Portal:Philosophy

Niels Henrik David Bohr (Danish: [ˈne̝ls ˈpoɐ̯ˀ]; 7 October 1885 – 18 November 1962) was a Danish physicist who made foundational contributions to understanding atomic structure and quantum theory, for which he received the Nobel Prize in Physics in 1922. Bohr was also a philosopher and a promoter of scientific research.

Bohr developed the Bohr model of the atom, in which he proposed that energy levels of electrons are discrete and that the electrons revolve in stable orbits around the atomic nucleus but can jump from one energy level (or orbit) to another. Although the Bohr model has been supplanted by other models, its underlying principles remain valid. He conceived the principle of complementarity: that items could be separately analysed in terms of contradictory properties, like behaving as a wave or a stream of particles. The notion of complementarity dominated Bohr's thinking in both science and philosophy. (Full article...)

William Edward Burghardt Du Bois (/djuːˈbɔɪs/ dew-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...)

A Vindication of the Rights of Woman: with Strictures on Political and Moral Subjects (1792), written by British philosopher and women's rights advocate Mary Wollstonecraft (1759–1797), is one of the earliest works of feminist philosophy. In it, Wollstonecraft responds to those educational and political theorists of the eighteenth century who did not believe women should receive a rational education. She argues that women ought to have an education commensurate with their position in society, claiming that women are essential to the nation because they educate its children and because they could be "companions" to their husbands, rather than mere wives. Instead of viewing women as ornaments to society or property to be traded in marriage, Wollstonecraft maintains that they are human beings deserving of the same fundamental rights as men.

Wollstonecraft was prompted to write the Rights of Woman after reading Charles Maurice de Talleyrand-Périgord's 1791 report to the French National Assembly, which stated that women should only receive domestic education. From her reaction to this specific event, she launched a broad attack against double standards, indicting men for encouraging women to indulge in excessive emotion. Wollstonecraft hurried to complete the work in direct response to ongoing events; she intended to write a more thoughtful second volume but died before completing it. (Full article...)

The Augustinian theodicy, named for the 4th- and 5th-century theologian and philosopher Augustine of Hippo, is a type of Christian theodicy that developed in response to the evidential problem of evil. As such, it attempts to explain the probability of an omnipotent (all-powerful) and omnibenevolent (all-loving) God amid evidence of evil in the world. A number of variations of this kind of theodicy have been proposed throughout history; their similarities were first described by the 20th-century philosopher John Hick, who classified them as "Augustinian". They typically assert that God is perfectly (ideally) good, that he created the world out of nothing, and that evil is the result of humanity's original sin. The entry of evil into the world is generally explained as consequence of original sin and its continued presence due to humans' misuse of free will and concupiscence. God's goodness and benevolence, according to the Augustinian theodicy, remain perfect and without responsibility for evil or suffering.

Augustine of Hippo was the first to develop the theodicy. He rejected the idea that evil exists in itself, instead regarding it as a corruption of goodness, caused by humanity's abuse of free will. Augustine believed in the existence of a physical Hell as a punishment for sin, but argued that those who choose to accept the salvation of Jesus Christ will go to Heaven. In the 13th century, Thomas Aquinas – influenced by Augustine – proposed a similar theodicy based on the view that God is goodness and that there can be no evil in him. He believed that the existence of goodness allows evil to exist, through the fault of humans. Augustine also influenced John Calvin, who supported Augustine's view that evil is the result of free will and argued that sin corrupts humans, requiring God's grace to give moral guidance. (Full article...)

Johannes Kepler (/ˈkɛplər/; German: [joˈhanəs ˈkɛplɐ, -nɛs -] ^ⓘ; 27 December 1571 – 15 November 1630) was a German astronomer, mathematician, astrologer, natural philosopher and writer on music. He is a key figure in the 17th-century Scientific Revolution, best known for his laws of planetary motion, and his books Astronomia nova, Harmonice Mundi, and Epitome Astronomiae Copernicanae, influencing among others Isaac Newton, providing one of the foundations for his theory of universal gravitation. The variety and impact of his work made Kepler one of the founders and fathers of modern astronomy, the scientific method, natural and modern science. He has been described as the "father of science fiction" for his novel Somnium.

Kepler was a mathematics teacher at a seminary school in Graz, where he became an associate of Prince Hans Ulrich von Eggenberg. Later he became an assistant to the astronomer Tycho Brahe in Prague, and eventually the imperial mathematician to Emperor Rudolf II and his two successors Matthias and Ferdinand II. He also taught mathematics in Linz, and was an adviser to General Wallenstein.
Additionally, he did fundamental work in the field of optics, being named the father of modern optics, in particular for his Astronomiae pars optica. He also invented an improved version of the refracting telescope, the Keplerian telescope, which became the foundation of the modern refracting telescope, while also improving on the telescope design by Galileo Galilei, who mentioned Kepler's discoveries in his work. (Full article...)

Atheism, in the broadest sense, is an absence of belief in the existence of deities. Less broadly, atheism is a rejection of the belief that any deities exist. In an even narrower sense, atheism is specifically the position that there are no deities. Atheism is contrasted with theism, which in its most general form is the belief that at least one deity exists.

Historically, evidence of atheistic viewpoints can be traced back to classical antiquity and early Indian philosophy. In the Western world, atheism declined as Christianity gained prominence. The 16th century and the Age of Enlightenment marked the resurgence of atheistic thought in Europe. Atheism achieved a significant position in the 20th century with legislation protecting freedom of thought. According to 2003 estimates, there are at least 500 million atheists in the world.^{[needs update]} (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. Considered 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, 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...)

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...)

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...)

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...)

A Vindication of the Rights of Men, in a Letter to the Right Honourable Edmund Burke; Occasioned by His Reflections on the Revolution in France (1790) is a political pamphlet, written by the 18th-century British writer and women's rights advocate Mary Wollstonecraft, which attacks aristocracy and advocates republicanism. Wollstonecraft's was the first response in a pamphlet war sparked by the publication of Edmund Burke's Reflections on the Revolution in France (1790), a defense of constitutional monarchy, aristocracy, and the Church of England.

Wollstonecraft attacked not only hereditary privilege, but also the rhetoric that Burke used to defend it. Most of Burke's detractors deplored what they viewed as his theatrical pity for Marie Antoinette, but Wollstonecraft was unique in her love of Burke's gendered language. By saying the sublime and the beautiful, terms first established by Burke himself in A Philosophical Enquiry into the Origin of Our Ideas of the Sublime and Beautiful (1756), she kept his rhetoric as well as his argument. In her first unabashedly feminist critique, which Wollstonecraft scholar Claudia Johnson describes as unsurpassed in its argumentative force, Wollstonecraft indicts Burke's justification of an equal society founded on the passivity of women. (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...)

In the philosophy of Baruch Spinoza, conatus (/koʊˈneɪtəs/; wikt:conatus; Latin for "effort; endeavor; impulse, inclination, tendency; undertaking; striving") is an innate inclination of a thing to continue to exist and enhance itself. This thing may be mind, matter, or a combination of both, and is often associated with God's will in a pantheist view of nature. The conatus may refer to the instinctive will to live of living organisms or to various metaphysical theories of motion and inertia. Today, conatus is rarely used in the technical sense, since classical mechanics uses concepts such as inertia and conservation of momentum that have superseded it. It has, however, been a notable influence on later thinkers such as Arthur Schopenhauer and Friedrich Nietzsche. (Full article...)

Samuel Johnson (18 September 1709 [OS 7 September] – 13 December 1784), often called Dr Johnson, was an English writer who made lasting contributions as a poet, playwright, essayist, moralist, literary critic, sermonist, biographer, editor, and lexicographer. The Oxford Dictionary of National Biography calls him "arguably the most distinguished man of letters in English history".

Born in Lichfield, Staffordshire, he attended Pembroke College, Oxford, until lack of funds forced him to leave. After working as a teacher, he moved to London and began writing for The Gentleman's Magazine. Early works include Life of Mr Richard Savage, the poems London and The Vanity of Human Wishes and the play Irene. After nine years' effort, Johnson's A Dictionary of the English Language appeared in 1755, and was acclaimed as "one of the greatest single achievements of scholarship". Later work included essays, an annotated The Plays of William Shakespeare, and the apologue The History of Rasselas, Prince of Abissinia. In 1763 he befriended James Boswell, with whom he travelled to Scotland, as Johnson described in A Journey to the Western Islands of Scotland. Near the end of his life came a massive, influential Lives of the Most Eminent English Poets of the 17th and 18th centuries. (Full article...)

Maximus the Confessor (Greek: Μάξιμος ὁ Ὁμολογητής, romanized: Maximos ho Homologētēs), also spelled Maximos, otherwise known as Maximus the Theologian and Maximus of Constantinople (c. 580 – 13 August 662), was a Christian monk, theologian, and scholar.

In his early life, Maximus was a civil servant, and an aide to the Byzantine Emperor Heraclius. He gave up this life in the political sphere to enter the monastic life. Maximus had studied diverse schools of philosophy, and certainly what was common for his time, the Platonic dialogues, the works of Aristotle, and numerous later Platonic commentators on Aristotle and Plato, like Plotinus, Porphyry, Iamblichus, and Proclus. When one of his friends began espousing the Christological position known as Monothelitism, Maximus was drawn into the controversy, in which he supported an interpretation of the Chalcedonian formula on the basis of which it was asserted that Jesus had both a human and a divine will. Maximus is venerated in both the Catholic and Eastern Orthodox Churches. He was eventually persecuted for his Christological positions; following a trial, his tongue and right hand were mutilated. (Full article...)

Hypatia (born c. 350–370; died 415 AD) was a Neoplatonist philosopher, astronomer, and mathematician who lived in Alexandria, Egypt, then part of the Eastern Roman Empire. She was a prominent thinker in Alexandria where she taught philosophy and astronomy. Although preceded by Pandrosion, another Alexandrian female mathematician, she is the first female mathematician whose life is reasonably well recorded. Hypatia was renowned in her own lifetime as a great teacher and a wise counselor. She wrote a commentary on Diophantus's thirteen-volume Arithmetica, which may survive in part, having been interpolated into Diophantus's original text, and another commentary on Apollonius of Perga's treatise on conic sections, which has not survived. Many modern scholars also believe that Hypatia may have edited the surviving text of Ptolemy's Almagest, based on the title of her father Theon's commentary on Book III of the Almagest.

Hypatia constructed astrolabes and hydrometers, but did not invent either of these, which were both in use long before she was born. She was tolerant toward Christians and taught many Christian students, including Synesius, the future bishop of Ptolemais. Ancient sources record that Hypatia was widely beloved by pagans and Christians alike and that she established great influence with the political elite in Alexandria. Toward the end of her life, Hypatia advised Orestes, the Roman prefect of Alexandria, who was in the midst of a political feud with Cyril, the bishop of Alexandria. Rumors spread accusing her of preventing Orestes from reconciling with Cyril and, in March 415 AD, she was murdered by a mob of Christians led by a lector named Peter. (Full article...)

Wilhelm Reich (/raɪx/ RYKHE, German: [ˈvɪlhɛlm ˈʁaɪç]; 24 March 1897 – 3 November 1957) was an Austrian doctor of medicine and a psychoanalyst, a member of the second generation of analysts after Sigmund Freud. The author of several influential books, The Impulsive Character (1925), The Function of the Orgasm (1927), Character Analysis (1933), and The Mass Psychology of Fascism (1933), he became one of the most radical figures in the history of psychiatry.

Reich's work on character contributed to the development of Anna Freud's The Ego and the Mechanisms of Defence (1936), and his idea of muscular armour—the expression of the personality in the way the body moves—shaped innovations such as body psychotherapy, Gestalt therapy, bioenergetic analysis and primal therapy. His writing influenced generations of intellectuals; he coined the phrase "the sexual revolution" and according to one historian acted as its midwife. During the 1968 student uprisings in Paris and Berlin, students scrawled his name on walls and threw copies of The Mass Psychology of Fascism at police. (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...)

Stoicism is a school of Hellenistic philosophy that flourished in Ancient Greece and Ancient Rome. The Stoics believed that the practice of virtue is enough to achieve eudaimonia: a well-lived life. The Stoics identified the path to achieving it with a life spent practicing the four virtues in everyday life: wisdom, courage, temperance or moderation, and justice, and living in accordance with nature. It was founded in the ancient Agora of Athens by Zeno of Citium around 300 BC.

Alongside Aristotle's ethics, the Stoic tradition forms one of the major founding approaches to virtue ethics. The Stoics are especially known for teaching that "virtue is the only good" for human beings, and that external things, such as health, wealth, and pleasure, are not good or bad in themselves (adiaphora) but have value as "material for virtue to act upon". Many Stoics—such as Seneca and Epictetus—emphasized that because "virtue is sufficient for happiness", a sage would be emotionally resilient to misfortune. The Stoics also held that certain destructive emotions resulted from errors of judgment, and they believed people should aim to maintain a will (called prohairesis) that is "in accordance with nature". Because of this, the Stoics thought the best indication of an individual's philosophy was not what a person said but how a person behaved. To live a good life, one had to understand the rules of the natural order since they believed everything was rooted in nature. (Full article...)

Taoism (/ˈdaʊ.ɪzəm/ ^ⓘ, /ˈtaʊ.ɪzəm/ ^ⓘ) or Daoism is a diverse tradition indigenous to China, variously characterized as both a philosophy and a religion. Taoism emphasizes living in harmony with the Tao—generally understood as being the impersonal, enigmatic process of transformation ultimately underlying reality. The concept originates in the Chinese word 道 (pinyin: dào; Wade–Giles: tao⁴), which has numerous related meanings: possible English translations include 'way', 'road', and 'technique'. Taoist thought has informed the development of various practices within the Taoist tradition and beyond, including forms of meditation, astrology, qigong, feng shui, and internal alchemy. A common goal of Taoist practice is self-cultivation resulting in a deeper appreciation of the Tao, and thus a more harmonious existence. There are different formulations of Taoist ethics, but there is generally emphasis on virtues such as effortless action, naturalness or spontaneity, simplicity, and the three treasures of compassion, frugality, and humility. Many Taoist terms lack simple definitions and have been translated in several different ways.

The core of Taoist thought crystallized during the early Warring States period, c. the 4th and 5th centuries BCE, during which the epigrammatic Tao Te Ching and the anecdotal Zhuangzi—widely regarded as the fundamental texts of Taoist philosophy—were largely composed. They form the core of a body of Taoist writings accrued over the following centuries, which was assembled by monks into the Daozang canon starting in the 5th century CE. Early Taoism drew upon diverse influences, including the Shang and Zhou state religions, Naturalism, Mohism, Confucianism, various Legalist theories, as well as the Book of Changes and Spring and Autumn Annals.Taoism is the most important ideology in Chinese thought, second only to Confucianism. Although almost completely different from Confucianism, it is not contradictory. Dao does not involve national affairs, secular or daily administrative affairs, or complex rituals; On the contrary, it encourages the avoidance of public responsibility and the search for a vision of a spiritual transcendent world. Later, when Buddhism was introduced to China, the two systems began influencing one another, with long-running discourses shared between Taoists and Buddhists; the distinct Mahayana tradition of Zen that emerged during the Tang dynasty incorporates many ideas from Taoism. (Full article...)

The celestial spheres, or celestial orbs, were the fundamental entities of the cosmological models developed by Plato, Eudoxus, Aristotle, Ptolemy, Copernicus, and others. In these celestial models, the apparent motions of the fixed stars and planets are accounted for by treating them as embedded in rotating spheres made of an aetherial, transparent fifth element (quintessence), like gems set in orbs. Since it was believed that the fixed stars did not change their positions relative to one another, it was argued that they must be on the surface of a single starry sphere.

In modern thought, the orbits of the planets are viewed as the paths of those planets through mostly empty space. Ancient and medieval thinkers, however, considered the celestial orbs to be thick spheres of rarefied matter nested one within the other, each one in complete contact with the sphere above it and the sphere below. When scholars applied Ptolemy's epicycles, they presumed that each planetary sphere was exactly thick enough to accommodate them. By combining this nested sphere model with astronomical observations, scholars calculated what became generally accepted values at the time for the distances to the Sun: about 4 million miles (6.4 million kilometres), to the other planets, and to the edge of the universe: about 73 million miles (117 million kilometres). The nested sphere model's distances to the Sun and planets differ significantly from modern measurements of the distances, and the size of the universe is now known to be inconceivably large and continuously expanding. (Full article...)

In pragmatics, a subdiscipline of linguistics, an implicature is something the speaker suggests or implies with an utterance, even though it is not literally expressed. Implicatures can aid in communicating more efficiently than by explicitly saying everything we want to communicate. The philosopher H. P. Grice coined the term in 1975. Grice distinguished conversational implicatures, which arise because speakers are expected to respect general rules of conversation, and conventional ones, which are tied to certain words such as "but" or "therefore". Take for example the following exchange:

: A (to passerby): I am out of gas.
: B: There is a gas station 'round the corner. (Full article...)

Maximilian Karl Emil Weber (/ˈveɪbər/; German: [ˈveːbɐ]; 21 April 1864 – 14 June 1920) was a German sociologist, historian, jurist, and political economist who was one of the central figures in the development of sociology and the social sciences more generally. His ideas continue to influence social theory and research.

Born in Erfurt in 1864, Weber studied law and history in Berlin, Göttingen, and Heidelberg. After earning his doctorate in law in 1889 and habilitation in 1891, he married his cousin Marianne Schnitger and taught in Freiburg and Heidelberg. In 1897, he had a breakdown after his father died following an argument. Weber ceased teaching and travelled until the early 1900s. He recovered and wrote The Protestant Ethic and the Spirit of Capitalism. During the First World War, he initially supported Germany's war effort but became critical of it and supported democratisation. He also gave the lectures "Science as a Vocation" and "Politics as a Vocation". After the war, Weber co-founded the German Democratic Party, unsuccessfully ran for office, and advised the drafting of the Weimar Constitution. Becoming frustrated with politics, he resumed teaching in Vienna and Munich. He possibly contracted the Spanish flu and died of pneumonia in 1920 at the age of 56. A book, Economy and Society, was left unfinished. (Full article...)

Philosophy of science is the branch of philosophy concerned with the foundations, methods, and implications of science. Amongst its central questions are the difference between science and non-science, the reliability of scientific theories, and the ultimate purpose and meaning of science as a human endeavour. Philosophy of science focuses on metaphysical, epistemic and semantic aspects of scientific practice, and overlaps with metaphysics, ontology, logic, and epistemology, for example, when it explores the relationship between science and the concept of truth. Philosophy of science is both a theoretical and empirical discipline, relying on philosophical theorising as well as meta-studies of scientific practice. Ethical issues such as bioethics and scientific misconduct are often considered ethics or science studies rather than the philosophy of science.

There is little consensus among philosophers about many of the central problems concerned with the philosophy of science, including whether science can reveal the truth about unobservable things and whether scientific reasoning can be justified at all as leading to definite knowledge. In addition to these general question, philosophers of science consider problems that apply to particular sciences (such as biology, physics and social sciences such as economics and psychology). Some philosophers of science also use contemporary results in science to reach conclusions about philosophy itself. (Full article...)

Quantum mechanics is a fundamental theory in physics that describes the behavior of nature at and below the scale of atoms. It is the foundation of all quantum physics, which includes quantum chemistry, quantum field theory, quantum technology, and quantum information science.

Quantum mechanics can describe many systems that classical physics cannot. Classical physics can describe many aspects of nature at an ordinary (macroscopic and (optical) microscopic) scale, but is not sufficient for describing them at very small submicroscopic (atomic and subatomic) scales. Most theories in classical physics can be derived from quantum mechanics as an approximation valid at large (macroscopic/microscopic) scale. (Full article...)

Hannah Arendt (/ˈɛərənt, ˈɑːr-/, US also /əˈrɛnt/, German: [ˌhana ˈaːʁənt] ^ⓘ; born Johanna Arendt; 14 October 1906 – 4 December 1975) was a German-American historian and philosopher. She was one of the most influential political theorists of the 20th century.

Her works cover a broad range of topics, but she is best known for those dealing with the nature of power and evil, as well as politics, direct democracy, authority, and totalitarianism. She is also remembered for the controversy surrounding the trial of Adolf Eichmann, her attempt to explain how ordinary people become actors in totalitarian systems, which was considered by some an apologia, and for the phrase "the banality of evil." She is commemorated by institutions and journals devoted to her thinking, the Hannah Arendt Prize for political thinking, and on stamps, street names, and schools, amongst other things. (Full article...)

Alice O'Connor (born Alisa Zinovyevna Rosenbaum; February 2 [O.S. January 20], 1905 – March 6, 1982), better known by her pen name Ayn Rand (/aɪn/ INE), was a Russian-born American author and philosopher. She is known for her fiction and for developing a philosophical system she named Objectivism. Born and educated in Russia, she moved to the United States in 1926. After two early novels that were initially unsuccessful and two Broadway plays, Rand achieved fame with her 1943 novel The Fountainhead. In 1957, she published her best-selling work, the novel Atlas Shrugged. Afterward, until her death in 1982, she turned to non-fiction to promote her philosophy, publishing her own periodicals and releasing several collections of essays.

Rand advocated reason and rejected faith and religion. She supported rational and ethical egoism as opposed to altruism. In politics, she condemned the initiation of force as immoral and supported laissez-faire capitalism, which she defined as the system based on recognizing individual rights, including private property rights. Although she opposed libertarianism, which she viewed as anarchism, Rand is often associated with the modern libertarian movement in the United States. In art, she promoted romantic realism. She was sharply critical of most philosophers and philosophical traditions known to her, with a few exceptions. (Full article...)

Kazi Nazrul Islam PB EP IA (Bengali: কাজী নজরুল ইসলাম, pronounced [kad͡ʒi ˈnod͡ʒɾul islam] ^ⓘ; 24 May 1899 – 29 August 1976), also known as the Rebel Poet, was a popular Bengali poet, writer, lyrist and the national poet of Bangladesh. Nazrul produced a large body of poetry, music, messages, novels, and stories with themes that included equality, justice, anti-imperialism, humanity, rebellion against oppression and religious devotion. Nazrul Islam's activism for political and social justice as well as writing a poem titled as "Bidrohī", meaning "the rebel" in Bengali, earned him the title of "Bidrohī Kôbi" (Rebel Poet). His compositions form the avant-garde music genre of Nazrul Gīti (Music of Nazrul).

Born into a Bengali Muslim Kazi family hailing from Burdwan district in Bengal Presidency (now in West Bengal, India), Nazrul Islam received religious education and as a young man worked as a muezzin at a local mosque. He learned about poetry, drama, and literature while working with the rural theatrical group Leṭor Dôl, Leṭo being a folk song genre of West Bengal usually performed by the people from Muslim community of the region. He joined the British Indian Army in 1917 and was posted in Karachi. Nazrul Islam established himself as a journalist in Calcutta after the war ended. He criticized the British Raj and called for revolution through his famous poetic works, such as "Bidrohī" ('The Rebel') and "Bhangar Gan" ('The Song of Destruction'), as well as in his publication Dhūmketu ('The Comet'). His nationalist activism in Indian independence movement led to his frequent imprisonment by the colonial British authorities. While in prison, Nazrul Islam wrote the "Rajbôndīr Jôbanbôndī" ('Deposition of a Political Prisoner'). His writings greatly inspired Bengalis of East Pakistan during the Bangladesh Liberation War. (Full article...)

Letters from an American Farmer is a series of letters written by French American writer J. Hector St. John de Crèvecœur, first published in 1782. The considerably longer title under which it was originally published is Letters from an American Farmer; Describing Certain Provincial Situations, Manners, and Customs not Generally Known; and Conveying Some Idea of the Late and Present Interior Circumstances of the British Colonies in North America. The twelve letters cover a wide range of topics, from the emergence of an American identity to the slave trade.

Crèvecœur wrote Letters during a period of seven years prior to the American Revolutionary War, while farming in the fertile Greycourt, blackdirt region of Chester, NY, a small town in Orange County, New York. It is told from the viewpoint of a fictional narrator in correspondence with an English gentleman, and each letter concerns a different aspect of life or location in the British colonies of America. The work incorporates a number of styles and genres, including documentary, as well as sociological observations. (Full article...)

Eliminative materialism (also called eliminativism) is a materialist position in the philosophy of mind. It is the idea that the majority of mental states in folk psychology do not exist. Some supporters of eliminativism argue that no coherent neural basis will be found for many everyday psychological concepts such as belief or desire, since they are poorly defined. The argument is that psychological concepts of behavior and experience should be judged by how well they reduce to the biological level. Other versions entail the nonexistence of conscious mental states such as pain and visual perceptions.

Eliminativism about a class of entities is the view that the class of entities does not exist. For example, materialism tends to be eliminativist about the soul; modern chemists are eliminativist about phlogiston; modern biologists are eliminativist about élan vital; and modern physicists are eliminativist about luminiferous ether. Eliminative materialism is the relatively new (1960s–70s) idea that certain classes of mental entities that common sense takes for granted, such as beliefs, desires, and the subjective sensation of pain, do not exist. The most common versions are eliminativism about propositional attitudes, as expressed by Paul and Patricia Churchland, and eliminativism about qualia (subjective interpretations about particular instances of subjective experience), as expressed by Daniel Dennett, Georges Rey, and Jacy Reese Anthis. (Full article...)