## 1. Life and Works


### 1.1 Date, Family, Teachers, and Influence



Next to nothing is known about Alexander's origin, life circumstances,
and career. His native city was (probably) the Aphrodisias in Caria,
an inland city of southwestern Asia Minor. His father's name was
Hermias. The only direct information about his date and activities is
the dedication of his *On Fate* to the emperors Septimius
Severus and Caracalla in gratitude for his appointment to an endowed
chair. Their co-reign lasted from 198 to 209 CE; this gives us a rough
date for at least one of Alexander's works. Nothing is known about his
background or his education, except that his teacher was Aristoteles
of Mytilene, rather than the more famous Aristocles of Messene, as had
been conjectured by certain scholars since the 16th. century. He is
also said to have been a student of Sosigenes and of Herminus, the
pupil of the commentator Aspasius, the earliest commentator on
Aristotle whose work has in part survived (for information concerning
Alexander's teachers and their philosophy, see Moraux 1984, 335-425).
How much Alexander owed to his teachers is hard to guess, for he
sometimes criticizes Sosigenes and Herminus extensively. But it is
clear from the scope and depth of his work that he was a well-trained
philosopher with a broad range of knowledge and interests.



Though the dedication to the emperors tells us that Alexander was
appointed to a chair in philosophy, there is not sufficient evidence
as to whether, as is often asserted, he obtained one of the four
chairs, representing the four traditional schools, established in
Athens by Marcus Aurelius in 176 CE. There were similar established
chairs in several cities (on Athens see Lynch 1972, 192-207;
213-216). Given the amount and scope of his writing he must have
been an active teacher with a flourishing school. It is therefore
possible that some of the short essays attributed to Alexander are
actually the production of one of his collaborators or disciples. But
nothing is known about any of his associates and students (cf.
Sharples 1990a). To us his work therefore represents both the heyday
and the end of the series of commentators who explained Aristotle
exclusively on the basis of Aristotelian texts, without commitment to
some other doctrine. Alexander concludes the series of these purely
'Peripatetic' commentators (beginning with Andronicus of
Rhodes in the first century BCE), who try to explain "Aristotle
by Aristotle" (Moraux 1942, xvi). Though later commentators,
starting with Porphyry, the disciple and editor of Plotinus, relied
heavily on his works, they had a Neo-Platonist approach. Since
Porphyry lived considerably later than Alexander (ca. 234-305/10
CE), Alexander's school may have continued to exist until it became
outmoded by the 'Neo-Platonist turn'. Porphyry's report
that Plotinus included texts by Alexander 'and related authors
in his discussions' (*The Life of Plotinus*, 14.13) makes
this quite likely. Alexander's commentaries formed a central part of
the Arabic tradition and was heavily used by Maimonides. It thereby
influenced the Latin West after the revival of Aristotelianism in the
Middle Ages. The scarcity of Latin translations of Alexander's
commentaries suggests a certain preference for the interpretation of
the later, Neoplatonist, commentators. If William of Moerbeke confined
his translations of Alexander's commentaries to those on the
*Meteorologica* and the *De sensu* that may in part be
due to the availability of Boethius' commentaries on Aristotle's
*Prior Analytics* and the *Topics*, but it leaves
unexplained why he did not translate the commentary on the
*Metaphysics*. 


### 1.2 Works and their history



As the list of his work shows, Alexander was a prolific writer. His
writings comprise both commentaries (*hupomnemata*) on
the works of Aristotle and several systematic treatises of his own
(including works on 'problems', consisting of series of
essays on different Aristotelian texts and topics). Of the
commentaries, the following are extant:  *On Prior Analytics*
*I*, *Topics, Metaphysics, Meteorologica,* and *On
Sense Perception*. Of the commentary on the *Metaphysics*
only the first five books are by general consent accepted as genuine;
the remaining nine books are attributed to the late commentator
Michael of Ephesus (11th-12th century CE.). The commentary on the
*Sophistical Refutations*, ascribed to Alexander in some
manuscripts, is considered spurious. References by later commentators
show that Alexander's commentaries covered all of Aristotle's
theoretical philosophy, including his physical writings (with the
exception of the biological works). The list of his lost work is long:
there are references to commentaries on the *Categories*,
*De interpretation*e, *Posterior Analytics*,
*Physics*, and *On the Heavens*, as well as *On the
Soul* and *On Memory*. Alexander did not write commentaries
on Aristotle's *Ethics* or *Politics*, nor on the
*Poetics* or the *Rhetoric*. That he had quite some
interest in ethical problems, however, is witnessed by the discussions
in his own treatises. Among the extant short systematic writings the
following are regarded as genuine: *Problems and Solutions, Ethical
Problems, On Fate*, *On Mixture and Increase*, *On the
Soul* and a *Supplement to On the Soul*
('Mantissa' lit. 'make-weight') that not only
contain discussions of questions concerning psychology but also
problems in physics, ethics, vision and light, as well as fate and
providence. The 'Mantissa' may not be by Alexander but a
compilation of notes by his students. The rest, *Medical Questions,
Physical Problems*, and *On Fevers* are considered
spurious. Of his lost works some have been preserved in Arabic because
they were highly influential (see D'Ancona & Serra 2002): *On
the Principles of the Universe*, *On Providence*,
*Against Galen on Motion*, and *On Specific
Differences*. Because of Alexander's prestige and authority as an
interpreter of Aristotle, many of his works now lost were incorporated
in the commentaries of his successors, whether they name him or not.
Nothing certain is known about the relative chronology of his
writings, but this is not an issue of much importance, since his
commentaries may well represent the results of many years of teaching,
with later insertions and additions, in a way quite similar to
Aristotle's own texts. This would explain the lack of any attempt at
elegance and the occurrence of inconsistencies or unclear transitions
in Alexander.


## 2. Alexander as commentator



In general, Alexander goes on the assumption that Aristotelian
philosophy is a unified whole, providing systematically connected
answers to virtually all the questions of philosophy recognized in his
own time. Where there is no single, clearly recognizable Aristotelian
point of view on some question, he leaves the matter undecided, citing
several possibilities consistent with what Aristotle says. Sometimes
Alexander tries to force an interpretation that does not obviously
agree with the text, but he avoids stating that Aristotle contradicts
himself and, with rare exceptions, that he disagrees with him. Readers
will not always be convinced by his suggestions but they will often
find them helpful and informative where Aristotle is overly compressed
and obscure. As a remark in his commentary on the *Topics*
shows, Alexander was quite aware that his style of philosophic
discussion was very different from that of the time of Aristotle
(*In top*. 27,13): "This kind of speech [dialectic
refutation] was customary among the older philosophers, who set up
most of their classes in this way -- not on the basis of books as
is now done, since at the time there were not yet any books of this
kind." As this explanation indicates, however, he seems to have
regarded the bookishness of his own time as an advantage over the
dialectic style rather than a disadvantage.



Like the other commentaries in the ancient tradition, Alexander's
derive from his courses of lectures ('readings') on
Aristotle's works. In commenting, Alexander usually refrains from
giving comprehensive surveys. He generally starts with a preface on
the work's title, its scope and the nature of the subject matter. He
then takes up individual passages in rough succession by citing a line
or two (this provides the '*lemma*' for the ensuing
discussion) and explaining what he considers as problematic (in
explanatory paraphrases, clarifications of expressions, or refutations
of the views of others), often in view of what Aristotle says about
the issue elsewhere. This procedure clearly presupposes that the
students had their own texts at hand and were sufficiently familiar
with Aristotle's philosophy as a whole. Alexander does not generally
go through the text line by line, but chooses to discuss certain
issues while omitting others. Paraphrases are interrupted by
clarifications of terminology, and sometimes, at crucial points, by
notes on divergent readings in different manuscripts and a
justification of his own preference concerning Aristotle's original
words. Decisions on such philological problems are based on what makes
better sense in conforming with Aristotle's intentions here or
elsewhere. As Alexander indicates, such philological explorations were
considered as part of the commentator's work (cf. *On Aristotle
Metaphysics* *A*, 59, 1-9): "The first reading,
however, is better; this makes it clear that the Forms are causes of
the essence for the other things, and the One for the Forms. Aspasius
relates that the former is the more ancient reading, but that it was
later changed by Eudorus and Euharmostus." Alexander's concern
with textual problems makes him a valuable source for textual
criticism, as can be seen from Kotwick's (2016) monograph on the text
of Aristotle's *Metaphysics*.



Though Alexander follows the Aristotelian texts quite conscientiously,
he often concentrates on special points and the respective passages
while passing over others with brief remarks. Thus in his comments on
the first book of Aristotle's *Metaphysics* he devotes more
than half of his exegesis to the two chapters in which Aristotle
attacks Plato's theory of Forms (*Metaph*. A, 6 & 9). Since
Aristotle there focuses on Plato's attempt to connect the Forms with
numbers, a theory that is not elaborated in the dialogues, Alexander's
disquisition turns out to be our most valuable source on the vexed
question of Plato's Unwritten Doctrine and also on the impact of this
doctrine on the members of the Early Academy (see Harlfinger &
Leszl, 1975; Fine 1993). Though on the whole Alexander adopts
Aristotle's critical stance towards Plato's separate Forms, he
sometimes at least indicates the possibility of dissent. When, for
instance, Aristotle claims that Plato recognizes only two of his own
four causes, the formal and the material cause, Alexander refers to
the demiurge's activities in the *Timaeus* as an example for an
efficient cause acting for the sake of a final cause. But then he adds
a justification to explain why Aristotle acknowledges neither of the
two causes in his report on Plato (59,28-60,2): "The
reason is either because Plato did not mention either of these in what
he said about the causes, as Aristotle has shown in his treatise
*On the Good*; or because he did not make them causes of the
things involved in generation and destruction, and did not even
formulate any complete theory about them."



There is not room here to discuss each of Alexander's commentaries
individually. Some remarks on his treatment of Aristotle's logic in
his commentary on *Prior Analytics I* can serve the purpose of
a general survey (cf. the Introduction in trsl. Barnes et al. 1991).
As his explanations show, Alexander was fully familiar with the
development of logic after Aristotle, under Theophrastus and the
Stoics. On the whole, he presents the Aristotelian kind of logic as
the obviously right one, treating the Stoic approach as wrong-headed.
When he confronts problems in Aristotle's syllogistic he sometimes
expresses bafflement, and indicates the difficulties or even
inconsistencies he sees in the text. But he usually tries to smooth
them over or offers an alleged Aristotelian solution. In any case he
avoids, if at all possible, openly criticizing Aristotle or
contradicting him. As his analyses show, Alexander was not an original
logician with innovative ideas of his own, as was his contemporary,
Galen. He does not always get Aristotle right and sometimes blunders
in his exegesis. In addition, his style is uninviting. If Aristotle is
hard to comprehend on account of his clipped and elliptic style,
Alexander is often hard to follow because of his long and tortuous
periods. In the past this has made his commentary on the *Prior
Analytics* inaccessible to all but experts. The English
translations try to make up for these deficiencies by cutting up long
periods into shorter sentences. This will greatly enhance the
usefulness of Alexander's reconstruction and assessment of those
aspects of Aristotle's logic that are still a matter of controversy
nowadays.



The idea that discrepancies in Aristotle's texts are due to the
development of his philosophy was as alien to Alexander as it was to
all other thinkers in antiquity. Instead, he treats Aristotle's
philosophy as a unitary whole and tries to systematize it by forging
together different trains of thought, and smoothing over
inconsistencies. Thereby he contributed to the emergence of what was
to become the canonical 'Aristotelianism' that was
attacked in early modern times as a severe obstacle to new ideas and
scientific development. Though Alexander indicates that he was aware
of changes at particular points (he regarded the *Categories*
as Aristotle's earliest work and notes that it does not yet observe
the systematic distinction between genus and species), he does not
consider the possibility that there were different phases with
substantial changes in the Master's work. If such conservatism
surprises us in view of the fact that Alexander's own work shows
traces of revisions and improvement, we must keep in mind that in the
eyes of 'The Commentator' Aristotle was an authority quite
outside the common order. The doctrine of the Master was not the
product of an ordinary human mind, subject to trial and error, but a
magisterial achievement in a class of its own.


## 3. Alexander as philosopher



As a philosopher, Alexander presents in his writings an Aristotelian
point of view that reflects in many ways the conditions of his own
time, on questions that were not or not extensively discussed by
Aristotle himself. His *Problems and Solutions*
(*Quaestiones*), in three books, are collections of short
essays, which were apparently grouped together in different books
already in antiquity. As their Greek title (*phusikai scholikai
aporiai kai luseis*. lit. 'School-discussion of problems and
solutions on nature', cf. Sharples 1992, 3) indicates, these
three books address problems in natural philosophy in the broadest
sense. The fourth collection, *Problems of Ethics*
(*ethika problemata*) proceeds in a similar way. As
the lists of the essays' titles at the beginning of each book
show, the collections contain a hodgepodge of topics, arranged in a
quite loose order. The intellectual level of these discussions is
uneven and the titles of the treatises are sometimes misleading. Some
of essays do present problems and solutions, but others contain
exegeses of problematic passages in Aristotle's texts. There are also
mere paraphrases or summaries of certain texts, collections of
arguments for a certain position, and sketches of larger projects that
were never worked out. It is unclear when and by whom these
collections were put together. As mentioned above, some of the essays
may be the work of Alexander's associates, or lecture-notes taken by
his students. Most interesting from our point of view are those
questions that deal with metaphysical issues, like the relation of
form and matter, and with the status of universals in general (see
Tweedale 1984, Sharples 2005, and Sirkel 2011). Of particular interest
are also those discussions in book II that are concerned with certain
aspects of Aristotle's psychology, because Alexander's commentary on
the *De anima* is lost; they supplement his treatise *On the
Soul*. Of special interest here is his work that has been dubbed
'*De anima libri Mantissa*' (=
'makeweight' for his book *On the Soul*) by its
first modern editor, I. Bruns. Of interest are also the essays on the
notion of providence (an important topic at Alexander's time, in part
due to the influence of the Stoics' focus on divine providence).
These essays defend the view that while there is no special care for
individuals, providence over the objects in the sublunary sphere is
exercised by the movement of the heavenly bodies in the sense that
they preserve the continuity of the species on earth.



Since Alexander did not write a commentary on Aristotle's ethics, his
*Ethical Problems*, despite their somewhat disorganized state,
are of considerable interest (cf. Madigan 1987; Sharples 1990; 2001,
2). For, apart from Aspasius' early commentary on parts of the
*Nicomachean Ethics* there are no extant commentaries on
Aristotle's ethics before the composite commentary by various hands of
the Byzantine age (Michael of Ephesus in the 11th/12th c. and his
contemporary Eustratius, together with some material extracted from
earlier authors, cf. Sharples 1990, 6-7, 95). This gap may
suggest that ethics had become a marginal subject in later antiquity.
Alexander's *Ethical Problems* are therefore the only link
between Aspasius and the medieval commentaries. Though Alexander's
collection of essays displays no recognizable order, it is worth
studying because many of the 'questions' address central
issues in Aristotle's ethics. Some, for instance, are concerned with
the notion of pleasure as a good and pain as an evil; with pleasure as
a supplement of activity supporting its connection with happiness;
with the relation between virtues and vices; with virtue as a mean;
and with the concept of the involuntary and the conditions of
responsibility. Alexander's discussions confirm not only his thorough
familiarity with Aristotle's ethics, but also reflect the debates of
the Peripatetics with the Epicureans and Stoics in Hellenistic times,
as shown especially by the terminology he uses. The Hellenistic
background also explains the fact that Alexander pays special
attention to logical and physical distinctions in connection with
ethical problems.



The best example of his procedure is Alexander's construal of an
Aristotelian conception of fate in the treatise *On Fate*.
Though its long, and at times inelegant, passages do not make for easy
reading, this is no doubt the essay that is most interesting for a
general public (cf. Sharples 1983 and 2001, 1). Not only is it the
most comprehensive surviving document in the centuries-long debate on
fate, determinism, and free will that was carried on between the
Stoics, the Epicureans and the Academic Skeptics, it also contains
some original suggestions and points of criticism, as a comparison
with Cicero's *On Fate* would show. It is unclear whether there
had been a genuinely Peripatetic contribution to this debate before
Alexander. If there was not, Alexander clearly filled a significant
gap. Though Aristotle himself in a way touches on all important
aspects of the problem of determinism -- logical, physical, and
ethical -- in different works, he was not greatly concerned with
this issue, nor does he entertain the notion of fate
(*heimarmene*) as a rational cosmic ordering-force, as
the Stoics were going to introduce. In *De interpretatione* 9,
he famously proposed to solve the problem of 'future
truth' by suspending truth-values for statements in the future
tense concerning individual contingent events. In his ethics he deals
with the question of whether individuals have free choice, once their
character is settled. As Aristotle sees it, there is little or no
leeway, but he holds individuals responsible for their actions because
they collaborated in the acquisition of their character (*EN*
III, 1-5). In his physical works Aristotle limits strict
necessity to the motions of the stars, while allowing for a wide range
of events in the sublunary realm that do not happen of necessity but
only for the most part or by chance (*Phys*. II, 4-6).
Though he subscribes to the principle that the same causal
constellations have the same effects, he also allows for 'fresh
starts' in a causal series (*Metaph*. E 3). Given these
various limitations, Aristotle had no reason to treat determinism as a
central philosophical problem either in his ethics or in his physics.
The situation changed, however, once the Stoics had established a
rigorously physicalist system ruled by an all-pervasive divine mind.
It is this radicalization of the determinist position that sharpened
the general consciousness of the problematic, as witnessed by the
relentless attacks on the Stoics by their opponents, most of all by
the Academic skeptics and the Epicureans, which lasted for
centuries.



This long-standing debate prompted Alexander to develop an
Aristotelian concept of fate by identifying it with the natural
constitution of things, including human nature (*On Fate*, ch.
2-6). Since there is always the possibility that something
happens against the natural and normal order of things, there are
exceptions to what is 'fated' and there is room for chance
and the fortuitous. Most of the treatise is occupied not with the
defense of this Peripatetic position, but rather with attacks on the
various aspects of the determinist position. Alexander claims to show
why the Stoics' attempt (though he nowhere names them) to defend
a compabilitist position must fail. The determinists, he says, are
neither entitled to maintain a coherent concept of luck and the
fortuitous, nor of contingency and possibility, nor of deliberation
and potency. The bulk of this polemical discussion concentrates on the
difficulties for the Stoic position by claiming that their concept of
fate makes human deliberation superfluous and therefore imports
disastrous consequences for human morality and life in general (chs.
7-21). Alexander also presents, albeit in a dialectical fashion
intended to lead to the defeat of the Stoic tenets, the arguments used
by the Stoics in their defense of contingency, chance, and human
responsibility. As he claims time and again, the Stoics can defend the
use of these terms at best in a verbal sense. In addition, their
notion of divine foreknowledge and prophecy turns out to be incoherent
(chs. 22-35). The stringency and originality of Alexander's
critique cannot be discussed here (cf. Sharples 1983; Bobzien 1998).
While his presentation is not free from repetition and while the order
of the arguments leaves something to be desired, it is an interesting
text that displays a lively engagement with the issues and quite some
philosophical sophistication. He argues that truly free action
requires that at the time one acts, it is open to one both to do and
not to do what one does in fact then do. Thus Alexander originates the
position later known as 'libertarianism' in the theory of
free action. Alexander's construction of an Aristotelian account of
fate and divine providence that limits them to nature and its overall
benign order clearly argues for a weak conception of fate; but it is
the only one that Alexander regards as compatible with the principles
of Aristotelian philosophy of nature and ethics. That the concept of
fate greatly intrigued him is confirmed by the fact that he returns to
the issue in his addendum ('Mantissa') to the treatise
*On the Soul* and in some of his *Problems* (2.4.5, cf.
Sharples 1983, esp. the Introduction).



The attempt to 'naturalize' crucial concepts in
Aristotle's philosophy is typical of Alexander's philosophical stance
in general. He regards universals as inseparable from particulars and
as secondary to them, and stresses the unity of matter and form.
Similarly, he treats the human soul as the perishable form imposed
upon the bodily elements to constitute a living human being. He argues
that the intellect develops from an embodied intellect (that is
focused upon the material world) to a state that eventually contains
forms that are not embodied. He rules out personal immortality by
identifying the active intellect with pure form and with God, the
Unmoved Mover (see *On the Soul* and Caston 2012). In his
emphasis on a naturalist point of view he appears remarkably free from
the increasingly spiritualistic and mystical tendencies of his own
time. In the treatise *On Mixture and Increase* Alexander
expands on problems that Aristotle touched upon only briefly in *On
Generation and Corruption* I 10, but his main concern is --
as it is in his *On Fate* -- to prove that the Stoic
position of a 'thorough' mixture of two substances cannot
be maintained. These treatises suggest that at the beginning of the
third century philosophical discussions between the traditional
schools were still lively. We have, of course, no other evidence on
that issue. But there would be little point in proving the superiority
of the Peripatetic doctrine, as he does in *On Fate*, to the
emperors if the issue was by general consent regarded as obsolescent.
It is unlikely, therefore, that Alexander's polemics are only a kind
of shadow-boxing against long-gone adversaries.



## 4. Importance and Influence



There is no information concerning the impact of Alexander's teaching
in his lifetime. But certain indications of critical attacks on his
contemporary Galen (129-216 CE) suggest that he was engaged in
controversy with other contemporaries as well. Whether his polemics
against contemporary versions of Stoic doctrine were part of a
personal exchange or rather a bookish exercise is unclear. If
Alexander held the chair of Peripatetic philosophy at Athens it is
quite possible that he was in direct contact with the incumbents of
the other philosophical chairs there. He was, of course, not the first
commentator on Aristotle. But posterior exegetes certainly treated as
exemplary his method and his standards for explaining problems and
obscurities in Aristotle's texts. This is indicated both by explicit
references in later commentators and by the unacknowledged
exploitation of his work in some extant later commentaries on the same
texts. As the translations of his work into Arabic and, to a lesser
degree, into Latin show, he continued to be treated as a leading
authority and his work influenced the Aristotelian tradition
throughout late antiquity, the Middle Ages, and in the Renaissance.
Scholars nowadays continue to make use of his commentaries, not only
for historical reasons but also because his suggestions are often
worth considering in their own right. Because in recent years much
more attention has been paid to the philosophers in late antiquity,
not only to the Neo-Platonists, Alexander's work has come under
detailed scrutiny in various respects by specialists, as witnessed by
an increase in publications both on general and on special aspects of
his exegetical and philosophical work. The accessibility of most of
his writings in English translations will make apparent to a more
general readership that Alexander's work is not only relevant for
specialists in the history of philosophy, but opens up an interesting
age of transition in the history of philosophical and scientific
ideas.