## 1. The Ingredients of Medieval Philosophy


### 1.1 Text and Commentary Traditions



In the Middle Ages, as in other periods, philosophy took many written
forms, from encyclopaedias and compendia to monographs and short
essays, from poetic, allegorical, and novelistic presentations to
texts based directly on school and university practice (such as
quodlibets) (see entry on
 Literary Forms of Medieval Philosophy).
 But there is one literary form that was used centrally in all the
four traditions, but has lost its importance in modern times: the
commentary. Much of the best medieval philosophy was done in
commentaries, many of which were far from mere aids to understanding
the text concerned. Whereas philosophers now, at least in the analytic
tradition, think of their subject as made up of *problems,*
which are tackled using what others have said and are saying as aids,
medieval philosophizing was frequently based on (often, but not
always, old and venerated) *texts*. But, although the aim was
usually to interpret them, the practice of interpretation frequently
led to new thinking, related only tangentially to the text under
discussion.



The central texts for commentary in the Greek, Latin, Jewish branches,
and among Arabic philosophers up to the twelfth century were
Aristotle's. The Byzantine philosophers used them in the
original, Latin and Arabic philosophers in translation, and the
Hebrew-writing Jewish philosophers usually indirectly, via epitomes
and paraphrase commentaries translated from Arabic. No other ancient
philosopher's texts received anything remotely near to this
level of attention, although various works of Boethius received
multiple commentaries in the Latin
 tradition;[3]
 commentary on Plato was
 sporadic.[4]
 But the many commentaries on the Bible and on the Quran sometimes
included substantial philosophical discussions.



In the Latin tradition, direct commentary on Aristotle remained
central to most higher education until late in the seventeenth century
 (SS5.2),
 but Arabic authors stopped commenting on his works directly after the
twelfth century, and earlier outside Spain. Instead, they began to
comment on Avicenna's rethinking of Aristotle
 (SS2.3,
 SS2.10). Commentaries on his work continued to be written, but
added to them were, successively, commentaries on later writers who
had themselves rethought and rewritten Avicenna's expositions.
Islamic scholars saw commentary as a way of thinking not just on the
basis of revered old texts, but on that of the best recent
 textbooks.[5]
 Although this constant replacement of texts to be commented was
foreign to the Latin tradition, three medieval Latin texts were
themselves vehicles for many commentaries. The two set texts in the
university theology faculties
 (SS2.7)
 were the Bible and a work written circa 1155 by Peter the Lombard,
the *Sentences*, where he set out systematically all the
problematic questions in theology and proposed solutions, quoting
extensively from Augustine (Evans and Rosemann 2002-14). Much of
the best theological and philosophical work in the period from
1250-1550 was done in commentaries on the *Sentences,*
but usually the Lombard's text was just the springboard for
debate. Peter of Spain's popular logical
 *Treatise* (SS4.2)
 received commentaries, as did the greatest philosophical poem of the
period, Dante's *Commedia Divina*
 (SS2.8).[6]



The types of commentaries were legion. They included: simple, literal
glosses, designed to help beginners (e.g., Latin twelfth-century
literal logic commentaries); sophisticated literal commentaries,
explaining an author's argument at a high level (e.g.,
Aquinas's Aristotle commentaries); line by line commentary, with
long discursive discussions and excursuses (e.g., Boethius and Abelard
on Aristotelian logic; Averroes's "Great"
commentaries); paraphrase-type abbreviations and rewritings of the
original texts, often with added material and ideas and a new emphasis
(e.g., Averroes's epitomes and "Middle"
commentaries); discursive rethinkings of a whole area of a past
author's work (e.g., Avicenna's and Albert the
Great's commentaries on Aristotle); allegorical readings of a
text (e.g., some Biblical commentary, both Christian and Jewish,
earlier medieval commentaries on Plato's *Timaeus* and
Book III, metrum 9 of Boethius's *Consolation*, which
epitomizes it, Dante commentaries). A distinctive form of commentary
used in the Latin universities was the Question Commentary, where a
book would be commented on by posing questions related to the content
of its sections or even, more vaguely, its larger divisions
(Bazan, Wippel, Fransen, & Jacquart 1985), with the text
often a mere peg on which to fit the commentator's own agenda for
philosophical discussion.


### 1.2 The Platonic Schools of Late Antiquity



The main root of the four branches of medieval philosophy--Greek,
Latin, Arabic, and Jewish--is in the two great so-called Platonic
Schools of Athens and Alexandria, although each tradition also had its
own special roots
 (SS1.4).
 The new version of Platonism formulated by Plotinus (d. 270) had
replaced the Hellenistic Schools (Stoics, Epicureans, Sceptics etc.)
as the dominant type of philosophy in the late Roman Empire. But
Plotinus's star pupil, Porphyry (c. 232-305), had given
his master's teaching a decisive twist. Plotinus considered
Aristotle an opponent of Plato and regarded him with hostility.
Porphyry held, rather, that Aristotle's thought, which was about
the sensibly-perceptible world, harmonized with Plato's, about
super-sensible reality. Following Porphyry's lead, students at
the "Platonic" Schools began by studying the whole
Aristotelian corpus, logic first, and only then moved on to
Plato's dialogues. In all four branches, it was the Aristotelian
curriculum that survived, in whole or part. Medieval philosophy is,
therefore, to some extent the history of Aristotelianism, but
transmitted within a Platonist context, shaped by the different
religious traditions and transformed both by individual thinkers and
various, changing cultural circumstances.


### 1.3 Translation Movements



Ancient texts were transmitted to medieval thinkers and the different
branches of the medieval tradition influenced one another's
development through a series of translation
 movements.[7]


#### 1.3.1 Greek to Arabic



The School of Alexandria was closed by the Muslim conquest in 641, but
between the eighth and the early tenth century, much of the treasury
of Greek scientific and philosophical texts it left was put into
Arabic, often by Syriac speaking Christians and sometimes through the
intermediary of Syriac. Almost the whole of Aristotle was translated,
along with commentaries from the Platonic schools and works
by the Aristotelian,
 Alexander of Aphrodisias
 (working c. AD 200) (Gutas 1998). Reworked versions of texts by
 Plotinus
 and the fifth-century Platonist
 Proclus
 were also made in Arabic, but Plato himself was hardly known except
through translations of epitomes. (See also
 Greek sources in Arabic and Islamic philosophy.)


#### 1.3.2 Greek to Latin



Translation from Greek into Latin went on almost continuously.
Writings by philosophically acute Greek Church Fathers were translated
in antiquity; in the fourth century, Calcidius translated part of
Plato's *Timaeus*, with an extensive commentary.
 Boethius
 (476-c. 525) translated Aristotle's logic and, in his
commentaries and textbooks, translating, selecting and rethinking,
made available in Latin large amounts of the teachings on Aristotelian
logic from the Platonic Schools. His *Consolation of
Philosophy,* written as a prosimetric dialogue when Boethius was
under sentence of death, was one of the most widely read and
translated texts in the Middle Ages: it was not a translation, but
transmitted Boethius's own understanding of late ancient
Platonism. Translations of pseudo-Dionysius and Maximus the Confessor
were made in the ninth century
 (SS2.1,
 SS2.2), and of John of Damascus (c. 660-c. 750) in the
twelfth century. In the twelfth and thirteenth centuries, the rest of
Aristotle untranslated by Boethius--his non-logical works and the
*Posterior Analytics*--was put into Latin, sometimes first
via Arabic; (Plato's *Phaedo* and *Meno* were also
translated, by Henry Aristippus, but they remained almost unknown).
The greatest of these translators was William of Moerbeke
(1215-1286), who made or produced by version very accurate,
extremely literal translations from the Greek of all Aristotle's
works, and texts by the late ancient Platonists Proclus,
 Ammonius
 and
 Simplicius.
 In the fifteenth century, there were many more translations from the
Greek, such as those of Plato and Plotinus by
 Marsilio Ficino
 (1433-99).


#### 1.3.3 Arabic to Latin



In the twelfth and thirteenth centuries, especially in Toledo and
Sicily, a large variety of Arabic texts were translated into Latin.
They included Arabic translations of some of Aristotle's own
texts, which helped to fill in gaps before direct translations from
the Greek were available, and works by the Arabic thinkers who worked
in the tradition of Aristotle and the ancient philosophers:
al-Kindi, al-Farabi and Solomon ibn Gabirol (a
Jew, but unrecognizable as such from his text) and, most important,
parts, including the sections on the soul and on metaphysics, from
Avicenna's largest encyclopaedic reworking of Aristotle, and
many of Averroes's commentaries on Aristotle. These
translations, along with the translations of Aristotle, transformed
the university syllabuses in the thirteenth century
 (SS2.7).


#### 1.3.4 Arabic to Hebrew



When Jews living in Latin Europe began to engage in philosophy, using
Hebrew, their language of law and liturgy, they turned primarily to
works in Arabic. A central text was Maimonides's *Guide of
the Perplexed*
 (SS2.4),
 translated into Hebrew twice soon after it was written, and a few
other Jewish philosophical texts were also translated. During the
thirteenth and early fourteenth centuries, translators also provided
an almost complete Aristotelian curriculum but, although there were
some direct translations, it was mostly by way of Averroes's
short and middle paraphrase commentaries, and
al-Farabi's short commentaries for the logic.
Other translations include al-Ghazali's *Intentions
of the Philosophers*
 (SS2.4)
 and Ibn Tufayl's philosophical novel
 (SS2.6).


#### 1.3.5 Latin to Greek



One group of Byzantine philosophers in the thirteenth to fifteenth
centuries was strongly interested by Latin thought. The texts its
members translated into Greek included works by Augustine and
Boethius, Thomas Aquinas, and Anselm, as well as part of Peter of
Spain's popular *Treatise* on logic.


#### 1.3.6 Latin to Hebrew



In the fourteenth and fifteenth centuries some works by a variety of
Latin university authors, among them Boethius, Aquinas,
 Albert the Great
 and William of Ockham were put into Hebrew, and also Peter of
Spain's *Treatise* (Manekin 1996). There was even a
Hebrew translation of Averroes's Great Commentary on *On the
Soul*
 (SS2.6)
 made in the fifteenth century from the Latin, because the Arabic
original was lost.


#### 1.3.7 Hebrew to Latin



Maimonides's *Guide*
 (SS2.6)
 was translated into Latin in the thirteenth century from one of its
Hebrew translations. In the fifteenth and sixteenth centuries, there
was a spate of Latin translations of Hebrew versions of Averroes, but
very little of Jewish philosophy in Hebrew was ever put into Latin
(Manekin 1996).


### 1.4 Other Philosophical Sources



As well as drawing on ancient Greek philosophy via the late ancient
Platonic Schools, each of the four main branches of medieval
philosophy had its own special sources.


* For Byzantine philosophy, there were philosophically educated
Greek Christian authors, such as
 Origen
 (c. 184-c. 253) and from the fourth century Basil, Gregory of
Nyssa and Gregory Nazianzen.
* The greatest influence on medieval Latin philosophy, as well as,
by some chronologies, the founder of the tradition, was
 Augustine
 (354-430). Augustine's thought was shaped in part by
Plotinus and Porphyry, some of whose texts he read in Latin
translation; in part by his personal experience of the competing
faiths of his time--Christianity, Manichaeism, Graeco-Roman
paganism; in part by a Latin philosophical and literary tradition; and
in the greatest part by his own, relentless self-critical genius as a
thinker. Latin philosophers also had direct access to eras of ancient
philosophy earlier than the Platonism of Plotinus through Latin
authors, such as Cicero (scepticism, stoicism), Seneca
(stoicism).
* In Arabic, there was the tradition of *kalam* theology
 (SS2.4).
 Philosophical thought about language was sometimes linked to Arabic
grammatical thought and both it and ethics to *adab,* the
tradition of literary and historical studies needed to make a person
cultivated. Sufism--an Islamic mystical tradition--also
deeply influenced some philosophers
 (SS2.4,
 SS2.6,
 SS2.10).
* Jewish thinkers inherited, not just the written Law of the Torah,
but oral law, recorded in the Mishna and the tradition of Talmudic
commentary on it. The central Jewish philosopher, Maimonides
 (SS2.6)
 is also the greatest of the Talmudic scholars.


## 2. Styles of Medieval Philosophy


### 2.1 Byzantine Philosophy (c. 450-c. 1450)



Thinkers in what had been the Eastern Roman Empire--they thought
of themselves as Romans; we call them
"Byzantines"--needed no translation movement to
access the heritage of the ancient
 schools.[8]
 In theory, the whole of the ancient tradition lay within their grasp.
But not only did this lead to encyclopaedism, as in the case of
Photius (820-91), whose *Bibliotheca* is an enormous
collection from ancient authors, philosophers included. It also made
the Church authorities suspect that commentators who went beyond logic
would be guilty of "hellenism"--putting loyalty to
their Greek cultural tradition above Christian doctrine. Of the three
most adventurous Aristotelian commentators, Michael Psellus
(1018-96), John Italos (1025-85) and Eustratius of Nicaea
(c. 1050-c. 1120), only the first escaped condemnation. Four
hundred years later, in the twilight of Byzantine civilization,
Gemistos Plethon (c. 1360-1454), gave substance to these fears
through his devotion to Plato and pagan Platonism (Siniossoglou
2011).



Some historians restrict Byzantine philosophy to this tradition, based
on the ancient texts of Aristotle and, occasionally, Plato and his
 followers.[9]
 But there were two other strands to philosophy in Byzantium. One is
that of those thinkers after 1200 who looked to Latin thought
 (SS1.3.5).
 The other goes back to the philosophically-inclined Greek Christian
Fathers, and above all to the (probably) Syrian monk who, late in the
fifth century, issued a set of writings under the name of Dionysius,
the Athenian Areopagite (learned judge) converted by St Paul. The
author had read the near contemporary pagan Platonist Proclus, who
envisaged a many-tiered universe, deriving ultimately from a One,
beyond even being.
 Pseudo-Dionysius
 substituted the Christian God for the One, and where Proclus
accommodated the pagan pantheon on the elaborately triadic rungs of
his pantheon, he placed the angels and the Church hierarchy. Maximus
the Confessor, schooled in ancient philosophy though hostile to it,
developed pseudo-Dionysius's thinking, especially his negative
theology. This line of Byzantine thinking has its most powerful later
expression in the work of a monk of Mount Athos, Gregory Palamas
(1296-1359), who combined the theme of God's unknowability
with the idea that he does make himself manifest even in this life to
some people who are helped by a special sort of
"*hesychastic*" (still, silent) prayer.


### 2.2 The Rule and Two Exceptions: Latin Philosophy, 800-1100



Philosophical thinking took place in the monasteries and, later,
cathedral schools in Latin Europe in the ninth to eleventh centuries,
although it was first stimulated at the end of the eighth century by
Alcuin, Theodulf of Orleans and other scholars at the court of
 Charlemagne.[10]
 Based on the seven Liberal Arts (the trivium: grammar, logic,
rhetoric; the quadrivium: arithmetic, geometry, astronomy, music), it
was usually focused on the first two. Grammar ran from elementary
language learning to complex semantic analysis. Logic, at first known
from encyclopaedic accounts and Roman textbooks, was studied from the
late tenth century on the basis of Boethius's translations of
and commentaries on Porphyry's *Isagoge* and
Aristotle's *Categories* and *On Interpretation*
and his own textbooks. Boethius's *Short Theological
Treatises* and *Consolation of Philosophy* were also used
as school texts. Augustine's works were not, but they were
extensively read and so provided another source, and inspiration, for
philosophers. In these centuries Latin philosophy acquired the
emphasis on linguistic analysis and logic it would develop further in
the twelfth century and retain in the universities, even when there
were many more ancient sources available.



The two outstanding Latin thinkers of the time shared to some extent
this style of thinking and yet were in many respects complete
exceptions to it.
 John Scottus Eriugena,
 an Irishman who worked at the court of Charles the Bald in northern
France from c. 850-c. 870, learned Greek, translated
pseudo-Dionysius and Maximus the Confessor and absorbed their ideas.
His masterpiece, the *Periphyseon*, systematizes and takes to
its rational conclusion the line of thought they drew from Proclus
(and ultimately Plotinus and Plato). Eriugena uses his
contemporaries' favourite logical textbook, a Latin paraphrase
of Aristotle's *Categories*, to argue that God is not
among the things that exist, before showing how he is manifest, never
in himself, but in the appearances that make up the story of the
world's creation, the Fall, and the final Return of all
things.



Born in Aosta,
 Anselm
 (1033-1109) became a monk at Bec in Northern France and,
eventually, Archbishop of Canterbury. At a time when thinkers referred
ostentatiously to their authoritative sources, ancient and patristic,
Anselm wrote dialogues and monographs that scarcely mentioned an
author. Having fully absorbed both Boethian logic and many facets of
Augustine's thought, he could use them to engage in his own
reasoning. He not only hit on--by his own account in a flash of
inspiration--an unprecedented argument for God's existence
(the "Ontological Proof"; see entry on
 ontological arguments),
 but elaborated and brilliantly advocated a notion of the will's
freedom Augustine had the sense to avoid, which cast a long shadow
from Scotus to Kant and beyond.


### 2.3 *Falsafa*



The abundant translations of Greek philosophical texts
 (SS1.3.1)
 made it possible for some thinkers in the Islamicate world themselves
to engage in the Greek-style philosophizing they called
 *falsafa*.[11]
 Its exponents (*falasifa*; sing. *faylasuf*) did
not, however, fit into the educational system, based around Islamic
law. The earliest *faylasuf* was the prince and polymath
 al-Kindi
 (c. 801-66), who was especially attracted to Platonist
material. In the next century, a circle of Peripatetics, Muslim and
Christian, flourished in Baghdad, dedicated to the close study and
exegesis of Aristotle's texts. The most outstanding,
 al-Farabi
 (c. 870-950/1), wrote shorter and longer commentaries on
Aristotle, including a discursive exposition of *On
Interpretation* full of original thought about both semantics and
determinism. Elsewhere, he provides a naturalistic account of the
origins of language, philosophy and religion, and he championed the
view, adopted by other *faylasuf,* that in their discipline
they provide demonstrative science (as described by Aristotle in the
*Posterior* Analytics)
 (SS4.1).
 His view of the ideal state is clearly influenced by knowledge of
Plato (through epitomes) and is linked to his conception of the order
of the universe, which melds Proclus's theory of emanation from
the One with Ptolemean cosmology (see entries on
 al-Farabi's metaphysics,
 al-Farabi's psychology and epistemology,
 al-Farabi's philosophy of logic and language,
 al-Farabi's philosophy of society and religion).



Unquestionably the most important *faylasuf*--fundamental
to the subsequent Arabic Islamic tradition, but highly influential too
on Jewish and Latin philosophy--was
 Ibn Sina
 (before 980-1037; known in Latin as "Avicenna", see
entries on
 Ibn Sina's logic,
 Ibn Sina's metaphysics,
 Ibn Sina's natural philosophy).
 Avicenna was born in present-day Uzbekistan and spent his life in the
Eastern part of the Islamicate world, serving various princes in the
area (he was also a renowned doctor and writer on medicine). He
distinguished his approach sharply from that of the
"Westerners", the Baghdad Peripatetics. Like them, he
considered himself an Aristotelian. But whereas they sought to expound
Aristotle's texts line by line, Avicenna believed his genius
allowed him to present the underlying truth in Aristotle's
thought, by rearranging, rethinking and systematizing it. His output
consisted mostly, therefore, of philosophical encyclopaedias each
covering much of the range of Aristotle's work,
longer--such as *The Cure*--or shorter--such as
*Pointers and Reminders*, the presentation most distant from
Aristotle's texts and most studied by his Arabic successors.



For Avicenna, as for al-Farabi, God moves the universe
not just as final cause, but as that from which emanate the series of
Intelligences and celestial spheres, down to the Agent Intellect,
giver of forms to our sublunar world and so assurer of the continued
regularity of nature. His innovation was to identify this first cause
as the one necessary being, that which is necessary through itself:
its nature is to exist and so it cannot but exist. All other things
are merely possible in themselves, but necessary through
another--that is, through God, the necessary being. Since
Avicenna's God, like that of al-Farabi, the
Platonists and Aristotle himself, is not a being that chooses and
wills, his theory of necessity in itself and through another binds the
whole history of the universe to a very strict Principle of Sufficient
Reason.


### 2.4 *Kalam*



A century before al-Kindi, a different style of philosophizing
had grown up in the Islamic world:
 *kalam*.[12]
 It has, indeed, been suggested that *falsafa* originated as a
rival to *kalam*--claiming to be a better way of
explaining the world than it could offer. *Kalam* was
based on problems suggested by the Quran, but it was also inspired by
the need to defend Islamic doctrine against philosophically based
attacks by Christians and may have been informed by some ideas from
the ancient Greek tradition. The dominant school of
*kalam* in the ninth century were the Mu'tazilites.
They were very confident in the ability of human reason to reach moral
truth, to which, they held, God's justice must
 correspond.[13]
 They strongly emphasized God's unity and, in common with other
*kalam* thinkers, developed an atomistic, materialistic
physics, very different from Aristotle's picture of a stable
world of substances belonging to natural kinds. A Jewish version of
*kalam* is found in the work of
 Saadya
 (882-942).[14]



Al-Ash'ari (d. 935/6) changed the direction of
*kalam*. He stressed the absolute omnipotence of God, who,
he said, from instant to instant is responsible for the arrangement of
the atoms, and for human will and action. A century later, however,
al-Juwayni (1028-85) began to introduce Avicennian notions
into *kalam*. His pupil,
 al-Ghazali
 (1058-1111) went far further.



Al-Ghazali studied *kalam* theology, Avicennian
philosophy and Sufism, a type of Islamic mysticism, and he wrote about
them all, as well as being one of the greatest Muslim legal theorists.
Among these writings are not just *The Intentions of the
Philosophers,* based on Avicenna's shortest philosophical
encyclopaedia (in Persian), but *The Incoherence of the
Philosophers,* directed against *falsafa* as presented by
Avicenna. This book was very influential, and al-Ghazali
used to be thought of as a diehard enemy of philosophy, who helped to
bring about the end of philosophizing in the Islamic world. In fact,
however, there are just three doctrines on which al-Ghazali
convicts Avicenna and his followers of heresy: the eternity of the
world
 (SS3.1),
 the restriction of God's knowledge to universals and the denial
of the bodily resurrection
 (SS3.3).
 His critique thus showed that, in general, so long as these
conclusions are avoided, Avicennian philosophy is acceptable for
Muslims. Indeed, al-Ghazali himself accepted it, but with
two important further changes. God, he insists, has will and is
capable of real choices between alternatives. Moreover--and this
is the central point of the *Incoherence*--the
philosophers such as Avicenna do not, as they claim
 (SS2.3),
 provide demonstrative knowledge, because the starting points for
their arguments are not all self-evident. Like the theologians, their
reasoning is dialectical (Griffel 2009).


### 2.5 The Twelfth-Century Parisian Schools



Paris became the centre of philosophy in Latin Europe in the twelfth
century, in part because the cathedral authorities, rather than just
running one school, allowed many, competing ones: masters flocked
there, and students began to head to Paris from all over
 Europe.[15]



Many of these masters concentrated on the logical curriculum, little
changed since the late tenth century, but now its texts had been
thoroughly absorbed. This curriculum gave them the opportunity, not
just to make advances in what is still considered logic, but also to
develop a whole metaphysics, starting not from Aristotle's
*Metaphysics*--which they did not know--but his
*Categories.* The boldest of all these metaphysicians was
 Peter Abelard
 (1079-1142). Aristotle's *Categories* seems to
imply that, as well as particular substances (this man, that dog) and
particular forms (this rationality, that whiteness), there are also
universal substances and forms. Abelard did not agree, and he tried to
construct the world and interpret Aristotle without admitting that any
universals exist. He also attended to the ontological status of what
sentences say--their *dicta*. *Dicta* play a
central role in his understanding of truth and of the basis of logical
consequence, but, he insists, they are not things at all. Gilbert of
Poitiers (c. 1085-90-1154) constructed an even more
complex metaphysical system, based on the distinction between types of
discourse (natural, "mathematical", theological,
ethical).



Both men, and their often innovative followers (Abelard's were
the *nominales,* Gilbert's the *Porretani*) in the
second half of the century, also wrote on theology. Indeed,
Gilbert's surviving works are all theological, the most
important of them a commentary on Boethius's short theological
treatises. Gilbert tried, unsuccessfully, to establish the method
Boethius used in his *Short Theological Treatises*--of
going as far as possible with parallels between natural phenomena and
sacred mysteries, and pointing out where he has to stop--as
standard. Abelard's own particular theological ideas--which
included an (arguably) rationalizing approach to the Trinity, and the
view that, unlike humans, God cannot act otherwise than he
does--were generally rejected, and some of them condemned. But
his method of trying to reconcile apparently contradictory
authoritative texts through conceptual analysis was widely adopted by
his contemporaries and would form the basis for later medieval
theology.



Other approaches to philosophy, less centred on logic and theology,
were also developed, especially outside Paris. William of Conches (d.
after 1155) concentrated on expounding texts such as Boethius's
*Consolation* and Plato's *Timaeus,* and on
physical science, in which he regarded Plato as an authority.


### 2.6 Islamic Spain, c. 1050-c. 1200



Just as a very particular way of doing philosophy grew up in
twelfth-century Paris, so at much the same time Islamic Spain was
marked out by its own distinctive style of thinking, which for the
most part placed great emphasis on the importance of science and
philosophy in the Greek
 tradition.[16]
 The earliest important thinker was the Jew,
 Solomon ibn Gabirol
 (1021/2(?)-1057/8(?)), heavily influenced by Platonism, but
insistent that the universe was produced at God's will, not by
necessary emanation, and that matter is present at every level of
creation, even in intellectual creatures.



**Ibn Tufayl** (before 1110-1185) is known through
a single work, *Hayy ibn Yaqzan*, a philosophical novel,
which tells how Hayy, spontaneously generated on a desert island,
teaches himself, through observation and rational thought, a system of
philosophy that corresponds not only perfectly to Avicenna's,
but also to the inner, spiritual meaning of Islamic teaching.



**Ibn Rushd** ("Averroes" in Latin;
1126-98) was an Islamic judge and legal theorist, servant of the
harshly anti-Jewish and anti-Christian Almohad regime, and also
perhaps the most devoted Aristotelian of the Middle Ages. Whereas
scholars in the Islamic East used Avicenna for studying
*falsafa,* Averroes commented the letter of Aristotle's
text, as the Baghdad Peripatetics had done. He wrote short and
"Middle" paraphrase commentaries on almost the entire
Aristotelian corpus, and "Great" (detailed section by
section expositions) on some of the texts. These detailed expositions
of Aristotle proved invaluable to the Jewish and Christian scholars
who read them in translation
 (SS1.3.3,
 SS1.3.4), although his interpretation of *On the Soul* in
his Great commentary would prove very controversial
 (SS3.3)
 (see also entry on
 Ibn Rushd's natural philosophy)
 .



**Moses ben Maimon**
 (Maimonides
 in Latin; in Jewish scholarship "Rambam";
1138-1204) was educated in Spain (see entry on
 the influence of Islamic thought on Maimonides)
 but was forced to flee by Almohad policy and settled in Egypt. Like
Averroes, Maimonides looked back to Aristotle himself and
al-Farabi, and believed that Aristotle had achieved as
perfect a science as possible. But how far was that science compatible
with Jewish teaching? In his voluminous writings on Jewish law, he
seems to have been willing to accept Aristotelian demonstration as
providing the literal truth. In the *Guide of the Perplexed*,
written late in his life, Maimonides undertakes a profound
investigation of this question of (in)compatibility, ostensibly
arguing against Aristotle's central contention that the world is
eternal
 (SS3.1),
 which, he says, destroys Jewish law. At the beginning of the
*Guide,* however, he explains that he will sometimes disguise
his meaning, and some scholars believe that, correctly interpreted,
the *Guide* supports the Aristotelian view, whilst others see
its ultimate conclusions as
 sceptical.[17]


### 2.7 University Philosophy



By about 1200, the Paris schools had become a university, and at much
the same time a university developed at Oxford. Universities were
split into Arts Faculties and the higher Faculties of Theology, Law
and
 Medicine.[18]
 Arts Faculties had by far the most students, and those who studied
the higher disciplines were older and had usually been trained in the
Arts Faculty or its equivalent. Grammar and logic were studied there
from the beginning, but, as translations of the complete Aristotle
gradually became available in the course of the thirteenth century,
after some decades of ecclesiastical opposition, Arts Faculties became
in effect Aristotelian Faculties, with the curriculum divided up
according to his texts. Although universities were under the aegis of
the Church, study in the Arts Faculties was supposed to be limited to
natural knowledge, of which Aristotle, a pagan, was considered by
almost all to be the supreme representative. Discussion of revealed
truth--in a highly argumentative manner, with many purely
philosophical digressions--took place in the Theology Faculties,
which quickly came to be dominated by Franciscan and Dominican
friars.



In the mid-thirteenth century, university philosophers were enthused
by the newly available Aristotelian material, complimented by
Avicenna's presentations and understood with the aid of
Averroes's
 commentaries.[19]
 The two most famous Parisian Arts masters, Siger of Brabant and
 Boethius of Dacia,
 working in the 1260 and 1270s, tried to develop Aristotelianism
within its own terms, not merely independently of revealed doctrine
(as they were required to do in the Faculty of Arts), but also
irrespective of whether it contradicted Christian teaching. The
Dominican theologian
 Thomas Aquinas
 (1225-74) was no less enthusiastic an Aristotelian, but he had
an almost unlimited confidence that Aristotle had reached
demonstrative conclusions which must, therefore, be true and, equally,
because true, not be in contradiction with Christian doctrine (though
Christian doctrine also included elements that could not be known
except through revelation)
 (SS3.1,
 SS3.3). Siger and Boethius of Dacia were among the targets of a
condemnation directed by the Bishop of Paris in 1277 (see entry on the
 Condemnation of 1277)
 against thinkers in the university. Aquinas, recently dead, did not
escape completely, and he remained a controversial figure, though an
authority for Dominicans (see also
 Aquinas's moral, political, and legal philosophy).



In the next generation,
 Henry of Ghent
 (d. 1293), a member of the commission that drew up the condemnations,
was the most influential Paris theologian. But it was
 John Duns Scotus
 (1265/5-1308), an Oxford Franciscan who was then sent to teach
at Paris, who transformed the subject. He thoroughly absorbed
Aristotelianism, but held that Aristotle's conception of God was
wrong, because it did not allow for divine choices
 (SS3.2).
 He rejected the Aristotelian conception of modality
 (SS3.2),
 stressed divine omnipotence and made divine will the determinant of
good and evil. In his metaphysics, he introduced a range of subtle
distinctions, vastly complicating the Aristotelian scheme.
 William of Ockham
 (c. 1287-1347), a Franciscan theologian who worked at Oxford
and London before joining the Emperor, Ludwig of Bavaria, in order to
flee a papal investigation, followed Scotus's line on
God's will, but substituted for his metaphysics a very sparse
ontology in which the distinctions Scotus had thrust on reality are
made through a mental language. Ockham was also a dedicated logician,
and he and his brilliant Oxford generation made great use of logical
and linguistic analysis, not unlike Abelard and the twelfth-century
Paris thinkers
 (SS4.2).
 In Paris,
 John Buridan
 (d. 1360), the leading Arts Master for decades, and an outstanding
logician, followed a similar programme, and, as an Aristotelian
commentator, strove to be at once faithful to the pagan texts and yet
respect the ultimate truth of Christian doctrine.



Although most accounts of Latin university philosophy tail off in the
mid-fourteenth century, this style of philosophizing continued
vigorously for at least three centuries
 (SS5.2),
 and in this period universities were established all over Europe.
Late in the fourteenth century, John Wyclif (d. 1384), trained at
Oxford, elaborated a sophisticated and idiosyncratic system of
philosophy and theology, aspects of which were taken up by
 Paul of Venice
 (d. 1429), the greatest logician of his time. The Arts Faculties of
Italian universities flourished especially in the late fifteenth and
sixteenth centuries;
 Pietro Pomponazzi
 (1462-1525) was the most famous of these teachers, and the most
audacious in defending the prerogative of Arts Masters to expound the
genuine thought of Aristotle, whatever its differences from Christian
doctrine
 (SS3.3).
 This tradition of university philosophy continued for nearly two more
centuries, with thinkers like
 Giacomo Zabarella
 (d. 1589) in Italy and a host of important figures in Spain and
Portugal
 (SS5.2).


### 2.8 Latin Philosophy Outside the Universities (c. 1200-c. 1500)



Philosophy was also done in the medieval Latin world outside the
universities, although historians are only just beginning to recognize
 it.[20]
 Indeed, some of the most famous and widely studied vernacular
literary masterpieces of the period are also works of philosophy. The
most obvious example is Dante's *Divina Commedia*, a
study in Italian verse of love and moral conduct through an allegory
of humans' post mortem destiny. Although without a university
education,
 Dante
 (who also wrote a highly original Latin treatise on politics) engages
with the great thirteenth-century thinkers--Aquinas and his
teacher, Albert the Great and, especially, the Arts Masters--on
equal terms and as an original thinker (Imbach 1996; De Libera,
Brenet, & Rosier-Catach 2019).



Dante was working in a tradition that went back to Boethius's
*Consolation of Philosophy*, a philosophical discussion using
personification and an elaborate prose and verse literary form. The
*Consolation* was translated into almost every European
vernacular; its influence mixed with that of twelfth-century Latin
works that looked back to it, such as Bernardus Silvestris's
*Cosmographia* (based also on the *Timaeus*) and Alain
of Lille's *Complaint of Nature.* The first of the
vernacular philosophical poems to draw on this heritage was the
continuation in the 1270s of the *Roman de la Rose* by Jean de
Meun, a lawyer who had close connections with the University of Paris
(Morton & Nievergelt 2020). With both the *Roman* and the
*Commedia* in mind, the late fourteenth-century English writers
Chaucer and Langland wrote philosophical poetry (*Troilus and
Criseyde, Piers Plowman*) (Coleman 1981).



Moreover, some highly educated philosophers writing mainly in Latin
worked outside the universities.
 Ramon Llull
 (1232-1315/16) wrote prolifically in Catalan as well as Latin
and reportedly also in Arabic, devising his own logical system,
unrelated to university logic, for thinking about God and his
attributes and demonstrating the truth of Christianity. In the
fifteenth century, non-university philosophers included the Cardinal
and papal diplomat
 Nicholas of Cusa
 (1401-64), courtier and papal secretary
 Lorenzo Valla
 (1407-57),
 Marsilio Ficino
 (1433-99), protege of the Medici in Florence, and
the nobleman
 Pico della Mirandola
 (1463-94). They all developed their ideas in forms different
from those common in the universities and held classical antiquity in
high regard; Ficino was a noted Platonist
 (SS1.3.2),
 Pico aimed to find wisdom in every available source, from the Kabbala
to ... university
 theology.[21]



Women were excluded from most forms of higher education in the Middle
Ages, but there were opportunities, none the less, for them to study
and engage in certain forms of philosophy. Some of those described as
"mystics" (such as Hildegard of Bingen, Margaret Porete,
Mechthild of Magdeburg and others) engaged with philosophical
 issues.[22]
 And there was Christine de Pizan (1364-c. 1430), a married
woman, educated by her father, astrologer to the King of France, who
supported her family by writing French poetry when her husband died.
Her writing, at first lyrical verse, became philosophical, with
Boethius but also Aquinas as points of reference, informed by a strong
consciousness both of the restrictions placed on women and of their
capabilities (Konig-Pralong 2012).


### 2.9 Jewish Philosophy in Christian Europe



Although distinctively Jewish philosophy in the Islamic world, written
in Arabic, died out after Maimonides, it began to flourish, in Hebrew
and using Hebrew translations of Arabic texts
 (SS1.3.4),
 in the Jewish communities of Christian Europe, especially those in
Spain, southern France and
 Italy.[23]
 The central texts were Maimonides's *Guide* and
Averroes's commentaries, especially his Middle ones, which
Jewish thinkers often used in preference to Aristotle's own
texts and on which some wrote super-commentaries.



As explained
 (SS2.6),
 Maimonides left it open how his *Guide* should be interpreted.
While some Jewish thinkers in the thirteenth and fourteenth centuries
thought that, even on a literal interpretation, his book conceded too
much to philosophical ideas, a number of them, such as
 Samuel ibn Tibbon
 (d. 1232), responsible for one of the Hebrew translations, favoured
an esoteric reading, which made the book more radically Aristotelian.
Moses of Narbonne (d. after 1362) also read the *Guide* in this
way and accepts most of Averroes's views, including the idea
that philosophy teaches the complete truth and religion provides a
metaphorical version of it, suitable to be understood by ordinary
people.



Levi ben Gershom
 (1288-1344; "Gersonides") was also a keen reader of
Maimonides and Averroes, but tried to reach his own view on the most
debated questions, after reviewing the arguments on all sides; and, in
his masterpiece, *The Wars of the Lord,* he also explains how
his conclusions, based on argument, do in fact accord with the Torah.
His views on divine prescience
 (SS3.2)
 and the immortality of the soul
 (SS3.3)
 are particularly striking examples of his wish to follow a
philosophical position through to its ultimate consequences.



*The Wars of Lord* competes with *Light of the Lord*, by
 Hasdai Crescas
 (c. 1340-1410/11) as the most profound and adventurous medieval
Hebrew philosophical treatise. Crescas too developed a bold theory
about divine prescience, completely opposed to Gersonides's
 (SS3.2).
 Crescas considered himself an upholder of Jewish orthodoxy in
opposition to Aristotelianism and found powerful arguments to
challenge many of the fundamental tenets of Aristotelian science: he
argued for the existence of a vacuum, the plurality of worlds, time
without bodies and common laws governing sublunar and superlunar
worlds.



Jewish thinkers were influenced not only by their own and the Arabic
traditions. Gersonides may well, informally, have come to know about
problems and techniques of Christian University Philosophy (Sirat,
Klein-Braslavy, & Weijers 2003). Latin works were translated into
Hebrew, and in the fifteenth century some Jewish thinkers, such as
Abraham Bibago (d. before 1489) and Judah Messer Leon (d. 1498) had
read widely in Latin philosophy (Zonta 2006), whilst
 Elijah Delmedigo
 (d. 1493) wrote in both Latin and Hebrew, mixed in Paduan university
circles and translated for Pico della Mirandola.


### 2.10 Post-Classical Arabic Philosophy



"Post-classical" is the telling epithet used by
specialists to denote Arabic philosophy after Avicenna, apart from
that in twelfth-century
 Spain.[24]
 It represents the mass of material that has not until recently been
studied historically (although it remained a living tradition in some
places even until the twentieth century). It is now exciting frontier
territory for research.



Besides the widespread study of logic
 (SS4.1),
 four factors shape philosophizing in this period: Avicenna,
*kalam,* Sufism and al-Ghazali, whose thinking
already combined the first three. Avicenna's encyclopaedias
almost completely replaced Aristotle's texts as points of
reference and a commentary tradition on them, especially
*Pointers*, continued for centuries. New encyclopaedias, on
Avicennian lines, were written and themselves received commentaries.
Although Avicenna had some faithful followers, the attitude to his
work was usually critical. In his *Book of What has Been Carefully
Considered,* Abu-l-Barakat al-Baghdadi (born
c. 1077), a Jew who converted to Islam only at the end of his life,
sets out his differences from Avicenna on many points. His critical
stance was taken up in the influential commentary on *Pointers*
by Fakhr al-Din al-Razi (c. 1150-1210), some of
whose attacks were answered in the commentary written by the leading
thinker of the next generation, the polymathic al-Tusi
((1201-74). Al-Razi was also a leading
*kalam* theologian: he responded to
al-Ghazali's criticism of *falsafa* by, it
seems, teaching two different sets of doctrines,
accepting--despite his criticisms--many of Avicenna's
central doctrines--in his commentary, but rejecting them in his
*kalam* writings (Griffel 2021). But, as even
al-Razi's own case shows--since he wrote in both
disciplines, in the post-classical period the distinctions between
*kalam* and philosophy (no longer usually known by the
Greek-derived term *falsafa* but as
*hikma*--"wisdom") were softened. For example,
the very influential *Book of Stations in Kalam* by
al-Iji (d. 1355), which was commented on by
al-Jurjani (and that commentary in its turn gathered
super-commentaries), sets out large parts of Avicenna's
teaching, although it argues against most of it (Dhanani 2017).



A different stream of reaction to Avicenna is found in the work of
 al-Suhrawardi
 (executed in 1191). He accepts Platonic Forms, while rejecting
Aristotle's view that there are universal forms within
particulars: rather, we know real, particular things better directly
through their presence than through discursive reasoning.
Al-Suhrawardi initiated a School of "Illuminationist"
(*ishraqi*) philosophers. Sufism was elaborated, with rich
philosophical vocabulary and close reference to the philosophical
tradition, though at a distance from it, by
 Ibn 'Arabi
 (1165-1240), whose ideas were put into a more systematic form
by al-Qunawi (d. 1273/4).



All these elements were combined in succeeding years. For instance, in
a famous debate at the beginning of the flowering of philosophy in
Iran, al-Dawani (d. 1501) read Avicenna in a manner
influenced by Suhrawardi (on whom he commented) and Ibn
'Arabi; whereas his critics, the al-Dashtakis, father
and son (d. 1498, d. 1542), kept closer to the
 text.[25]


## 3. Three Medieval Problems



The three problems that will be discussed now in more detail--the
eternity of the world; divine omniscience and human freedom; the soul
and immortality--have been chosen for three reasons. They were
each considered very important in all the traditions of medieval
philosophy. They are, in the form discussed, specifically medieval
(given the long and broad understanding of the Middle Ages advocated
here), although closely linked to philosophical issues discussed
before and since. Moreover--and it is for this reason above all
that these three topics and not others were selected--they each
cast a light on how religious concerns interacted with reasoning and
on the different ways in which this took place within the spheres of
each of the different religious traditions, and between these
spheres.


### 3.1 The Eternity of the World



For Aristotle, the universe has no beginning, because every change
requires a preceding change. The system of nature has always been as
it is, and so it will
 continue.[26]



The Aristotelian eternity of the world (everything apart from God) was
acceptable to the late ancient Platonists, who held that the
intelligible world emanates from God, but not to most Jews, Christians
and Muslims. Their revealed religions hold that the world had a
beginning, when it was created by God. Moreover, it seemed to them
that God cannot be a creator, if the world is eternal.



John Philoponus
 (c. 490-570s), a Monophysite Christian who studied at the still
pagan School of Alexandria, was eager to show, using their own tools,
that his masters were wrong about the eternity of the world. According
to his argument, taken up later in the Middle Ages, the world's
eternity is incompatible with Aristotle's own principles.
Aristotle held that there could not be an actual infinity: the
infinity of days that precedes today if the world is eternal is merely
potential. Philoponus claims, however, that, because each day is
countable, an eternity of past time would be actually infinite. Since
that is impossible, the world must have had a beginning (Philoponus,
*On Aristotle Physics 3* [1994: 428-430, 467-478]
and *Against Aristotle on the Eternity of the World* [1987:
143-146]; Sorabj 1983: 214-215)



Exponents of *falsafa* from al-Farabi onwards
took a different approach. They accepted that the world is eternal,
although they also maintained, in accord with Islamic teaching, that
God is its agent and maker. In al-Ghazali's view
(*Incoherence,* third discussion [2000: 55-77]), however,
because they accepted the eternity of the world (and for some other
reasons), they were entitled to use these descriptions only
metaphorically. Averroes tried to rebut this accusation, minimizing
the difference between his position and that of the theologians
(*Incoherence of the Incoherence,* third discussion [1954:
87-155]). He claims (*Decisive Treatise;* [2001:
14-15]) that *faylasuf* and
*kalam*theologians agree that there are three sorts
of things: the bodies that make up the world, which are caused and the
existence of which is preceded by time; God, who is uncaused and is
not preceded by time; and the world as a whole, which time does not
precede (because time does not exist without the motion of bodies),
but which is brought into existence by an agent. The only difference
is that the *faylasuf* hold that time has been going on
infinitely, which the theologians deny.



By contrast, Maimonides--at least on a literal reading of his
*Guide of the Perplexed*--rejects any attempt to reconcile
the eternity of the world with the creative role of the Abrahamic God,
which for him involves will and choice. Rather, he denies that
Aristotle had succeeded in demonstrating the eternity of the world and
claims even that Aristotle himself accepted he had not done so (II, 15
[1963: II, 289-293]). He does not, however, like Philoponus, try
to demonstrate that the world has a beginning, but just provides
strong, but non-demonstrative arguments for the position. The
strongest of them binds his views here even more tightly with his idea
of God as a wilful agent. Maimonides argues that his account of
physics in the sublunary world, Aristotle's account of how the
universe derives from the One (Maimonides has in mind the emanation
theory developed by al-Farabi) is explanatorily
insufficient. The only way he sees that the required explanation can
be provided is through God's will: it happens in this way,
because God so chooses. But God can will and choose, Maimonides
thinks, only if the world he created has a beginning (II, 19-25
[1963: II, 302-330]).



For Christians, it was clear Church doctrine that the world has a
beginning, and in the thirteenth-century Latin universities some
theologians tried to use Philoponian arguments to claim this position
could be demonstrated. Like Maimonides, Boethius of Dacia (Boethius of
Dacia [1987]), the leading Arts Master in the 1260s-70s, did not
accept that either these arguments, or those for the eternity of the
world, are demonstrative. But he also thought that a practitioner of
Aristotelian natural science (one of the roles of an Arts Master) had
to go further and actually deny the world has a beginning, because
natural science is founded on the principle that every change requires
a preceding change. In order to save Arts Masters from heresy,
Boethius advocates a limited relativism. When natural scientists state
that the world has no beginning, they are saying that the world has no
beginning *according to the principles of natural science*, a
position in harmony with the true Christian doctrine, according to
which it does have a beginning.



In his *On the Eternity of the World,* Aquinas's position
is in some ways similar. He accepts on faith that, in fact, the world
had a beginning, but rejects rather contemptuously the Philoponian
arguments used by some of his contemporaries. He wishes, however, to
argue for a different point: that it *could* have been the case
that the world has always existed and yet "is caused by God
according to everything that is in it". Aquinas sharply
distinguishes this position from the view that "something other
than God could have always existed, as if something could exist and
not be made by him"--which, he says, not just Christian
teaching, but the philosophers reject as an "abominable
error". He is right, indeed, that the philosophers--not
Aristotle, but Avicenna and Averroes!--did hold that the world
was "made" by God. But, as al-Ghazali pointed
out, it is very unclear how--within the Aristotelian modal scheme
Avicenna, Averroes and he all accepted
 (SS3.2)--an
 eternal world leaves room for God to make the world in the sense
Aquinas certainly meant: that of willing and choosing it.


### 3.2 Divine Omniscience and Human Freedom: The Problem of Prescience



God, according to almost every late ancient and medieval philosopher,
whether pagan, Jew, Christian, or Muslim, is omniscient, and so, they
believed, he knows the
 future.[27]
 But if he already knows my future volitions and actions, how can they
be free, since it would seem that I cannot will or act otherwise than
as he knows I shall? There are ways of formulating this Problem of
Prescience in which it becomes a pseudo-problem, based on failing to
see that the wide scope necessity that necessarily (if God--or
anyone--knows that *p*, then *p*) does not entail
the necessity of *p*. Peter Abelard thought that, by pointing
out this fallacious reasoning, he had solved the problem. His solution
was influential, but it misses what Boethius had noticed, six
centuries previously in his *Consolation,* Book V (Marenbon
2005: 55-116). There *is* a genuine problem, because God
does not just know, but *fore*knows. Boethius sees the argument
as follows (see entry
 Boethius, SS6).
 Future contingent events are ones that may turn out one way or the
other, but to be *known*--rather than opined or guessed
about--the future must be fixed. For God to know the future, as
he does, it must therefore be fixed, and so there are no contingent
events. But this, he believes, removes the foundation for morality and
the value of prayer. Boethius rejects this unwelcome conclusion by
appealing to the principle that



> 
> 
> everything that is perceived is grasped not according to its own force
> but rather according to the capability of those who perceive it
> (*Consolation* V, pr. 4.25 [2001: 138])
> 
> 
> 



a principle that relativises cognition to different types of cognizer.
On its basis, he can say that many future events (such as those that
depend on the exercise of my will) are in themselves unfixed and
contingent, but they are fixed and necessary as known by God. This
divine mode of cognition can to some extent be explained by
God's relation to time. He exists in eternity, not time.
According to many interpreters, God is thereby atemporal, but it is
more likely that Boethius meant that God has a special relationship to
time, by which he intellectually grasps all its fleeting moments at
once and so he perceives every moment of time as if it were the
present. Just as we can watch a chariot race and know who is in the
lead, without thereby constraining the competitors, so God knows all
things, past, present and future, as if they were present.



Aquinas followed Boethius, though with greater understanding of the
logical structure of the
 question.[28]
 Scotus, however, took a completely different approach (*Lectura I
39* [1994]). Almost all medieval thinkers accepted that
God's knowledge does not depend on its objects, as human
knowledge does, but brings them about. Boethius put this problem
aside, but Scotus faces up directly to explaining how, if God brings
about all things about by knowing them, anything can be contingent.
The incompatibility is avoided, Scotus argues, if and only if God
himself wills contingently. But the understanding of necessity most
thirteenth-century university thinkers took from Aristotle would not
allow God to will or act contingently. What is necessary, they held,
is equivalent to what is always the case, and so the will of God, who
all agreed exists always and never changes, is necessary. Scotus made
explicit a different understanding of modality, in which possibility
and necessity are not reducible to temporal conditions. God's
will is unchanging through all time, but it might have been different.
(Knuuttila 1993: 139-149; and entry on
 medieval theories of modality).



Avicenna and Averroes, who followed Aristotle in holding that God does
not know particulars, but only universals, do not face the Problem of
Prescience. Rather, both thinkers felt the need to explain how, in
some indirectway, God's knowledge is not strictly limited to
 universals.[29]
 Maimonides tried to reconcile both the tension between
Aristotle's God and a providential one, and divine prescience
and contingency, through his radically negative theology, according to
which everything about God's essence, as opposed to his effects,
is unknowable for us. "Know" as applied to God, he
explains, is used equivocally from "know" as we usually
employ the word, about humans. We cannot understand what it means for
God to know (although we can gain some glimmer of understanding by
thinking of the special grasp a maker has of what he makes), but we
can be sure that he knows everything, including future contingents
(Maimonides, *Guide* III, 20 [1963: 480-484]).



Gersonides was, understandably, dissatisfied with Maimonides's
position. Maimonides was celebrated for insisting that belief in
God's incorporeality is fundamental to Judaism: anyone who
denies it is not a Jew. But if language used about God is really
equivocal, Gersonides points out, how does Maimonides know that
"God is a body" is false? (*Wars* III.3 [1987:
107-115]). Gersonides himself is willing, not unlike Avicenna
and Averroes, to restrict God's knowledge to the general
outlines of how the world is ordered, but he holds that the precise
details of humans' lives, though not the rest of nature, are
determined by him indirectly, through the stars. He escapes the
determinism that this might imply, however, by allowing for an
exception. Humans have the power, by using their intellects, to change
what is astrally determined for them. Suppose it is astrally
determined that I spend this evening partying, I am none the less able
to grasp intellectually that it would be better to devote it to
reading Gersonides and, despite the stars, stay at home with *The
Wars of the Lord* (*Wars* III, 3-4 [1987:
107-131]).



By contrast, Crescas firmly held that God foreknows the particular
events of people's lives, and that these are causally
determined, ultimately by God. He accepts the deterministic
consequences of this view, because, like compatibilists today, he does
not think them inconsistent with human striving to achieve ends and
being punished for misdeeds. He distinguishes between what an agent
does because of its nature and what it does because it is causally
determined (the latter, he says, is possible in itself, but
necessary through another). If humans became rich as part of their
nature, then their efforts to make money would be in vain. But, given
that this is not the case, the fact that their efforts are causally
necessary does not make them futile: on the contrary, they belong to
the chain of causes that results in becoming rich. Similarly,
although, if I desist in the future from committing some crime it will
be causally necessary that I do so, the punishment laid down for it is
valuable because it (through its deterrent effect) is part of that
causal
 chain.[30]


### 3.3 The Soul and Immortality



Plato thought of human souls as distinct substances from their bodies,
capable of existing separately and being reincarnated. The late
ancient Platonists retained this dualism and aimed so far as possible
even in their mortal lives to release their souls from their bodies
and find union with the One. By contrast, for Aristotle the soul is
the form of a living body, that which accounts for its life functions,
just as the form of a non-living thing--the form of stoneness in
a stone--accounts for its being the sort of thing it is. A plant,
then, grows and goes through its life cycle in virtue of its
vegetative soul. A non-human animal's soul is not just
vegetative but also sensitive: it accounts for the animal's
ability to move and to perceive with its senses. The human soul
accounts for all these capabilities, and it also has intellect: it can
think intellectually about universals. If the soul is the form of a
body, survival independently of the body would seem impossible in
principle. There are, however, passages in Aristotle's *On
the Soul* (especially 430a [Chapter 5]) that suggest that the
intellect is imperishable, but they probably are not intended to refer
to individual human souls.



By contrast with both Plato and Aristotle, a core belief for Jews,
Christians, and Muslims is in a bodily resurrection, which is linked
to punishment for sins and reward for a good life. Christians also
developed the doctrine that, in the period between death and the Final
Judgement, people's souls survive separately and can be
rewarded, purged, or consigned to eternal punishment.



Avicenna went against the Islamic doctrine of bodily resurrection and,
reading Aristotle from a Platonist perspective, argued that each human
has an intellect which, unlike the other parts of the soul, is
immaterial--if it were not immaterial, he argues, it could not
perceive universals--and, being immaterial, is immortal (see,
e.g., the passage from *The Salvation* translated in Khalidi
2005: 27-58). Averroes, too, was unwilling to accept bodily
resurrection in any straightforward way, and, in face of
al-Ghazali's criticisms of Avicenna in this regard, he
falls back on saying that philosophers uphold resurrection because
they hold that the masses should believe this widely-held religious
doctrine and so they do not contradict it publicly (Averroes
*Incoherence* [1954: 359-363]). Averroes does not,
however, at all follow Avicenna's Platonizing interpretation of
Aristotle's views about the soul: in his Great Commentary on
*On the Soul,* he argues that there is, indeed, an imperishable
intellect, but it is an independently existing immaterial being. It
needs humans, however, for thinking to take place, since thinking
requires images, which humans process in their corporeal brains. Just
as the book in front of me makes the visual perception I am having of
it veridical, so the processed images in our brains of bodily things
enable the one independent, immaterial intellect to think truly using
 universals.[31]



Maimonides considered that the only genuine pleasures are intellectual
ones, and the type of bodily rewards that were often associated with
the Resurrection are not only without value, except as incentives for
those who lack wisdom, but also misleading, because we should act in
accord with God's law for love of God, not from hope of reward
(Commentary on *Mishnah,* Introduction to *Sanhedrin*
[translated in "Maimonides on the Jewish Creed", 1906]).
He none the less asserted the Resurrection as part of the Jewish
creed, and rejected criticisms that he had ever denied it. As in many
places, his genuine position is open to interpretation.



Avicenna's interpretation of Aristotle proved very attractive to
the earlier thirteenth-century Latin university thinkers, since it
harmonized with Augustine's dualistic view of soul and body,
which had predominated until *On the Soul* became known (see
Hasse 2000). Once it was understood properly, Averroes's theory
was recognized as clearly contrary to Christian teaching, since it
excluded individual immortality. But many Arts Masters from the 1260s
through to the sixteenth century continued to champion it as the
correct interpretation of Aristotle and the best theory so far as
natural reason is concerned, although wrong, because contradicted by
revealed truth. Aquinas, however, castigated Averroes's theory
as a misunderstanding of Aristotle, and also as incoherent, since it
makes humans into the objects of thought rather than
 thinkers.[32]
 He also rejected Avicenna's dualist reading, insisting that
each human has their own intellective soul, which is the form of their
body. He then explained the separate survival of the human soul by
arguing that its special activity, thinking intellectually, is one
that does not take place in a corporeal organ (as sight takes place in
the eyes), and so it is a subsisting thing, independent of the
 body.[33]



The fiercest medieval criticism of Aquinas's theory was in
*On the Immortality of the Soul,* published by Pietro
Pomponazzi in 1516. Pomponazzi begins by declaring that he accepts the
immortality of the human soul as a truth, known by revelation, and
that Aquinas's argument for its immortality is the best that can
be made. He opposes both Averroes's view and a Platonic dualism,
which Ficino had quite recently revived. But he seems to have just as
many objections to Aquinas. In particular, he points out that,
according to Aristotle, although intellectual thinking is immaterial,
it cannot take place without there going on at the same time a play of
mental images, which are sensible things and require a bodily organ,
the brain. The human intellect is, therefore, dependent on the body,
not in the activity of thinking itself, but with respect to a
necessary condition for it. Some historians think that, given the
strength of his attack, and the fact that he goes on to explain why a
rejection of the soul's immortality need not have bad moral
consequences, Pomponazzi did not really accept Christian teaching
about the afterlife. It is more plausible, however, that he--like
Boethius of Dacia in the thirteenth century--was mainly concerned
to protect the prerogative of Arts Masters to interpret Aristotle and
work within natural reason, even when that meant contradicting Church
doctrine.


## 4. The Importance of Logic



In the Ancient World, sophisticated systems of logic were developed by
Aristotle and by the Stoics, but, unlike rhetoric, logic was never a
standard part of education
 then.[34]
 By contrast, in both the Islamic world and in Latin Europe during the
Middle Ages logic became a fundamental discipline, not just within
philosophy (as it has been for the last century in the Anglophone
world), but for anyone receiving more than the most basic
education.


### 4.1 Arabic Logic



By the early tenth century, the whole of Aristotle's
*Organon* was available in Arabic. It was an extended
*Organon,* which included the *Rhetoric* and the
*Poetics.* Logic was seen as providing the rules for different
sorts of discourse, of varying levels of intellectual value. At the
bottom were poetic syllogisms, then rhetoric, then the dialectical
syllogisms of the *Topics* and finally, as the peculiar
preserve of philosophers, demonstration, the theory set out in the
*Prior Analytics* and applied to knowledge in the *Posterior
Analytics* and, so it was thought, according to which Aristotle
constructed his entire system of thought. Avicenna did not reject this
overall view, but he was mainly interested in refashioning
Aristotle's (demonstrative) syllogistic, even more thoroughly
than he reshaped his metaphysics and natural science. He combined
categorical and hypothetical syllogistic into a single theory, and he
vastly complicated Aristotle's system by introducing temporal
qualifications into every sort of syllogism (see entry on
 Ibn Sina's logic).
 Except in Islamic Spain, Avicenna's logic replaced
Aristotle's.



*Falsafa*, however, always remained the pursuit of a small
minority, at the edges of the world of Islamic education. The position
of logic was transformed by al-Ghazali. Whereas his attitude
to *falsafa* was ambiguous, he declared that logic--he had
in mind Avicenna's version of Aristotelian syllogistic--was
useful, even essential, for the Islamic sciences, such as law, that
occupied much of the curriculum in the madrasas, which were beginning
to flourish in his time. Following his lead, logic became a fixed part
of madrasa education. In the thirteenth century, succinct logical
textbooks were written, such as al-Abhari's
*Isaghuji* and al-Katibi's
*Shamsiyya*, which were then the subject of many commentaries.
The concerns of *madrasa* logic were formal: developing further
Avicenna's path in syllogistic, especially modal syllogistic,
relational syllogisms and the Liar Paradox. This tradition was
continued in Iran, Turkey and India, each of these regions
increasingly separated from the others, down to the nineteenth
century. (See the entry on
 Arabic and Islamic philosophy of language and logic.)[35]


### 4.2 Latin Logic



In the Latin world, the pattern of education established from c. 800
in monasteries and cathedral schools
 (SS2.2)
 gave logic a central role, in what was the mainstream of higher
education, despite very limited access to the ancient
 sources.[36]



Although the sophisticated philosophy developed in this context by
thinkers like Abelard was the preserve of the elite twelfth-century
Paris schools, it had by then become normal for everyone being trained
intellectually in Latin Europe to learn at least basic Aristotelian
logic and the theory of topical inference, as developed in later
antiquity and transmitted by Boethius. With the founding of the
universities and the expansion of the syllabus to include the whole
range of disciplines covered by Aristotle, it might seem that logic
lost its preeminent position. But it had not, for two reasons. First,
the early years of the Arts course were almost entirely devoted to
logic, and many students did not remain at university any longer;
moreover, they would often have received some instruction in logic
before coming (in their early teens) to university, and there was
further study of logic in the higher faculties of Law and Medicine
(see Brumberg 2021: 95-97). Second, while the influx of new
texts made many of the leading thirteenth-century university thinkers
more interested in metaphysics, natural science, epistemology and
ethics than in logic, the Oxford thinkers of the 1320s--not just
Ockham, but his fellow Franciscans
 Walter Chatton
 (d. 1343/4) and
 Adam Wodeham
 (d. 1358) and the Dominican
 Robert Holcot/Holkot
 (d. 1349)--made frequent use of sophisticated logical techniques
in their theological discussions, setting a fashion that would also be
imitated in Paris (see Courtenay 1987: 171-306).



In the Arabic tradition, Aristotelian logic was at first studied by
close reading of Aristotle's own texts, but Avicenna then
replaced Aristotle as the authority, and then often later textbooks
replaced his work
 (SS1.1).
 Almost the reverse process took place in the Latin world. From
consisting mainly of encyclopaedic accounts, the logical syllabus
moved to being constituted of a couple of Aristotle's works,
supplemented by Porphyry and Boethius (the *logica vetus*) by
the eleventh century, and once the rest of the *Organon* (the
*logica nova*) became available, by the early thirteenth
century, Aristotle's logic (augmented just by Porphry's
*Introduction* and a twelfth-century text supplementing the
*Categories*) was studied in detail in the universities,
continuing to the sixteenth century, and even later in Spain. This
tradition of commentary, although never abandoning
Aristotle's text, often resulted in sorting out the difficulties
in his presentation and reworking his logic (as, for example, in the
commentary on the *Prior Analytics* by
 Robert Kilwardby
 from the 1240s: see Thom
 2019).[37]



From the late twelfth century there also developed in the Latin
tradition what was called the *logica modernorum*
("contemporary logic")--a variety of new branches of
the subject not found in Aristotle. The most important of them concern
the properties of terms (the analysis of the reference of
words--their "supposition"--within the context
of sentences (see entry on
 Medieval theories: properties of terms);
 *consequentiae* (propositional logic, by contrast with
Aristotelian term logic--see entry on
 medieval theories of consequence);
 *sophismata* (deliberately ambiguous sentences and/or ones with
apparently puzzling consequences that can be explained by semantic
analysis, such as "Something white will be black");
 insolubles
 (*insolubilia*--paradoxes, such as that of the Liar); and
 *obligations*
 (an argument game, involving counterfactual statements and testing
the contestants' ability to remain consistent). Specialized
treatises were written on each of these topics, but the most popular
textbook of all, the *Treatise,* known as the *Summule
logicales*, written by
 Peter of Spain
 probably c. 1125-50, which combines the *logica vetus*
and *nova* with a long exposition of the theory of the property
of terms. Peter (whoever he was: see Peter of Spain
*Summaries,*1-9) was not in fact an outstanding
logician, but his work, by then the standard textbook, was adapted,
with enormous licence, in the mid-fourteenth century as a vehicle for
his also very widely-read *Summule de dialectica*, by the
greatest logician of the time, John Buridan. Work within the
*logica modernorum* went on until the mid-sixteenth
 century.[38]


### 4.3 Logic in Byzantium and among the Jews



Although logic did not have the same prominent place in Byzantine
education as in the Latin schools and universities, or in the
madrasas, there was a continuous tradition of its study, based on
exegesis of the *Organon* and strongly influenced by the late
ancient School of
 Alexandria.[39]



There were no outstanding logicians among the Jews in the Islamicate
world, but in Christian Europe from the thirteenth century onwards a
lively tradition of logic grew up. It was based initially on Hebrew
translations of al-Farabi's short commentaries
and Averroes's middle commentaries on Aristotle's
*Organon* and the logical part of al-Ghazali's
*Opinions.* But Jewish scholars also became familiar with some
Latin material, such as Peter of Spain's *Treatise*
(especially the parts on the *logica vetus*). Gersonides was an
original logician, who wrote widely-studied supercommentaries on
Averroes's middle commentaries, where he is often critical of
Averroes, and a treatise, the *Book of the Correct Syllogism,*
remarkable for its degree of formalization (see Manekin 2012).


## 5. When Was Medieval Philosophy?



Whereas specialists are mostly agreed, in theory at least, about the
new, broad conception of the geography of medieval philosophy, opinion
about the period's chronology remains divided. There is, indeed,
a widespread view (e.g., De Rijk 1985: 1-64; Luscombe 1997: 1;
Flasch 1986 [2000: 27-29]; Lagerlund 2020: v) that period
divisions are unimportant and are chosen for purely practical reasons
in order to allow for a division of labour. But, as will emerge below,
the choice of period divisions makes a great difference to how the
history of philosophy is written, and arguments can be made from the
continuity and breaks in traditions for different periodizations
(Marenbon 2011).


### 5.1 When Did Medieval Philosophy Begin?



There are three main points commonly chosen for the beginning of
medieval philosophy:


1. c. 500, a date often chosen by historians for the start of the
Middle Ages and corresponding roughly to the end of the Roman Empire
in the West (the last Emperor was deposed in 476);
2. with the earliest Christian philosophers in the second century
(but usually omitting the pagan Greek tradition; or
3. around 800, because this was the time of both the philosophical
stirrings at Charlemagne's court and the start of
*falsafa* in
 Baghdad.[40]



There are problems with each view:


1. The justification for c. 500 applies only to Latin philosophy,
and
2. that for the second century only to Christian philosophy;
while
3. ignores Greek philosophy and also threatens to leave Latin
philosophy between 500 and 800, which historians of classical
philosophy disdain, outside consideration.



If the medieval tradition is being envisaged in all four of its main
branches, there is some virtue in seeing the point of departure in the
work of Plotinus (d. 270) and Porphyry (d. 305?) and including too the
other Greek pagan material. All four branches are rooted in the
so-called Platonic Schools, and they took their orientation from these
two philosophers. Of course, historians of ancient philosophy will
also want to include some of the thinkers in the earliest centuries of
this period in their field, but that is not a problem, because there
is no reason why periods in the history of philosophy should not
overlap.


### 5.2 When Did Medieval Philosophy End?



Many different answers might be given to this question, but a
plausible (and to many people surprising) one is: around about 1700,
except that the Arabic tradition, in logic especially, lasted rather
longer.



The Arabic tradition continued, especially in Persia, Turkey and India
through the seventeenth century and, especially in logic (see
 SS4.1),
 beyond. The outstanding centre was Safavid Iran, where Sadr
al-Din Shirazi (known as
 Mulla Sadra,
 1571-1636) developed an original system of thought on the basis
of Avicennian Aristotelianism itself, and as modified by
Suhrawardi, and the mystical ideas of Ibn 'Arabi. New
research shows that in the seventeenth century the Ottoman Empire,
too, was the home to innovative philosophizing, sometimes taking the
earlier Iranian tradition as its starting point (El-Rouayheb
2015).



The tradition of Jewish philosophy in Hebrew in Christian Europe
largely came to an end with the expulsion of the Jews from Spain in
1492, though it continued for another century in Turkey (see
Tirosh-Samuelson 1997: 529-545). But Jewish philosophy in Europe
continued with the *Dialogues of Love* by
 Judah Abrabanel,
 known as Leone Ebreo (d. after 1521), preserved and probably written
in Italian. If, as proposed below, the Latin tradition of medieval
philosophy is considered to stretch on until around 1700, then perhaps
 Spinoza
 (1632-77), who wrote in Latin and, rarely, in Dutch, an outcast
from his people and a critical admirer of Descartes, but also steeped
in the thought of Maimonides and Hasdai Crescas, should be
regarded as the last of the medieval Jewish philosophers.



The Byzantine tradition was afflicted by the Fall of Constantinople in
1453, but theological and philosophical speculation in Greek continued
under Turkish rule, strongly linked with the earlier tradition, but
influenced by Latin scholastic thinking in the seventeenth century,
and by new trends in European thinking in the eighteenth (Podskalsky
1988).



Fixing the end point of the Latin medieval tradition is difficult.
Although the traditional and still widespread date of 1500 is often
today said to have no significance, that year has often been chosen by
general historians to mark the beginning of modern times, as a round
figure near to 1492, the date of Columbus's first voyage to the
New World, and 1517, the beginning of the Reformation, which would
destroy the apparent unity of Catholic Europe. Many medieval
historians now, however, do not wish to place a boundary at this time
and stress the continuities in economic and social life that lasted
until the Industrial Revolution. In any case, there is no reason why
periodizations in the history of philosophy should coincide with those
in other areas.



In many multi-part or multi-volume presentations, Medieval Philosophy
is followed by Renaissance Philosophy and then by (Early) Modern
Philosophy, beginning with Descartes. "Renaissance
philosophers" are identified as usually working outside the
universities; many of them enthusiasts for Plato and other ancient
philosophers, as well as, or instead of, Aristotle; many eager to
write elegant classical Latin and to learn Greek, and to use literary
forms such as the dialogue. There was indeed a group of such
philosophers, but they do not fit into a chronology that places
Renaissance Philosophy after Medieval Philosophy: the most famous of
them are Marsilio Ficino and Pico della Mirandola
 (SS2.8),
 neither of whom survived until
 1500.[41]



University philosophy continued in its established patterns, with some
important changes (such as dropping study of the *Metaphysics*)
in Protestant countries, until late in the seventeenth century. In the
Iberian peninsula, the sixteenth and seventeenth centuries were the
period in which philosophical theology, studied in the established
university manner, flourished (see entry on the
 School of Salamanca).
 The tradition is continuous with the earlier Parisian one, since its
founder, Francisco de Vitoria (1486-1546) was a pupil of the
last of the great Paris University theologians, the Scot John Major
(1467-1550). Among Vitoria's well-known successors were
Domingo de Soto (d. 1560), Luis de Molina (d. 1600)--who held
that God has a special knowledge of the choices we shall make, but
that he does not control these choices, and
 Francisco Suarez
 (b. 1548), one of the deepest and most powerful thinkers in the whole
Latin tradition. One of the few big differences from earlier medieval
university thinking was the central importance given to Aquinas
(although Suarez was also influenced by Scotus and Ockham),
whose *Summa Theologiae* was now an object of commentary.
Suarez's death in 1617 (more than twenty years
after Descartes's birth) does not mark the end of this
university tradition, but its development into the adventurous
thought, striking out in new directions in metaphysics and
meta-ethics, of until recently forgotten thinkers such as Pedro
Hurtado de Mendoza (d. 1641), his pupil, Rodrigo de Arriaga (d. 1667)
and Juan Caramuel y Lobkowitz (d. 1682).



The interest of this "baroque scholasticism" is now
beginning to be recognized (see Novotny 2009). At the same
time, some of the best scholars in the field have written studies that
deliberately cut across the usual medieval to modern philosophy
divide, looking at metaphysics from 1274 to 1671 (Pasnau 2011) or
theories about emotion from 1270 to 1670 (Perler 2011 [2018]). These
approaches still tend to accept the standard idea that medieval
philosophy ended, and modern philosophy began sometime around 1500 or
at least before 1600, underlining continuities or pleading for the
existence of "medieval philosophy after the Middle
 Ages".[42]
 A radical suggestion, however, would be to place the ending of
medieval Latin philosophy round about 1700 (allowing, of course, for
an overlap with early modern philosophy), since it was only by then
that the effects of the New Science and Cartesianism had worked their
way into university education and the Aristotelian tradition was
disappearing (although by no means everywhere in
 Europe).[43]