Portal:Philosophy

Shen Kuo (Chinese: 沈括; 1031–1095) or Shen Gua, courtesy name Cunzhong (存中) and pseudonym Mengqi (now usually given as Mengxi) Weng (夢溪翁), was a Chinese polymath, scientist, and statesman of the Song dynasty (960–1279). Shen was a master in many fields of study including mathematics, optics, and horology. In his career as a civil servant, he became a finance minister, governmental state inspector, head official for the Bureau of Astronomy in the Song court, Assistant Minister of Imperial Hospitality, and also served as an academic chancellor. At court his political allegiance was to the Reformist faction known as the New Policies Group, headed by Chancellor Wang Anshi (1021–1085).

In his Dream Pool Essays or Dream Torrent Essays (夢溪筆談; Mengxi Bitan) of 1088, Shen was the first to describe the magnetic needle compass, which would be used for navigation (first described in Europe by Alexander Neckam in 1187). Shen discovered the concept of true north in terms of magnetic declination towards the north pole, with experimentation of suspended magnetic needles and "the improved meridian determined by Shen's [astronomical] measurement of the distance between the pole star and true north". This was the decisive step in human history to make compasses more useful for navigation, and may have been a concept unknown in Europe for another four hundred years (evidence of German sundials made circa 1450 show markings similar to Chinese geomancers' compasses in regard to declination). (Full article...)

Alfred Russel Wallace OM FRS (8 January 1823 – 7 November 1913) was an English naturalist, explorer, geographer, anthropologist, biologist and illustrator. He independently conceived the theory of evolution through natural selection; his 1858 paper on the subject was published that year alongside extracts from Charles Darwin's earlier writings on the topic. It spurred Darwin to set aside the "big species book" he was drafting and quickly write an abstract of it, which was published in 1859 as On the Origin of Species.

Wallace did extensive fieldwork, starting in the Amazon River basin. He then did fieldwork in the Malay Archipelago, where he identified the faunal divide now termed the Wallace Line, which separates the Indonesian archipelago into two distinct parts: a western portion in which the animals are largely of Asian origin, and an eastern portion where the fauna reflect Australasia. He was considered the 19th century's leading expert on the geographical distribution of animal species, and is sometimes called the "father of biogeography", or more specifically of zoogeography. (Full article...)

Eric Alfred Havelock (/ˈhævlɒk/; 3 June 1903 – 4 April 1988) was a British classicist who spent most of his life in Canada and the United States. He was a professor at the University of Toronto and was active in the Canadian socialist movement during the 1930s. In the 1960s and 1970s, he served as chair of the classics departments at both Harvard and Yale. Although he was trained in the turn-of-the-20th-century Oxbridge tradition of classical studies, which saw Greek intellectual history as an unbroken chain of related ideas, Havelock broke radically with his own teachers and proposed an entirely new model for understanding the classical world, based on a sharp division between literature of the 6th and 5th centuries BC on the one hand, and that of the 4th on the other.

Much of Havelock's work was devoted to addressing a single thesis: that all of Western thought is informed by a profound shift in the kinds of ideas available to the human mind at the point that Greek philosophy converted from an oral to a literate form. The idea has been controversial in classical studies, and has been rejected outright both by many of Havelock's contemporaries and modern classicists. Havelock and his ideas have nonetheless had far-reaching influence, both in classical studies and other academic areas. He and Walter J. Ong (who was himself strongly influenced by Havelock) essentially founded the field that studies transitions from orality to literacy, and Havelock has been one of the most frequently cited theorists in that field; as an account of communication, his work profoundly affected the media theories of Harold Innis and Marshall McLuhan. Havelock's influence has spread beyond the study of the classical world to that of analogous transitions in other times and places. (Full article...)

In political philosophy, a throffer is a proposal (also called an intervention) that mixes an offer with a threat which will be carried out if the offer is not accepted. The term was first used in print by political philosopher Hillel Steiner; while other writers followed, it has not been universally adopted and it is sometimes considered synonymous with carrot and stick. Though the threatening aspect of a throffer need not be obvious, or even articulated at all, an overt example is: "Kill this man and receive £100; fail to kill him and I'll kill you."

Steiner differentiated offers, threats and throffers based on the preferability of compliance and noncompliance for the subject when compared to the normal course of events that would have come about were no intervention made. Steiner's account was criticised by philosopher Robert Stevens, who instead suggested that what was important in differentiating the kinds of intervention was whether performing or not performing the requested action was more or less preferable than it would have been were no intervention made. Throffers form part of the wider moral and political considerations of coercion, and form part of the question of the possibility of coercive offers. Contrary to received wisdom that only threats can be coercive, throffers lacking explicit threats have been cited as an example of coercive offers, while some writers argue that offers, threats and throffers may all be coercive if certain conditions are met. For others, by contrast, if a throffer is coercive, it is explicitly the threat aspect that makes it so, and not all throffers can be considered coercive. (Full article...)

Evolutionary thought, the recognition that species change over time and the perceived understanding of how such processes work, has roots in antiquity—in the ideas of the ancient Greeks, Romans, Chinese, Church Fathers as well as in medieval Islamic science. With the beginnings of modern biological taxonomy in the late 17th century, two opposed ideas influenced Western biological thinking: essentialism, the belief that every species has essential characteristics that are unalterable, a concept which had developed from medieval Aristotelian metaphysics, and that fit well with natural theology; and the development of the new anti-Aristotelian approach to modern science: as the Enlightenment progressed, evolutionary cosmology and the mechanical philosophy spread from the physical sciences to natural history. Naturalists began to focus on the variability of species; the emergence of palaeontology with the concept of extinction further undermined static views of nature. In the early 19th century prior to Darwinism, Jean-Baptiste Lamarck (1744–1829) proposed his theory of the transmutation of species, the first fully formed theory of evolution.

In 1858 Charles Darwin and Alfred Russel Wallace published a new evolutionary theory, explained in detail in Darwin's On the Origin of Species (1859). Darwin's theory, originally called descent with modification is known contemporarily as Darwinism or Darwinian theory. Unlike Lamarck, Darwin proposed common descent and a branching tree of life, meaning that two very different species could share a common ancestor. Darwin based his theory on the idea of natural selection: it synthesized a broad range of evidence from animal husbandry, biogeography, geology, morphology, and embryology. Debate over Darwin's work led to the rapid acceptance of the general concept of evolution, but the specific mechanism he proposed, natural selection, was not widely accepted until it was revived by developments in biology that occurred during the 1920s through the 1940s. Before that time most biologists regarded other factors as responsible for evolution. Alternatives to natural selection suggested during "the eclipse of Darwinism" (c. 1880 to 1920) included inheritance of acquired characteristics (neo-Lamarckism), an innate drive for change (orthogenesis), and sudden large mutations (saltationism). Mendelian genetics, a series of 19th-century experiments with pea plant variations rediscovered in 1900, was integrated with natural selection by Ronald Fisher, J. B. S. Haldane, and Sewall Wright during the 1910s to 1930s, and resulted in the founding of the new discipline of population genetics. During the 1930s and 1940s population genetics became integrated with other biological fields, resulting in a widely applicable theory of evolution that encompassed much of biology—the modern synthesis. (Full article...)

William Edward Burghardt Du Bois (/duːˈbɔɪs/ doo-BOYSS; February 23, 1868 – August 27, 1963) was an American sociologist, socialist, historian, and Pan-Africanist civil rights activist.

Born in Great Barrington, Massachusetts, Du Bois grew up in a relatively tolerant and integrated community. After completing graduate work at the Friedrich Wilhelm University in Berlin and Harvard University, where he was its first African American to earn a doctorate, Du Bois rose to national prominence as a leader of the Niagara Movement, a group of black civil rights activists seeking equal rights. Du Bois and his supporters opposed the Atlanta Compromise. Instead, Du Bois insisted on full civil rights and increased political representation, which he believed would be brought about by the African-American intellectual elite. He referred to this group as the talented tenth, a concept under the umbrella of racial uplift, and believed that African Americans needed the chances for advanced education to develop its leadership. (Full article...)

Maria: or, The Wrongs of Woman is Mary Wollstonecraft's unfinished novelistic sequel to her revolutionary political treatise A Vindication of the Rights of Woman (1792). The Wrongs of Woman was published posthumously in 1798 by her husband, William Godwin, and is often considered her most radical feminist work.

Wollstonecraft's philosophical and gothic novel revolves around the story of a woman imprisoned in an insane asylum by her husband. It focuses on the societal rather than the individual "wrongs of woman" and criticizes what Wollstonecraft viewed as the patriarchal institution of marriage in eighteenth-century Britain and the legal system that protected it. However, the heroine's inability to relinquish her romantic fantasies also reveals women's collusion in their oppression through false and damaging sentimentalism. The novel pioneered the celebration of female sexuality and cross-class identification between women. Such themes, coupled with the publication of Godwin's scandalous Memoirs of Wollstonecraft's life, made the novel unpopular at the time it was published. (Full article...)

Joseph Priestley FRS (/ˈpriːstli/; 24 March 1733 – 6 February 1804) was an English chemist, Unitarian, natural philosopher, separatist theologian, grammarian, multi-subject educator and classical liberal political theorist. He published over 150 works, and conducted experiments in several areas of science.

Priestley is credited with his independent discovery of oxygen by the thermal decomposition of mercuric oxide, having isolated it in 1774. During his lifetime, Priestley's considerable scientific reputation rested on his invention of carbonated water, his writings on electricity, and his discovery of several "airs" (gases), the most famous being what Priestley dubbed "dephlogisticated air" (oxygen). Priestley's determination to defend phlogiston theory and to reject what would become the chemical revolution eventually left him isolated within the scientific community. (Full article...)

The Fountainhead is a 1943 novel by Russian-American author Ayn Rand, her first major literary success. The novel's protagonist, Howard Roark, is an intransigent young architect who battles against conventional standards and refuses to compromise with an architectural establishment unwilling to accept innovation. Roark embodies what Rand believed to be the ideal man, and his struggle reflects Rand's belief that individualism is superior to collectivism.

Roark is opposed by what he calls "second-handers", who value conformity over independence and integrity. These include Roark's former classmate, Peter Keating, who succeeds by following popular styles but turns to Roark for help with design problems. Ellsworth Toohey, a socialist architecture critic who uses his influence to promote his political and social agenda, tries to destroy Roark's career. Tabloid newspaper publisher Gail Wynand seeks to shape popular opinion; he befriends Roark, then betrays him when public opinion turns in a direction he cannot control. The novel's most controversial character is Roark's lover, Dominique Francon. She believes that non-conformity has no chance of winning, so she alternates between helping Roark and working to undermine him. (Full article...)

Archimedes of Syracuse (/ˌɑːrkɪˈmiːdiːz/ AR-kim-EE-deez; c. 287 – c. 212 BC) was an Ancient Greek mathematician, physicist, engineer, astronomer, and inventor from the ancient city of Syracuse in Sicily. Although few details of his life are known, he is regarded as one of the leading scientists in classical antiquity. Regarded as the greatest mathematician of ancient history, and one of the greatest of all time, Archimedes anticipated modern calculus and analysis by applying the concept of the infinitely small and the method of exhaustion to derive and rigorously prove a range of geometrical theorems. These include the area of a circle, the surface area and volume of a sphere, the area of an ellipse, the area under a parabola, the volume of a segment of a paraboloid of revolution, the volume of a segment of a hyperboloid of revolution, and the area of a spiral.

Archimedes' other mathematical achievements include deriving an approximation of pi (π), defining and investigating the Archimedean spiral, and devising a system using exponentiation for expressing very large numbers. He was also one of the first to apply mathematics to physical phenomena, working on statics and hydrostatics. Archimedes' achievements in this area include a proof of the law of the lever, the widespread use of the concept of center of gravity, and the enunciation of the law of buoyancy known as Archimedes' principle. He is also credited with designing innovative machines, such as his screw pump, compound pulleys, and defensive war machines to protect his native Syracuse from invasion. (Full article...)

The problem of religious language considers whether it is possible to talk about God meaningfully if the traditional conceptions of God as being incorporeal, infinite, and timeless, are accepted. Because these traditional conceptions of God make it difficult to describe God, religious language has the potential to be meaningless. Theories of religious language either attempt to demonstrate that such language is meaningless, or attempt to show how religious language can still be meaningful.

One prevalent position in Islamic philosophy holds that religious language is meaningful and positive, demonstrating the shared attributes of God and His creatures. According to this view, the semantic commonality of attributes between God and humans indicates ontological commonalities between them. This is because factual concepts refer to and are abstracted from realities in the external world. (Full article...)

Zhang Heng (Chinese: 張衡; AD 78–139), formerly romanized Chang Heng, was a Chinese polymathic scientist and statesman who lived during the Eastern Han dynasty. Educated in the capital cities of Luoyang and Chang'an, he achieved success as an astronomer, mathematician, seismologist, hydraulic engineer, inventor, geographer, cartographer, ethnographer, artist, poet, philosopher, politician, and literary scholar.

Zhang Heng began his career as a minor civil servant in Nanyang. Eventually, he became Chief Astronomer, Prefect of the Majors for Official Carriages, and then Palace Attendant at the imperial court. His uncompromising stance on historical and calendrical issues led to his becoming a controversial figure, preventing him from rising to the status of Grand Historian. His political rivalry with the palace eunuchs during the reign of Emperor Shun (r. 125–144) led to his decision to retire from the central court to serve as an administrator of Hejian Kingdom in present-day Hebei. Zhang returned home to Nanyang for a short time, before being recalled to serve in the capital once more in 138. He died there a year later, in 139. (Full article...)

The lifetime of British writer, philosopher, and feminist Mary Wollstonecraft (1759–1797) encompassed most of the second half of the eighteenth century, a time of great political and social upheaval throughout Europe and America: political reform movements in Britain gained strength, the American colonists successfully rebelled, and the French Revolution erupted. Wollstonecraft experienced only the headiest of these days, not living to see the end of the democratic revolution when Napoleon crowned himself emperor. Although Britain was still revelling in its mid-century imperial conquests and its triumph in the Seven Years' War, it was the French revolution that defined Wollstonecraft's generation. As poet Robert Southey later wrote: "few persons but those who have lived in it can conceive or comprehend what the memory of the French Revolution was, nor what a visionary world seemed to open upon those who were just entering it. Old things seemed passing away, and nothing was dreamt of but the regeneration of the human race."

Part of what made reform possible in Britain in the second half of the eighteenth century was the dramatic increase in publishing; books, periodicals, and pamphlets became much more widely available than they had been just a few decades earlier. This increase in available printed material helped facilitate the rise of the British middle class. Reacting against what they viewed as aristocratic decadence, the new professional middle classes (made prosperous through British manufacturing and trade), offered their own ethical code: reason, meritocracy, self-reliance, religious toleration, free inquiry, free enterprise, and hard work. They set these values against what they perceived as the superstition and unreason of the poor and the prejudices, censorship, and self-indulgence of the rich. They also helped establish what has come to be called the "cult of domesticity", which solidified gender roles for men and women. This new vision of society rested on the writings of Scottish Enlightenment philosophers such as Adam Smith, who had developed a theory of social progress founded on sympathy and sensibility. A partial critique of the rationalist Enlightenment, these theories promoted a combination of reason and feeling that enabled women to enter the public sphere because of their keen moral sense. Wollstonecraft's writings stand at the nexus of all of these changes. Her educational works, such as her children's book Original Stories from Real Life (1788), helped inculcate middle-class values, and her two Vindications, A Vindication of the Rights of Men (1790) and A Vindication of the Rights of Woman (1792), argue for the value of an educated, rational populace, specifically one that includes women. In her two novels, Mary: A Fiction and Maria: or, The Wrongs of Woman, she explores the ramifications of sensibility for women. (Full article...)

Hilary Whitehall Putnam (/ˈpʌtnəm/; July 31, 1926 – March 13, 2016) was an American philosopher, mathematician, computer scientist, and figure in analytic philosophy in the second half of the 20th century. He contributed to the studies of philosophy of mind, philosophy of language, philosophy of mathematics, and philosophy of science. Outside philosophy, Putnam contributed to mathematics and computer science. Together with Martin Davis he developed the Davis–Putnam algorithm for the Boolean satisfiability problem and he helped demonstrate the unsolvability of Hilbert's tenth problem.

Putnam applied equal scrutiny to his own philosophical positions as to those of others, subjecting each position to rigorous analysis until he exposed its flaws. As a result, he acquired a reputation for frequently changing his positions. In philosophy of mind, Putnam argued against the type-identity of mental and physical states based on his hypothesis of the multiple realizability of the mental, and for the concept of functionalism, an influential theory regarding the mind–body problem. In philosophy of language, along with Saul Kripke and others, he developed the causal theory of reference, and formulated an original theory of meaning, introducing the notion of semantic externalism based on a thought experiment called Twin Earth. (Full article...)

Candide, ou l'Optimisme (/kɒnˈdiːd/ kon-DEED, French: [kɑ̃did] ^ⓘ) is a French satire written by Voltaire, a philosopher of the Age of Enlightenment, first published in 1759. The novella has been widely translated, with English versions titled Candide: or, All for the Best (1759); Candide: or, The Optimist (1762); and Candide: Optimism (1947). It begins with a young man, Candide, who is living a sheltered life in an Edenic paradise and being indoctrinated with Leibnizian optimism by his mentor, Professor Pangloss. The work describes the abrupt cessation of this lifestyle, followed by Candide's slow and painful disillusionment as he witnesses and experiences great hardships in the world. Voltaire concludes Candide with, if not rejecting Leibnizian optimism outright, advocating a deeply practical precept, "we must cultivate our garden", in lieu of the Leibnizian mantra of Pangloss, "all is for the best" in the "best of all possible worlds".

Candide is characterized by its tone as well as by its erratic, fantastical, and fast-moving plot. A picaresque novel with a story similar to that of a more serious coming-of-age narrative (bildungsroman), it parodies many adventure and romance clichés, the struggles of which are caricatured in a tone that is bitter and matter-of-fact. Still, the events discussed are often based on historical happenings, such as the Seven Years' War and the 1755 Lisbon earthquake. As philosophers of Voltaire's day contended with the problem of evil, so does Candide in this short theological novel, albeit more directly and humorously. Voltaire ridicules religion, theologians, governments, armies, philosophies, and philosophers. Through Candide, he assaults Leibniz and his optimism. (Full article...)

The Lviv pogroms were the consecutive pogroms and massacres of Jews in June and July 1941 in the city of Lwów in German-occupied Eastern Poland/Western Ukraine (now Lviv, Ukraine). The massacres were perpetrated by Ukrainian nationalists (specifically, the OUN), German death squads (Einsatzgruppen), and urban population from 30 June to 2 July, and from 25 to 29 July, during the German invasion of the Soviet Union. Thousands of Jews were killed both in the pogroms and in the Einsatzgruppen killings.

Ukrainian militia as well as Ukrainian residents and to a lower degree Poles targeted Jews in the first pogrom, which was triggered by the discovery of thousands of bodies in three Lviv prisons of victims of the Soviet NKVD prisoner massacres, which were widely blamed on "Jewish Bolsheviks". The subsequent massacres were directed by the Germans in the context of the Holocaust in Eastern Europe. The pogroms have been widely debated in the historiography, including the extent to which Ukrainian nationalists played a central or complicit role. (Full article...)

According to different scholars, the history of anarchism either goes back to ancient and prehistoric ideologies and social structures, or begins in the 19th century as a formal movement. As scholars and anarchist philosophers have held a range of views on what anarchism means, it is difficult to outline its history unambiguously. Some feel anarchism is a distinct, well-defined movement stemming from 19th-century class conflict, while others identify anarchist traits long before the earliest civilisations existed.

Prehistoric society existed without formal hierarchies, which some anthropologists have described as similar to anarchism. The first traces of formal anarchist thought can be found in ancient Greece and China, where numerous philosophers questioned the necessity of the state and declared the moral right of the individual to live free from coercion. During the Middle Ages, some religious sects espoused libertarian thought, and the Age of Enlightenment, and the attendant rise of rationalism and science, signalled the birth of the modern anarchist movement. (Full article...)

Joseph Hunter Guthrie SJ (January 8, 1901 – November 11, 1974) was an American academic philosopher, writer, Jesuit, and Catholic priest. Born in New York City, he entered the Society of Jesus in 1917, and began his studies at Woodstock College. Following his undergraduate and graduate work there, he taught at Jesuit institutions in the Philippines until 1927. Following his ordination in 1930, he received doctorates in theology and philosophy from the Pontifical Gregorian University and the University of Paris, respectively. He then returned to the United States, where he became a professor of philosophy at Woodstock College and Fordham University.

In 1943, Guthrie became the chairman of graduate philosophy at Georgetown University and dean of the Graduate School of Arts and Sciences. In this role, he admitted the first women to the school on equal terms as men. For twenty years, he promoted the belief that intellectuals must play a central role in combatting the ideologies that led to World War II. To that end, he was a member of the drafting committee of the UNESCO charter, was a co-founder of an American academy of Catholic intellectuals, and travelled the world with the U.S. State Department, for which he received honors from several countries and organizations. (Full article...)

Georg Philipp Friedrich Freiherr von Hardenberg (2 May 1772 – 25 March 1801), pen name Novalis (/noʊˈvɑːlɪs/; German: [noˈvaːlɪs]), was a German aristocrat and polymath, who was a poet, novelist, philosopher and mystic. He is regarded as an influential figure of Jena Romanticism.

Novalis was born into a minor aristocratic family in Electoral Saxony. He was the second of eleven children; his early household observed a strict Pietist faith. He studied law at the University of Jena, the University of Leipzig, and the University of Wittenberg. While at Jena, he published his first poem and befriended the playwright and fellow poet Friedrich Schiller. In Leipzig, he then met Friedrich Schlegel, becoming lifelong friends. Novalis completed his law degree in 1794 at the age of 22. He then worked as a legal assistant in Tennstedt immediately after graduating. There, he met Sophie von Kühn. The following year Novalis and Sophie became secretly engaged. Sophie became severely ill soon after the engagement and died just after her 15th birthday. Sophie's early death had a life-long impact on Novalis and his writing. (Full article...)

"In Praise of Polytheism (On Monomythical and Polymythical Thinking)" (German: Lob des Polytheismus. Über Monomythie und Polymythie) is an essay by the German philosopher Odo Marquard, which was held as a lecture at Technische Universität Berlin in 1978. It was first published in 1979 in an anthology, and was published again in 1981 in Marquard's book Farewell to Matters of Principle (German: Abschied vom Prinzipiellen).

The essay posits that monotheism and the Enlightenment are based on "monomythical thinking", meaning that they only allow one story. It also posits that the separation of powers and the individual have their origin in polytheism, and argues that people should embrace what Marquard calls "enlightened polymythical thinking"—the recognition of several stories in the modern world. Marquard was a professor of philosophy and proponent of scepticism and pluralism. He belonged to a part of German philosophy that viewed the issues of modernity through political theology, which associates modern political concepts with theological concepts. Some of the points in the essay have precursors in the writings of Max Weber, Erik Peterson and Friedrich Nietzsche. (Full article...)

Natural Theology or Evidences of the Existence and Attributes of the Deity is an 1802 work of Christian apologetics and philosophy of religion by the English clergyman William Paley (1743–1805). The book expounds his arguments from natural theology, making a teleological argument for the existence of God, notably beginning with the watchmaker analogy.

The book was written in the context of the natural theology tradition. In earlier centuries, theologians such as John Ray and William Derham, as well as philosophers of classical times such as Cicero, argued for the existence and goodness of God from the general well-being of living things and the physical world. (Full article...)

Karma is the basic principle within an overarching psycho-cosmology in Jainism. Human moral actions form the basis of the transmigration of the soul (jīva). The soul is constrained to a cycle of rebirth, trapped within the temporal world (saṃsāra), until it finally achieves liberation (mokṣa). Liberation is achieved by following a path of purification.

Jains believe that karma is a physical substance that is everywhere in the universe. Karma particles are attracted to the soul by the actions of that soul. Karma particles are attracted when we do, think, or say things, when we kill something, when we lie, when we steal and so on. Karma not only encompasses the causality of transmigration, but is also conceived of as an extremely subtle matter, which infiltrates the soul—obscuring its natural, transparent and pure qualities. Karma is thought of as a kind of pollution, that taints the soul with various colours (leśyā). Based on its karma, a soul undergoes transmigration and reincarnates in various states of existence—like heavens or hells, or as humans or animals. (Full article...)

Alan Mathison Turing OBE FRS (/ˈtjʊərɪŋ/; 23 June 1912 – 7 June 1954) was an English mathematician, computer scientist, logician, cryptanalyst, philosopher and theoretical biologist. He was highly influential in the development of theoretical computer science, providing a formalisation of the concepts of algorithm and computation with the Turing machine, which can be considered a model of a general-purpose computer. Turing is widely considered to be the father of theoretical computer science.

Born in London, Turing was raised in southern England. He graduated from King's College, Cambridge, and in 1938, earned a doctorate degree from Princeton University. During World War II, Turing worked for the Government Code and Cypher School at Bletchley Park, Britain's codebreaking centre that produced Ultra intelligence. He led Hut 8, the section responsible for German naval cryptanalysis. Turing devised techniques for speeding the breaking of German ciphers, including improvements to the pre-war Polish bomba method, an electromechanical machine that could find settings for the Enigma machine. He played a crucial role in cracking intercepted messages that enabled the Allies to defeat the Axis powers in many crucial engagements, including the Battle of the Atlantic. (Full article...)

The Proof of the Truthful (Arabic: برهان الصديقين, romanized: burhān al-ṣiddīqīn, also translated Demonstration of the Truthful or Proof of the Veracious, among others) is a formal argument for proving the existence of God introduced by the Islamic philosopher Avicenna (also known as Ibn Sina, 980–1037). Avicenna argued that there must be a "necessary existent" (Arabic: واجب الوجود, romanized: wājib al-wujūd), an entity that cannot not exist. The argument says that the entire set of contingent things must have a cause that is not contingent because otherwise it would be included in the set. Furthermore, through a series of arguments, he derived that the necessary existent must have attributes that he identified with God in Islam, including unity, simplicity, immateriality, intellect, power, generosity, and goodness.

Historian of philosophy Peter Adamson called the argument one of the most influential medieval arguments for God's existence, and Avicenna's biggest contribution to the history of philosophy. It was enthusiastically received and repeated (sometimes with modification) by later philosophers, including generations of Muslim philosophers, Western Christian philosophers such as Thomas Aquinas and Duns Scotus, and Jewish philosophers such as Maimonides. (Full article...)

Martin Luther King Jr. (born Michael King Jr.; January 15, 1929 – April 4, 1968) was an American Baptist minister, activist, and political philosopher who was one of the most prominent leaders in the civil rights movement from 1955 until his assassination in 1968. King advanced civil rights for people of color in the United States through the use of nonviolent resistance and nonviolent civil disobedience against Jim Crow laws and other forms of legalized discrimination.

A black church leader, King participated in and led marches for the right to vote, desegregation, labor rights, and other civil rights. He oversaw the 1955 Montgomery bus boycott and later became the first president of the Southern Christian Leadership Conference (SCLC). As president of the SCLC, he led the unsuccessful Albany Movement in Albany, Georgia, and helped organize some of the nonviolent 1963 protests in Birmingham, Alabama. King was one of the leaders of the 1963 March on Washington, where he delivered his "I Have a Dream" speech on the steps of the Lincoln Memorial, and helped organize two of the three Selma to Montgomery marches during the 1965 Selma voting rights movement. The civil rights movement achieved pivotal legislative gains in the Civil Rights Act of 1964, the Voting Rights Act of 1965, and the Fair Housing Act of 1968. There were several dramatic standoffs with segregationist authorities, who often responded violently. (Full article...)

The Demands of Liberal Education is a 1999 political philosophy book by Meira Levinson that establishes a liberal political theory of children's education that fits the mutual needs of the state and its diverse citizenry. She writes that the intent of a liberal education—an education that follows from a liberal society's values—is to maximize the autonomy of individual children through increasing their capacity for liberty. Levinson argues autonomy as a right to children. The book, published by Oxford University Press, aims to address a lacuna between educational policy and liberal political theory.

Levinson advocates for a weak perfectionist state that can promote thick autonomy while accepting citizens who do not agree. She argues for public schools "common" to all citizens and "detached" from individual citizen or community values, and argues for a constitutional mandate to this end. (Full article...)

Ancient, medieval and Renaissance astronomers and philosophers developed many different theories about the dynamics of the celestial spheres. They explained the motions of the various nested spheres in terms of the materials of which they were made, external movers such as celestial intelligences, and internal movers such as motive souls or impressed forces. Most of these models were qualitative, although a few of them incorporated quantitative analyses that related speed, motive force and resistance. (Full article...)

Mathematics and art are related in a variety of ways. Mathematics has itself been described as an art motivated by beauty. Mathematics can be discerned in arts such as music, dance, painting, architecture, sculpture, and textiles. This article focuses, however, on mathematics in the visual arts.

Mathematics and art have a long historical relationship. Artists have used mathematics since the 4th century BC when the Greek sculptor Polykleitos wrote his Canon, prescribing proportions conjectured to have been based on the ratio 1:√2 for the ideal male nude. Persistent popular claims have been made for the use of the golden ratio in ancient art and architecture, without reliable evidence. In the Italian Renaissance, Luca Pacioli wrote the influential treatise De divina proportione (1509), illustrated with woodcuts by Leonardo da Vinci, on the use of the golden ratio in art. Another Italian painter, Piero della Francesca, developed Euclid's ideas on perspective in treatises such as De Prospectiva Pingendi, and in his paintings. The engraver Albrecht Dürer made many references to mathematics in his work Melencolia I. In modern times, the graphic artist M. C. Escher made intensive use of tessellation and hyperbolic geometry, with the help of the mathematician H. S. M. Coxeter, while the De Stijl movement led by Theo van Doesburg and Piet Mondrian explicitly embraced geometrical forms. Mathematics has inspired textile arts such as quilting, knitting, cross-stitch, crochet, embroidery, weaving, Turkish and other carpet-making, as well as kilim. In Islamic art, symmetries are evident in forms as varied as Persian girih and Moroccan zellige tilework, Mughal jali pierced stone screens, and widespread muqarnas vaulting. (Full article...)

Varaha Upanishad (Sanskrit: वराह उपनिषद्, "boar") is a minor Upanishad of Hinduism composed between the 13th and 16th centuries CE. Composed in Sanskrit, it is listed as one of the 32 Krishna Yajurveda Upanishads, and classified as one of 20 Yoga Upanishads.

The text has five chapters, structured primarily as a discussion between Vishnu in his Varaha (boar) avatar and the sage Ribhu. The discussion covers the subjects of Tattvas, the nature and relationship between the individual soul (Self, Atman) and the Ultimate Reality (Brahman), the seven stages of learning, the characteristics of Jivanmukti (inner sense of freedom while living), and the four types of Jivanmuktas (liberated persons). The last chapter of the text is dedicated to Yoga, its goals and methods. (Full article...)

Su Song (Chinese: 蘇頌; Pe̍h-ōe-jī: So͘ Siōng, 1020–1101), courtesy name Zirong (Chinese: 子容; Pe̍h-ōe-jī: Chú-iông), was a Chinese polymathic scientist and statesman. Excelling in a variety of fields, he was accomplished in mathematics, astronomy, cartography, geography, horology, pharmacology, mineralogy, metallurgy, zoology, botany, mechanical engineering, hydraulic engineering, civil engineering, invention, art, poetry, philosophy, antiquities, and statesmanship during the Song dynasty (960–1279).

Su Song was the engineer for a hydro-mechanical astronomical clock tower in medieval Kaifeng, which employed an early escapement mechanism. The escapement mechanism of Su's clock tower had been invented by Tang dynasty Buddhist monk Yi Xing and government official Liang Lingzan in 725 AD to operate a water-powered armillary sphere, although Su's armillary sphere was the first to be provided with a mechanical clock drive. Su's clock tower also featured the oldest known endless power-transmitting chain drive, called the tian ti (天梯), or "celestial ladder", as depicted in his horological treatise. The clock tower had 133 different clock jacks to indicate and sound the hours. Su Song's treatise about the clock tower, Xinyi Xiangfayao (新儀象法要), has survived since its written form in 1092 and official printed publication in 1094. The book has been analyzed by many historians, such as the British biochemist, historian, and sinologist Joseph Needham. The clock itself, however, was dismantled by the invading Jurchen army in 1127 AD, and although attempts were made to reassemble it, the tower was never successfully reinstated. (Full article...)