Leibniz and the Religion of the Mohammadans

Abstract

Throughout his correspondence and writings, Leibniz made a number of passing references to the religion of the Mohammadans (Islam) and to several Islamic commentators. Recent literature on these references has placed them in the context of Leibniz’s political and historical interests that largely reflect his Eurocentric prejudices. The purpose of this paper is to extract a more detailed and systematic view of Leibniz’s knowledge of and interest in the religion, through Leibniz’s remarks on Islam in relation to Christian doctrines such as the Trinity and the Incarnation, through the commentary of Maimonides and the Christian Averroists, and through a (partly speculative) comparison of three types of theodicy. The paper concludes that while Leibniz knew very little about Islam’s actual doctrines, and that he was subject to the prejudicial views of his time, he understood Islam, as he did Christianity, as largely in conformity with natural (rational) religion. At the same time, his interest in its specific doctrines was primarily instrumental, that is, as correctives to certain abusive practices and misunderstandings persisting within Christianity, which could then explain for him why Islam prevailed in the East.

1. Introduction

In the extant literature, several key papers have focused on Leibniz’s interests in Islam, or what Leibniz variously called Mahometism, the religion of the Turks, or the religion of the Mohammadans. These papers show that Leibniz’s interests were primarily political (e.g., his attempt to persuade Louis XIV to invade Egypt for the purpose of dissuading France from invading Holland and Germany); philological or historical (an interest in the origin and character of the Arabic language and people); and religious, in highlighting Islam’s inferiority and danger to Christianity.1 It must be admitted that Leibniz did not possess any direct knowledge of Islamic religious doctrines since, despite repeated attempts to attain a copy, he never read any of the ‘Alcoran’ (as it was commonly called), nor did he indicate any knowledge of the Hadith, nor did he personally know anyone belonging to the faith. As a result, Leibniz’s remarks on ‘Mahometism’ and the Mohammadans, dispersed throughout his works from as early as 1671 until 1716, the year of his death, are spotty, infrequent, based on hearsay, and mostly, but not always, negative. It is difficult, thereby, to show whether Leibniz held any kind of philosophically systematic view of the religion. The extant literature tends to focus on Leibniz’s attitude towards the religion, without focusing on the details, as scant as they may be, of his understanding of it.

This paper aims to provide a detailed and systematic account of what Leibniz knew of Islam’s specific doctrines and the Islamic commentators with whom he was familiar. The first section will provide some of Leibniz’s initial impressions of the religion that he gathered from his correspondents in an effort to obtain a faithful edition of the Qur’an. The second will discuss Leibniz’s positions on several doctrines of direct relevance to the Qur’an: idolatry, the Trinity, the Incarnation, and usury. The third will extract Leibniz’s notes on Maimonides’ Guide for the Perplexed for his reaction to the Mutakallimun, the Mutazila, and Assaria schools on various issues of theological import. The fourth will examine his arguments against the Christian Averroists on the immortality of the soul and the doctrine of the twofold truth. The final section focuses on three theodicies: Islamic fate, the preponderance of evil in al-Razi, and optimism in al-Ghazali (best possible world). While Leibniz had no knowledge of al-Ghazali, a comparison will show how Leibniz might have engaged him on an issue of great significance for them both. In the end, even if Leibniz’s knowledge of Islam is slight, indirect, and prejudicial, it is hoped that we gain a richer understanding of his knowledge of and interest in the religion of the Mohammadans.

2. What Did Leibniz Know of the Qur’an?

Leibniz never read the primary text of Islam, the Qur’an, either in its original Arabic (which he could not read) or in any translation he could read (Latin, German, French). Nor had he read any other of the canonical Islamic texts, such as the Hadith, nor directly any Arabic sources.2 As Daniel Cook observes,

His encounters with the Islamic Orient were strictly textual. His knowledge of Islam was filtered through a European language. As far as we know, he never even met a Muslim. Nevertheless, he did comment on Islam (and the Arabic sources available in Europe at the time) and displayed a growing interest in it.

(Cook 2008, p. 169)

Most of Leibniz’s comments were informed by correspondents and writers, some of whom had read the sacred texts, but whose opinions (except for certain commentators, discussed below) were typically Christocentric. While Leibniz himself often expressed much disdain for ‘the Turks’ in his political writings3—and took for granted that others shared his disdain—his interest in an authentic and direct knowledge of the religion began to grow in the early to mid 1690s. By tracing this growing interest, we can discover most of the sources of his knowledge of the religion as well as the impressions he gathered of it along the way. For example, in this letter to Henri Justel in 1692, Leibniz writes:

The book of Father Maracci, confessor of the late Pope Innocent XI, on the Alcoran, has just now appeared. This Father, who is of an order other than the Jesuits, has extensively read the Arab commentators on the Alcoran, and his goal is to teach us the true sense of this book that our Christian authors often take wrongly.

(A I 8, 373)

Maracci’s book had not in fact appeared and would not until 1698. Leibniz repeatedly sought it but would never receive it. Yet Leibniz had other sources of knowledge about the Qur’an, for example, this correspondent, Daniel Larroque, who in 1693 writes:

I had already learned that in Padua they had prepared an edition of the alcoran in 2 volumes, in folio, and that the edition was made with the support of Cardinal Barbarigo. The diversity of manuscripts will not teach us anything, since never was a text less altered than this one, because the respect Musulmans had for their Law was greater than the Christians had for theirs, or because deception and animosity had from all times been attached to the purest belief.

(Larroque to Leibniz, A I 9, 614)

Larroque was replying to Leibniz’s previously expressed concern about possible alterations of the Hebrew text of the Bible,4 while he assures Leibniz of the fidelity and unity of this recent edition of the Qur’an. Leibniz would not obtain this text, either. But Larroque’s criticism of respect for the law lacking among Christians will reflect Leibniz’s criticisms of certain Christian practices and how Islam may have played a role in leading potential converts away from Christianity, as we will see.

The following passage again displays Leibniz’s persistent effort to obtain Maracci’s commentary, a sense of why Leibniz wanted it, and his interest in obtaining a faithful translation.

There has been published in Rome, not the Koran itself, but Maracci’s observations on the Koran;5 he is a learned man, one versed in reading the Arabs, and his observations are taken not so much from the prejudices of the Christians as from the commentaries of the Muslims themselves. Ultimately I would like the entire Koran to appear with an accurate translation along with notes suitable for elucidating the meaning. But there are, I suppose, few people among us who are able to do such a thing. And I think that the Arabism of most is mediocre, although one-eyed people are rightly valued among the blind. For me there is no access to these studies because the occasion [to study them] was lacking in my youth.

(Leibniz to Johann Reiske, 1693, A I 9, 426 (Leibniz 1923). Cited in (Cook 2008, p. 179))

This letter conveys Leibniz’s awareness that the mainstream western-European scholarship on the Qur’an had long been, and still was, rather tenuous and unreliable. It is not clear how Leibniz can be so sure that Maracci’s edition was not taken from Christian prejudice. Evidently, he did not know that Maracci’s commentary was quite hostile to Islam. The subtitle of Maracci’s edition reads: ‘a refutation of the Koran, in which an ax is laid at the root of Mohammadan superstition; and Mahomet himself is slain with his own sword’ (Varani 2008, p. 58).

Nevertheless, Leibniz would rely on those few he could trust to have first-hand knowledge of the sacred text, such as Pierre-Daniel Huet.6 Huet read Arabic, since he reports on several new Arabic editions of the Alcoran and judges two of them to be defective. He adds:

It is the fifth reading I have made of the Alcoran, and I do not find it as contemptible as does Mr Bochart;7 when one enters in the spirit, in the morals, and in the teaching of this people and of this century, one finds there a rather consistent system of morals and Theology, even though its foundations are vicious.

(Nov. 1696. A II 3B, 239–40)

What these vicious foundations are Huet does not say, nor does Leibniz. They seem to be taking for granted a widely shared judgment. But what is surprising here is that Latin and French translations of the Qur’an were in fact available. Huet mentions that he eagerly wishes to read a forthcoming edition by A. Acoluthus. That edition would not appear until 1701; but Huet does not mention that it would include translations of the Qur’an into Persian, Turkish, and Latin, which Leibniz, fluent in Latin, certainly could have read.8 There is no record that Leibniz ever saw or tried to obtain it. The other edition Huet mentions is Andre du Ryer’s, which includes a French translation published in 1649. It is remarkable that Huet did not mention this, either, since Leibniz certainly could have read the French. Perhaps his negative judgment of its Arabic compared with other editions (‘it is not literal, and it often departs from the original’) dissuaded him from mentioning the translation. Neither did Huet mention that a German translation by Johann Langes, based on this French translation, appeared in 1688 (Varani 2008, p. 65), which Leibniz should easily have known about. It is also remarkable that Leibniz did not find out about these editions from some other source.

In any case, Leibniz’s response to Huet focuses on the anticipated Maracci commentary and why it may not be available:

I am assured that Pope Innocent XI has blocked the edition of the good father Maracci, although he was his confessor, because he regarded his remarks as a kind of apology for the Alcoran, in which he showed that the commentators very often gave it a reasonable sense. The Arabs have had philosophers whose sentiments on divinity have been as elevated as the most sublime Christian philosophers could be. This can be known by the excellent book of the self-taught philosopher that M. Pococke has published in Arabic.

(Leibniz to Claude Nicaise, March 1697, A II 3B, 274 (Leibniz 1923))

The latter comment is curious, since surely the Pope knew that Maracci’s commentary constituted an indictment rather than an apology. In any case, we find here Leibniz’s positive estimation, not so much of the religion itself, but of its commentators, since they compare well with the best of Christian commentators, such as Thomas Aquinas, no doubt. The self-taught philosopher who provides Leibniz with evidence for this opinion turns out to be Ibn Tuyfal, the 12th century Andalusian-Arabic writer famous for his philosophical novel, Hayy ibn Yaqzan.9

Finally, one of Leibniz’s later remarks again reveals his abiding interest in obtaining direct access to the Arabic religious texts. In a letter to Thomas Burnett of 1697, Leibniz boasts that his Combinatory Art (1666)—built on the idea that written characters should convey a one-to-one correspondence with an ‘analysis of thoughts’—might serve to clarify a number of questionable texts, implying that such a method could be applied to the study of the original Arabic texts. But any clarification or analysis would require that the source text be reliable:

To know well the life of Mahomet, author of the religion of the Saracens, it will be necessary to consult the Arab Manuscripts, otherwise one runs the risk of being mistaken.

(Gerhardt 1875–1890, 3.216)

In sum, these sparse remarks drawn from Leibniz’s correspondence show that Leibniz could not read Arabic, that he tried but never obtained a translation of the Qur’an, that he was not aware of available French, German, and Latin translations, and that some of his opinions on the religion (not entirely negative) were based on the opinions of correspondents who actually had direct knowledge of the original text, but whose judgments appear to be biased or negative. Thus, while Leibniz made sincere efforts to obtain a fair and comprehensive understanding of the religion, he actually possessed little knowledge of it. Next, we will look at Leibniz’s treatment of the specifically religious topics with which he was most concerned, although still without possessing any direct knowledge of the religion.

3. On Idolatry, the Trinity, and the Incarnation

In a piece titled ‘On the Worship of the Saints’ (1677)10 Leibniz engages in a debate with his frequent correspondent, Herman Conring and Dionysis Werlensis, a Capuchin Friar and theologian, over how saints should be properly revered. Leibniz argues that worship or excessive honor granted to saints ‘is to the detriment of God’ and ‘that God should be honored is the fundamental principle of all piety and religion’ (Leibniz 2026, A IV 6, p. 673). But the question of saint worship is also relevant to the question of idolatry in Islam and Christianity. Leibniz goes on to argue that worshipping the saints not only has no great benefit but is actually harmful, and he sets out four distinct types of harm, the fourth characterized as a ‘scandal to the Jews and [a] loss of the Orient through the Mohammadans’ (Leibniz 2026, A IV 6, p. 677). The ‘scandal’ is mainly idolatry. As Leibniz asserts, without indicating how he knows this, at the founding of the religion Muhammad ‘gathered together a rabble of Jews, semi-Christians, and Arabs’ and ‘thundered against the Christians as idolaters, and accused them of transferring to creatures the worship due to the one God’ (A IV 6, 679). Leibniz also conjectures that Christian worship of the bread in the Eucharist must seem ‘abominable’ to the Mohammadans (Leibniz 2026, A IV 6, p. 679), presumably because it gives material things (bread and wine) divine significance. In fact, this is what the Qur’an would call a ‘shirk’.

Although, of course, Leibniz had not read them, numerous passages in the Qur’an certainly attest to the prohibition of idolatry, or what are called acts of shirk, that is, the sharing or associating Allah’s attributes with things that are not Allah, such as images of Allah, Jesus, and the jinn.11 Of course, Judaism and Christianity also forbid idolatry.12 But Leibniz believes that idolatrous practices persisting among Christians and potential converts turned them away from Christianity and toward the Mohammadans. The intensity of the Jews and Mohammadans’ hatred for image worship, Leibniz claims, either drove early Christians and ‘semi-Christians’ to adopt Mohametism, or, much later, Church practices encouraging idolatry drove Muslims away from Christianity. Evidence supporting the latter view is given in his letter to Bossuet, in which

we find Leibniz lamenting how the early church’s prohibition of images was overturned by the second Council of Nicaea. If the abuse of image-worship had been checked early on, remarks Leibniz, ‘Christianity would not have become reproachable [meprisable] in the Orient, and Mohammed would never have prevailed’.13

Along these lines, Leibniz had later conveyed to Madame de Brinon that the ‘wholly sensuous devotion of Roman Catholicism has resulted in abuses which have contributed a great deal to frightening away many Mohammedans from Christianity’.14

These are fairly serious criticisms of Christian practice. But another contributing factor to the Christian ‘loss of the orient’ is the Jewish and Islamic opposition to the Christian doctrines of the Trinity and the Incarnation. Leibniz does not indicate how he knows that these doctrines are antithetical to Islam, but it was likely common knowledge. To Islam, the Trinity (the Father, Son, and the Holy Spirit) looks like tri-theism, which is not only idolatrous for its attribution of divinity to a creature (Jesus), but antithetical to Islam’s insistence on the unity of God. The first of the five Pillars of Islam is the ‘testimony of faith’: ‘to testify that there is no god but Allah, and Mohammad is his messenger’ (Book 1, Hadith 21).15 Moreover, while the Qur’an reveres Jesus as a prophet (a fact which Leibniz knows16) it insists he was ‘no more than a messenger’ (5: 72–75). Mary, too, is highly revered, but was not divinely impregnated nor immaculately conceived. Those who identify Christ with Allah have fallen into disbelief (5: 17 and 5: 73). It follows that the Incarnation of a divine spirit in Jesus would amount to a ‘shirk’, i.e., the attribution of divine attributes to an entity that is not divine.

Yet the Mohammedans’ opposition to the Trinity rests on a misunderstanding, Leibniz claims, a misunderstanding which also persists among Christians. His own explanation for how the Trinity does not imply tri-theism is given succinctly in a letter to Electress Sophie (April 1709):

To come down to detail, there are some who, while teaching the Holy Trinity, go to Tritheism, by conceiving three completely distinct infinite substances, which have only a perfect agreement between them. But this is to lay oneself open to the Jews and to the Mohammedans and to overthrow natural religion, which teaches us that what makes and fills all cannot be three, and that the perfect substance, the source of beings, the ultimate reason of things, is unique. Everything beyond that is impossible and superfluous, and if there are three perfect and absolute substances, nothing stops there being an infinity of them. The Holy Trinity should be conceived as three principles in one and the same substance, which have an essential relation between them, without it being possible that there be more of them, and it should be compared with power, knowledge, and will: three principles of actions in a single intelligent substance which has to be able, to know, and to will; even though this comparison taken from our conceptions cannot be entirely accurate when it is related to God.

(Leibniz 2011, pp. 398–99)

In other words, unless it is understood that the three principles (Father, Son, and Holy Spirit) form a single substance, a single being, the doctrine of the Trinity is susceptible to being misunderstood as consisting of three distinct deities. Similarly, God’s primary attributes (power, knowledge and will) should not be conceived of as separate essences, but as forming a single, unified, essence. So, there should be no question here of applying divine attributes to non-divine entities—in keeping with the Islamic prohibition against ‘shirk’. Leibniz’s position is also consistent, he could claim, with both natural religion (philosophy) and revelation.17

Leibniz’s defense of the Incarnation (that is, the hypostatic union in Christ of divine and human natures) is much more complicated (see Antognazza 2007). To put it simply, Leibniz argues that the Incarnation is a mystery ‘above reason’ but not contrary to it—hence, reason and revelation do not conflict (Antognazza 2007, p. xv). A truth is ‘above reason’ when it is not contradictory (against reason) but is however beyond human experience and comprehension (Leibniz [1710] 2007, Preliminary Dissertation §23). He also explains it in terms of an analogy: we accept the relationship between the mind and body as real, and not contradictory, but inaccessible to human reason; just so is the relationship between the divine and human in the hypostatic union (Antognazza 2007, p. 36). Likely, however, the subtleties of these arguments, had they been given at the time of the founding of Mahometism, would not have been sufficient to persuade ‘the rabble’ that these doctrines do not imply the worship of idols. Nevertheless, Leibniz offers a much more straightforward position he thinks could be easily understood:

For neither the dogma of the Trinity nor that of the Incarnation greatly changes worship, because it is certain that we worship one God, the creator of heaven and earth, by himself and with principal latria.

(Leibniz 2026, A IV 6, p. 679)

Thus, for him there need be no conflict with the Mohammadans on these Christian dogmas.

4. Trinitarianism, Socianism, and Usury

Certainly, a main source, though late, of Leibniz’s knowledge of the religion of the Mohammadans came from an essay by Maturinus La Croze, called Historical and Critical Reflections on Mahometism and Socinianism. In 1706, Leibniz sent his review of La Croze’s essay to La Croze, who published it in his book in 1707.18 The review begins:

I have read with pleasure and profit your Treatise, which draws a parallel between Mohammedans and Socinians, wherein you have shown a great deal of erudition and zeal. I am not surprised by the great progress of Mohammedanism. It is a kind of Deism, joined to the belief in some facts [faits], and to the observation of some practices, which Mohammed and his followers have added, sometimes quite inappropriately, to natural religion. We are obliged to that sect for the destruction of paganism in many parts of the world, and that would be one step to lead people towards the more sublime religion of Christianity, if ours was preached as it ought to be, and if the ill-founded prejudices of the Mohammedans did not put a great obstacle in the way.

(Leibniz 2016, p. 338)

The ‘parallel’ between Islam and Socianism is that the Socinians also reject the Trinity for its implied tri-theism.19 But Leibniz is more interested, at least here, in how the Mohammedans succeeded where Christianity did not. It is not clear which inappropriate ‘facts’ and ‘practices’ Leibniz is referring to, but he credits Mohammad for leading the pre-Islamic Arabs to a religion that shares some features of natural religion, i.e., the belief in one God possessing the attributes of omniscience, omnipotence, and omnibenevolence. Thus, it appears that Leibniz thinks favorably of Islam insofar as it conforms to natural religion. Yet as this passage implies, while ‘Islam has some intrinsic value for Leibniz, its primary role [for him] is instrumental’, namely, as a gateway to Christianity (Cook 2008, p. 183). At the same time, he believes that Christianity would have better succeeded at that time, had it been taught and practiced rightly. As we saw above, the persistence of idol worship as well as misconceptions about the Trinity and Incarnation made it difficult for the Mohammedans, as well as the pre-Islamic Arabs, to put aside their ‘ill-founded prejudices’ against Christianity. But in fact, as Leibniz says here, ‘Christianity was already burdened with many superstitions and made itself vulnerable in many ways when Mohammed arose to establish a religion which was fairly similar to the Jewish and not entirely different from Christian sects, which soon gave him a great number of followers’ (Leibniz 2016, p. 339). So, two main factors, the Mohammadans’ misconceptions of Christianity and Christianity’s own tendencies toward idolatry, contributed to the Arabs’ turn toward Islam.

Leibniz’s review of La Croze’s book contains several additional remarks worth noting. The first concerns the Islamic prohibition against usury.20

As far as usury, condemned by the Mahometans, one could say that it is permitted to distribute profits among those to whom one lends in order to make a profit; but it is not at all just to burden miserable and poor persons who must borrow in order to live.

(Leibniz 2016, pp. 339–40)

A simpler way to put this is that it is unjust to profit from another’s misery. Notably, Leibniz’s remarks here reflect a maxim of natural law he finds in the ancient Roman Digest: ‘ne quis alterius damno fiat locupletior, that is, that no one should be enriched as a result of harm which befalls another’ (Leibniz [1765] 1996, 425/A VI 6, p. 425).21 For Leibniz this law is not primarily a civil law nor a law mandated by God, but rather, as he goes on to say, a ‘fundamental maxim which constitutes the law itself’ and is ‘taught by pure reason’. It is possible then for Leibniz to understand the prohibition against usury in Islam to be consistent with natural reason and natural religion.

Of greater concern to Leibniz is, again in La Croze’s book, the impact that the impression of tri-theism, stemming from the doctrine of the Trinity, had as an impediment to converting the Mahometans: ‘the main thing is to remove the opinion they have of us that we multiply the divinity’, though he also warns that Christians with poor education or poor understanding are susceptible to falling into tritheism (Leibniz 2016, p. 340). Leibniz then criticizes the Socinians, characterizing them as ‘very similar to the Mohammedans inasmuch as [Mohammad] contests the Trinity and Incarnation’ (Leibniz 2016, p. 340). However, he claims that the Socinians are inconsistent: While both deny Christ’s divinity, only the Socinians worship Christ; but then they worship a mere creature, which the Mohammedans do not (Leibniz 2016, p. 341).

Another way in which Socinians are criticized is that they deny God’s foreknowledge of contingent events and contest the immortality of the soul, while the Mahometans do not. For the Socinians, if God had such foreknowledge, then the free will of creatures would not be possible. For Leibniz and the Mohammedans, it is false that God/Allah does not have knowledge of future contingencies. The implications of this position upon free will are discussed in the section below on the so-called Fatum Mahometanum.

Finally, Leibniz expresses some sympathy toward Anti-Trinitarians, whether Socinians or ‘Turks’, who have met some ‘unfortunate end’ (such as the execution of Michael Servetus in 1553) or some punishment by God for reasons unknown to us, or due to ‘the irregularity of their heart’ rather than ‘their error of understanding’. Since these people are ‘living morally good lives’, the proper attitude toward them is pity, leniency, and the mercy of God (Leibniz 2016, pp. 343–44).

To summarize Leibniz’s comparison of Socinianism with Mahometism, we find that, on the issues of the Trinity, Incarnation, God’s foreknowledge, and immortality of the soul—all of which the Socinians reject, Leibniz has a higher regard for Islam, which also rejects the Trinity and Incarnation. But why then the higher regard? It would seem that Leibniz finds Mahometism to be more consistent with natural theology. At one point he says that the Socinian denial of God’s foreknowledge of contingencies weakens natural theology (Leibniz 2016, p. 341). But (and presumably Leibniz somehow knows this) Islam upholds God’s foreknowledge22—which is consistent with natural theology, at least for Leibniz. As for the Trinity, the Socinians, whose methodology is based on rational interpretations of Scripture, reject the Trinity on the grounds that the doctrine is not sufficiently scriptural (see Cunningham 1863, p. 155). But Islam rejects it on the grounds (though incorrect) that it is inconsistent with the unity of God—a position which is, again, consistent with natural theology. Socinians reject the pre-existence of Jesus and the Incarnation based on their rationalist-scriptural methodology, while Islam rejects these doctrines as idolatrous. But that is only because, Leibniz could say, those doctrines are thought by them to be inconsistent with the unity of God; thus, their rejection once again displays their consistency with natural (rational) theology.

5. Engagement with Islamic Commentators

Let us turn now to what Leibniz knew or surmised of the religion based on his exposure to Islamic commentators. These commentators make no reference to the sacred texts of Islam, but rather focus on theological and metaphysical doctrines that may or may not be based on the sacred texts. It must be acknowledged that, as Cook observes: ‘to this date’ no sustained discussion of any Islamic thinker has been found in the Leibnizian corpus (Cook 2008, p. 177). Nevertheless, if it is reasonable to assume that Leibniz associated Islamic thinkers with the religion itself, just as Christian thinkers believe their philosophical theology is consistent with Christianity, it makes sense to know how he understood those thinkers. This section will be divided into two foci: Leibniz’s notes on Maimonides, and his arguments against the Averroists on immortality and the doctrine of the twofold truth.

5.1. Leibniz’s Notes on Maimonides’ Guide to the Perplexed

The primary source of Leibniz’s knowledge of Islamic commentators is Moses Maimonides’ Guide to the Perplexed.23 His notes on that text provide several insights into his opinion on their positions.24 These commentators consist of the Mutakallimun sect on an implication of God becoming non-existent and on whether God’s existence can be proven; the Mutazila on whether accidents can exist apart from their substances; and the Ishmaelites on free will. Leibniz also comments on a theologian named al-Razi, but since his comments are in Theodicy and not in these Notes, they will be discussed below in Section 6.

Leibniz’s first set of remarks have to do with the speculative theology of the Mutakallimun, or scholars of the word of the Qur’an, who Maimonides refers to as ‘Mohammedan theologians’ (Maimonides 2002, p. 105). The main aim of these scholars was to provide demonstrative arguments for God’s existence and attributes and to draw implications therefrom. Leibniz’s notes on Part 1, Chapter 69 of the Guide simply paraphrase Maimonides’ characterization of the school’s position on the implications of God becoming non-existent. His paraphrase, while short and obscure, begins with their claim that ‘even if God did not exist, it would not follow that things would come to naught’ (Hilliger 2022, p. 66). But to understand this claim, which Leibniz calls ‘insane’, requires taking in the context that Maimonides provides in the Guide itself. According to the Guide, the sect claims that if God ceased to exist, the universe would continue to exist, since its continued existence does not depend on God. This would be correct, Maimonides notes, if God were only the creator of the universe and not the continual cause of its existence. But God is the continual cause, since God is the form of the material universe that sustains it. The Mutakallimun, then, have apparently ignored the form of God. As Leibniz puts it, following Maimonides, ‘they ignored that God is also [in addition to being the creator] the form and end (final cause) of the universe’ (Hilliger 2022, p. 66). Without these (Aristotelian) causes, form and end, the universe cannot exist or be sustained.

Continued criticism of the Mutakallimun sect occurs soon after, in Part 1, Chapter 71, where Leibniz makes two brief remarks. First, that these orators ‘confuse imagination with intellect’ (Hilliger 2022, p. 68). He must be referring to Maimonides’ assertion in the Guide that their demonstrative method is ‘guided by their imagination, [whereas they] thought that they were following the dictates of the intellect’ (Maimonides 2002, p. 110). For example, their demonstration of God’s existence is based on the premise that the universe was created out of nothing, a premise which Maimonides rejects because ‘all proofs for the creation are questionable’ as are proofs for the eternity of the world, and therefore cannot be demonstrated ‘with mathematical certainty’ (Maimonides 2002, pp. 110–11). Leibniz’s remark must mean, then, that the sect has not sufficiently reflected on its premise, thus imagining it is true, rather than proving it with demonstrative certainty. This explains Leibniz’s second remark, and his implied agreement with Maimonides, that these orators ‘wanted to demonstrate the newness [novitatem or beginning] of the world through philosophy, which Maimonides denies to be possible’ (Hilliger 2022, p. 68). Maimonides thinks that God’s existence can be proven independently of the question of how the world began, and Leibniz would seem to agree.

Next, in part 1, chapter 73, Leibniz lists 12 principles of the Mutakallimun, as Maimonides understood them, and responds to each one; for example, that there is an abstract substance [the atom]; that there is a void; that time consists of instants, and other such metaphysical propositions, but none of theological significance.

In part 3, chapter 15, Leibniz is interested in a metaphysical issue of theological significance raised by a different sect of the Kalam, the Mutazila. He repeats Maimonides’ observation in the Guide that this sect ‘believed that an accident could exist by God’s will outside of its substance’ (Hilliger 2022, p. 118; Maimonides 2002, p. 279). The issue raises the theological question of whether God can make contradictions true by virtue of his will. Suppose we say that a color (an accident) could be removed from a triangle (the substance). Could God will such a thing? Why not? It is easy to imagine. Leibniz’s response to this question is simply: ‘Possibilities are not those things that can be imagined, but those which can be understood’ (Hilliger 2022, p. 118). What he means is that for an idea to represent a real possibility it is not sufficient for it to be imagined; it must be non-contradictory. As Leibniz had explained elsewhere,25 the idea of ‘a greatest speed’ may be imagined; but since the idea involves a contradiction, it is not a possible idea. So, while I might be able to imagine that the color (accident) of an object (substance) could be removed from the object—after all, we can imagine that accidents of a substance can change—it is not logically possible for an accident to subsist apart from its substance. In other words, it is essential to the idea of ‘accident’ that it belong to a substance. So, a self-subsisting accident is a contradictory, impossible idea. Thus, since God cannot make contradictions true, God could not will that accidents exist apart from their substance.

In Part 3, Chapter 17, another sect, the Assaria of the Ishmaelite tribe, raise some specifically theological difficulties: all events occur by a special decree of God. Notably, this position is arguably consistent with the Qur’an’s.26 But Leibniz notes several dire consequences of this: ‘that nothing belongs to man’, and all events are either necessary or impossible (Hilliger 2022, p. 122). Furthermore, ‘that there is no purpose to divine actions, that even God can punish the one who has not sinned’ (Hilliger 2022, p. 122).

In response to the Assaria, Leibniz notes that the Mutazila hold that (1) man should have some power over his actions and (2) ‘no one who does good should be punished’ (Hilliger 2022, p. 123). Thus, humankind must have free will, and God must be just. We can also suppose that he opposes the ‘Spinozism’ implied in the notion that all events are (metaphysically) necessary. We may also note that the Mutazila have views that resonate with Leibniz’s own: that God’s foreknowledge does not preclude free will (Leibniz 2023, §13); and that ‘God provides the best for all and that men are born imperfect’ (Hilliger 2022, p. 123). Leibniz even says that the Mutazila are effectively Christians, since they believe that ‘when a good man is killed, it is for a greater reward in the world to come’ (Hilliger 2022, p. 122). Then, reflecting Maimonides, ‘it is our opinion and our Torah [law27]: man has free will, and there is no iniquity in God’ (Hilliger 2022, p. 123). So, we can assume that the Mutazila, Leibniz, and Maimonides agree on these points. Following Maimonides, Leibniz mentions the ‘afflictions of love’ (castigones amoris) (Hilliger 2022, p. 123). Maimonides clarifies the point in the Guide itself.

According to this doctrine it is possible that a person be afflicted without having previously committed any sin, in order that his future reward may be increased; a view which is held by the Mu’tazilites, but is not supported by any Scriptural text.

(Maimonides 2002, p. 286)

Leibniz seems to think this point is worth noting for its extension of God’s justice: those who do not deserve the afflictions and sufferings of life will be well compensated in the afterlife.

In Part 3, Chapter 22, his final remark on the Mutazila, Leibniz paraphrases Maimonides’ remarks on the Book of Job. The only remark of interest here is that one of Job’s friends, Bildad, would agree with the Mutazila, since Bildad says that Job’s reward would be all the greater since he is a righteous man. If this is a Christian viewpoint, as suggested by Leibniz’s remark on the Mutazila sect above, we can assume Leibniz agrees with Bildad as well (Hilliger 2022, p. 130).

Leibniz ends his notes thusly: ‘Maimonides very clearly distinguishes throughout [the Guide] between the intellect and the imagination and teaches that the former should judge of possibility, not the latter’.28 This statement indicates Leibniz’s affinity for natural theology, that is, a theology based fundamentally on rational possibility. We have seen this affinity in the arguments he put forward in these notes: He rejects the Mutakallimuns’ positions for containing faulty premises on God’s nature; he rejects the Mutazila for misunderstanding the nature of logical possibility; but he finds much affinity with their positions (against the Assaria) on free will, necessity, and divine punishment.

5.2. Averroism: The Immortality of the Active Intellect and the Twofold Truth

The so-called Averroists, or Paduan Averroists, were not Islamic philosophers, but rather Renaissance-era Christian followers of Averroes, the famous commentator on Aristotle.29 They did not, however, necessarily represent Averroes’ own doctrines. The doctrines Leibniz was most concerned with were the immortality of the soul, specifically, of the active intellect, and the doctrine of ‘twofold truth’—the latter certainly not held by Averroes himself. Moreover, these doctrines are not taught in the specifically theological circles of Islam. But let us take a close look at Leibniz’s engagement with these views.

The Averroists held, following Aristotle, that the rational soul consists of two parts or functions: the passive intellect and the active intellect, both of which play distinct roles in human perception and knowledge. Due to extensive commentary on a notoriously obscure passage in Aristotle (On the Soul, Bk III, 5), the Averroists, in agreement with other commentators, maintained that upon death only the active intellect survives by becoming one with God, or the universal mind from which it came and by means of which (prior to bodily death) the individual would grasp the most universal types of knowledge.

Leibniz provides a clue to his problem with this view in §28 of his Discourse on Metaphysics (1686). The main subject of this section is a dispute between Malebranche and Arnauld on whether God is the immediate cause of our perceptions. Leibniz indicates agreement with the Biblical characterization of God as ‘the light of the soul’ (John 1: 9) as well as the generally Christian scholastic interpretation of God as the source of ‘the active intellect of the rational soul’ (Leibniz 2023, §28). He then accuses the Averroists of giving the active intellect, a ‘bad sense’. His complaint, not mentioned in the Discourse, is that, according to the Averroists, upon death the soul becomes one with the universal soul, God; but if so, then it would no longer be an individual soul, and the loss of individuality is equivalent to death. In other words, the Averroist doctrine entails that the soul is not immortal, since dissipating into a ‘sea of divinity’, as Leibniz often puts it, means that the individual soul no longer has consciousness or memory of its existence or even of itself as one with God. This loss of the self would also undermine the incentives of morality, since there would be no self to punish or reward. Nor would they be of consequence in the present, because the individual would have no reason to anticipate them.30 The soul may very well be immortal, for the Averroists, but not in any way that could matter to an individual, according to Leibniz.

In Theodicy, Leibniz’s dispute with the Averroists is not so much over the immortality or dissipation of the soul, but rather with the way their account of immortality figures into their doctrine of the ‘twofold truth’. That doctrine says that where the truths of philosophy (Aristotle) and those of faith (revelation) are in conflict, both must be upheld as true. It should be noted that Averroes himself did not advance a twofold doctrine in quite the way the Christian Averroists suppose, nor is it found in Islam’s sacred texts.31 Leibniz’s main concern is that the doctrine fails to preserve the unity of faith and reason for which he argued at length, especially in Theodicy.32 The notion of a ‘divorce’ between faith and reason was also rejected by the Lateran Council under Leo X (Theodicy §110). But let us see how Leibniz understands and refutes the Averroists.

In §7 of Theodicy we find Leibniz disputing with the Averroists’ claims for the immortality of the soul (as an argument from reason), since their argument amounts to mortality of the soul, against faith. Here is the argument he attributes to them:

• The human species is eternal (common assumption).
• Suppose the individual soul is immortal.
• Therefore,
  • Individual souls must transmigrate (rejected by Aristotle)
  • Or, if individual souls must be continually generated anew, and since the species is eternal, then there must be an actual infinity of souls (rejected by Aristotle).
• The rational part of the individual soul has two parts: passive intellect and active intellect (Aristotle).

  c.

  The passive intellect dies with the body of which it is the form (Aristotle).

  d.

  The active intellect becomes part of the universal soul (Averroist assumption).

• Therefore, the passive intellect is mortal while the active intellect is immortal.

Leibniz is not so much concerned with the soundness or validity of the Aristotelian argument (though he indicates that he takes premise 3b to be false—there is an actual infinity), but rather with the Averroists’ claim that the active intellect part of the soul, ‘common to all men’, is immortal. While Leibniz agrees with that claim, for him this entails that the active intellect, since it ‘participates’ in a single, universal intellect, effectively no longer exists as an individual—which, for Leibniz, is tantamount to the death of the soul. The upshot is that the Averroists’ argument contradicts faith, insofar as the passive soul is mortal; yet it conforms with faith, insofar as the active intellect is immortal. However, as Leibniz has shown, their argument entails that the whole soul is mortal, conflicting with faith, since the active intellect is effectively mortal as well. For Leibniz, the immortality of the individual soul is demonstrably true, and since the demonstration is consistent with faith, no conflict between faith and reason obtains on this point. In his ‘Contribution to a General Science’ (c. 1682) Leibniz criticizes the Averroists’ notion of a twofold truth as impious and hypocritical for supposing that God can maintain contradictions. Not only is this contrary to reason, but ‘nothing can be truly demonstrated that is contrary to faith’ (A VI 4, 464).

In a letter to Sophie Charlotte (1702) entitled ‘Reflections on the Doctrine of a Single Universal Spirit’, Leibniz provides greater detail on his arguments against the Averroists. He directly attributes to Aristotle and Averroes the doctrine that the passive intellect is particular to each individual and ‘withdraws’ from the individual upon death, whereas the active intellect is external to us ‘and universal for all’ (Leibniz 2011, p. 279). But this means it is not an individual soul. Leibniz goes further in his criticism by associating the doctrine of a single universal spirit with Spinozism, which held there is only one substance, God, as well as with the Cartesian doctrine that God is the only acting substance, positions which Leibniz forcefully rejects.

6. Engagements with Islamic Theodicies

So far, we have seen Leibniz’s engagement with several specific issues, such as the Trinity, Incarnation, usury, God’s foreknowledge, the extent of God’s will, and the immortality of the soul. Now we will turn to his engagement with three themes and two figures on a systematic matter, one for which Leibniz is best known: theodicy. First, it should be noted that he was certainly not the first to have developed a theodicy.

As Eric Ormsby has shown, every major strategy for reconciling reason with faith in the matter of evil was first introduced by the medieval Islamic theologians, whose discussion of the problem is, until Leibniz’s time, unsurpassed in thoroughness and detail.

(Wilson 1989, p. 273)

Wilson also notes that ‘the common source of Christian and Islamic discussion [on theodicy] is a passage from Plato’s Timaeus, which Leibniz surely knew.33 While Leibniz knew very little about these medieval theologians, let alone any full-blown Islamic theodicy, it is instructive to see how he might have engaged with them. These theodices focus on (1) the ‘Turkish fate’, (2) al-Razi and whether the amount of good in the world is greater than the amount of evil, and (3) al-Ghazali on optimism, or whether this world is the best possible.

6.1. Theodicy and Turkish Fate

It is uncertain what Leibniz’s source is for the so-called Fatum Mahometanum, or ‘Turkish fate’ he mentions in Theodicy. He seems to have coined the term himself, but it likely represents a common European stereotype of Islam as the religion of total submission to God’s will. The stereotype is not without ground, since ‘the central tenet of Islam is the self-surrender to the will of Allah’ (Acevedo 2008, p. 1725). Indeed, in the Qur’an the word ‘Islam’ is used to mean what ‘submission’ means in English. While admittedly most Europeans had not read the Qur’an, its central tenet was likely widely known. Leibniz himself remarks that ‘Fatum is derived from fori, that is, to pronounce, to decree, and in its right sense, it signifies the decree of providence’ (Leibniz and Clarke 2000, p. 38, par. 13). Thus, it would make sense for him to associate ‘fate’ with submission, or with a sort of ‘necessity’ for an individual to act in accord with God’s will. But does Islamic submission entail the type of necessity that Leibniz assumes is at work in his Fatum Mahometanum? Let us look more closely at his criticism of it in two key texts. In Theodicy (1710), he writes:

The false conception of necessity, being applied in practice, has given rise to what I call Fatum Mahometanum, fate after the Turkish fashion, because it is said of the Turks that they do not shun danger or even abandon places infected with plague, owing to their use of such reasoning as that just recorded.

(Leibniz [1710] 2007, Preface, p. 56)

The ‘false conception of necessity’ Leibniz refers to is that of the ‘lazy reason’ or ‘lazy sophism’ argument that he assumes is endemic to Islamic fate.34 This ancient Stoic argument, both advocated and refuted by the Stoics, purports to show that due to our powerlessness over fate, it is pointless and futile to act in any way to try to change it.35

Leibniz’s understanding of ‘lazy reason’ is generally similar, in that it discourages us from doing anything, except perhaps from acting upon ‘the inclination for the pleasure of the moment’ (pp. 55–56). But his main targets are the types of necessity he takes the Stoics to assume: (1) Epistemic necessity: that the Divinity either foresees or pre-determines future events; (2) Causal necessity: that the concatenation of causes renders all events necessary; (3) A type of logical necessity: due to the principle of bivalence, since every assertion must be either true or false, every assertion about the future must be either true or false; thus, the future is determined.36 The upshot is that any future which accords with divinity, causation, or logic is unavoidable (p. 56). Thus, the ‘lazy reason’ argument

ended in a decision to do nothing: for (people would say) if what I ask is to happen it will happen even though I should do nothing; and if it is not to happen it will never happen, no matter what trouble I take to achieve it.

(Leibniz [1710] 2007, §55)

It would, then, make no sense to attempt to ‘abandon places infected with plague’, because the plague will come to you (or not) no matter what you do.

Leibniz’s refutation of the lazy sophism amounts to a practical refutation of its claims for causal necessity: ‘The connexion of causes with effects, far from causing an unendurable fatality, provides rather a means of obviating [that necessity]’ (Leibniz [1710] 2007, §55). In other words, a series of causes and effects will lead you with certainty to catch the plague; so, if you do nothing, you will certainly catch it. However, there is a series of causes and effects, equally certain, by means of which you can avoid that fate; and if you act on them (by abandoning infected places), you can avoid the plague. Clearly, then, you should act rather than not. But then the Turkish fate is the worst kind, since it ‘overthrows’ the sort of ‘foresight and good counsel’ that would enable us to act properly (§59). That is, it discourages us from employing our capacity to imagine in the present what practical reason would council for avoiding an undesirable future.

We need not determine whether Leibniz’s refutation of the lazy sophism succeeds in showing that our fate can be avoided. On the plus side, he suggests that the sophism might account for a certain fearlessness among Turkish soldiers who figure that if they are fated to die in battle, they might as well die heroically. However, he attributes this fearlessness more to hashish than to any courage derived from the fatalism of the lazy sophism (§55).

Leibniz goes on to contrast the Fatum Mahometanum with a Fatum Stoicum, which at least provides us with an internal state of tranquility in the face of necessity, and would seem to be closer to Christianity, which teaches that the troubles of today, rather than of tomorrow, are of sufficient concern.37 As a point of further contrast, while the Fatum Christianum is no less fatal or necessary than the others, it offers a sort of contentment in knowing, if we could sufficiently understand, ‘that it is not even possible to wish for anything better’ than what God decrees. This does not, however, entail that we can or should do nothing, or that we should become ‘quietists’, as Leibniz had earlier argued in the Discourse (§4). Rather,

Do your duty and be content with that which shall come of it, not only because you cannot resist divine providence, or the nature of things (which may suffice for tranquility, but not for contentment), but also because you have to do with a good master.

(Leibniz [1710] 2007, pp. 56–57)

That is all Leibniz has to say in Theodicy about the Fatum Mahometanum. In his correspondence with Samuel Clarke (1715—1716), he characterizes the Turkish fate as holding that an effect will happen, come what may, even though its cause is absent, ‘as if there was an absolute necessity’ (Leibniz and Clarke 2000, Fifth letter to Clarke, no. 13, p. 58). In view of this absolute necessity, the Stoic counsels patience, while the Fatum Christianum provides ‘a certain destiny of everything, regulated by the foreknowledge and providence of God’ (Leibniz and Clarke 2000, p. 38). Leibniz does not say whether Christian fate preserves free will or provides a way for the individual to change or avoid her fate. Rather, similar to his stand in Theodicy, he says it provides the sort of pleasure and contentment that comes with knowing that God ‘does everything for the best and not only for the greatest good in general, but also for the greatest particular good of those who love him’ (Leibniz and Clarke 2000, p. 38). The overall lesson, in relation to the Fatum Mahometanum, is that only the Fatum Christianum provides a theodicy for the necessity of events, while the Turkish fate gives us nothing to do and nothing to hope for.

It can be pointed out, however, that Leibniz did not much understand the example he gives of Turkish fate. That is, the Turk in the plague scenario need not be taken to be submitting to fate by remaining in infected areas; but rather, he remains where he is in order not to spread the disease to others (Diagne 2010, p. 78). On the other hand, Leibniz’s example ‘is not without some basis in the Islamic tradition’. According to Diagne,

The philosopher from Hanover probably ignored when giving that illustration that he was actually repeating a truncated oral narrative which is presented in different versions among which the most consistent is the following account of what happened once when the second caliph of Islam, Umar, was on an expedition in Syria: ‘On hearing that plague was raging in a particular town of Syria, Umar decided not to visit that place. In reply to abu Ubaydah ibn al-Jarrah, who had objected to his fleeing from a divinely ordained destiny, he said that Abd al-Rahman ibn Awf had told him that the holy Prophet had said; ‘If plague breaks out in a place, do not enter it, if you are not already inside it, but if you are, do not leave it’.

(Diagne 2010, p. 78)

It is clear that the reason for the Prophet (Mohammed’s) instruction is to prevent the plague from spreading. Evidently, Leibniz knew only enough of this narrative to give himself a wrong impression. But given that the narrative was part of Islamic oral tradition, we should not expect Leibniz to have known its context.

However, it should not need to be said that a much more in-depth treatment of Islamic fate ought to have been asked for and expected. As Diagne points out, there had long been a debate within that tradition on the relationship between free will and predestination, a tradition that Leibniz had some familiarity with through his reading of Maimonides.

The school of theology known as the Mutazila was famously born out of the rationalist view that God’s Justice could only make sense if human beings have absolute free will. They were opposed by the partisans of predestination who emphasized God’s omnipotence and omniscience. This question of the true meaning of God’s decree and sentence has been ceaselessly debated before it simply amounted, at a period of decadence in Islamic thought, to the popular notion of مكتوب, ‘what is [already] written’ which conveyed resignation and irresponsibility.

(Diagne 2010, p. 78)

No doubt the post 11th century Islamic turn away from philosophy contributed to Leibniz’s lack of access to a richer understanding of Islamic fate. But perhaps more can be done here to correct Leibniz’s view. As Diagne argues, Leibniz’s conception of the future as already present in its entirely, does not comport with a Quranic understanding of time as a dynamic, organic, whole. To quote contemporary Indian-Pakistani philosopher, Muhammad Iqbal:38

Pure time is an organic whole in which the past is not left behind, but is moving along with, and operating in, the present. And the future is given to it not as lying before (my emphasis), yet to be traversed; it is given only in the sense that it is present in its nature as an open possibility. It is time regarded as an organic whole that the Qur’an describes as تقدیر, or the destiny—a word that has been so much misunderstood both in and outside the world of Islam.

(Diagne 2010, p. 81, quoted from Iqbal 1986, p. 40)

On this view ‘there is no future to be foreseen or foreknown’ (Diagne 2010, p. 81). The future is shaped, rather, through a dynamic process involving both the will of God and the will of an individual, giving neither absolute necessity, nor absolute primacy. Islamic submission, therefore, ‘should not be thought of as irrational or dismissed as the product of a passive or fatalistic mentality. On the contrary, the type of surrender Islam requires is a deliberate, conscious, and rational act’ (Acevedo 2008, p. 1728, quoted from Cornell 1999, p. 67).

6.2. Theodicy: Al-Razi and the Preponderance of Evil over Good

In Theodicy, §262–3, Leibniz returns to Maimonides’ Guide for the Perplexed, quoting from Part 3, chapter 12 of the Guide,39 which says that ‘a celebrated writer named Alrasi [sic]’,40 has stated the ‘absurd’ view that ‘there are more evils than goods in the world’ since the amount of pains and torments in the course of one’s life is greater than the amount of pleasure and tranquility; such that life must amount to a sentence and a punishment.

Maimonides is then said to add that this ‘extravagant error’ is caused by imagining that the universe ‘was made for [men] only’ without considering the whole world (Theodicy §262). While Leibniz maintains that ‘there is incomparably more good than evil in the universe’ (beginning of §262), he seems more interested in Maimonides’ refutation of the ‘general’ viewpoint that Leibniz takes al-Razi to hold as well, which says that human misfortune is greater than the amount of good in the whole of creation. Leibniz then agrees with Maimonides that even if evil were preponderant within humankind, other species of beings have more good than evil: angels, celestial bodies, the elements, inanimate beings, and ‘many kinds of animals’ (Theodicy §263). Thus, presumably, if we sum the amount of good in these other species, the amount of good would be greater than the amount of evil within humankind.

Leibniz then says that if the number of damned exceeds the number of saved, there would be more evil than good in the human species; but then he gives three brief reasons to believe there is overall a preponderance of good: (1) There is ‘incomparably more good than evil, both moral and physical, in rational creatures in general’ (Theodicy §263) presumably since angels are also rational creatures. This might strike us as odd in one respect, since angels, not having bodies, do not experience physical goods. (2) The city of God (the perfect, or spiritual city, as named in Psalms 46: 5) ‘contains all creatures, in the most perfect state’. This would seem to point to a condition of things to come, as a promise sufficient to ameliorate the present misery of moral and physical evils. (3) All substances contain good and evil ‘metaphysically’, that is, it is the nature of all substances to possess a certain degree of perfection, entailing a privation of good, but nevertheless more good than evil. Altogether, these three conditions constitute ‘the best of all systems’. Thus the ‘absurd’ claim of al-Razi’s, that there is a preponderance of evil over good, can be thoroughly dismissed.

6.3. Theodicy: Al-Ghazali and the Best Possible World

Arguably the most prominent of the medieval Islamic theologians mentioned by Wilson in the above quotation is al-Ghazali.41 Although Leibniz never mentioned him and presumably did not know anything about him, their respective optimist theodicies bear some striking resemblances. The following is a sketch of Ormsby’s comparison of the two philosopher-theologians in his Theodicy in Islamic Thought: The Dispute over Al-Ghazali’s Best of all Possible Worlds.

Ormsby remarks that a special problem of a theodicy, normally concerned with reconciling God’s justice with the abundance of evil, is the problem of optimism.42 Has God/Allah created the best world possible? Could God /Allah have created a world better than this one? There is a basis for optimism in the Qur’an itself, which explicitly says throughout that Allah is all-powerful as well as most-merciful, compassionate, and benevolent (For example, (Quran 2024, 2: 20)). If the answer to the latter question is yes, then God’s justice, benevolence, and power could be called into question. Furthermore, Allah is in some sense morally required, or ‘obligated’, to create the best possible world, and yet cannot be ‘necessitated’ to create such a world since creation must result from God’s free decision. For Leibniz, the matter of obligation is resolved through the notion of ‘moral necessity’, which says that God creates the world from the necessity of his benevolent nature, which does not necessitate God in the strong, geometrical, Spinozist sense. But then some account of ‘benevolence’ must be given—which is difficult in the face of the quantity of evil—unless evil can be justified.

With the above background in mind, let us outline the optimist theodicy of al-Ghazali, who, notably, rejected a certain version of optimism. First, it was generally understood that ‘the best’ or ‘optimum’ meant ‘the most appropriate’, according to God’s wisdom and providence; or it meant what was most beneficial to God’s creatures (Ormsby 1984, p. 21). Al-Ghazali rejected this, believing that ‘optimum’ meant that what was actual was perfect (the perfect rightness of the actual). But for him, this did not entail that the actual was most appropriate or beneficial. We can see why in this outline of the main components of al-Ghazali’s optimism.43 Then we will see how Leibniz might respond.

• The perfect rightness of the actual: This follows from God’s wisdom. All that is actual has been decreed by God, and since God is most wise, the actual must be right and just. Notably, al-Ghazali does not say that this world is the best, but rather that it is ‘most wonderful’. As Ormsby says, ‘’most wonderful’ and ‘optimal’ are not equivalent. God may create, and does create, the less than perfect, but this is itself most wonderful’ (Ormsby 1984, p. 238). Nor is ‘most wonderful’ equivalent to perfect, since, for example, blindness in a human, normally a privation or an evil, is still most wonderful since, ‘divine wisdom requires it, be it perfect or imperfect’ (Ormsby 1984, p. 143). We do not know why God has decreed it, but we do know that since God has decreed it, it is most wise. We should not mistake this view to mean that God’s decree makes something most wise. Al-Ghazali is not a voluntarist but is enough of a rationalist to hold that God’s decrees are issued just because they are most wise. On possibility, as opposed to actuality, al-Ghazali says that possibility cannot be more wonderful (abda) than actuality, that is, more wonderful than ‘the form of this world or more excellent in arrangement or more complete in construction’ (Ormsby 1984, p. 35). With this aesthetic notion of ‘wonderful’, al-Ghazali may have wanted to ‘emphasize the startling and admirable artistry of the world order’ in distinction from the Mutazila’s conception of the optimum (al-aslah) as beneficial. In sum, we can say that the actual is perfect because it is wonderful.
• The radical contingency of the world: The world could have been completely different than it is. Every individual, action, and event could have been otherwise than it is. However, the way of the world is also necessary. That is, given God’s decree, which is a contingent choice for God, everything follows necessarily (unavoidably, but not geometrically) from that decree. But God does not simply issue arbitrary decrees—His decrees are always most wise, and we can know this because the actual world is a sure sign that it is superior to any possible world, just because it is actual rather than possible. But what does the divine wisdom aim for? Why did God decree such a world? The answer may be clarified by the third principle.
• The contribution of imperfection: Even though the world contains disease, destruction, vice, and whatever suffering, these evils and imperfections contribute to this most wonderful world by enabling us to perceive distinctions among phenomena, enabling us to have knowledge of phenomena. It also enables us to perceive perfection, most importantly God’s perfection, so that we may become more perfect ourselves. In the end, since God willed imperfection, it must be most wise. To deny this is to impugn God’s wisdom. In sum, we can say that God aims to produce a most wonderful world by means of including imperfection.

Now, how might Leibniz respond to al-Ghazali’s principles of optimism? Likely, he would find much to agree with:

• Regarding the perfect rightness of the actual, Leibniz would say that the actual world is the best possible world. However, this is not equivalent to saying this world is unqualifiedly perfect, for Leibniz admits there is evil and that God permits it, although humans are responsible for moral evil. Nevertheless, Leibniz denies that a world containing less evil, sin, and suffering would be better (Leibniz [1710] 2007, p. 131). The best possible world is that combination of individuals that together comprise the most reality, despite their inherent imperfections.44 Imperfection is to be controlled and mitigated through the free exercise of moral virtue. Leibniz also says that God designs the world like a most efficient craftsman employing a single rule of perfection: the simplest means productive of the richest effects (Leibniz 2023, §5). In this, Leibniz and al-Ghazali have in common a rationalist viewpoint: the rules of wisdom morally necessitate the optimal, or best possible, world. In addition, both philosophers include a metaphysics of imperfection compatible with, if not ameliorative of, the best (or most wonderful) world.
• Leibniz would find al-Ghazali’s ‘radical contingency’ quite similar to his own conception of ‘hypothetical necessity’. Like al-Ghazali, Leibniz wants to avoid the strong necessitarian consequence in which God has no agency or freedom. Hypothetical necessity means that the series of events in the world are contingent in themselves, and theoretically could have been otherwise; but they are necessary (will not be otherwise) because they stem from God’s decree, which is itself contingent. But how can a decree be both contingent and necessary? The sense of necessity Leibniz employs in ‘hypothetical necessity’ is not geometric, in which God cannot choose another world without contradiction; or the ‘blind necessity’ of Spinoza, in which God has no intellect to choose which world to actualize.45 This necessity is, rather, a moral necessity, according to which God chooses the best possible world, even though God could have chosen to actualize a lesser world. While it would contradict God’s good nature not to actualize the best possible world, it would not be a logical contradiction. It is a choice that a supremely rational and good mind would certainly make, precisely because it is rational and good.
• On the contribution of imperfection: as already seen, Leibniz similarly permits imperfections, as they are built-in to the nature of created substances, but considers imperfections as compensated by a whole that is overall more perfect.

So, the limitation or original imperfection of creatures brings it about that even the best plan of the universe cannot admit more good, and cannot be exempted from certain evils, these, however, being only of such a kind as may tend towards a greater good. There are some disorders in the parts which wonderfully enhance the beauty of the whole, just as certain dissonances, appropriately used, render harmony more beautiful.

(Leibniz [1710] 2007, p. 387)

There is also a sense in which the aesthetic quality of harmony resonates with al-Ghazali’s notion that the whole of creation, including its imperfections, comprises a ‘most wonderful’ world.

Ormsby points out that ‘the hidden problem of theodicy’ is ‘to affirm the necessary rightness of things without simultaneously subjecting God to necessity’ (264). Leibniz can claim to accomplish this through the hypothetical moral necessity of the best possible world; whereas al-Ghazali can say similarly that the world is hypothetically necessitated by God’s wisdom. In sum, it is notable that an Islamic and Christian theodicy should share such similarity. This is largely due to their shared understanding of the nature of God and the fundamental problems of theodicy; and their attempt to solve these problems by means of shared logical and metaphysical assumptions. Consequently, of course, they inherit all the philosophical problems that go with those solutions. No doubt a more extensive and precise mapping of their respective theodices would reveal additional points of convergence, and divergence as well.

7. Conclusions

What general characterization can we make of Leibniz’s encounter with the religion of the Mohammadans? This quotation from Theodicy neatly encapsulates the views we have seen above.

Later also Mahomet showed no divergence from the great dogmas of natural theology: his followers spread them abroad even among the most remote races of Asia and of Africa, whither Christianity had not been carried; and they abolished in many countries heathen superstitions which were contrary to the true doctrine of the unity of God and the immortality of souls.

(Leibniz [1710] 2007, p. 53)

The most general characterization is that Islam, like Christianity, is a religion that conforms to natural theology, that is, a theology discoverable by reason, apart from revelation, but specifically a theology whose foundation is the unity of God—that God is one being containing multiple attributes, primarily: omniscience, omnipotence, and omnibenevolence.

Leibniz’s interest in the Christian dogmas of the Trinity and Incarnation was driven in part by his orientation in natural theology, but in the context of his engagement with the Mohammadans, by his worry that these dogmas are susceptible to being misunderstood as idolatrous—whether by pagans, Muslims, Christians, or potential converts. He regards the Mohammadans positively insofar as they insist on the unity and uniqueness of God; and he attributes the success of Islam among the people of Asia and Africa largely to the religion’s persistent denunciation of the idolatry endemic to those doctrines and to a tendency toward idolatry among Christians. Thus, he thinks that the Trinity can be rightly understood (as not idolatrous) in terms of natural theology, that is, through a rational understanding of God’s nature as three persons in one substance. The apparent contradiction involved in the hypostatic union (the Incarnation) can be resolved by admitting that this conception is ‘above reason’ yet still in conformity with it. However, it is not altogether clear how this conception avoids becoming a mystery entirely outside the bounds of reason.

Leibniz’s emphasis on natural theology may be seen in a number of other issues related to the Mohammadans. God’s foreknowledge is consistent with free will; faith is consistent with reason; and the prohibition against usury is consistent with natural law discoverable by reason. His criticisms of Islamic commentators also rest on natural theology: that God’s nature as form and final cause was misunderstood (against the Mutakallimun); that God cannot will contradictory existences (accidents cannot subsist apart from their substances), as against the Mutazila, but in agreement with them on the view that God’s foreknowledge must be consistent with future contingents and free will.

Natural theology enters into Leibniz’s disagreement with the Averroists: Just as God’s unity must be insisted on, so must be the unity of the individual soul. Leibniz’s rejection of the Averroists’ account of the active intellect, that it dissipates the soul into a ‘sea of divinity’ means that individual immortality is lost, and the possibility of justice along with it, in the form of reward and punishment for the individual. Leibniz also insists, against the Averroist doctrine of twofold or double truth, that scripture and reason are never in conflict.

On matters of theodicy, or God’s justice, Leibniz again appeals to natural theology. He believes, although through a misrepresentation, that the fate of the Mohammadans is subject to an unavoidable necessity. His argument against al-Razi on the preponderance of evil is based on natural theology, in which the moral goodness of rational beings, the promise of a better world to come, and the metaphysics of perfection all entail a preponderance of good. Against the Mutazila, God’s will is rational since it is bound by the law of non-contradiction. And finally, in the best possible world of al-Ghazali, Leibniz would agree that the rightness of the actual can be affirmed without compromising God’s goodness, wisdom, and free will.

It is unfortunate that Leibniz never obtained a translation of the Qur’an. If he had, his opinion of the Mohammadans’ religion certainly would have been more accurate and likely more favorable than he obtained from his correspondents. We would be right to expect him to bring to light its rational (as opposed to its ‘vicious’) foundations. As it stands, his efforts to obtain a faithful translation of the ‘Alcoran’ seems to have been driven by two main motives. Firstly, to understand the religion on its own terms rather than through received prejudices. Secondly, he thought that the religion of the Mohammadans could have an instrumental role in correcting abuses within Christianity, namely, idolatry and tritheism, and that the appeal of Islam, its prohibition against those doctrines, served for him as an explanation for why Islam prevailed over Christianity in the East. Leibniz’s interest in the religion of the Mohammadans surely had political motives as well, as recent commentators have attested. But his endeavor to understand the religion through the lens of natural theology must have compensated somewhat for his otherwise minute comprehension of the religion itself.