Thinkers Timeline

Socrates (c. 470–399 BCE) was a philosopher in ancient Athens, Greece. He wrote nothing himself — everything we know about him comes from the writings of his students, especially Plato. He spent his life in the streets and public spaces of Athens, asking people questions about the things they claimed to know — justice, courage, virtue, knowledge. He was famously described as the wisest man in Athens, but said this could only be true because he alone knew that he knew nothing. In 399 BCE he was put on trial by the Athenian government, charged with corrupting the youth and not respecting the gods. He was found guilty and sentenced to death by drinking poison. He refused to escape when he had the chance, saying a philosopher must obey the law even when it is unjust.

Plato was an ancient Greek philosopher. He is one of the most important thinkers in human history. The whole tradition of Western philosophy has been called 'a series of footnotes to Plato'. He was born around 428 BCE in Athens, the great Greek city of his time. He died around 348 BCE, aged about 80. He came from a wealthy aristocratic family. His real name was probably Aristocles. 'Plato' (meaning 'broad' in Greek) seems to have been a nickname, possibly from his physical build. As a young man, he expected to enter politics. The political life of Athens, however, made him turn away. He was a student of Socrates, the philosopher who walked the streets of Athens questioning everyone. In 399 BCE, when Plato was about 29, the Athenian democracy executed Socrates on charges of corrupting the young and disrespecting the gods. Plato never got over it. The death shaped his philosophy and his deep distrust of democracy. After Socrates' death, Plato travelled. He went to southern Italy, Sicily, and possibly Egypt. Around 387 BCE, he returned to Athens and founded the Academy, a school for philosophy. The Academy lasted in some form for nearly 900 years. Aristotle studied there as a young man. Plato wrote about 35 dialogues, almost all of which survive. The dialogues are conversations, usually with Socrates as the main speaker. They cover almost every philosophical topic: justice, knowledge, beauty, love, the soul, government, education. The Republic is his most famous. The Symposium and the Phaedo are also widely read. He died in his eighties, still teaching at the Academy.

Aristotle was an ancient Greek philosopher. He is one of the most important thinkers in the history of Western philosophy and science. He was born in 384 BCE in Stagira, a small city in northern Greece. His father was a doctor to the royal court of Macedonia. At seventeen, Aristotle travelled to Athens and joined the Academy, the school founded by Plato. He stayed there for twenty years as a student and then as a teacher. When Plato died in 347 BCE, Aristotle left Athens. He travelled, taught, and did natural history research on the island of Lesbos. Around 343 BCE, he was invited by King Philip II of Macedonia to tutor Philip's son, the teenager who would become Alexander the Great. This is one of the most famous teacher-student relationships in history, though its actual influence on Alexander is hard to measure. In 335 BCE, Aristotle returned to Athens and founded his own school, the Lyceum. He taught there for twelve years and wrote many of his most important works. After Alexander's death in 323 BCE, anti-Macedonian feeling in Athens made Aristotle's position dangerous. He fled the city, reportedly saying he would not let Athens 'sin twice against philosophy', a reference to the execution of Socrates. He died a year later in 322 BCE, aged 62. His surviving works, which are mostly lecture notes rather than polished books, cover logic, biology, psychology, ethics, politics, poetry, rhetoric, and metaphysics. Together they shaped Western thought for more than two thousand years. Almost every field of inquiry has at some point been measured against Aristotle.

Mencius was a Chinese philosopher. His Chinese name was Meng Ke, which means 'Master Meng'. Later Chinese tradition called him the 'Second Sage', meaning second only to Confucius himself. The Latin name 'Mencius' was given to him by European Jesuit missionaries in the 17th century. He was born around 371 BCE in the small state of Zou, in what is now Shandong province in eastern China. This was the same region where Confucius had lived over a century earlier. Mencius's father died when he was three years old. His mother raised him alone. Stories about her wisdom became famous in China. In one story, she moved house three times to find a place where her son would have good influences around him. The story of 'Mencius's Mother's Three Moves' is still told in China today. Mencius lived during the Warring States Period. This was a violent time. Several Chinese kingdoms fought each other constantly. Armies swept across the land. Ordinary people suffered terribly from war, high taxes, and harsh rulers. Mencius spent much of his adult life travelling from one kingdom to another, offering advice to their rulers. He wanted them to govern more humanely. Some listened for a while. Most did not take his advice seriously. In the end, he retired from public life, disappointed. His students collected his conversations and teachings in a book. It is called simply the Mencius. The book is long and often funny. Mencius argues with rulers, other philosophers, and his own students. He is sharp, stubborn, and clear. He died around 289 BCE, aged about 82. Nearly 1500 years later, the Mencius became one of the 'Four Books' that every educated Chinese person had to study. His ideas shaped China, Korea, Japan, and Vietnam for centuries.

Zhuangzi was a Chinese philosopher of the 4th century BCE. His name means 'Master Zhuang'. His personal name was Zhuang Zhou. He lived during a period called the Warring States, when several Chinese kingdoms fought each other constantly. This was a violent and unstable time. It was also a golden age of Chinese thought. Many of China's most important thinkers lived then: Confucius had lived a generation earlier, Mencius and Laozi were also writing in this period. We know very little for certain about Zhuangzi's life. The historian Sima Qian, writing about 150 years after his death, says he was a minor official in a place called Qiyuan, in what is now Henan province. He was offered a high position by the king of the state of Chu but turned it down. He preferred to live simply. He married and had children. He died in peace, probably in his sixties. The book known as the Zhuangzi is named after him. It has 33 chapters and is one of the great works of world literature. Modern scholars think Zhuangzi himself wrote only the first seven chapters, sometimes called the 'Inner Chapters'. These contain the most famous and powerful writing. The rest of the book was written by his students and later followers over several generations. The Zhuangzi is, along with the Daodejing, the foundation of Daoist philosophy. Together the two books form the core of the Daoist tradition. Unlike most philosophers of his time, Zhuangzi wrote mostly in stories. His book is full of talking animals, wise cooks, strange encounters, and dream sequences. He is one of the first great storytellers in world philosophy. His influence on Chinese literature, art, and humour has been enormous.

Epictetus (c.50-135 CE) was a Greek Stoic philosopher who was born into slavery in Hierapolis, a city in what is now Turkey. His name means acquired, or something like the purchased one, which reflects his status. He was owned by a freedman named Epaphroditus who worked in the imperial court of the Emperor Nero in Rome. Epictetus was permitted to study philosophy, and he became a student of the Stoic teacher Musonius Rufus. He was eventually freed, probably after Nero's death, and established his own philosophical school first in Rome and later, after the Emperor Domitian expelled philosophers from Rome, in the city of Nicopolis in northwestern Greece. He was lame, probably as a result of mistreatment during his time in slavery, though ancient accounts of the specific circumstances differ. He left no writings himself: everything we have from him is in the notes taken by his student Arrian, who compiled them into two works, the Discourses and the shorter Enchiridion or Handbook. He had an enormous influence on later Stoic thinkers including Marcus Aurelius.

Nagarjuna (approximately 150-250 CE) was an Indian Buddhist philosopher, widely considered one of the most important and influential thinkers in the entire history of Asian philosophy. He was born in South India, probably in what is now Andhra Pradesh, and became a Buddhist monk and teacher. He is the founder of the Madhyamaka school of Buddhist philosophy, which became one of the dominant schools of Buddhist thought across India, Tibet, China, Korea, Japan, and Southeast Asia. Very little is known about his life as a historical person: later tradition attributed extraordinary feats and a legendary biography to him, making it difficult to separate fact from story. What we do have are his philosophical texts, above all the Mulamadhyamakakarika, the Fundamental Verses on the Middle Way, a short but extraordinarily dense philosophical work in verse form that argues for one of the most radical positions in the history of philosophy: that nothing whatsoever has fixed, independent existence. He died sometime in the second or third century CE, but his ideas have continued to shape Buddhist philosophy and practice across Asia for nearly two thousand years.

Philo of Alexandria was a Jewish philosopher who lived in Egypt. He was born around 20 BCE and died around 50 CE. Alexandria, his home city, was one of the largest and most learned cities in the ancient world. It had a big Jewish community and also a famous tradition of Greek philosophy. Philo lived in both of these worlds at once. He came from a wealthy and important Jewish family. His brother was one of the richest men in the city. Philo had a full Greek education. He read Plato, the Stoics, and other Greek thinkers closely. But he was also a devout Jew who knew the Hebrew scriptures well. He spent his life trying to bring these two traditions together. Most of what Philo wrote was about the first five books of the Bible, called the Torah. He read them mostly in Greek, in a translation called the Septuagint. He wrote long commentaries explaining their deeper meaning. We know one firm fact about his life. In the year 39 or 40 CE, he led a Jewish group from Alexandria to Rome. They went to ask the emperor Caligula to protect the Jews after violent attacks in their city. Philo wrote about this dangerous mission himself. The year of his death is not known exactly, but it was probably soon after.

Adi Shankara (traditionally 788-820, though some scholars propose earlier dates) was an Indian philosopher and theologian whose consolidation of the Advaita Vedanta school shaped Hindu thought more decisively than any other single figure in the tradition. He was born in Kaladi in what is now Kerala, in southern India, into a Nambudiri Brahmin family. Traditional biographies describe his father as dying when he was young and his mother as devout and learned. He is said to have become a renunciate at eight — a striking step taken, according to tradition, with his mother's reluctant consent. He studied under Govinda Bhagavatpada, himself a student of Gaudapada, whose commentary on the Mandukya Upanishad provided Shankara with much of his philosophical starting point. Shankara spent his short life travelling across the Indian subcontinent, debating rival philosophers, establishing monasteries, and writing prolifically. He founded four major monastic centres (mathas) at the cardinal points of India — at Sringeri in the south, Puri in the east, Dwarka in the west, and Jyotirmath in the north — each to be led by a lineage-holder called a Shankaracharya. This institutional network remains active today. His writing output was extraordinary for someone who lived only thirty-two years by traditional reckoning. His commentaries on the three foundational texts of Vedanta — the Upanishads (particularly the ten principal Upanishads), the Bhagavad Gita, and the Brahma Sutras — are the authoritative statements of Advaita Vedanta. He also wrote shorter philosophical works including the Upadesasahasri (A Thousand Teachings), and devotional hymns including the Bhaja Govindam, that remain widely recited. Traditional accounts place his death at Kedarnath in the Himalayas. The dating of his life has been contested — some scholars propose sixth- or seventh-century dates based on textual evidence — but the ninth century remains the conventional position.

Ibn Sina (980-1037 CE), known in the Western world as Avicenna, was a Persian Muslim philosopher and physician. He was born near Bukhara in what is now Uzbekistan. He was exceptionally gifted: he is said to have memorised the Quran by age ten, and by eighteen was a practising physician whom established doctors came to consult. He lived an active and often difficult life, working as a physician and court official for various rulers across Central Asia and Persia while writing philosophy and science at an extraordinary pace. He wrote more than 200 books. His most important works are the Canon of Medicine, which became the standard medical textbook across Europe and the Islamic world for five centuries, and the Book of Healing (Kitab al-Shifa), a massive encyclopaedia of philosophy and science. He died at 57 years old, in 1037 CE, in what is now western Iran.

Peter Abelard was a French philosopher, theologian, and teacher. He was one of the most influential and controversial intellectual figures of the 12th century. He helped lay the foundations of the Scholastic method that would dominate medieval European universities. He was born in 1079 in Le Pallet, near Nantes in western France. He died in 1142, aged about 63. He came from a minor noble family. He was the eldest son. He could have inherited the family's modest lands. He gave up the inheritance to study philosophy. He became a wandering student in northern France, going from teacher to teacher. He was clever, ambitious, and difficult. He repeatedly fell out with his teachers and set up rival schools. By his thirties he was the most famous teacher of philosophy in Paris. In the 1110s he met Heloise, the brilliant niece of a Paris cathedral canon named Fulbert. Heloise was about 20 years younger than Abelard. He arranged to lodge in Fulbert's house and tutor her. They became lovers. She became pregnant. Abelard arranged a secret marriage to protect her reputation, though Heloise initially resisted. When Fulbert discovered the relationship, he had Abelard attacked and castrated. Abelard withdrew to a monastery. Heloise became a nun. They never lived together again, though they corresponded for the rest of their lives. Abelard kept teaching and writing. He produced original works on logic, ethics, and theology. His positions were sometimes radical for his time. He was condemned for heresy twice, in 1121 and 1140. He died in a monastery while travelling to defend himself in Rome. His remains were eventually buried with Heloise's at Pere Lachaise cemetery in Paris, where their joint tomb is still a popular site for visitors.

Heloise was a French abbess, philosopher, and letter-writer. She was one of the most original intellectual voices of the 12th century. She is often remembered chiefly for her tragic love affair with the philosopher Peter Abelard, but she was a serious thinker in her own right and a successful religious leader for over 30 years. She was probably born around 1100 in France. She died in 1164, aged about 64. Her family background is unclear. She seems to have come from minor French nobility. She was raised partly in the convent of Argenteuil near Paris. By her teens she was already famous for her learning. She read Latin, Greek (very rare for a woman of her time), and Hebrew. She studied Cicero, Seneca, Augustine, the Church Fathers, and the philosophy of her own day. Her uncle Fulbert, a canon at Notre Dame Cathedral in Paris, brought her to live with him in the city to continue her education. In her late teens she became a private student of Peter Abelard, the most famous philosopher in Paris. He was about 20 years older than her. They became lovers. She became pregnant with their son Astrolabe. Abelard arranged a secret marriage, which Heloise initially opposed because she thought it would damage Abelard's career. When her uncle Fulbert tried to publicise the marriage, Abelard sent Heloise to a convent. Fulbert thought Abelard had abandoned her and arranged Abelard's castration in revenge. After the catastrophe, Abelard pushed Heloise to take religious vows. She became a nun, then prioress, then abbess of a community Abelard had founded called the Paraclete. She ran it successfully for over 30 years. She was widely respected by religious authorities including Peter the Venerable, abbot of Cluny. The famous correspondence with Abelard came years later, after she happened to read his autobiography. She died at the Paraclete and was eventually buried with Abelard.

Ibn Rushd (1126-1198), known in Latin Europe as Averroes, was a philosopher, jurist, physician, and astronomer from Al-Andalus, the Muslim-ruled region of the Iberian Peninsula. He was born in Córdoba into a distinguished family of Maliki jurists: his grandfather and father had both served as chief judges of the city. He received a rigorous education in Islamic law, theology, medicine, philosophy, and the natural sciences. He served as a judge in Seville and later as chief judge of Córdoba, and also worked as court physician to the Almohad caliphs. In 1169, the caliph Abu Yaqub Yusuf asked him to write commentaries on the works of Aristotle that would make them more accessible, and this became his life's greatest project. He wrote short, middle, and long commentaries on nearly all of Aristotle's surviving works, along with his own treatises on law, medicine, and philosophy. Late in life he fell out of favour during a period of religious reaction: his books were burned and he was exiled to a small town outside Córdoba. He was rehabilitated before his death but died in Marrakesh in 1198. His commentaries were quickly translated into Latin and Hebrew, where they shaped medieval European philosophy more deeply than they shaped the Islamic world that produced them.

Zhu Xi was a Chinese philosopher, teacher, and government official of the Southern Song dynasty. He was born on 18 October 1130 in Youxi, in Fujian province. His father was a minor official who lost his job shortly before Zhu Xi was born. The family was not rich, but his father valued education and taught his son the Confucian classics. Zhu Xi was a gifted student. He passed the highest civil service exam, called the jinshi, at age eighteen. Most people who passed this exam did so around age thirty-five. As a young man, he studied Buddhism and Daoism as well as Confucianism. In his late twenties he met a teacher named Li Tong, who convinced him to commit fully to Confucianism. Li Tong came from a new wave of Chinese thinkers called the Neo-Confucians. Zhu Xi absorbed their ideas and went much further, producing a grand philosophical system that would shape Chinese thought for centuries. He held government posts only for about nine years in total. He preferred teaching and writing. He rebuilt and taught at the famous White Deer Hollow Academy. He edited and wrote commentaries on classical texts. His sharp criticism of corrupt officials earned him enemies. In 1196, his opponents attacked his teachings as 'false learning' and stripped him of his posts. He died on 23 April 1200, aged 69, still in political disgrace. Several thousand people braved official disapproval to attend his funeral. Within a few decades of his death, his teachings were rehabilitated. They then became the official philosophy of China for more than 600 years.

Thomas Aquinas (1225-1274) was an Italian Dominican friar, philosopher, and theologian whose synthesis of Christian theology with Aristotelian philosophy became the most influential intellectual achievement of medieval Catholic thought and remains a central reference in Catholic philosophy and theology today. He was born around 1225 at the family castle of Roccasecca, in the Kingdom of Sicily (in present-day Italy), to the noble family of the Counts of Aquino. His parents sent him at age five to the nearby Benedictine abbey of Monte Cassino, intending him for a monastic career that would eventually make him abbot. In 1239 political conflicts disrupted this plan and he was sent to the University of Naples, where he encountered the works of Aristotle and the new Dominican Order. In 1244 he joined the Dominicans — a decision his family opposed so strongly that they kidnapped him and held him under house arrest for over a year. He persisted, reached Paris in 1245, and became a student of the great Dominican scholar Albertus Magnus. He followed Albertus to Cologne, then returned to Paris, where he became a master of theology in 1256. Over the next eighteen years he wrote at an extraordinary rate — the Summa contra Gentiles (1259-1265), the Summa Theologiae (begun 1265, unfinished), extensive commentaries on Aristotle, commentaries on several books of the Bible, disputed questions, and many other works. He held teaching posts at Paris and at the Dominican study house in Rome and spent his final years in Naples. In December 1273, while celebrating Mass, he had some experience that he described only as straw compared to what he had seen, and he stopped writing. He died a few months later, in March 1274, while travelling to attend the Council of Lyon. He was canonised in 1323. His works have been studied continuously in Catholic institutions for over seven centuries and have influenced philosophy and theology well beyond Catholicism.

Wang Yangming was a Chinese philosopher, scholar, and military general. He is one of the most important Confucian thinkers of the second millennium CE. His ideas about knowledge, action, and the human mind shaped Chinese, Japanese, and Korean thought for centuries. He was born in 1472 in what is now Zhejiang province, in eastern China. He died in 1529, aged 56. His full name was Wang Shouren. 'Yangming' is a name he later took from a place where he lived for some years. He came from a scholarly family. His father had passed the highest level of the imperial civil service examinations. Wang Yangming was clever from childhood. He passed the highest examinations himself in 1499. For most of his career he served as an official in the Ming dynasty government. He was sometimes successful, sometimes in trouble. In 1506 he protested against a corrupt eunuch official at court. He was beaten with bamboo rods and exiled to a remote post in southwestern China. The exile lasted three years. During this time, in a bamboo hut in the mountains, he had what is sometimes called his philosophical awakening. He understood, he said later, that the principles of right action were already inside the human mind. They did not need to be sought outside, in books or in the external world. After his return from exile, he continued government service. He became a respected military commander. He put down major rebellions in the Ming Empire. Despite this success, he had political enemies. He was repeatedly given difficult assignments and then attacked when they were not perfectly resolved. He died in 1529 from illness, far from home, on his way back from another military campaign. His philosophy survived him and reshaped East Asian thought.

Thomas Hobbes (1588–1679) was an English philosopher who lived through one of the most turbulent periods in British history — the English Civil War, the execution of King Charles I, and the Interregnum. He spent years in exile in France and worked as a tutor to the future King Charles II. His most famous work, Leviathan (1651), is one of the foundational texts of Western political philosophy. In it he argued that without government, human life would be solitary, poor, nasty, brutish, and short — and that people therefore have a rational self-interest in submitting to the authority of a sovereign state. He is considered one of the founders of modern political science and social contract theory.

Zera Yacob was an Ethiopian philosopher of the seventeenth century. His main work is a short book called the Hatata, which means 'inquiry' or 'investigation'. According to the Hatata itself, he was born on 28 August 1599 near Aksum, an ancient city in northern Ethiopia. His father was a poor farmer. Despite this, his father sent him to school. He studied the Psalms of David and was educated in the Ethiopian Orthodox Christian faith. He was a quick learner and went on to higher religious schooling for ten years. The Hatata describes a hard turning point in his life. The Ethiopian emperor Susenyos had converted to Roman Catholicism in 1622 and ordered all his subjects to follow him. Zera Yacob refused. He was denounced by enemies and feared for his life. He fled with a small bag of gold and the Book of Psalms. He found a cave near the Tekezé River and lived there as a hermit for two years. He prayed, thought, and developed his philosophy. After the death of Susenyos in 1632, his son Fasilides became emperor and restored the Orthodox faith. Zera Yacob came out of hiding. He was given shelter by a wealthy man named Habtu, whose son Walda Heywat became his student. Zera Yacob worked as a teacher and scribe. In 1668, when he was about 68, he wrote down the Hatata at Walda Heywat's request. He died in 1692 or 1693, aged about 93. The text was rediscovered in Europe in the early 1900s.

Baruch Spinoza was a Dutch philosopher. He is one of the most important thinkers of the early modern period. He was born on 24 November 1632 in Amsterdam. His family was Portuguese Jewish. They had fled Portugal to escape violent persecution by Catholic rulers. The Netherlands at the time was unusual in Europe. It was more tolerant of Jews than most countries. But Jewish communities there stayed careful, afraid of upsetting their Christian neighbours. Young Baruch (Hebrew for 'blessed') was a brilliant student of Hebrew and Jewish religious texts. His father ran a small trading business. When the father died, Spinoza helped manage it for a short time. But by his early twenties, he was moving away from traditional Jewish belief. He read Descartes and other new European philosophers. He began to question the Bible. He asked whether miracles really happened. He doubted that God was a person who ruled the world from outside it. In 1656, when he was 23, the Jewish community of Amsterdam formally expelled him. The document is one of the harshest such orders in Jewish history. It cursed him and forbade any Jew from speaking to him or even coming within four paces of him. The exact reasons were not recorded. His dangerous religious ideas are the most likely cause. He never tried to rejoin. He made his living grinding lenses for microscopes and telescopes. This was precise, patient work. He lived simply, in rented rooms, never marrying. He refused a university chair at Heidelberg because he feared it would limit his freedom to think. He published only two books in his lifetime, one of them anonymously. His greatest work, the Ethics, came out after his death. He died on 21 February 1677, aged 44, probably from a lung disease made worse by glass dust from his work.

John Locke was an English philosopher. He is one of the most influential political thinkers in world history. He was born on 29 August 1632 in a small village in Somerset, in the south-west of England. His father was a country lawyer who had fought on the side of Parliament in the English Civil War. Young John grew up during that war, watching England struggle over who should rule. He was a brilliant student. He went to Westminster School in London and then to Christ Church, Oxford. He stayed at Oxford as a teacher for many years. He studied medicine and science as well as philosophy. He worked with the famous scientist Robert Boyle. He was one of the first members of the Royal Society, Britain's most important scientific group. His medical training later saved the life of his friend and patron, Lord Ashley, by performing an operation to remove a cyst from his liver. Lord Ashley (later the Earl of Shaftesbury) became a powerful politician. Locke worked as his secretary, adviser, and family doctor. This brought Locke deep into English politics. When Shaftesbury fell out with King Charles II in the early 1680s, Locke too was in danger. He fled to the Netherlands in 1683. He stayed there for six years, writing the books that would make him famous. In 1688, King James II was overthrown in what English people called the Glorious Revolution. William and Mary took the throne. Locke returned home safely. In 1689 and 1690, he published three of the most important books of his age: A Letter Concerning Toleration, Two Treatises of Government, and An Essay Concerning Human Understanding. Each changed its field. He never married. He spent his last years at a country house in Essex, writing and corresponding with scholars across Europe. He died on 28 October 1704, aged 72.

Jean-Jacques Rousseau was a philosopher and writer. He is one of the most important thinkers of the European Enlightenment. He was born on 28 June 1712 in Geneva, which was then an independent city-state, not part of France or Switzerland. His mother died nine days after his birth. His father was a watchmaker who taught him to read and love books. When Rousseau was ten, his father got into a fight and had to flee Geneva. Young Jean-Jacques was left with relatives. At fifteen, he left Geneva and wandered across Europe. He worked as a servant, a private tutor, and a music copyist. He taught himself by reading. He met a wealthy older woman named Madame de Warens, who took him in for several years. His early life was unstable. He had little formal education. He would later turn this outsider experience into a source of philosophical insight. He moved to Paris in 1742. He made his name in 1750 when he won an essay competition on whether progress in arts and sciences had improved human morals. His answer, surprisingly, was no. The essay made him famous. For the next twenty years, he wrote a series of books that changed European thought. The Discourse on the Origin of Inequality (1755) argued that civilisation had corrupted humanity. Julie, or the New Heloise (1761) was one of the bestselling novels of the 18th century. The Social Contract (1762) proposed a new theory of political legitimacy. Emile, or On Education (1762) proposed a revolutionary theory of how to raise children. Rousseau had six children with his partner, Thérèse Levasseur, and placed all of them in a foundling hospital. He did this against her wishes. The facts are hard to reconcile with his writing on education and family. He spent his final years moving from country to country, often in conflict with authorities who banned his books. He died on 2 July 1778 in Ermenonville, France, aged 66.

Adam Smith (1723-1790) was a Scottish philosopher and economist. He was born in Kirkcaldy, Scotland, and studied at the University of Glasgow and then at Oxford. He became a professor of moral philosophy at Glasgow, where he taught ethics, politics, and economics. He is best known for two books: The Theory of Moral Sentiments (1759), which is about how human beings understand right and wrong through imagining how others feel, and The Wealth of Nations (1776), which examined how economies work and what makes countries rich or poor. He lived during a time of enormous economic change: the beginning of the industrial revolution in Britain and the rapid growth of international trade. He was trying to understand these changes and work out what principles should guide economic life. He has often been called the father of modern economics, though his ideas are more complex than they are often presented to be.

Immanuel Kant was a German philosopher. He is one of the most influential thinkers in the history of Western philosophy. He was born on 22 April 1724 in Königsberg, a city in East Prussia (now Kaliningrad, Russia). His family was Lutheran and not wealthy. His father was a saddle-maker. His mother, who died when he was 13, was a strong early influence and encouraged his studies. He studied at the University of Königsberg from the age of 16. He worked for several years as a private tutor for noble families before returning to the university as a lecturer in 1755. He became a full professor of logic and metaphysics in 1770. He stayed in Königsberg his whole life. He is said never to have travelled more than about 150 kilometres from his birthplace. His daily routine was famously strict: neighbours were said to set their watches by his afternoon walks. For most of his career he was a respected but not famous teacher. Then, starting in his late fifties, he wrote a series of huge books that changed philosophy. The Critique of Pure Reason (1781), the Critique of Practical Reason (1788), and the Critique of Judgement (1790) set out a new system. He wrote important shorter works on ethics, religion, politics, and history. He continued writing until his death on 12 February 1804, aged 79. His work is hugely influential, but parts of it are also troubling. He wrote racist statements about non-European peoples. These texts sat alongside his claims about universal human dignity. Modern scholarship has taken this tension seriously, and honest study of Kant now includes this difficulty.

Jeremy Bentham was an English philosopher and legal reformer. He was the founder of modern utilitarianism. He was born on 15 February 1748 in London, into a wealthy lawyer's family. He was a child prodigy. He started learning Latin at age three and entered Oxford University at twelve. He qualified as a lawyer but never practised law. He thought the English legal system was a mess of confused rules that harmed the people it was meant to serve. He spent the rest of his life trying to reform it. He inherited enough money to live without working. For nearly 60 years, he wrote almost every day. He produced thousands of pages on law, government, punishment, economics, and ethics. Much of his work was not published during his lifetime. He would start a book, follow his thoughts into new topics, and leave the book unfinished. His friends and disciples, including James Mill and later James's son John Stuart Mill, edited and published large parts of his work. Bentham's main book, An Introduction to the Principles of Morals and Legislation, appeared in 1789. It set out his core principle: the measure of a good action or a good law is whether it produces the greatest happiness for the greatest number of people. This principle, called the 'principle of utility', became the foundation of utilitarianism. His influence on law and politics in Britain was enormous. He helped design prisons, wrote model constitutions for foreign governments, and shaped the reform movements of the early 19th century. He had unusual ideas. He designed a new kind of prison, the Panopticon, that has since become a famous image of surveillance. He argued against laws punishing homosexual acts, centuries before this became widely accepted. He left instructions for his body to be preserved after death and displayed in a wooden cabinet. His preserved body, called the 'auto-icon', is still on display at University College London, which he helped inspire. He died on 6 June 1832 in London, aged 84.

Georg Wilhelm Friedrich Hegel was a German philosopher. He was the last of the great system-builders in Western philosophy. He was born on 27 August 1770 in Stuttgart in southern Germany. His father was a civil servant. His mother taught him Latin before he started school but died when he was eleven. He had one sister, Christiane, who became very close to him. Hegel studied philosophy and theology at the University of Tübingen. There he became friends with two other young men who would become famous: the poet Friedrich Hölderlin and the philosopher Friedrich Schelling. The three were excited by the French Revolution, which broke out in 1789 when Hegel was nineteen. For years Hegel struggled to find an academic post. He worked as a private tutor in Switzerland, then in Frankfurt. In 1801 he became an unpaid lecturer at the University of Jena. There he wrote his first major book, the Phenomenology of Spirit. He famously finished the manuscript on the same day Napoleon's army arrived in the city in October 1806. The book was published in 1807. Hegel's career then bounced around. He worked as a newspaper editor in Bamberg, then as a high school principal in Nuremberg. He married Marie von Tucher in 1811. In 1816 he became a professor at Heidelberg, then at Berlin from 1818. By the 1820s he was the most famous philosopher in Germany. His lectures filled large halls. He died of illness, possibly cholera, on 14 November 1831 in Berlin, aged 61.

Mary Anning (1799-1847) was an English fossil collector and self-taught palaeontologist whose discoveries on the cliffs of Lyme Regis in Dorset transformed scientific understanding of the deep past. She was born into a poor Dissenting Protestant family that made part of its living by selling curiosities — fossils and shells — to summer visitors on the south coast of England. Her father Richard taught her and her brother Joseph how to find fossils in the crumbling cliffs of the Blue Lias. He died when she was eleven, leaving the family in debt. Mary took up fossil hunting as a trade to support her mother and brother. At about twelve, she and Joseph uncovered the first complete ichthyosaur skeleton known to science, a marine reptile that had been unknown before. Over the following decades Mary made many further extraordinary finds on her own: the first complete plesiosaur, the first British pterosaur outside the usual fossil record, important ichthyosaurs, and fossil fish with preserved ink sacs. She learned enough anatomy, geology, and classical languages to read the scientific papers written about her finds — and to correct them. The gentlemen geologists who bought her specimens and published descriptions of them sometimes credited her by name and sometimes did not. She died of breast cancer at forty-seven, still poor despite the scientific importance of what she had found.

Søren Kierkegaard (1813-1855) was a Danish philosopher, writer, and theologian. He was born in Copenhagen, the youngest of seven children, and spent almost his entire life in that city. His father was a wealthy merchant who was deeply religious and had a dark, guilt-ridden character that had a profound effect on Søren. Kierkegaard studied theology at the University of Copenhagen and fell deeply in love with a young woman named Regine Olsen, who he became engaged to and then, mysteriously, broke off the engagement with. This rupture haunted much of his later writing. He wrote an enormous amount in a short life: philosophical works, religious meditations, literary criticism, and a sustained public argument with the established Danish Lutheran church, which he believed had become comfortable and dishonest. He published many works under pen names, using different voices to explore different philosophical positions. He died at forty-two, and much of his work was not read widely outside Denmark until the twentieth century, when it became a major influence on existentialism, theology, and literary theory.

Friedrich Wilhelm Nietzsche was a German philosopher, cultural critic, and classicist. He was one of the most influential and most misunderstood thinkers of the 19th century. He was born on 15 October 1844 in Röcken, a small village in Prussia. His father was a Lutheran pastor who died when Friedrich was four. His grandfather and great-grandfather were also pastors. He grew up in a household of women: his mother, sister, and two aunts. He was a brilliant student. At 24, before he had even finished his doctorate, he was offered the chair of classical philology at the University of Basel in Switzerland. He held this post for ten years. His first major book, The Birth of Tragedy (1872), was a study of Greek culture that was considered wildly unorthodox by other classical scholars. His academic career stalled. Health problems forced him to retire at 35. He spent the next decade as a wandering philosopher, moving between Switzerland, Italy, and France. He wrote his major works in this period: Thus Spoke Zarathustra (1883-1885), Beyond Good and Evil (1886), and On the Genealogy of Morality (1887). He was almost unknown during his lifetime. His books sold poorly. In January 1889, in Turin, Italy, Nietzsche collapsed in the street. He had a complete mental breakdown. He spent the last eleven years of his life in the care of his mother and then his sister, unable to work or speak coherently. He died on 25 August 1900, aged 55. After his death, his sister Elisabeth edited his unpublished notes to push them in a nationalist and antisemitic direction. She aligned his legacy with the rising German right and later with the Nazis, despite the fact that Nietzsche himself had opposed antisemitism sharply.

Edmund Husserl was a German philosopher. He is the founder of phenomenology, one of the most important schools of twentieth-century thought. He was born on 8 April 1859 in Prossnitz, a town in Moravia, then part of the Austrian Empire (today Prostějov in the Czech Republic). His family was Jewish and middle class. They spoke German rather than Czech. His father ran a business. As a young man, he studied mathematics in Leipzig, Berlin, and Vienna. He earned a doctorate in mathematics in 1883. He could have had a career as a mathematician. But he became interested in deeper questions: what does it mean to know something? What are the foundations of mathematics itself? In 1884, he attended lectures by the philosopher Franz Brentano in Vienna and was so impressed that he switched to philosophy. He taught at the University of Halle from 1887. In 1891 he published Philosophy of Arithmetic. The mathematician Gottlob Frege criticised it sharply. The criticism pushed Husserl in new directions. In 1900-1901 he published Logical Investigations, the work that founded phenomenology. He taught at Göttingen from 1901 to 1916, then at Freiburg from 1916 to 1928. Many of the most important philosophers of the twentieth century were his students or were shaped by his work. In 1933 the Nazis came to power. Although Husserl had converted to Lutheran Protestantism in 1887, the Nazi racial laws still classified him as Jewish. He was banned from his own university library. He died on 27 April 1938 in Freiburg, aged 79.

John Dewey was an American philosopher, psychologist, and educator. He was one of the most important thinkers in the United States during the first half of the twentieth century. He was born on 20 October 1859 in Burlington, Vermont. He studied at the University of Vermont and then earned a PhD in philosophy at Johns Hopkins University in 1884. He taught first at the University of Michigan. In 1894 he moved to the new University of Chicago. In 1896 he founded the Laboratory School there. This was a small school where his new ideas about learning could be tested with real children. During his Chicago years he became close to Jane Addams at Hull House. The two thinkers shaped each other's ideas about democracy. After a dispute with the university, he resigned in 1904. He moved to Columbia University in New York, where he stayed until his retirement in 1930. At Columbia he wrote most of his major books. These included Democracy and Education (1916), Experience and Nature (1925), The Public and Its Problems (1927), and Art as Experience (1934). He travelled widely. He spent more than two years in China (1919-1921), where he gave famous lectures. He also visited Japan, Turkey, Mexico, and the Soviet Union. In 1937 he led a public inquiry into Stalin's charges against Leon Trotsky. He helped found the NAACP, a major American civil rights organisation. He wrote over forty books and around a thousand articles. He died on 1 June 1952, aged 92.

Volodymyr Ivanovych Vernadsky (in Russian: Vladimir Ivanovich Vernadsky) was a mineralogist, geochemist, and philosopher of science. He helped found three modern scientific disciplines: geochemistry, biogeochemistry, and radiogeology. He was born in 1863 in Saint Petersburg, the capital of the Russian Empire. His father, Ivan Vernadsky, came from a Ukrainian Cossack family and had been a professor of political economy in Kyiv before moving to Saint Petersburg. His mother was a Russian noblewoman. Vernadsky himself spent much of his childhood in Ukraine and considered himself Ukrainian by descent. He studied natural sciences at the University of Saint Petersburg, then did postgraduate work in mineralogy and crystallography in Italy and France, including study under leading European chemists. He returned to Russia and built one of the first geochemistry research programmes in the world. He read widely across science and philosophy and corresponded with major scientists across Europe, including Marie Curie. His political life was complicated. He was a liberal in tsarist Russia, a member of the constitutional democratic party, and briefly served in a 1917 provisional government. After the Bolshevik revolution, he chose to stay in Soviet science. In 1918 he played a leading role in founding the Ukrainian Academy of Sciences in Kyiv and became its first president. He published his most important work, The Biosphere, in 1926. He continued to lead Soviet scientific institutions until his death in Moscow in 1945, aged 81. His ideas about the biosphere and the noosphere have shaped modern environmental science.

Kitaro Nishida (1870–1945) was a Japanese philosopher and the founder of what is known as the Kyoto School — the first major tradition of Japanese philosophy to engage systematically with Western philosophy on equal terms while remaining rooted in East Asian thought. He spent most of his career at Kyoto University, where he developed a highly original philosophical system that brought together Zen Buddhist concepts of experience and nothingness with European traditions including Hegel, Kant, William James, and Husserl. His most famous work, An Inquiry into the Good (1911), is the founding text of modern Japanese philosophy and one of the most important philosophical works produced outside the Western tradition in the 20th century.

Ludwig Wittgenstein was an Austrian-British philosopher. Many consider him the greatest philosopher of the twentieth century. He was born on 26 April 1889 in Vienna, Austria, into one of the wealthiest families in the Austro-Hungarian Empire. His father was a powerful steel industrialist. His mother was a gifted musician. The family home was visited by composers like Brahms and Mahler. Three of his brothers died by suicide. Ludwig was first trained as an engineer in Berlin and Manchester, where he worked on aeroplane design. While studying, he became fascinated by the foundations of mathematics. In 1911 he travelled to Cambridge to work with the philosopher Bertrand Russell, who quickly recognised his genius. When the First World War broke out in 1914, Wittgenstein volunteered for the Austro-Hungarian army. He fought bravely and was decorated. While at the front and in a prisoner-of-war camp, he wrote his first book. That book, the Tractatus Logico-Philosophicus, was published in 1921. He believed it had solved all the major problems of philosophy. He gave away his vast inherited fortune and became a primary school teacher in remote Austrian villages. He also designed an austere house for his sister in Vienna. In 1929 he returned to Cambridge, having decided his earlier work contained serious mistakes. He spent the rest of his life developing a very different philosophy. He served as a hospital porter during the Second World War. He died of prostate cancer in Cambridge on 29 April 1951, aged 62. His last words to his housekeeper were: 'Tell them I've had a wonderful life.'

Antonio Gramsci (1891-1937) was an Italian Marxist philosopher, journalist, and political organiser. He was born in Sardinia, the island off the coast of Italy, into a poor family and grew up in significant poverty. He won a scholarship to the University of Turin, where he became involved in socialist politics. He was one of the founders of the Italian Communist Party in 1921 and became its leader. When Mussolini's fascist government came to power, Gramsci was arrested in 1926 and sentenced to twenty years in prison. The fascist prosecutor famously said at his trial: we must prevent this brain from functioning for twenty years. The effort failed. In prison, Gramsci wrote the Prison Notebooks, a collection of philosophical and political reflections covering more than three thousand pages, which he smuggled out in fragments and which were published after his death. He died in prison in 1937, aged 46, his health destroyed by years of harsh imprisonment. The Prison Notebooks were eventually published in the 1950s and became one of the most important works of political philosophy of the twentieth century.

Karl Popper was an Austrian-British philosopher of science and politics. He was born in 1902 in Vienna into a well-off, secular Jewish family that had converted to Lutheran Christianity. His parents loved books, and Popper grew up reading widely. As a young man he tried out many of the big intellectual movements of his time. He attended Marxist meetings, studied Freudian psychology, and worked briefly with the Adlerian school of psychology. He was struck by something that bothered him for the rest of his life. The followers of these movements seemed able to explain everything. Whatever happened in the world, Marxism, Freudianism, and Adlerian theory could fit it into their system. Popper began to wonder whether this was a strength or a weakness. He trained as a teacher and earned a doctorate in philosophy from the University of Vienna in 1928. In 1934 he published his first major book, Logic of Scientific Discovery, which made his name in philosophy of science. As Hitler rose to power, Popper, with his Jewish background, knew he had to leave Europe. In 1937 he took a teaching post in New Zealand. There, during the Second World War, he wrote The Open Society and Its Enemies, his great defence of liberal democracy. In 1946 he moved to the London School of Economics, where he stayed for the rest of his career. He was knighted in 1965. He wrote on philosophy of science, politics, the mind, and many other subjects. He died in 1994 in London at the age of 92.

Simone de Beauvoir (1908-1986) was a French philosopher, novelist, and feminist thinker. She was born in Paris and studied philosophy at the Sorbonne, where she came second in the national philosophy examination, beaten only by Jean-Paul Sartre, who became her lifelong intellectual partner and companion. She spent most of her adult life in Paris, writing philosophy, fiction, essays, and memoirs. Her most important philosophical work is The Second Sex, published in 1949, which is one of the founding texts of modern feminist philosophy. In it she argued that women are not born inferior but are made to be subordinate through social processes, cultural norms, and internalised beliefs. She was a committed political activist throughout her life, supporting Algerian independence, signing a petition supporting the right to abortion in France at a time when this was dangerous to do, and consistently speaking out on behalf of those without power. She lived by her philosophy: her own life, including her refusal to marry and her insistence on her independence as a thinker, was a demonstration of what she argued was possible.

Simone Weil (1909-1943) was a French philosopher, political activist, and mystic. She was born in Paris into a secular Jewish family of considerable intellectual distinction — her brother André became one of the greatest mathematicians of the twentieth century. She was educated at the École Normale Supérieure, where she studied alongside Simone de Beauvoir, graduating first in her class. She taught philosophy in several provincial schools but was also committed to a different kind of knowing: she worked for a year in a Renault car factory to experience industrial labour from the inside, went to the front during the Spanish Civil War, and worked as an agricultural labourer. She developed a profound mystical Christian spirituality while remaining outside the institutional church. She died in 1943 at the age of thirty-four in England, where she had gone to work for the Free French government in exile. The immediate cause of her death was tuberculosis, but she had refused to eat more than the ration allowed to people in occupied France. She left behind an extraordinary body of writing, much of it published posthumously, covering philosophy, theology, political theory, labour, affliction, and attention.

Gertrude Elizabeth Margaret Anscombe was a British philosopher. She was one of the most important philosophers writing in English in the 20th century. She was born on 18 March 1919 in Limerick, Ireland, where her father was stationed with the British Army. The family moved back to England soon after. She studied at Sydenham School in south London and then at St Hugh's College, Oxford, from 1937 to 1941. At Oxford she earned the highest degree in classics and philosophy. As a teenager, she read herself into Catholicism and converted, against her Anglican family's wishes. She remained a devout Catholic for the rest of her life. Her religion shaped her philosophy but did not limit it. She was also ferociously independent. As an Oxford undergraduate in 1939, she co-wrote a pamphlet arguing that Britain's entry into the Second World War was not justified. She kept this position even as most of her country and family disagreed. In 1942 she moved to Cambridge to study with Ludwig Wittgenstein, one of the most important philosophers of the 20th century. He became her teacher and friend. She was one of very few students he trusted. When he died in 1951, he named her as one of his three literary executors. She translated his major work, Philosophical Investigations, from German into English in 1953. This translation became the standard English version and is still read today. She married the philosopher Peter Geach in 1941. They had seven children. She held positions at Oxford for almost twenty years, then moved to Cambridge in 1970 to take the chair in philosophy once held by Wittgenstein. She was a striking figure: she wore trousers and men's clothes in an era when this was unusual, smoked cigars, and did not take her husband's name. She died in Cambridge on 5 January 2001, aged 81.

Iris Murdoch was an Irish-British philosopher and novelist. She is one of the most important moral philosophers of the 20th century. She was also one of the most successful British novelists of her time. She published 26 novels alongside her philosophical work. She was born in 1919 in Dublin, Ireland. Her family moved to London when she was very young. She studied classics and ancient philosophy at Oxford from 1938. The Second World War interrupted her studies. She worked for the British Treasury and then for the United Nations relief agency in displaced persons camps in Europe after the war. She saw the human consequences of the war directly. The experience shaped her later thinking about moral life. In 1948 she became a philosophy fellow at St Anne's College, Oxford. She taught there for many years. In 1956 she married John Bayley, a literary critic. The marriage lasted until her death and was unconventional in many ways. She had several intense relationships with both men and women throughout her life, often while married. Her first novel, Under the Net, came out in 1954. The book was successful. She continued writing novels alongside philosophy for the rest of her career. Her novels are full of complicated relationships, moral struggles, and sudden surprising events. Some readers love them. Some find them odd. Her philosophical books include The Sovereignty of Good, one of the most loved short books in 20th-century moral philosophy. In the early 1990s, she developed Alzheimer's disease. The illness slowly destroyed her ability to think and write. She died in 1999, aged 79. Her husband John Bayley wrote a famous memoir about her decline.

Mary Midgley was a British moral philosopher. She is one of the most original ethical thinkers of the 20th century. She is best known for her work on animals, evolution, science, and what makes humans morally serious. She wrote in plain language for general readers as well as academic ones. She was born in 1919 in London. She died in 2018, aged 99. She was active and writing books well into her 90s. She studied classics and philosophy at Oxford from 1938. She belonged to a remarkable generation of women philosophers there, including Iris Murdoch, Elizabeth Anscombe, and Philippa Foot. They all attended Oxford during the Second World War, when many male students had been called away. The reduced male presence created an unusual opportunity. Together these four women, sometimes called the Oxford Quartet, would later help reshape Anglo-American moral philosophy. After Oxford, Midgley married the philosopher Geoffrey Midgley in 1950. They moved to Newcastle in northern England, where Geoffrey took a teaching post. Mary raised three sons. She did not publish her first book until she was 59. Beast and Man came out in 1978. The book was a major statement on the relationship between human beings and other animals. It launched her late and remarkable writing career. From 1978 until her death 40 years later, she wrote book after book. She criticised what she saw as scientific over-reach by figures like Richard Dawkins. She wrote about ethics, religion, evolution, and the role of myth in scientific thinking. She became known as a sharp, clear, plain-spoken critic of bad ideas. She finished her last book just months before her death at 99.

Thomas Kuhn (1922-1996) was an American philosopher and historian of science. He studied physics at Harvard University and then became interested in the history of science: how scientific ideas had actually developed over time, rather than how scientists described the process. What he found surprised him. Science did not progress smoothly by adding new facts one by one. Instead, it went through long periods of normal work, interrupted by sudden, dramatic changes when the whole way of thinking about a subject was replaced. He described this in his book The Structure of Scientific Revolutions, published in 1962. It became one of the most widely read and discussed books in the history of science. Kuhn spent his career at universities including Harvard, Berkeley, Princeton, and the Massachusetts Institute of Technology. His ideas changed not only how people think about science but how they think about knowledge and change in many other fields too.

Michel Foucault was a French philosopher and historian. He was one of the most influential thinkers of the 20th century. He was born on 15 October 1926 in Poitiers, France, into a middle-class family. His father was a surgeon. He was expected to follow his father into medicine but chose philosophy instead. This caused serious tension at home. As a young man, he struggled with depression and attempted suicide at least once while a student. He studied at the prestigious École Normale Supérieure in Paris in the late 1940s, where his classmates included future major thinkers like Louis Althusser. After university, he worked in Sweden, Poland, Germany, and Tunisia before returning to France. He completed his doctorate in 1961. The thesis, published as Madness and Civilization, was the first of his major books. He held teaching positions at several French universities and in 1970 was elected to the Collège de France, the most prestigious academic institution in France. His yearly lectures there, now published in full, drew large audiences. He wrote a series of major books including The Order of Things (1966), Discipline and Punish (1975), and the three volumes of The History of Sexuality (1976-1984). He was openly gay in a time when this was still unusual for a public intellectual. He was politically active, involved in campaigns around prison reform, gay rights, and opposition to French immigration policy. He died of AIDS on 25 June 1984 in Paris, aged 57. He was one of the first major public figures to die of the disease.

Jacques Derrida was a French philosopher. He is best known for a way of reading texts called deconstruction. He was born on 15 July 1930 in El-Biar, a small town near Algiers, in what was then French Algeria. His family was Sephardic Jewish. They had lived in Algeria for many generations. French was the language spoken at home. In 1942, when Derrida was twelve, his life changed. The Vichy government in France had passed anti-Jewish laws. These laws reached Algeria too. On the first day of school that year, he was told he could not come back. He was sent away because he was Jewish. He did not attend school for a whole year. He later said this moment marked him for life. After the war, he returned to school. He read hungrily. He discovered Rousseau, Nietzsche, and Sartre. In 1949 he moved to Paris. After two tries, he got into the École Normale Supérieure in 1952. This is France's top university for philosophy. He met great teachers and students there. He also met his future wife, Marguerite. He published his first major books in 1967. There were three of them in one year: Of Grammatology, Writing and Difference, and Speech and Phenomena. These books made him famous, first in France and then around the world. He taught in Paris and at many universities in the United States. He wrote more than forty books in total. He died on 9 October 2004 of pancreatic cancer, aged 74.

Umberto Eco (1932-2016) was an Italian philosopher, semiotician, literary theorist, and novelist. He was born in Alessandria in northern Italy and studied philosophy at the University of Turin, writing a doctoral thesis on the medieval philosopher Thomas Aquinas. He then worked in Italian public broadcasting and as a journalist before becoming a professor of semiotics, the study of signs and meaning, at the University of Bologna, where he taught for the rest of his career. He was an enormously prolific scholar who published major academic works on medieval aesthetics, semiotics, the interpretation of texts, and the philosophy of language. In 1980, when he was nearly fifty, he published his first novel, The Name of the Rose, a detective story set in a fourteenth-century Italian monastery. It became an international bestseller translated into dozens of languages, and was followed by several more novels of similar ambition. Eco was unusual in being genuinely important both as an academic philosopher and as a popular novelist, and he saw these two activities as deeply connected: both were explorations of how human beings make and interpret meaning.

Kwame Gyekye (1939-2019) was a Ghanaian philosopher. He was born in Kumasi, Ghana, and studied philosophy at the University of Ghana and Harvard University. He taught philosophy at the University of Ghana for most of his career and became one of the most important African philosophers of the twentieth century. He worked on African philosophy, moral philosophy, political philosophy, and the philosophy of culture. His two most important books are An Essay on African Philosophical Thought (1987), which used Akan philosophical concepts to show that African traditional thought is a genuine philosophical tradition, and Tradition and Modernity (1997), which asked how African societies should think about the relationship between their traditional values and the modern world. He is particularly important for his idea of moderate communitarianism: a view of society that values community without removing the rights of individuals.

Valentin-Yves Mudimbe was a Congolese philosopher, novelist, and linguist. He was one of the most important African thinkers of the late 20th century. He was born in 1941 in Likasi, in what was then the Belgian Congo. His family was Catholic and he was educated in Catholic schools. As a young man, he entered a Benedictine monastery in Rwanda and considered becoming a monk. He left the monastery after a few years but remained interested in religion throughout his life. He studied Romance philology and philosophy, gaining a doctorate from the Catholic University of Louvain in Belgium in 1970. He returned to Congo and taught at universities there. In 1979, he left Congo for the United States, unable to continue working under the Mobutu dictatorship. He taught at Haverford College, then at Duke University, then at Stanford. He wrote in French and English. His academic writing was deep and difficult. He also wrote novels and poetry that many readers found more accessible. His most famous book is The Invention of Africa, published in 1988. It changed how scholars think about African studies. He followed it with The Idea of Africa in 1994 and many other books and essays. He retired from Duke University in 2014. He died on 21 April 2025, aged 83, in North Carolina. His death was widely mourned across the African intellectual community.

Bernard Mullu Narokobi was a Papua New Guinean philosopher, jurist, parliamentarian, and poet, best known for developing the concept of 'the Melanesian Way' as a guiding philosophy for newly independent Papua New Guinea. He is one of the most important political thinkers the Pacific has produced. He was born around 1943 in Wautogik village in the Prince Alexander Mountains of what is now East Sepik Province, Papua New Guinea. The exact date is not known; he was born during the Second World War. His people were the Arapesh. His father Anton (also known as Kukum) Narokobi had been taught by Catholic missionaries and worked as a catechist serving Boiken and Dagua villages. His mother was Maria Mokoi. Narokobi was the second eldest of five siblings. His younger brother Camillus is also a lawyer. Narokobi left home in 1960 to attend Kerevat School in New Britain, one of the first government-run schools educating Papua New Guineans at high levels. He went on to study law in Australia and became one of PNG's first generation of indigenous lawyers. He served on the Constitutional Planning Committee that drafted Papua New Guinea's constitution before independence in 1975. With John Momis and others, he drafted the National Goals and Directive Principles and Basic Social Obligations that form the preamble to the constitution. He published Foundations for Nationhood in 1975 and his most famous work, The Melanesian Way, in 1980. He served as a Member of Parliament for Wewak Open from 1987 to 1997, three terms, and held senior positions including Minister for Justice. He was a strong supporter of West Papuan independence. His wife Regina died of breast cancer in 2007. He was serving as Papua New Guinea's High Commissioner to New Zealand at the time of his own death in March 2010. He was about 67.

María Lugones (1944-2020) was an Argentine-American philosopher. She was born in Buenos Aires, Argentina, and moved to the United States as a young woman, where she completed her doctorate in philosophy and spent her career teaching at Binghamton University in New York. She was a feminist philosopher, a Latina scholar, and a community activist who worked extensively with migrant and indigenous communities in the American Southwest. She is best known for two connected contributions to philosophy. The first is her concept of world-travelling: the practice of genuinely entering another person's world to see reality as they see it, which she proposed as the foundation of a loving and just way of relating across difference. The second is her concept of the coloniality of gender: the argument that the gender system as it now exists across most of the world was imposed through colonialism, and that many indigenous and non-Western communities had very different and often more complex and flexible understandings of gender before colonial contact. She died in 2020, widely recognised as one of the most important feminist philosophers of the late twentieth and early twenty-first centuries.

Mogobe Ramose (born 1944) is a South African philosopher. He was born in the North West Province of South Africa and grew up under the apartheid system, which enforced racial segregation and denied Black South Africans basic rights. He studied philosophy in South Africa, Belgium, and the Netherlands, and has taught at universities in South Africa and across Africa. He is best known for his philosophical work on ubuntu, an African philosophical concept that he has developed into a full philosophical system, and for his arguments that African philosophy is a genuine and legitimate philosophical tradition. He has also written about the philosophy of law, the concept of sovereignty, and the moral case for reparations for colonialism and apartheid.

Peter Singer is an Australian philosopher. He is one of the most widely read living philosophers and one of the most controversial. He was born on 6 July 1946 in Melbourne, Australia. His parents were Austrian Jews who had escaped Vienna in 1938 after the Nazi annexation of Austria. Three of his grandparents were killed in the Holocaust. This family history shaped his lifelong concern with preventable suffering. He studied law, history, and philosophy at the University of Melbourne, then went to Oxford for his graduate work. It was at Oxford in the early 1970s that he began serious work on the ethics of how humans treat animals. His 1975 book Animal Liberation became a founding text of the modern animal rights movement. It has sold over half a million copies and has been translated into many languages. He has taught at La Trobe University in Australia, Monash University, New York University, and since 1999 at Princeton University in the United States, where he holds the Ira W. DeCamp Professorship of Bioethics. His appointment at Princeton caused controversy. Disability rights activists protested some of his views on severely disabled newborns. He has written or edited more than forty books and hundreds of articles. His most influential are Animal Liberation (1975), Practical Ethics (1979), The Life You Can Save (2009), and The Most Good You Can Do (2015). He co-founded The Life You Can Save organisation, which encourages effective giving to reduce global poverty. He is one of the founding figures of the effective altruism movement. He is still active in his late seventies.

Martha Craven Nussbaum is an American philosopher. She is one of the most influential and widely read philosophers of the past fifty years. She was born on 6 May 1947 in New York City. Her family was wealthy and Protestant, with roots in the American South. She later said her comfortable childhood made her acutely aware of inequality and the contingencies of privilege. She converted to Judaism in 1969. She studied classics at New York University and earned her PhD from Harvard in 1975. Her doctoral work was on ancient Greek philosophy, especially Aristotle. Classical scholarship has remained central to her work throughout her career. She has taught at Harvard, Brown, and, since 1995, at the University of Chicago, where she holds a joint appointment in the Law School and the Philosophy Department. She has written more than thirty books and hundreds of articles. Her major works include The Fragility of Goodness (1986) on ancient Greek ethics, Women and Human Development (2000) on her capabilities approach, Upheavals of Thought (2001) on emotions, and Political Emotions (2013) on how societies cultivate good feelings. She has worked with the economist Amartya Sen on the capabilities approach to human development, which has influenced the United Nations Human Development Index. She has been a public intellectual throughout her career. She has written on women's rights, LGBT equality, disability, animal welfare, and the role of emotions in law and politics. She has received many honours, including the Kyoto Prize and the Berggruen Prize. She is still active, writing and teaching in 2026.

Cornel West is an American philosopher, theologian, and public intellectual. He was born in 1953 in Tulsa, Oklahoma, and grew up in a Black Baptist family in Sacramento, California. His father was a civilian air force administrator. His mother was a teacher and later a school principal. The Black Baptist church shaped him deeply from childhood. He has often said that his thinking grew out of three traditions: the Black church, the Black freedom struggle, and the love of music, especially jazz and the blues. West entered Harvard at sixteen and graduated in three years. He went on to do an MA and PhD in philosophy at Princeton, finishing in 1980. His teachers there included the philosopher Richard Rorty, who shaped his interest in American pragmatism. After Princeton he taught at Union Theological Seminary in New York, then Yale, then Princeton, then Harvard, then Princeton again, then Harvard again, and is now back at Union Theological Seminary as the Dietrich Bonhoeffer Chair. He has written more than twenty books. The best known is Race Matters (1993), a bestseller about race, democracy, and inequality in America. Democracy Matters (2004) followed. He has been a constant public presence on television, radio, and stages around the world, mixing philosophy with political activism. He has been arrested in protests for civil rights and against war. In 2024 he ran for president of the United States as an independent candidate. He continues to teach, write, and speak today.

Judith Butler is an American philosopher and gender theorist. They are one of the most influential thinkers in the humanities in recent decades. They were born on 24 February 1956 in Cleveland, Ohio, into a Jewish family of Hungarian and Russian descent. Their parents were active in the synagogue. Several of their mother's relatives had been killed in the Holocaust. This family history of persecution shaped Butler's later concerns with violence, grief, and vulnerable lives. As a teenager, Butler started studying philosophy in a special class at their synagogue. This was in part a punishment for disruptive behaviour. The class, taught by a rabbi, introduced them to Jewish ethics and philosophical questions. They later studied philosophy at Bennington College and Yale, where they completed a PhD in 1984 on Hegel's influence on 20th-century French thought. They have taught at several universities, including Johns Hopkins, and since 1993 at the University of California, Berkeley. Their 1990 book Gender Trouble changed how scholars think about gender. It made Butler famous and controversial. They have since written many books, including Bodies That Matter (1993), Precarious Life (2004), Frames of War (2009), and Who's Afraid of Gender? (2024). Butler is also known for their public writing on politics, including on Israel and Palestine, the war on terror, and recent global movements against queer and trans people. They identify as non-binary and use they/them pronouns. They are still active, writing and teaching in 2026.