123 - Philosopher of the Arabs: al-Kindī

Posted on 7 April 2013

Al-Kindī uses Hellenic materials to discuss the eternity of the world, divine attributes, and the nature of the soul.

Further Reading

• P. Adamson and P.E. Pormann (trans.),The Philosophical Works of al-Kindī (Karachi: Oxford University Press, 2012).

• P. Adamson, Al-Kindī (New York: Oxford University Press, 2007).

• P. Adamson, Studies on Plotinus and al-Kindī (Aldershot: 2014).

• P. Adamson, “Al-Kindī and the Mu'tazila: Divine Attributes, Creation and Freedom,” Arabic Sciences and Philosophy 13 (2003), 45-77.

• A. Ivry, Al-Kindi’s Metaphysics (Albany: 1974).

• C. D'Ancona, “Aristotelian and Neoplatonic Elements in Kindi’s Doctrine of Knowledge,” American Catholic Philosophical Quarterly 73 (1999), 9-35.

• H.A. Davidson, “John Philoponus as a Source of Medieval Islamic and Jewish Proofs of Creation,” Journal of the American Oriental Society 89 (1969), 357-91.

• D. Gutas, “Geometry and the Rebirth of Philosophy in Arabic with al-Kindi,” in R. Arnzen and J. Thielmann (eds), Words, Texts and Concepts Cruising the Mediterranean Sea (Leuven: 2004), 195-209.


Rhys W. Roark 7 April 2013

Dear Peter,

I am intrigued by your reference on Aristotle and the distinction between actual vs. potential infinities.

Perhaps, incorrectly, I thought the whole notion of any infinity for Aristotle was potential only, for, like in the understanding of the counting of number, or the elapsing or (meta)physically, pure matter that lacks the impartation of the eidos (which can be potentially anything), any infinity lacks that sine qua non for Greek thought, form and limit.

So does Aristotle admit to the existence of an actual infinity, i.e., a substantial infinity? (I tend to think of this idea more in terms of later Scholasticism, their Pure Act, in contrast to Aristotle’s Pure Act, the former that must be infinite in essence, owing to the Christian doctrine of creation, where as the latter is still finite in essence as thought thinking itself, thus a dlimitation).

Or have I just misunderstood your intent here: you are simply pointing to a logical gap is al-Kindi’s reasoning? Not that Aristotle actually posits any substantive infinity (or my take on him nonetheless), but if something was infinite in size, it would, because physical extension is substantive, it would be actually infinite. But this would still be a contradiction because substantive things, to be substantive, must possess form and limit.

Set me straight.


Hi Rhys,

Sorry if that wasn't clear -- what I meant was that Aristotle accepts that there are potential infinities (every magnitude is potentially infinitely divisible for instance) but not that there are actual infinities. So, by devoting most of his attention to arguing against the possibility of actual infinities, al-Kindi is doing nothing to touch Aristotle. Aristotle would simply agree, but then say that eternal time is a potential and not an actual infinity. That's why I say that only the argument about "could we reach the present moment?" is at all helpful against Aristotle: it is a way of trying to show that eternal time would be actually rather than potentially infinite. (Because the number of moments that must _already_ have elapsed up until now would be actually infinite.)

Does that help?


Fatih 23 November 2013

Hi there, first I want to thank you for this great webpage. I v just found this page and I really liked it. I'm from Turkey, and sometimes i might have troubles understanding some topics as a foreigner. So i have a question to you:
Is it possible to add the text too ? I think it'd be great for foreigners to understand the topic better if you do this.

Also I m trying to understand Kindi's ideas. And sorry if i put comment in the wrong place :)

Again , thank you very much!

From Turkey, with love :)

Peter Adamson 24 November 2013

In reply to by Fatih

Thanks for your message - I get that question a lot actually. The scripts will appear in revised version as a series of books with Oxford University Press. Volume 1, covering Classical Greek Philosophy up to Aristotle, will be out next year.

mobin 11 November 2014

First of all I have to thank you for this fantastic and very interesting podcast, my dear professor. Even in paradise I would listen to it.
But now I want to ask you something because this question appeared in my mind:
Is it right that Al-Kindi has used a different terminology in comparison to the theologicans of his time or in comparison to the Koran? Was there a reason for using a different nomenclature or was it more arbitrarily and without any importance?

Allah = Al-bȃri`(creator)
Allah = Al-`illat al ulȃ (the first cause)
Khalq = ibdȃ` (creatio ex nihilo)
Jism = Jirm (matter)

Sincerely yours

Well, Kindi does use Koranic language also, including of course the word Allah. But you're right that these are technical terms he employs in his philosophy; they are basically being used to reflect ideas from the Greek tradition that came into Arabic through the translation movement (like they also spoke of "first cause"). 

Your last item is an interesting one; he uses both jirm and jism, usually as synonyms but there is one brief text (I think it is a fragment of a longer work) which contrasts jirm to jism using the former for earthly bodies and the latter for heavenly bodies.

If you haven't checked it out you might want to get a hold of Peter Pormann and my book of translations of Kindi; one text that could interest you there is his "Book of Definitions," where we give the Arabic terms being defined in brackets.

Chris Backes 4 October 2015

What of Philoponus's corpus did Kindi have available to him? For example, could we say with any certainty that Kindi had Philoponus's commentary on the De Anima (I mean the full one that is a report of the lecture of Ammonius)? I think of this because Philoponus has an interesting distinction between doxa and dianoia in the beginning of the Proemium that was slightly different than some other Neo-Platonists (like Proclus in Elements of Theology Sec. 123)?

Good question - you could look at my book on Kindi for more detail but the short answer is that an Arabic paraphrase of the De Anima (ed and German trans by R. Arnzen, published with Brill, costs a fortune) weaves in material from Philoponus' commentary. That paraphrase seems to date from Kindi's period if not come from his circle, even. In some of my work I've shown that there are parallels between it and Kindi for instance in the theory of light and vision. So, my guess is that Kindi wouldn't have necessarily been able to read that commentary itself but he was indirectly influenced. Also of course he knew some arguments of Philoponus against the eternity of the world; and again it's not entirely clear what form the textual transmission took there.

Thanks for the comment. Having had more time over the weekend, I did see that Philoponus follows roughly Aristotle in his distinction, substituting dianoia for episteme in Post. An. I.33. I just seems interesting because when Kindi talks about prophecy (whether in this letter on Aristotle's corpus or in the beginning of the "Prostration"), it sort of lines up with this distinction (specifically that knowledge and opinion can have the same object, depending on whether the definitions of the objects are known), albeit adding that this knowledge concerns divine truths (and having to account for the certainty of the knowledge from prophecy in a different way than by syllogism). I'm not sure if you have any thoughts about it, but I was researching for a paper for a class with Dr. Druart (who thinks you are one of the funniest people) and had a bit of trouble finding what the circle had available (as I'm sure everyone does).

I see - so you're interested in whether Kindi has a "two world" theory of knowledge as is sometimes ascribed to Plato. Actually I have argued that he does, in the section in my book on the "epistemic gap". But you're right that he occasionally follows what is pretty clearly Aristotle's view, and says that the same thing (proposition?) can be the object of both knowledge and belief. On the other hand he could mean that targets of intellective knowledge ("divine things") can be known OR believed, the latter in cases where the criteria for knowledge haven't been met. Usually though he contrasts the levels of cognition not by comparing knowledge to belief, but rather intellection ('aql) to sensation.

And I would prefer that Therese think I'm both brilliant and funny, but failing that I'll settle for funny.

I think it goes without saying that she does think that you are intelligent. and thank you for the additional comments. And thanks for doing this podcast. I preach the virtues of it to everyone in my grad school.

Michel Accad 30 December 2016


First, let me add my name to the many who are enchanted with your podcast series and are thankful for your teaching.  You are providing an invaluable service.  

I have been listening carefully since episode 1, working my way up.  My question is this: why was Aristotle so appealing to the Islamic philosophers?  If the oneness of God is so central to Islamic theology, I can see why the Islamic philosophers would view the neoplatonists favorably, but I'm not sure why they would been so keen to study Aristotle thoroughly.

Thanks again and Happy New Year!


Thanks, glad you like the podcast! Your question is a good one and perhaps there is no single answer, but I think the main reason is that Aristotle had already come, in late antiquity, to provide the basic curriculum for philosophical education. His works were effectively the standard textbooks on each branch of philosophy that were assigned to students in Alexandria and elsewhere. This also meant his writings were pretty widely available in mansucripts. Hence when they decided to translate philosophical and scientific works, starting with Aristotle was not just appealing but nearly inevitable. By contrast Plato, for instance, was studied only as an advanced topic and would have been both harder to get hold of and less obvious as part of the "core" philosophical curriculum.

Guy of Jerusalem 11 June 2021

It sounds like Al-Kindi was indeed quite a character. (By the way, what does the "Kindi" surname mean? I speak Hebrew and frequently Arabic names have recognizable Semitic roots, but here I can't see anything familiar). 

Anyway, theologically speaking, you talk about how for Al Kindi, everything is in some sense one, but in another sense many, except for God, who is pure, true One. He is true One as he bestows upon things thier oneness. In other words God is the principle of Oneness itself. This is how I understand what you say around in minute 13 of the podcast. But then there must be some other principle(s), let's call it (them) Olympus, who bestows Manyness. Why is God (Oneness) supreme? Moreover, according to this way of thinking, God is not the lone deity, for Olympus exists too. 

Is this not a problem for this kind(i) of theology? 

(I guess it would not be a dramatic problem for a pagan like Plotinus, because he does not need the One to be the only deity). 



The name al-Kindī is a reference to his family background, from an ancient Arab tribe called the "Kinda".

And yes, that's a good point: why isn't there also a "true many" that is the source of multiplicity. One reason would be that, as al-Kindī argues, the notion of a "true many" that has no unity (the way the True One lacks all multiplicity) is incoherent. For example, this many would be made of many things, each of which must be many (since they can't have unity); but then they would all have something in common, namely "many-ness" and this itself would be a sort of unity, i.e. they would all be united in being many (like humans who belong to a single species). This is an argument he presents in On First Philosophy.

Beyond that I think he could perhaps also argue that ultimately manyness or multiplicity is more like a failure to be one, much as Neoplatonists said that evil is a lack of goodness; but as far as I can recall he does not say that explicitly.

Saad Mehmood 19 August 2021

Dear Adamson,
I am a physicist from Pakistan and I have been reading about al-Kindi's life. While talking about how orthodoxy got al-Kindi persecuted, the Pakistani physicist Pervez Hoodbhoy says in his book:
"But then came the ascendancy of the orthodox Sunni Caliph AI-Mutawwakil, and with it the end of a long period of liberalism. It was not hard for the ulema to convince the ruler that the philosopher had very dangerous beliefs. Mutawwakil soon ordered the confiscation of the scholar's personal library, known to all Baghdad as al-Kindiyah. But that was not enough. The sixty-year-old Muslim philosopher also received fifty lashes before a large crowd which had assembled. Observers who recorded the event say the crowd roared approval with each stroke..AI-Kindi was the first major figure of Islamic scholarship to fall victim to the orthodox reaction against rationalism"

(Islam And Science – Religious Orthodoxy And The Battle For Rationality, by Pervez Hoodbhoy, London, ZED Books 1991, p.111, he cites 'The Genius o.f Arab Civilization. ed. J. R. Hayes. (Mass .. MIT Press. 1983). p. 69,')

Could you please comment on the historicity of what Hoodbhoy said, that is, were orthodoxy Ulama involved in getting al-Kindi persecuted as mentioned by Hoodbhoy?

Looking forward to hearing from you

Best Regards,

Well, that version is half right. He did have his books confiscated and he was beaten, or at least we are told that in a biographical source. But according to the same source it had nothing to do with orthodoxy or lack thereof: it was a court intrigue in which rival scholars, the Banu Musa, turned the caliph against him.

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