says to himself that, if there was truth in religion, it would not have escaped those who have displayed so much keenness of intellect in the study of mathematics.

Next, when he becomes aware of the unbelief and rejection of religion on the part of these learned men, he concludes that to reject religion is reasonable. How many of such men gone astray I have met whose sole argument was that just mentioned. And supposing one puts the following objection: “It does not follow that a man who excels in one branch of knowledge excels in all others, nor that he should be equally versed in jurisprudence, theology, and medicine. It is possible to be entirely ignorant of metaphysics, and yet to be an excellent grammarian. There are past masters in every science who are entirely ignorant of other branches of knowledge. The arguments of the ancient philosophers are rigidly demonstrative in mathematics and only conjectural in religious questions. In order to ascertain this one must proceed to a thorough examination of the matter.” Supposing, I say, one make the above objection to these ‘apes of unbelief,’ they find it distasteful. Falling a prey to their passions, to a besotted vanity, and the wish to pass for learned men, they persist in maintaining the preeminence of mathematicians in all branches of knowledge. This is a serious evil, and for this reason those who study mathematics should be checked from going too far in their researches. For though far removed as it may be from the things of religion, this study, serving as it does as an introduction to the philosophic systems, casts over religion its malign influence. It is rarely that a man devotes himself to it without robbing himself of his faith and casting off the restraints of religion.

Now tell me: has he missed the mark?