Anaxagoras of Clazomenae (500 BC-428 BC) was reportedly the first Presocratic philosopher to settle in Athens. He was a friend of Pericles and his ideas are reflected in the works of Sophocles and Aristophanes. Anaxagoras asserted that Mind is the ordering principle of the cosmos, he explained solar eclipses, and he wrote on a myriad of astronomical, meteorological, and biological phenomena. His metaphysical claim that everything is in everything and his rejection of the possibility of coming to be or passing away are fundamental to all his other views. Because of his philosophical doctrines, Anaxagoras was condemned for impiety and exiled from Athens.
Summa Contra Gentiles by Thomas Aquinas
The Summa Contra Gentiles is not merely the only complete summary of Christian doctrine that St. Thomas has written, but also a creative and even revolutionary work of Christian apologetics composed at the precise moment when Christian thought needed to be intellectually creative in order to master and assimilate the intelligence and wisdom of the Greeks and the Arabs. In the Summa Aquinas works to save and purify the thought of the Greeks and the Arabs in the higher light of Christian Revelation, confident that all that had been rational in the ancient philosophers and their followers would become more rational within Christianity. This exposition and defense of divine truth has two main parts: the consideration of that truth that faith professes and reason investigates, and the consideration of the truth that faith professes and reason is not competent to investigate.
The Complete Works of Aristotle
Aristotle was an ancient Greek philosopher and scientist born in the city of Stagira, Chalkidiki, in the north of Classical Greece. Along with Plato, he is considered the “Father of Western Philosophy”. Aristotle provided a complex and harmonious synthesis of the various existing philosophies prior to him, including those of Socrates and Plato, and it was above all from his teachings that the West inherited its fundamental intellectual lexicon, as well as problems and methods of inquiry. As a result, his philosophy has exerted a unique influence on almost every form of knowledge in the West and it continues to be central to the contemporary philosophical discussion.
St Augustine, bishop of Hippo, was one of the central figures in the history of Christianity, and City of God is one of his greatest theological works. Written as an eloquent defence of the faith at a time when the Roman Empire was on the brink of collapse, it examines the ancient pagan religions of Rome, the arguments of the Greek philosophers and the revelations of the Bible. Pointing the way forward to a citizenship that transcends the best political experiences of the world and offers citizenship that will last for eternity, City of God is one of the most influential documents in the development of Christianity.
The son of a pagan father and a Christian mother, Saint Augustine spent his early years torn between conflicting faiths and world views. His Confessions, written when he was in his forties, recount how, slowly and painfully, he came to turn away from his youthful ideas and licentious lifestyle, to become instead a staunch advocate of Christianity and one of its most influential thinkers. A remarkably honest and revealing spiritual autobiography, the Confessions also address fundamental issues of Christian doctrine, and many of the prayers and meditations it includes are still an integral part of the practice of Christianity today.
The Meditations by Marcus Aurelius
Few ancient works have been as influential as the Meditations of Marcus Aurelius, philosopher and emperor of Rome (A.D. 161–180). A series of spiritual exercises filled with wisdom, practical guidance, and profound understanding of human behavior, it remains one of the greatest works of spiritual and ethical reflection ever written. Marcus’s insights and advice—on everything from living in the world to coping with adversity and interacting with others—have made the Meditations required reading for statesmen and philosophers alike, while generations of ordinary readers have responded to the straightforward intimacy of his style. For anyone who struggles to reconcile the demands of leadership with a concern for personal integrity and spiritual well-being, the Meditations remains as relevant now as it was two thousand years ago.
The Consolation of Philosophy by Boethius
Boethius was an eminent public figure under the Gothic emperor Theodoric, and an exceptional Greek scholar. When he became involved in a conspiracy and was imprisoned in Pavia, it was to the Greek philosophers that he turned. The Consolation was written in the period leading up to his brutal execution. It is a dialogue of alternating prose and verse between the ailing prisoner and his ‘nurse’ Philosophy. Her instruction on the nature of fortune and happiness, good and evil, fate and free will, restore his health and bring him to enlightenment. The Consolation was extremely popular throughout medieval Europe and his ideas were influential on the thought of Chaucer and Dante.
The Dhammapada is a collection of sayings of the Buddha in verse form and one of the most widely read and best known Buddhist scriptures. The original version of the Dhammapada is in the Khuddaka Nikaya, a division of the Pali Canon of Theravada Buddhism.
The Buddhist scholar and commentator Buddhaghosa explains that each saying recorded in the collection was made on a different occasion in response to a unique situation that had arisen in the life of the Buddha and his monastic community. His commentary, the Dhammapada Atthakatha, presents the details of these events and is a rich source of legend for the life and times of the Buddha.
The Vagrakkhedikâ Or Diamond-Cutter by Buddha
The Diamond Sūtra is a Mahāyāna (Buddhist) sūtra from the Prajñāpāramitā sutras or ‘Perfection of Wisdom’ genre. Translated into a variety of languages over a broad geographic range, the Diamond Sutra is one of the most influential Mahayana sutras in East Asia, and is particularly prominent within the Chan (or Zen) tradition, along with the Heart Sutra.
A copy of the Tang-dynasty Chinese version of the Diamond Sūtra was found among the Dunhuang manuscripts in 1907 by Daoist monk Wang Yuanlu on June 25, 1900, and sold to Aurel Stein. They are dated back to May 11, 868. It is, in the words of the British Library, “the earliest complete survival of a dated printed book.”
It is also the first creative work with an explicit public domain dedication, as its colophon at the end claims it was created “for universal free distribution.”
Letters of Marcus Tullius Cicero
Marcus Tullius Cicero (106 BC – 43 BC) was a Roman statesman, lawyer, scholar, philosopher, and academic skeptic, who tried to uphold optimate principles during the political crises that led to the establishment of the Roman Empire. His extensive writings include treatises on rhetoric, philosophy and politics. He is considered one of Rome’s greatest orators and prose stylists. He came from a wealthy municipal family of the Roman equestrian order and served as consul in 63 BC. The writings of Cicero constitute one of the most renowned collections of historical and philosophical work in all of classical antiquity.
Cicero is generally held to be one of the most versatile minds of ancient Rome. He introduced the Romans to the chief schools of Greek philosophy, and also created a Latin philosophical vocabulary; distinguishing himself as a linguist, translator, and philosopher. A distinguished orator and successful lawyer, Cicero likely valued his political career as his most important achievement. Today he is appreciated primarily for his humanism and philosophical and political writings. His voluminous correspondence, much of it addressed to his friend Atticus, has been especially influential, introducing the art of refined letter writing to European culture.
On Moral Duties (De Officiis) by Marcus Tullius Cicero
De Officiis (On Duties or On Obligations) is a political and ethical treatise by the Roman orator, philosopher, and statesman Marcus Tullius Cicero written in 44 BC. The treatise is divided into three books, in which Cicero expounds his conception of the best way to live, behave, and observe moral obligations. The work discusses what is honorable (Book I), what is to one’s advantage (Book II), and what to do when the honorable and one’s private interest apparently conflict (Book III). In the first two books Cicero was heavily influenced by the Stoic philosopher Panaetius, but wrote more independently for the third book. In addition to being a central component of liberal education for centuries, the work was held in high regard among many prolific philosophers and statesman including Augustine, Thomas Aquinas, Hugo Grotius, Montesquieu, Voltaire, and the American Founding Fathers. De Officiis, along with Xenophon’s Cyropaedia, are considered among the foundational works in the genre of the mirrors for princes, now most famously associated with Machiavelli’s The Prince.
The Enchiridion, or Manual by Epictetus
Epictetus was a crippled Greek slave of Phrygia during Nero’s reign (54-68 CE) who heard lectures by the Stoic Musonius before he was freed. Expelled with other philosophers by the emperor Domitian in 89 or 92 he settled permanently in Nicopolis in Epirus. There, in a school which he called ‘healing place for sick souls’, he taught a practical philosophy, details of which were recorded by Arrian, a student of his, and survive in four books of Discourses and a smaller Enchiridion, a handbook which gives briefly the chief doctrines of the Discourses. He apparently lived into the reign of Hadrian (117-138 CE).
Letter to Menoeceus by Epicurus
Principal Doctrines by Epicurus
Epicurus was an ancient Greek philosopher who founded a highly influential school of philosophy now called Epicureanism. He was born on the Greek island of Samos to Athenian parents. Influenced by Democritus, Aristotle, and possibly the Cynics, he turned against the Platonism of his day and established his own school, known as “the Garden”, in Athens. He and his followers were known for eating simple meals and discussing a wide range of philosophical subjects, and he openly allowed women to join the school as a matter of policy. An extremely prolific writer, he is said to have originally written over 300 works on various subjects, but the vast majority of these writings have been lost. Only three letters written by him—the Letters to Menoeceus, Pythocles, and Herodotus—and two collections of quotes—the Principle Doctrines and the Vatican Sayings—have survived intact, along with a few fragments and quotations of his other writings. His teachings are better recorded in the writings of later authors, including the Roman poet Lucretius, the philosopher Philodemus, the philosopher Sextus Empiricus, and the biographer Diogenes Laërtius.
In Praise of Folly by Desiderius Erasmus
Erasmus of Rotterdam (c. 1466-1536) is one of the greatest figures of the Renaissance humanist movement, which abandoned medieval pieties in favour of a rich new vision of the individual’s potential. Praise of Folly, written to amuse his friend Sir Thomas More, is Erasmus’s best-known work. Its dazzling mixture of fantasy and satire is narrated by a personification of Folly, dressed as a jester, who celebrates youth, pleasure, drunkenness and sexual desire, and goes on to lambast human pretensions, foibles and frailties, to mock theologians and monks and to praise the ‘folly’ of simple Christian piety. Erasmus’s wit, wordplay and wisdom made the book an instant success.
Heraclitus (535 – 475 BC) was a pre-Socratic Greek philosopher, and a native of the city of Ephesus, then part of the Persian Empire. He was famous for his insistence on ever-present change as being the fundamental essence of the universe, as stated in the famous saying, “No man ever steps in the same river twice”. This is commonly considered to be one of the first digressions into the philosophical concept of becoming, and has been contrasted with Parmenides statement that “what-is is” as one of the first digressions into the philosophical concept of being. As such, Parmenides and Heraclitus are commonly considered to be two of the founders of ontology.
On Aristotle’s Categories by Ammonius Hermiae
Ammonius Hermiae (440 – 520 AD) was a Greek philosopher, and the son of the Neoplatonist philosophers Hermias and Aedesia. He was a pupil of Proclus in Athens, and taught at Alexandria for most of his life, writing commentaries on Plato, Aristotle, and other philosophers.
On First Philosophy by Al-Kindi
Abu Yūsuf Yaʻqūb ibn ʼIsḥāq aṣ-Ṣabbāḥ al-Kindī (801–873 AD) was an Arab Muslim philosopher, polymath, mathematician, physician and musician. Al-Kindi was the first of the Islamic peripatetic philosophers, and is hailed as the “father of Arab philosophy”.
Al-Kindi was born in Kufa and educated in Baghdad. He became a prominent figure in the House of Wisdom, and a number of Abbasid Caliphs appointed him to oversee the translation of Greek scientific and philosophical texts into the Arabic language. This contact with “the philosophy of the ancients” (as Hellenistic philosophy was often referred to by Muslim scholars) had a profound effect on him, as he synthesized, adapted and promoted Hellenistic and Peripatetic philosophy in the Muslim world. He subsequently wrote hundreds of original treatises of his own on a range of subjects ranging from metaphysics, ethics, logic and psychology, to medicine, pharmacology, mathematics, astronomy, astrology and optics, and further afield to more practical topics like perfumes, swords, jewels, glass, dyes, zoology, tides, mirrors, meteorology and earthquakes.
The central theme underpinning al-Kindi’s philosophical writings is the compatibility between philosophy and other “orthodox” Islamic sciences, particularly theology. And many of his works deal with subjects that theology had an immediate interest in. These include the nature of God, the soul and prophetic knowledge. But despite the important role he played in making philosophy accessible to Muslim intellectuals, his own philosophical output was largely overshadowed by that of al-Farabi and very few of his texts are available for modern scholars to examine.
The Tao Te Ching is a Chinese classic text traditionally credited to the 6th-century BC sage Lao-Tzu. The Tao Te Ching, along with the Zhuangzi, is a fundamental text for both philosophical and religious Taoism. It also strongly influenced other schools of Chinese philosophy and religion, including Legalism, Confucianism, and Buddhism, which was largely interpreted through the use of Taoist words and concepts when it was originally introduced to China. Many Chinese artists, including poets, painters, calligraphers, and gardeners, have used the Tao Te Ching as a source of inspiration. Its influence has spread widely outside East Asia and it is among the most translated works in world literature.
With the goal of describing man with complete frankness and using himself as his most frequent example, Michel de Montaigne first published his “Essays” in 1580. This collection of essays encompasses a wide variety of subjects, originally inspired by his study of Latin classics, and later by the lives of the leading figures of his time. Michel de Montaigne saw the most basic elements of man as variety and unpredictability, and this idea permeates the entire work, even as he explores a myriad of topics, including theology, philosophy, law, fame, memory, death, and his own daily schedule. The longest essay, entitled ‘Apology for Raymond Sebond,’ contains his most famous quote: “What do I know?” This perhaps embodies the spirit of the entire volume, for it reflects both the inquisitory search for intellectual knowledge as well as the more personal anecdotal quality of a work that has had an enduring impact on both French and English literature for hundreds of years.
Fragments and Commentary of Parmenides
Parmenides (late sixth or early fifth century BC) was a pre-Socratic Greek philosopher from Elea in Magna Graecia (Greater Greece, which included Southern Italy). He was the founder of the Eleatic school of philosophy. The single known work by Parmenides is a poem, On Nature, only fragments of which survive. In it, Parmenides prescribes two views of reality. In “the way of truth” (a part of the poem), he explains how reality (coined as “what-is is”) is one, change is impossible, and existence is timeless, uniform, necessary, and unchanging. This is generally considered one of the first digressions into the philosophical concept of being, and has been contrasted with Heraclitus’s statement that “No man ever steps into the same river twice” as one of the first digressions into the philosophical concept of becoming.
The Complete Works of Philo of Alexandria
Philo of Alexandria (20 BCE – 50 CE), also called Philo Judaeus, was a Hellenistic Jewish philosopher who lived in Alexandria, in the Roman province of Egypt.
Philo’s deployment of allegory to harmonize Jewish scripture, mainly the Torah, with Greek philosophy was the first documented of its kind, and thereby often misunderstood. Many critics of Philo assumed his allegorical perspective would lend credibility to the notion of legend over historicity. Notwithstanding, when one actually reads Philo’s works in both translated and original Greek forms, one finds Philo often advocated a literal understanding of the Torah and the historicity of such described events, while at other times finding allegorical readings more suited to the text.
Though never properly attributed, Philo’s marriage of Jewish exegesis and Stoic philosophy provided a formula later picked up by other Midrash content from the 3rd and 4th centuries C.E. Some claimed this lack of credit or affinity for Philo by the Rabbinic leadership at the time, was due to his adoption of allegorical instead of literal interpretations of the Hebrew Bible, though it was likely due to his criticism of Rabbinic scholars, citing their works and ideas were “full of Sybaritic profligacy and licentiousness to their everlasting shame”, “eager to give a specious appearance to infamous actions, so as to secure notoriety for disgraceful deeds”, and ultimately, that he “disregards the envious disposition of such men, and shall proceed to narrate the true events of Moses’ life” of which Philo felt were unjustly hidden and covered over.
According to Josephus, Philo was largely inspired by Aristobulus of Alexandria and the Alexandrian school. The only event in Philo’s life that can be decisively dated is his participation in the embassy to Rome in 40 CE; whereby he represented the Alexandrian Jews in a delegation to the Roman Emperor Gaius Caesar Augustus Germanicus (Caligula) following civil strife between the Alexandrian Jewish and Greek communities.
Plato (424 – 348 BC) was a philosopher in Classical Greece and the founder of the Academy in Athens, the first institution of higher learning in the Western world. He is widely considered the pivotal figure in the development of Western philosophy. Unlike nearly all of his philosophical contemporaries, Plato’s entire work is believed to have survived intact for over 2,400 years.
Along with his teacher, Socrates, and his most famous student, Aristotle, Plato laid the foundations of Western philosophy and science. Alfred North Whitehead once noted: “the safest general characterization of the European philosophical tradition is that it consists of a series of footnotes to Plato.” In addition to being a foundational figure for Western science, philosophy, and mathematics, Plato has also often been cited as one of the founders of Western religion and spirituality.
The Enneads is the collection of writings of Plotinus, edited and compiled by his student Porphyry (270 AD). Plotinus was a student of Ammonius Saccas and they were founders of Neoplatonism. His work, through Augustine of Hippo, the Cappadocian Fathers, Pseudo-Dionysius the Areopagite and several subsequent Christian and Muslim thinkers, has greatly influenced Western and Near-Eastern thought. In his philosophy, described in the Enneads, there are three principles: the One, the Intellect, and the Soul.
Plutarch (46-120 CE) was something like a celebrity in Ancient Rome. Born in Boetia, a place thought to produce dim-witted men, Plutarch truly defied the regional superstition. He was a celebrated historian, essayist, biographer, and mayor. He travelled all over the Mediterranean, but lived most of his life in Chaeronea. Just twenty miles from his home, he held the position of senior priest at the storied Oracle of Delphi, and translated the prophecies of Pythia. He wrote many biographies, as well as philosophical and moral essays that have hugely impacted English and French literature. His influence is seen in the works of Shakespeare, Emerson, and Montaigne, among so many others. Contained here are a collection of his essays on morality.
The Presocratic Philosophers by G.S. Kirk & J.E. Raven
Beginning with a long and extensively rewritten introduction surveying the predecessors of the Presocratics, this book traces the intellectual revolution initiated by Thales in the sixth century BC to its culmination in the metaphysics of Parmenides and the complex physical theories of Anaxagoras and the Atomists in the fifth century. It is based on a selection of some six hundred texts in Greek and a close English translation which in this edition is given more prominence. These provide the basis for a detailed critical study of the principal individual thinkers of the time. Besides serving as an essential text for undergraduate and graduate courses in Greek philosophy and in the history of science, this book will appeal to a wide range of readers with interests in philosophy, theology, the history of ideas and of the ancient world, and indeed to anyone who wants an authoritative account of the Presocratics.
Fragments and Commentary by Pythagoras
Pythagoras of Samos (570 – 495 BC) was an ancient Ionian Greek philosopher and the eponymous founder of Pythagoreanism. His political and religious teachings were well known in Magna Graecia and influenced the philosophies of Plato, Aristotle, and, through them, Western philosophy. The teaching most securely identified with Pythagoras is metempsychosis, or the “transmigration of souls”, which holds that every soul is immortal and, upon death, enters into a new body. He may have also devised the doctrine of musica universalis, which holds that the planets move according to mathematical equations and thus resonate to produce an inaudible symphony of music.
Letters from a Stoic by Lucius Annaeus Seneca
Lucius Annaeus Seneca the Younger (4 BC – AD 65), usually known mononymously as Seneca, was a Stoic philosopher of Ancient Rome, a statesman, dramatist, and, in one work, satirist, from the post-Augustan age of Latin literature.
Seneca was born in Córdoba in Hispania, and raised in Rome, where he was trained in rhetoric and philosophy. His father was Seneca the Elder, his elder brother was Lucius Junius Gallio Annaeanus, and his nephew was the poet Lucan. In AD 41, Seneca was exiled to the island of Corsica under emperor Claudius, but was allowed to return in 49 to become a tutor to Nero. When Nero became emperor in 54, Seneca became his advisor and, together with the praetorian prefect Sextus Afranius Burrus, provided competent government for the first five years of Nero’s reign. Seneca’s influence over Nero declined with time, and in 65 Seneca was forced to take his own life for alleged complicity in the Pisonian conspiracy to assassinate Nero, in which he was probably innocent. His stoic and calm suicide has become the subject of numerous paintings.
As a writer, Seneca is known for his philosophical works, and for his plays, which are all tragedies. His prose works include 12 essays and 124 letters dealing with moral issues. These writings constitute one of the most important bodies of primary material for ancient Stoicism. As a tragedian, he is best known for plays such as his Medea, Thyestes, and Phaedra. Seneca’s influence on later generations is immense—during the Renaissance he was “a sage admired and venerated as an oracle of moral, even of Christian edification; a master of literary style and a model [for] dramatic art.”
On the Shortness of Life & On the Happy Life by Lucius Annaeus Seneca
De Brevitate Vitae (On the Shortness of Life) is a moral essay written by Seneca the Younger, a Roman Stoic philosopher, sometime around the year 49 AD, to his father-in-law Paulinus. The philosopher brings up many Stoic principles on the nature of time, namely that people waste much of it in meaningless pursuits. According to the essay, nature gives people enough time to do what is really important and the individual must allot it properly. In general, time is best used by living in the present moment in pursuit of the intentional, purposeful life. Similar ideas can be found in Seneca’s treatise De Otio (On Leisure) and discussion of these themes can often be found in his Letters to Lucilius (letter 49, 101, etc.).
De Vita Beata (On the Happy Life) is a dialogue written by Seneca the Younger around the year 58 AD. It was intended for his older brother Gallio, to whom Seneca also dedicated his dialogue entitled De Ira (On Anger). It is divided into 28 chapters that present the moral thoughts of Seneca at their most mature. Seneca explains that the pursuit of happiness is the pursuit of reason – reason meant not only using logic, but also understanding the processes of nature.
Fragments and Commentary of Thales of Miletus
Thales of Miletus (624 – c. 546 BC) was a pre-Socratic Greek philosopher, mathematician, and astronomer from Miletus in Asia Minor (present-day Milet in Turkey). Many, most notably Aristotle, regarded him as the first philosopher in the Greek tradition, and he is otherwise historically recognized as the first individual in Western civilization known to have entertained and engaged in scientific philosophy. Thales is recognized for breaking from the use of mythology to explain the world and the universe, and instead explaining natural objects and phenomena by theories and hypotheses, in a precursor to modern science. Almost all the other pre-Socratic philosophers followed him in explaining nature as deriving from a unity of everything based on the existence of a single ultimate substance, instead of using mythological explanations.
On Moral Characters by Theophrastus
Theophrastus (371 – 287 BC), a Greek native of Eresos in Lesbos, was the successor to Aristotle in the Peripatetic school. He came to Athens at a young age and initially studied in Plato’s school. After Plato’s death, he attached himself to Aristotle who took to Theophrastus his writings. When Aristotle fled Athens, Theophrastus took over as head of the Lyceum. Theophrastus presided over the Peripatetic school for thirty-six years, during which time the school flourished greatly. He is often considered the father of botany for his works on plants. After his death, the Athenians honored him with a public funeral. His successor as head of the school was Strato of Lampsacus.
The interests of Theophrastus were wide-ranging, extending from biology and physics to ethics and metaphysics. His two surviving botanical works, Enquiry into Plants (Historia Plantarum) and On the Causes of Plants, were an important influence on Renaissance science. There are also surviving works On Moral Characters, On Sense Perception, On Stones, and fragments on Physics and Metaphysics. In philosophy, he studied grammar and language and continued Aristotle’s work on logic. He also regarded space as the mere arrangement and position of bodies, time as an accident of motion, and motion as a necessary consequence of all activity. In ethics, he regarded happiness as depending on external influences as well as on virtue.
Note: You can find free philosophy e-books and free online philosophy courses at Open Culture. Project Gutenberg and Internet Archive both host vast libraries of e-books for free to the public.