bluuebunny/crossref_metadata_2025 huggingface dataset:
Diogenes of Apollonia (5th century BC)
Authors: Schofield Malcolm
Published: September 2018

Diogenes was the last of the early Greek physicists. He claimed that interactions between things would be impossible unless all were forms of one basic substance. Adapting ideas of Anaximenes and Anaxagoras, he identified the basic substance as air, which in its optimal form possesses intelligence and thereby controls the universe at large and animal life in particular. Diogenes worked out a detailed psychology and physiology, explaining sense perception as an exercise of intelligence due to interaction between air in the region of the brain and atmospheric air. This theory was mocked by Aristophanes, but influenced various Hippocratic writings.
Diogenes Laertius (c. AD 300–50)
Authors: Runia David T.
Published: September 2018

Diogenes Laertius is the author of a famous work entitled Lives of the Philosophers consisting of nearly one hundred accounts of individual philosophers. These contain mainly biographical information, but sometimes also include doctrinal summaries. The work is extremely valuable because it preserves much information on Greek philosophers from sources now lost.
Diogenes of Sinope (412/403–324/321 BC)
Authors: Branham R. Bracht
Published: September 2018

Diogenes of Sinope was considered, along with Antisthenes, the founder of Cynicism. His nickname ‘Cynic’, literally ‘doglike’, reflects the highly unconventional lifestyle he lived and advocated. Radically re-evaluating mankind’s relation to both nature and civilization, Diogenes redefined the individual’s freedom and self-sufficiency, advocating a training (askēsis) for achieving both.
Doxography
Authors: Runia David T.
Published: September 2018

Doxography is a term describing the method of recording opinions (doxai) of philosophers frequently employed by ancient Greek writers on philosophy. It can also refer to texts or passages consisting of such accounts. The ancient tradition of doxographical writing finds its origin in the dialectical method of Aristotle and Theophrastus. Later works by authors such as Aëtius and Arius Didymus record much valuable material on ancient philosophers, although usually with little analysis or argumentation. Doxographical passages are also found in other ancient philosophical works, usually as a prelude to the discussion of a theme.
Epictetus (AD c.50–c.120)
Authors: Inwood Brad
Published: September 2018

Epictetus was a Greek Stoic philosopher of the late first and early second centuries ad. He developed Stoic ideas of responsibility into a doctrine of autonomy and inner freedom based on his concept of moral personality (prohairesis). Ethics and practical moral training are central to his thought, but he was also responsible for innovations in epistemology. He emphasized the need to achieve freedom from the passions and to maintain equanimity in the face of a world determined by a providential, though often inscrutable, fate. He frequently treats the Stoic Zeus as a personal deity, and his distinctive combination of personal piety and stringent rationalism (together with his pungent style) have contributed to his enduring influence.
Galen (AD 129–c.210)
Authors: Hankinson R.J.
Published: September 2018

Galen was the most influential doctor of late Greco-Roman antiquity. But he was also a notable philosopher, who desired to effect a synthesis of what was best in the work of his predecessors, not only in medicine but also in logic, epistemology, philosophical psychology and the philosophy of science and explanation. In logic he made use of both Aristotelian and Stoic material, but supplemented them with his own treatment of relational logic. His epistemology, while resolutely anti-sceptical on the grounds that nature could not have furnished us with systematically delusive sense-organs, was none the less sober and cautious: some philosophers’ questions are simply unanswerable. He attacked the Stoics’ unitary psychology, establishing by means of detailed experiments that the brain was the source of voluntary action. Finally, drawing on the philosophical and medical tradition, he crafted a theory of cause and explanation sophisticated enough to rebut the sceptical challenges to such notions, and rich enough to enable him to construct a comprehensive physiology and pathology on its basis.
Hellenistic philosophy
Authors: Sedley David
Published: September 2018

The Hellenistic schools dominated the Greco-Roman world from c.300 bc to the mid first century bc, making it an era of great philosophical brilliance. The principal doctrinal philosophies were Stoicism and Epicureanism, but this was also the age in which scepticism emerged as a philosophical movement. The central issues of debate were the nature and origin of the world, the means to attaining truth and the ethical goal.
Hesiod (c.700 BC)
Authors: Most Glenn W.
Published: September 2018

One of the earliest surviving Greek poets, Hesiod was a direct precursor of the first philosophers. He composed one poem on mythic cosmogony and cosmology (Theogony) and another on work and justice in human life (Works and Days).
Leucippus (5th century BC)
Authors: Taylor C.C.W.
Published: September 2018

The early Greek philosopher Leucippus was the founder of atomism. Virtually nothing is known of his life, and his very existence was disputed in antiquity, but his role as the originator of atomism is firmly attested by Aristotle and Theophrastus, although the evidence does not allow any distinction between his doctrines and those of his more celebrated successor Democritus. He wrote a comprehensive account of the universe, the Great World-System . The single surviving quotation from his work asserts universal determinism.
Logos
Authors: Stead Christopher
Published: September 2018

The noun logos derives from the Greek verb legein, meaning ‘to say’ something significant. Logos developed a wide variety of senses, including ‘description’, ‘theory’ (sometimes as opposed to ‘fact’), ‘explanation’, ‘reason’, ‘reasoning power’, ‘principle’, ‘ratio’, ‘prose’.

Logos emerges as a philosophical term with Heraclitus (c.540–c.480 bc), for whom it provided the link between rational discourse and the world’s rational structure. It was freely used by Plato and Aristotle and especially by the Stoics, who interpreted the rational world order as immanent deity. Platonist philosophers gave pre-eminence to nous, the intuitive intellect expressed in logos. To Philo of Alexandria and subsequently to Christian theologians it meant ‘the Word’, a derivative divine power, at first seen as subordinate but eventually coordinated with the Father.
Mimēsis
Authors: Most Glenn W.
Published: September 2018

A crucial term in the literary theories of Plato and Aristotle, mimesis describes the relation between the words of a literary work and the actions and events they recount. In Plato, the term usually means ‘imitation’ and suggests that poetry is derived from and inferior to reality; in Aristotle, it loses this pejorative connotation and tends to mean simply ‘representation’ and to indicate that the world presented in a poem is much like, but not identical with, our own.
Neoplatonism
Authors: Siorvanes Lucas
Published: September 2018

Neoplatonism was the final flowering of ancient Greek thought, from the third to the sixth or seventh century ad. Building on eight centuries of unbroken philosophical debate, it addressed questions such as: What is the true self? What is consciousness and how does it relate to reality? Can intuition be reconciled with reason? What are the first causes of reality? How did the universe come into being? How can an efficient cause retain its identity and yet be distributed among its effects? Why does the soul become embodied? What is the good life?

There were several flavours of Neoplatonism, reflecting the concerns and backgrounds of its practitioners, who ranged from Plotinus and his circle of freelance thinkers to the heads of the university schools of the Roman Empire, Proclus, Ammonius and Damascius. In the later, more analysed form, we see a rich scheme of multi-layered metaphysics, epistemology and ethics, but also literary theory, mathematics, physics and other subjects, all integrated in one curriculum. Neoplatonism was not just a philosophy but the higher education system of its age.

The Neoplatonism that came to dominate the ancient world from the fourth century was an inseparable mixture of inspired thought and scholastic order. To this may be traced some of its internal conceptual conflicts: for example, the free individual soul versus the ranks of being, personal experience versus demonstrative knowledge. To this may also be traced its appeal to polar audiences: mystics and mathematizing scientists, romantics and rationalists.

To the Neoplatonist, knowledge consists of degrees of completion. Take the example of tutor and student. Both study the same things, but the tutor has a wider and more intimate knowledge. The tutor opens the student’s mind to the breadth and intricacies of the study-matter, and corrects the student’s deliberations. So it is with the Neoplatonic levels of knowledge. Every level has access to the entire spectrum of what there is to know, but each with its appropriate adverbial modifier. At the ‘lower’ level an individual comprehends things ‘particularly’ and is concerned with the ‘images’ or presentations of mind and sense-impressions of the qualities of physical things. At the ‘higher’ level, an individual apprehends things ‘wholly’, as universal statements (often called ‘laws’ and ‘canons’). The concern is with propositions about what is true or false, self-grounded and logically necessary. Thus the higher level corrects and supplies the ‘criterion’ for the lower level.

Knowledge, however, is not an end in itself, but a means to salvation. Increasing awareness puts us in touch with the levels of reality of which we ourselves are part. The ultimate reality is none other than the fundamental unity out of which all came into being: God. In this union we recover our true good.

As the summation of ancient Greek philosophy, Neoplatonism was transmitted to Byzantium, Islam and western Europe. It was the prime intellectual force behind the protagonists of the Italian Renaissance, and its influence was felt until the nineteenth century.
Numenius (fl. c. mid 2nd century AD)
Authors: Dillon John
Published: September 2018

Numenius was a Platonist philosopher. He came from Apamea (Syria) and wrote in Greek. His work – now lost – is usually considered Neo-Pythagorean in tendency, and exercised a major influence on the emergence of Neoplatonism in the third century. A radical dualist, he postulated the twin principles of god – a transcendent and changeless intellect, equated with the Good of Plato’s Republic – and matter, identified as the Pythagorean Indefinite Dyad: god is good, matter evil. In addition to this supreme god, he added at a secondary level a creator-god, one of whose aspects is the world-soul, itself further distinguished into a good and an evil world-soul. He had a strong interest in Oriental wisdom, especially Judaic, and famously called Plato ‘Moses speaking Attic’.
Philo the Dialectician (late 4th–early 3rd centuries BC)
Authors: Denyer Nicholas
Published: September 2018

A member of the Dialectical school, Philo was a Greek philosopher whose claim to fame is twofold. First, he maintained that one proposition implies another if and only if either the former is false or the latter is true, however irrelevant the two propositions may be to one another. Second, he maintained that some things are necessarily prevented from happening and are nevertheless possible: the water around them prevents shells at the bottom of the ocean from ever being actually perceived; nevertheless, such things are perceptible. As often happened with Dialecticians’ ideas, these ideas of Philo elicited (and perhaps were meant to elicit) notoriety rather than agreement.
Philo of Larissa (c.159–c.83 BC)
Authors: Barnes Jonathan
Published: September 2018

Philo, head of the Academy from 110 to 88 bc, likened philosophy to medicine. No doubt he was a conscientious therapist himself; but we know little enough about his methods and practices. For most of his life he seems to have been a happy sceptic, and an unremarkable one. But towards the end of his career he introduced – or was deemed to have introduced – startling innovations into the Academy: in particular, by rejecting or modifying the reigning definition of knowledge he was able to separate himself from the scepticism of his school and to rewrite its history.
Philoponus (c. AD 490–c.570)
Authors: Wildberg Christian
Published: September 2018

John Philoponus, also known as John the Grammarian or John of Alexandria, was a Christian philosopher, scientist and theologian. Philoponus’ life and work are closely connected to the city of Alexandria and its famous Neoplatonic school. In the sixth century, this traditional centre of pagan Greek learning became increasingly insular, located as it was at the heart of an almost entirely Christian community. The intense philosophical incompatibilities between pagan and Christian beliefs come to the surface in Philoponus’ work.

His œuvre comprised at least forty items on such diverse subjects such as grammar, logic, mathematics, physics, psychology, cosmology, astronomy, theology and church politics; even medical treatises have been attributed to him. A substantial body of his work has come down to us, but some treatises are known only indirectly through quotations or translations. Philoponus’ fame rests predominantly on the fact that he initiated the liberation of natural philosophy from the straitjacket of Aristotelianism, through his non-polemical commentaries on Aristotle as well as his theological treatises deserve to be appreciated in their own right.

Philoponus’ intellectual career began as a pupil of the Neoplatonic philosopher Ammonius, son of Hermeas, who had been taught by Proclus and was head of the school at Alexandria. Some of his commentaries profess to be based on Ammonius’ lectures, but others give more room to Philoponus’ own ideas. Eventually, he transformed the usual format of apologetic commentary into open criticism of fundamental Aristotelian-Neoplatonic doctrines, most prominently the tenet of the eternity of the world. This renegade approach to philosophical tradition, as well as the conclusions of his arguments, antagonized Philoponus’ pagan colleagues; they may have compelled him to abandon his philosophical career. Philoponus devoted the second half of his life to influencing the theological debates of his time; the orthodox clergy condemned him posthumously as a heretic, because of his Aristotelian interpretation of the trinitarian dogma, which led him to enunciate three separate godheads (tritheism).

The style of Philoponus’ writing is often circuitous and rarely entertaining. However, he combines an almost pedantic rigour of argument and exposition with a remarkable freedom of spirit, which allows him to cast off the fetters of authority, be they philosophical or theological. Although his mode of thinking betrays a strong Aristotelian influence, it also displays a certain doctrinal affinity to Plato, stripped of the ballast of Neoplatonic interpretation. His works were translated into Arabic, Latin and Syriac, and he influenced later thinkers such as Bonaventure, Gersonides, Buridan, Oresme and Galileo.
Plutarch of Chaeronea (c. AD 45–c.120)
Authors: Dillon John
Published: September 2018

The Greek biographer and philosopher Plutarch of Chaeronea is the greatest Greek literary figure of the first century ad. He is properly called Plutarch of Chaeronea, to distinguish him from the minor fourth-century ad Platonist Plutarch of Athens. His fame rests not so much on his contributions to philosophy as on those to history and biography. Indeed, despite the survival of a large body of philosophical and semi-philosophical writings known under the collective title Moralia, most of his more technical philosophical treatises have perished. Nevertheless, his importance for our understanding of the development of Middle Platonism is great. Plutarch is a reasonably orthodox Platonist (in so far as that expression has any meaning), although his Platonism has some distinctive features. Against Antiochus, he accepts the sceptical New Academy as part of the Platonic tradition, but he also exhibits a degree of cosmic dualism (postulating a pre-cosmic evil soul) which goes rather beyond the Platonist norm. It is misleading, however, to oppose him to a supposed tradition of ‘school-Platonism’.

As the ethical ‘end’ or ‘goal’ (telos), he adopts the normal later Platonist one of ‘likeness to god’. In ethics, as in logic, he tends to favour Aristotelianism rather than Stoicism (advocating, for example, moderation of the passions rather than their extirpation, and appropriating as authentically Platonic the Aristotelian categories and syllogistic). A tendency to favour New Academic scepticism seems indicated in the titles of some of his lost works, but is not very evident in the surviving ones.

As first principles, he postulates a pair consisting of God – who is one, the Good, and really existent – and the Platonic-Pythagorean Indefinite Dyad, which is a principle of multiplicity, and ultimately material. As secondary principles, he seems to adopt a logos, or active reason-principle of god, although the evidence for this is not copious, and a world-soul, which is essentially irrational but desirous of ‘impregnation’ with reason by the logos. There is also in the universe, however, an active principle of disorder, which can never be entirely mastered by the divinity. A hint of Persian dualism seems to enter here into Plutarch’s thought. Such a system is derivable above all from his essay On Isis and Osiris, which may not be entirely typical. Other distinctive features include a tendency to triadic divisions of the universe, a developed demonology, and an interesting combination of Aristotelian and Stoic logics.
Porphyry (c.233–309 AD)
Authors: Siorvanes Lucas
Published: September 2018

The late ancient philosopher Porphyry was one of the founders of Neoplatonism. He edited the teachings of Plotinus into the form in which they are now known, clarified them with insights of his own and established them in the thought of his time. But, in reaction to Plotinus, he also advanced the cause of Aristotle’s philosophical logic. Indeed, Porphyry is responsible for the resurgence of interest in Aristotle, which continued to the Middle Ages and beyond. Because of Porphyry, later Greek philosophy recovered both its Platonic and its Aristotelian roots, and Neoplatonism aimed to combine inspired thought with academic precision.

He was a scholar of great learning, with interests ranging from literary criticism and history to religion. An example is his defence of vegetarianism, which anticipated the modern debate on ecological preservation. Humans and animals belong to the same family. Seeking to preserve life is a matter of extending philanthropy and respect to all living species, which are our natural siblings. Ideally we ought to display ‘harmlessness’ even towards plants, except that our bodies, being composite and mortal, need to consume something else for food. Thus we should be ever conscious of the destructive effect that our eating habits and consumerism have on the creation of which we are part, and should try to keep to a simple lifestyle.

Porphyry’s attention to logic, metaphysics and all other topics was driven by his firm belief that reason exercised by pure mind leads to the true essence of things, the One God. Intellectual activity detaches the soul from passions and confusions, and concentrates its activity on the real things. Porphyry attacked Christianity and Gnosticism because he thought they appealed to the irrational. Mysteries and rituals are fitted for those who are unable to practise inward contemplation. Salvation comes to those leading the life of the philosopher-priest.
Posidonius (c.135–c.50 BC)
Authors: Algra Keimpe A.
Published: September 2018

Posidonius of Apamea (Syria) was a Stoic philosopher and student of Panaetius. He taught in Rhodes. He combined a passion for detailed empirical research with a general commitment to the basic systematics of Stoic philosophy (which, however, he was willing to revise where necessary). As such he was probably the most ‘scientific’ of the Stoics. His wide-ranging investigations of all kinds of physical phenomena (especially in the areas of physical astronomy and meteorology) became particularly renowned, the best known case being his explanation of Atlantic tides as connected with the motions of the moon.

His most original philosophical contributions are to be located in the connected areas of psychology and ethics. Posidonius appears to have been committed to a slightly Platonizing version of Stoic psychology, according to which the passions are no longer regarded as a malfunctioning of the rational faculty, but as motions of the soul which take their origin in two separate irrational faculties (anger and appetite). This revised moral psychology is accompanied by some corresponding revisions in ethics such as the conception of moral education as the blunting of the motions of the irrational faculties.
Proclus (c. AD 411–85)
Authors: Siorvanes Lucas
Published: September 2018

The Greek Neoplatonist Proclus aimed to find a logical and metaphysical structure in which unity embraces but does not stifle diversity. He assumed the underlying unity of reality and of self, but was anxious to maintain the diversity of thought and existence. This led him to conceive of things as different species of one general whole, each part comprehending the rest but in its own specific, limited way. There are successive levels of awareness, thought and existence, ranging from that of ordinary experience, where we continuously have a passing understanding of the equally fleeting world, to that of ultimate unity, where we see the first principles and the total whole unqualified, as if by super-intuition. Reason, aided by imagination, and exercised by philosophy and science, elevates us towards that supreme state, which is at once the foundation of religious and of ethical values.

Proclus was interested in an integrated account of the nature of things. Asking questions about how and what we know, our perceptions and beliefs, prompts questions of the sort: what is the origin of knowledge? What is the nature of mind? Of the things we think and perceive? Of existence? For Proclus even questions about virtue, moral judgment and action, God, faith and salvation are all clarified by referring them to questions about their origins and nature. No subject escaped his attention, including the interpretation of poetic works by literary figures such as Homer, where Proclus saw language as a mediator to deeper truths. Philosophical inquiry leads to asking what order of reality substantiates things, whether in the field of mind, values, science or literature.

Proclus’ system is complex, and he uses highly technical terms (most of which have their roots in Plato, Aristotle and Plotinus). But for him this is only appropriate to the richness of our conceptual world. We have complex and varied concepts about our surroundings and selves, not because humans necessarily have flamboyant fancies but because reality itself is complex. That we have glimpses of knowledge means that there is some unity between our mind and the objects of thought. Moreover, unity is essential to the identity of things, and without it they would be unintelligible, and conceptually unreal. The ‘One’ is a primitive absolute, and is fundamental to intelligibility and existence. Thinker, thoughts and realities are in some way one. Things are not disconnected but share layers of ever-increasing unity. Consequently questions about different kinds of being, knowledge, good, and so on, become questions about degrees.

Studying all this was not just a cerebral affair. To the Neoplatonist, understanding the scheme of things provided a guide on leading a good life and achieving what since Plato’s days had been praised as the goal of human endeavour, ‘true happiness’ or eudaimonia.
Protagoras (c.490–c.420 BC)
Authors: Kahn Charles H.
Published: September 2018

Protagoras was the first and most eminent of the Greek Sophists. Active in Athens, he pioneered the role of professional educator, training ambitious young men for a public career and popularizing the new rationalist worldview that was introduced from Ionian natural philosophy. But unlike his contemporary Anaxagoras, Protagoras was sceptical of the dogmatic claims of the new science. His famous formula – ‘Man is the measure of all things, of things that are, that they are, and of things that are not, that they are not’ (fr. 1) – makes him the father of relativism and even, on some interpretations, of subjectivism. He was also considered the first theological agnostic: ‘Concerning the gods, I am unable to know either that they exist or that they do not exist or what form they have’ (fr.4). He was sometimes associated with the claim ‘to make the weaker argument (logos) the stronger’.
Pythagoras (c.570–c.497 BC)
Authors: Schibli Hermann S.
Published: September 2018

Pythagoras of Samos was an early Greek sage and religious innovator. He taught the kinship of all life and the immortality and transmigration of the soul. Pythagoras founded a religious community of men and women in southern Italy that was also of considerable political influence. His followers, who became known as Pythagoreans, went beyond these essentially religious beliefs of the master to develop philosophical, mathematical, astronomical, and musical theories with which they tended to credit Pythagoras himself. The tradition established by Pythagoras weaves through much of Greek philosophy, leaving its mark particularly on the thought of Empedocles, Plato, and later Platonists.
Simplicius (fl. first half 6th century AD)
Authors: Wildberg Christian
Published: September 2018

Simplicius of Cilicia, a Greek Neoplatonic philosopher and polymath, lived in the eastern part of the Roman Empire. He is the author of the most learned commentaries on Aristotle produced in antiquity, works which rest upon the accumulated accomplishments of ancient Greek philosophy and science. In them he gives numerous illuminating references and explanations that not only lead to a fuller understanding of Aristotle, but also allow one to reconstruct the history of the interpretation and criticism of Aristotelian doctrines in antiquity. The main principle that guides Simplicius’ exegesis is the conviction that most Greek philosophers, including some Presocratics, can be brought into agreement with Neoplatonism. Simplicius adduces copious quotations to prove his point, thereby supplying us with substantial fragments from lost works of thinkers like Parmenides, Empedocles, Anaxagoras, Eudemus and the Stoics. A devout pagan, Simplicius sought to defend traditional Greek religion and philosophy against the oppressive dominance of Christianity. His commentaries have influenced the reception and interpretation of Aristotle’s philosophy ever since.
Thales (fl. c.585 BC)
Authors: McKirahan Richard
Published: September 2018

Known as the first Greek philosopher, Thales initiated a way of understanding the world that was based on reason and nature rather than tradition and mythology. He held that water is in some sense the basic material, that all things are full of gods and (purportedly) that all things possess soul. He predicted an eclipse of the sun and was considered the founder of Greek astronomy and mathematics.
Thrasymachus (late 5th century BC)
Authors: Hobbs Angela
Published: September 2018

Thrasymachus, a Greek Sophist and orator, is known principally for his role in book 1 of Plato’s Republic, in which he argues that justice is simply a social institution created by rulers to further their own interests. It is intended solely for the subjects; the rulers themselves need not practise it. Since justice thus consists in promoting another’s advantage rather than one’s own, injustice is far more profitable. Apart from issues of internal coherence, his claims raise many questions. What, for example, are our true interests? And what are the actual and ideal operations of power?
Xenophanes (c.570–c.478 BC)
Authors: Lesher J.H.
Published: September 2018

Xenophanes was a philosophically minded poet who lived in various cities of ancient Greece. He is best remembered for an early comment on the limits of knowledge, a critique of anthropomorphism in religion and an advance towards monotheism. The surviving fragments of his poems span a wide range of topics, from proper behaviour at symposia and the measures of personal excellence to the nature of the divine, the forces that rule nature and how much can be discovered by mortals concerning matters in either realm. Both Plato and Aristotle characterized him as the founder of Eleatic philosophy, a view echoed in the pseudo-Aristotelian treatise, On Melissus, Xenophanes and Gorgias, and in ancient doxographical summaries. But in many of his poems Xenophanes speaks as a civic counsellor and inquirer into nature in the tradition of the philosopher-scientists of Miletus. While his one, unmoving, whole and eternal divinity bears some resemblance to Parmenides’ ‘being’, in other teachings he anticipates the views of Heraclitus and Empedocles. His comments on divine perfection, the limited utility of the victorious athlete and the need to restrict poetic expression all foreshadow views expressed by Plato in the Republic.
Xenophon (c.427–355/50 BC)
Authors: O'Connor David K.
Published: September 2018

The Greek historian and philosophical writer Xenophon was a companion of Socrates, and is second in importance only to Plato as a source for our knowledge of him. He was also a penetrating and influential political thinker in his own right. He left Athens to embark on a spectacular military career in 401 bc, two years before Socrates’ execution, and his military experiences had a deep impact on his thought and writings. An important historian and an innovator in literary forms, Xenophon limited his philosophical interests to political and ethical themes. Two questions are especially prominent: (1) What are the psychological roots of human virtue, and how can it be taught? (2) What are the limits of and the prospects for human attainment of self-sufficiency? He develops these themes most fully in two major works that present two competing models of the best human being. His Memoirs (usually referred to by the Latin title Memorabilia) presents the model of the philosophical life, mainly by recounting conversations between Socrates and a wide variety of human types. His The Education of Cyrus (often referred to by its Latin title Cyropaedia) presents the model of the political life, mainly by giving a fictionalized account of the rise to power of Cyrus the Great, founder of the Persian empire. Generally speaking, Xenophon seems in these works less willing than Plato and Aristotle to privilege the claims of philosophy over the claims of politics, and less optimistic about the power of reason to produce happiness. His works were highly esteemed by the Romans, as well as by such moral thinkers as Machiavelli, Montaigne and Rousseau.
Eudoxus (c.390–c.340 BC)
Authors: Taub Liba
Published: September 2018

Eudoxus of Cnidos was a Greek mathematician with wide-ranging philosophical and scientific interests. He was known in antiquity for his mathematical astronomy and his philosophical hedonism, and placed, if loosely, within the Pythagorean tradition. More recently, debate about the correspondence between mathematical models produced by astronomers and the physical motions of the astronomical bodies themselves has focused especially on Eudoxus, since he is generally regarded as the first to have used a mathematical model in astronomy.
Innateness in ancient philosophy
Authors: Scott Dominic
Published: September 2018

The idea that knowledge exists latently in the mind, independently of sense experience, is put forward in three of Plato’s dialogues: the Meno, the Phaedo and the Phaedrus. The claim is that the human soul exists before it enters a body, and that in its pre-existent state it knows certain things, which it forgets at birth. What we call ‘learning’ during our mortal lives is in fact nothing but the recollection of pre-existent knowledge. In a particularly famous passage in the dialogue the Meno, the character Socrates sets an uneducated slave boy a geometrical puzzle. After asking a series of questions, he elicits the correct answer from the boy, which he claims existed in him all along, merely needing to be aroused by the process of recollection. Aristotle dismisses recollection quite brusquely and tries to explain human learning by appeal to sense perception. In post-Aristotelian philosophy, it unclear how far any theory of innateness was accepted. Most probably, the Stoics thought that in some sense moral concepts and beliefs arise from human nature, though they did not endorse a theory of pre-existence or recollection.
Augustinianism
Authors: Jordan Mark D.
Published: September 2018

The influence of Augustine on Western philosophy is exceeded in duration, extent and variety only by that of Plato and Aristotle. Augustine was an authority not just for the early Middle Ages, when he was often the lone authority, but well into modern times. He was in many ways the principal author in contention during the Reformation and Counter-Reformation, and in France alone he was variously received by authors as diverse as Montaigne, Descartes, Malebranche, Arnauld and Pascal. The breadth of Augustine’s influence makes it difficult to give precise sense to the term ‘Augustinianism’, even when considering only a single period.

Historians of medieval philosophy use the term ‘Augustinianism’ to describe three rather different relations to the thought of Augustine. The first relation is a comprehensive dependence on Augustine both for philosophical principles or arguments, and for instruction in the topics and procedures of ancient philosophy. Augustine serves as the trustworthy guide to philosophy as a whole. The second kind of relation is a defence of specific Augustinian teachings in the face of rival teachings, most especially those of Aristotle. These Augustinian teachings include the function of divine ideas in knowledge, the unity of the human soul’s essential powers, and the unfolding of potential intelligibilities in material substances. The third relation is the reappropriation of Augustinian principles, especially those of his later writings, to address quandaries newly formulated with the tools of nominalist semantics and the mathematics of continuities. Among these quandaries are the contingency of future human actions and the certainty of human cognition.

These three relations to Augustine can be found in texts throughout the medieval period. They are not neatly correlated with particular centuries, but one or another does tend to be predominant at different times. Thus the first relation, of comprehensive dependence, is seen in the great majority of Latin writers on philosophic topics through the twelfth century. The second relation, of topical defence, appears prominently during the thirteenth-century contest between so-called ‘Augustianians’ and ‘Aristotelians’. The third relation, of reappropriation in reaction to newly formulated quandaries, is found particularly in writings of the fourteenth century and beyond.
Bacon, Roger (c.1214–92/4)
Authors: Sinkler Georgette
Published: September 2018

Associated with both the University of Paris and Oxford University, Roger Bacon was one of the first in the Latin West to lecture and comment on Aristotle’s writings on subjects other than logic. After he came to know Robert Grosseteste’s work in natural philosophy, he became the advocate of a curricular reform that emphasized scientific experiment and the study of languages. His views were often unpopular, and he constantly belittled all who disagreed with him.

Bacon’s work in logic and semantic theory had some influence during his lifetime and immediately after his death. His work in science, however, had little impact. His renown in the history of science is due in part to his being viewed as a precursor of the Oxford Calculators, who in turn anticipated certain important developments in seventeenth-century science.
Bernard of Clairvaux (1090–1153)
Authors: Murphy Sean Eisen
Published: September 2018

Bernard was recognized by his contemporaries as the spiritual leader of western Europe. He was an indefatigable advocate of the monastic life and occasionally criticized the schools on moral grounds, but he was by no means an anti-intellectual. He encouraged a number of early scholastic philosopher-theologians in their work. Although he devoted the better part of his efforts to his wide-ranging pastoral duties, Bernard’s own sermons and treatises make a significant contribution to twelfth-century theology and philosophy.
Bradwardine, Thomas (c.1300–49)
Authors: Sylla Edith Dudley
Published: September 2018

Thomas Bradwardine was a leading figure in fourteenth-century philosophy and theology from 1328, when he completed De proportionibus velocitatum in motibus (On the Ratios of Velocities in Motions), until his death in 1349, shortly after becoming Archbishop of Canterbury. His theory of ratios of velocities in motions was an important reinterpretation of Aristotle and was influential throughout Europe. The author of numerous mathematical and logical works, Bradwardine helped to initiate a style of natural philosophical analysis using a standard set of logical and mathematical tools. On the Continent, Nicole Oresme, Albert of Saxony and many others wrote works on the ratios of velocities in motions following Bradwardine’s lead. In his De futura contingentibus (On Future Contingents) and De causa Dei Pelagium (On the Cause of God Against the Pelagians), Bradwardine staked positions emphasizing the symmetry of God’s omniscience with respect to past, present and future.
Brito, Radulphus (c.1270–c.1320)
Authors: Ebbesen Sten
Published: September 2018

Radulphus Brito was a prominent master of arts at the University of Paris around 1300. In order to secure the foundation of concepts in extramental reality, he devised a system of four types of ‘intentions’, first and second, abstract and concrete. As a philosopher of language, similar concerns made him claim a formal identity between the modes of signifying (of words) and the modes of being signified (of things).
Chartres, School of
Authors: Marenbon John
Published: September 2018

In the first half of the twelfth century, the most advanced work in teaching and discussion of logic, philosophy and theology took place in the schools attached to the great cathedrals. Chartres was undoubtedly one of the more important of these schools, and Gilbert of Poitiers and Thierry of Chartres were certainly connected with it. To some historians, Chartres was the great intellectual centre of the period, and the greatest achievement of early twelfth-century thought was a brand of Platonism distinctive of this school. However, this view has been challenged by scholars who stress the pre-eminence of Paris, where the schools emphasized logic.
Chatton, Walter (c.1290–1343)
Authors: Brown Stephen F.
Published: September 2018

Chatton was an English philosopher and theologian who developed a detailed critique of the work of William of Ockham, causing the latter to revise some of his earlier writings. Chatton was also at times an opponent of Peter Aureol and Richard of Campsall; he generally, though not always, followed John Duns Scotus and responded to his critics. He is known also for his writings on physics, where he held views in line with those of Pythagoras and Plato, and on the Trinity, where he was strongly attacked by Adam Wodeham.
Clement of Alexandria (AD 150–215)
Authors: Chadwick Henry
Published: September 2018

Clement of Alexandria, a Christian Platonist, came to conversion through philosophy. In a series of allusive writings he presented a Hellenized Christianity along with the philosophical syncretism of his age: Stoic ethics, Aristotelian logic and especially Platonic metaphysics. Just as Paul saw the Hebrew prophets and law as a preparation for the Gospel, Clement saw Christianity as making possible a confluence of Plato and the Old Testament, both offering anticipations of Jesus’ teaching. Clement’s fusion of Platonism and Christianity vehemently opposed the dualism and determinism of gnostic theosophy, and stressed free choice and responsibility as fundamental to moral values. Central to his writing is the vindication of faith as the foundation for growth in religious knowledge by philosophical contemplation and biblical study.
Durandus of St Pourçain (1275?–1334)
Authors: Beonio-brocchieri Mariateresa Fumagalli
Published: September 2018

Although strongly Aristotelian in outlook, Durandus rejected certain classic points of Thomist doctrine such as the speculative ‘scientific’ and unique nature of theology, the theory of the active intellect and the doctrine of species. After carrying out a detailed examination of the Thomist theses, Durandus decided firmly in favour of theology being faith in revelation, something aenigmatica and therefore meritorious. In this way, in the opinion of some modern scholars, he anticipated the position of William of Ockham; the position later known as ‘Ockham’s razor’ appears more than once in his writings.
Encyclopedists, medieval
Authors: Barnish Samuel
Published: September 2018

The modern encyclopedic genre was unknown in the classical world. In the grammar-based culture of late antiquity, learned compendia, by both pagan and Christian writers, were organized around a text treated as sacred or around the canon of seven liberal arts and sciences, which were seen as preparatory to divine contemplation. Such compendia, heavily influenced by Neoplatonism, helped to unite the classical and Christian traditions and transmit learning, including Aristotelian logic, to the Middle Ages.

Writers in the encyclopedic tradition include figures such as Augustine and Boethius, both of whom were extremely influential throughout the medieval period. Other important writers included Macrobius, whose Saturnalia spans a very wide range of subjects; Martianus Capella, whose De nuptiis Philologiae et Mercurii (The Marriage of Philology and Mercury) covers the seven liberal arts and sciences; Cassiodorus, who presents the arts as leading towards the comtemplation of the heavenly and immaterial; and Isidore, whose Etymologies became one of the most widely referred-to texts of the Middle Ages. These writers also had a strong influence which can be seen later in the period, particularly in the Carolingian Renaissance and again in the twelfth century.
Gerbert of Aurillac (938–1003)
Authors: Somerset Fiona
Published: September 2018

Gerbert is chiefly remembered as an educational reformer. He established a syllabus for the university course in logic, the logica vetus, that remained in use until the mid-twelfth century. Most of his academic writings are instructional works on mathematics. In his single philosophical work, De rationali et ratione uti (On That Which is Rational and Using Reason), he uses Boethius’ logical commentaries to develop a distinctly Platonic solution to a problem he derives from Porphyry’s Isagōgē.
Giles of Rome (c.1243/7–1316)
Authors: Del punta Francesco , Trifogli Cecilia
Published: September 2018

Giles of Rome was one of the most eminent theologians and commentators on the works of Aristotle at the University of Paris in the second half of the thirteenth century. He was probably a pupil of Thomas Aquinas, who exerted a deep influence on Giles’ metaphysical and theological thought. Giles’ reception of Aquinas’ positions, however, was often critical and original.

For historians of medieval philosophy, Giles’ name is mainly associated with the doctrine of ‘the real distinction’ between essence (essentia) and existence (esse). According to this doctrine, essence and existence are two completely distinct things (res) of which the ontological structure of every created being is composed. On the issue of the relationship between essence and existence Giles took a firm position against his contemporary Henry of Ghent, who maintained that existence is a mere relation of the essence of a created being to its creator. Giles was also involved in the debate over the unity of the substantial form in composite substances, another burning issue in the thirteenth century. As a commentator on Aristotle’s works, Giles made original contributions to the tradition of Aristotelian natural philosophy, especially in his treatment of extension, place, time and motion in a vacuum.
Hervaeus Natalis (d. 1323)
Authors: Perler Dominik
Published: September 2018

The French scholastic philosopher and theologian Hervaeus Natalis was not only one of the most influential early Thomists, but was also an original thinker who made an important contribution to the medieval debate on intentionality. He examined carefully the ontological question of what intentional objects are, and discussed the epistemological problem of how they are generated in a cognitive act. Hervaeus argued that intentional objects are ‘third entities’ that cannot be reduced to extramental or mental entities, a thesis that sparked controversy in the fourteenth century.
Heytesbury, William (before 1313–1372/3)
Authors: Longeway John
Published: September 2018

William Heytesbury, an English logician of the mid-fourteenth century, is, with Richard Kilvington, Richard Swineshead, Thomas Bradwardine and John Dumbleton, one of several philosophers known as the Oxford Calculators. In his works, Heytesbury examined mathematical topics related to motion and the continuum as well as paradoxes of self-reference and problems arising from intentional contexts, all within the context of terminist logic, through the resolution of sophismata. He is most noted for developing the mathematics of uniform acceleration, and for his contributions to developing the mathematical treatment of physical qualities such as heat.
Holcot, Robert (c.1290–1349)
Authors: Pasnau Robert
Published: September 2018

Earlier scholars labelled Robert Holcot a sceptic, a nominalist and an Ockhamist. In fact, the work of this English Dominican friar is too complex and original for any simple label. What can be said with justice is that Holcot belongs among philosophers who work not at developing their own systematic philosophies but at criticizing the speculative efforts of their predecessors. Holcot questions the scope of Aristotelian logic, the extent of theological knowledge and even the extent to which we can have knowledge of the world around us.
Hus, Jan (c.1369–1415)
Authors: Bostick Curtis V.
Published: September 2018

From his appointment as rector of the Bethlehem chapel in Prague in 1402 until his execution at the Council of Constance in 1415, Jan Hus advanced the goals of an ecclesiastical reform movement with Czech national overtones. Hus’ ministerial and academic posts provided a broad platform for his leadership. He preached tenaciously against clerical abuses. At the University of Prague he taught philosophical and ecclesiological doctrines which, his opponents charged, were taken from the radical Oxford reformer, John Wyclif. Whereas Wyclif’s philosophical realism (for example, the indestructibility of ‘being’) led him to adopt several positions condemned as heretical, Hus’ polemic, in which he castigated the fiscalization and bureaucratization of the papacy, sprang more from his ideals of evangelical minority and apostolic poverty.
John of Damascus (c.675–c.750)
Authors: Longeway John
Published: September 2018

John of Damascus, who lived in the seventh and eighth centuries, is known for his Fount of Knowledge, which became the standard textbook of theology in the Eastern Orthodox tradition, and his opposition to the Iconoclasts, who opposed the use of images in Christian worship. The Fount of Knowledge, which drew heavily on patristic sources, was translated in the West by Robert Grossteste, where it had an influence on writers such as Peter Lombard.