123 - Philosopher of the Arabs: al-Kindī

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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 on 7 April 2013

RE: Aristotle on infinity (From episode # 123, Al-Kindi)

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.


In reply to by Rhys W. Roark

Peter Adamson on 7 April 2013


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 on 23 November 2013

Audio - Text

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 :)

In reply to by Fatih

Peter Adamson on 24 November 2013


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 on 11 November 2014

Terminology of Al-Kindi

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

In reply to by mobin

Peter Adamson on 12 November 2014

al-Kindi's terminology

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 on 4 October 2015

Kindi's Sources

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)?

In reply to by Chris Backes

Peter Adamson on 4 October 2015

Kindi and Philoponus

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.

In reply to by Peter Adamson

Chris Backes on 5 October 2015

Thanks for the comment.

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).

In reply to by Chris Backes

Peter Adamson on 5 October 2015

Prophecy in Kindi

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.

In reply to by Peter Adamson

Chris Backes on 5 October 2015

I think it goes without

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 on 30 December 2016

Appeal of Aristotle to the Islamic philosophers


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!


In reply to by Michel Accad

Peter Adamson on 1 January 2017

Aristotle's appeal

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 on 11 June 2021

Kindi's theology

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). 



In reply to by Guy of Jerusalem

Peter Adamson on 11 June 2021


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 on 19 August 2021

al-Kindi's persecution

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,


In reply to by Saad Mehmood

Peter Adamson on 20 August 2021

Persecution of Kindi

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.

In reply to by Peter Adamson

Saad Mehmood on 21 August 2021

Thank you so much!

Thank you so much!

In reply to by Peter Adamson

Shershah Khan on 16 May 2023

Persecution of al-Kindi?

Professor in your book "Al-Kindi" you mentioned that al-Kindi got into a controversy with the Banu Musa brothers (p. 4-5). But I didn't see anything there on the point that he was beaten. Is the source for this latter claim (being flogged) Ibn Abi Usaybia, who also informs us of the controversy between the Musa bros and Al-Kindi? Also, you mentioned that the return of the books to al-Kindi from the Musa bros is "our last biographical information about alKindi apart from a report of how he died." (p.5) That's why I thought since this is the last, there logically won't be any information regarding his flogging.

Lastly, there is the claim that he even lost his sanity due to the flogging, a claim which I think is not valid. What would you say about that?

Thank you.

In reply to by Shershah Khan

Peter Adamson on 17 May 2023

Flogging of Kindi

Yes, the same report about the Banu Musa also mentions he was whipped. Here is the whole story (from the biographical report of Ibn ʾAbī ʾUṣaybiʿa, translated in the volume I did with Peter Pormann). As you'll see there is nothing about him losing his sanity, so not sure where that idea would have come from.

Muḥammad and Aḥmad, the Banū Mūsā, in the time of Mutawakkil [reg.847–61], conspired against all who discussed prognostics. They sent Sind ibn ʿAlī away to the City of Peace [i.e., Baghdad] and separated him from Mutawakkil. And they hatched a plot against al-Kindī so that Mutawakkil had him beaten. They went to his house and took all his books, and set these aside in a storehouse that they called the ‘Kindīya’. They were able to do so because al-Mutawakkil despised moving instruments. Mutawakkil commissioned these two to oversee the digging the canal called al-Ǧaʿfarī, and they entrusted the job to Aḥmad ibn Kaṯīr al-Furġānī, who had built the new measuring instrument for the Nile in Egypt. The latter’s knowledge was greater than his success, for hardly had he completed the task, [it became apparent that] he committed a mistake at the mouth of the canal known as al-Ǧaʿfarī: he had made it lower than the rest, so that [the water] that submersed the mouth did not flow into the rest of the canal. Al-Muḥammad and Aḥmad, the Banū Mūsā, defended the work that he had undertaken. Mutawakkil, however, required them to go quickly and take up the matter with [Sind ibn ʿAlī]. Al-Mutawakkil promptly summoned Sind ibn ʿAlī back from Baghdad, who duly appeared. (8) Once the Banū Mūsā confirmed that Sind ibn ʿAlī had left, they were ripe for destruction (ʾaynaʿā bi-l-halkati), and despaired of their lives. Al-Mutawakkil summoned Sind and said to him, ‘every time these two scoundrels speak ill of someone, it is always aimed at you. These two have wasted a great deal of my money on the canal. Go out to the canal to inspect it and see what is wrong. I have sworn by my life that if things stand as they have been described to me, then I will crucify them [sc. the Banū Mūsā] on its shores.’ Muḥammad and Aḥmad, the Banū Mūsā, got wind of all of this. As he [Sind] went out with them, Muḥammad ibn Mūsā said to him, ‘ʾAbū Ṭayyib, a gentleman does not bear a grudge. We beg for your help [in saving] our lives, which are so dear to us. We do not deny that we did wrong, but confession removes commission, so absolve us, as you will.’ Sind said to them, ‘By God, surely you know the enmity and estrangement between myself and al-Kindī, but it is the truth that I follow. Was it kind of you to take his books? By God, your reputation will not be restored until you return his books to him.’ So Muḥammad ibn Mūsā proceeded to bring the books to him. al-Kindī acknowledged receipt of the books in full, with a note saying that they have all been delivered. (10) [Sind] said, ‘it is incumbent upon me to offer you protection, since you have returned this man’s books. You have protection in knowledge, which we must keep between us: the mistake in this canal will be hidden for four months, thanks to the rise of the Tigris. And the astrologers (al-ḥussāb) agree that Mutawakkil will not live that long. I will immediately inform him that you made no mistake regarding the canal, so you may live. If the astrologers are right then we three will escape; but if they are wrong, then he will live long enough for the Tigris to recede, and he will attack all three of us.’ Muḥammad and Aḥmad thanked him for this, and he let them sneak away. He went to al-Mutawakkil and said to him, ‘they made no mistake.’ The Tigris rose and the water flowed into the canal, and hid its true state. Al-Mutawakkil was killed after two months and Muḥammad and Aḥmad were saved, after confronting such a terrifying fate.

In reply to by Peter Adamson

Saad Mehmood on 14 December 2023

Al-kindi's Persecution

Thank you so much. I have a quick question: did Banu Musa belong to Mutazilite group? Could you recommend a biographical source on these brothers containing details on their theological inclination?

Kenneth Connally on 27 March 2024

Philosophical Works of al-Kindī

I was just looking into getting a copy of your book of translations of Kindī's works, but it looks like it's out of print. The link to the book's page on the Oxford UP website is dead, and Google searches only turn up copies being resold for hundreds of dollars. Hope Oxford UP does a reprint at some point! I love to see the works of major philosophers beyond the European tradition being made accessible through translation.

In reply to by Kenneth Connally

Peter Adamson on 27 March 2024


Indeed - I was just asking OUP about that recently and they said they are going to reprint it, I will actually follow up now since I haven't heard anything on this since September.

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