German philosophy

Aristotelianism and Neoplatonism

Latin literacy had declined so much that Notker Labeo (c. 950–1022) translated the Roman Neoplatonist Boethius, Capella, and some Aristotle, inventing the first German philosophical vocabulary.^[10][11]

The few twelfth-century Renaissance German philosophers during the High Middle Ages begin with Hugh of Saint Victor (c. 1096–1141), who studied at the abbey of Saint Victor in Paris, and was a Neoplatonic mystic influenced by Plato's Timaeus and Pseudo-Dionysius the Areopagite, the "progenitor of apophatic or negative theology."^[12][13][14]

Otto of Freising (c. 1111–1158) was likely Hugh's student^[15][16] and introduced to Germans the new, complete logic of Aristotle.^[17] Hugh also influenced Italian philosopher Peter Lombard, author of the Sentences (c. 1150).^[18][19]

Neoplatonist nun and polymath Hildegard von Bingen (c. 1098–1179) called the "Sibyl of the Rhine" knew Latin and wrote on theology, cosmology, and natural philosophy.^[b] In works like Scivias (1151), she wrote God infused life with viriditas.^[21]

Albertus Magnus

Aristotle's other works became available from translators in Spain, one of whom was Herman the German. The most eminent German Scholastic, Dominican friar Saint Albert the Great (c. 1200–1280), taught the Physics and Nicomachean Ethics at Paris and Cologne.^[22][23][24] He influenced students such as Neoplatonist Theodoric of Freiberg (c. 1250–c. 1311),^[25] Italian Aristotelian Thomas Aquinas,^[26] and Aristotle translator William of Moerbeke (c. 1225–c. 1286).^[27]

German Dominicans were usually Albertists, Aristotelians with a blend of Neoplatonism like Theodoric, such as Ulrich (c. 1225–1277) and Hugh Ripelin of Strassburg (c. 1205–c. 1270).^[28]

Albertists were contrasted with the purely Aristotelian Thomists following Aquinas,^[29] such as John of Lichtenberg, Heinrich of Lübeck, Heinrich of Gorkum, Nicholas and Thomas of Strassburg, and John and Gerhard of Sterngassen.^[30]

Franciscan Duns Scotus died shortly after coming to teach in Cologne, and so despite exceptions such as Heinrich von Werl, Scotism had limited influence in Germany.^[4] Scotus is buried in the Church of the Friars Minor.^[31]

Meister Eckhart

Meister Eckhart (c. 1260–c. 1328), an influential Neoplatonic mystic at Cologne, wrote the Book of Divine Consolation.^[32] Eckhart combined Theodoric's mysticism with the non-philosophical mysticism found among beguine orders, like Mechthild of Magdeburg (c. 1207–c. 1282), author of The Flowing Light of the Godhead.^[4][33][34]

Meister Eckhart was posthumously condemned for heresy, and defended by Henry Suso (1295–1366).^[35] Eckhart influenced the Friends of God and Brabantine priest John of Ruusbroec,^[36] who influenced the Brethren of the Common Life and Devotio Moderna proponent Thomas à Kempis, author of The Imitation of Christ.^[37]

Albertist Berthold of Moosburg (d. c. 1365) succeeded Eckhart at Cologne,^[38] influencing Johannes Tauler (c. 1300–1361)^[39] and Heymeric de Campo (1395–1460).^[40] A contemporary Thomist at Cologne was Lambertus de Monte (c. 1430–1499).^[41]

Nominalism

British philosopher and Franciscan William of Ockham (c. 1287–1347) spent his final years taking refuge with Louis IV, Holy Roman Emperor at the Alter Hof in Munich.^[44][45] Ockham's nominalism proved influential in Germany.^[46]

The Schism of 1378 drove many nominalists from France to Germany.^[4][46] The first university in the Holy Roman Empire was the University of Prague (1347), modeled after the University of Paris, then influenced by Ockhamist Jean Buridan.^[47] Buridan's student Albert of Saxony (c. 1320–1390) contributed to logic, and physics with a theory of impetus, a precursor to inertia.^[48] He became the first rector at the second, the University of Vienna (1365).^[48] Henry of Langenstein (c. 1325–1397), who with Henry of Oyta (c. 1330–1397) followed Albert of Saxony at Vienna, taught Ockham's conciliar theory.^[49][50] Albert of Saxony's student Marsilius of Inghen (c. 1340–1396) became first rector at the third, the University of Heidelberg (1386).^[51] The Dominican Cologne was converted to a studium generale (c. 1388) and was the fourth.^[4]

The most notable German Ockhamist was University of Tübingen professor Gabriel Biel (c. 1420–1495),^[52] both an "articulate spokesman of the via moderna and … a discerning user of the thought of via antiqua".^[53]

Humanism

Nicholas of Cusa (1401–1464) and Dutch philosopher Desiderius Erasmus of Rotterdam (c. 1466–1536) were two major figures of Northern Renaissance and German Renaissance humanism, along with Conrad Celtis (1459–1508).^[54]

Cusa was a student of Heymeric de Campo^[55] and a dialetheist mystic affirming the coincidentia oppositorum and denying the law of non-contradiction.^[56] Cusa's Of Learned Ignorance (1440) maintains the finite, human mind cannot fully know the divine, infinite mind ('the Maximum'), but can nonetheless attain "learned ignorance".^[38]

Johannes Gutenberg (1406–1468) invented the printing press and created the Gutenberg Bible (c. 1455) which marked the start of the Gutenberg Revolution and age of the printed book in the Western world.^[57]

Desiderius Erasmus was a skeptic and scholar of medieval Christianity^[58] charged by contemporaries with “laying the egg that Luther hatched.”^[59] Erasmus is best known for works like The Praise of Folly (1511) and Handbook of a Christian Knight (1501).^[60]

Other humanists were realist opponent of nominalism Johann Heynlin (c. 1425–1496);^[61] and Johann Reuchlin (1455–1522),^[62] who advocated teaching Greek and Hebrew, and wrote on the Jewish mysticism of Kabbalah in De Arte Cabalistica (1517).^[63]

Reformation

University of Wittenberg professor Martin Luther (1483–1546) started the Reformation and is considered one of the most influential figures in Western and Christian history.^[64][65]

Luther's German translation of the Bible made it vastly more accessible to the laity, having a wide impact on both the Church and German culture. Luther sparked an international debate on indulgences and other Church practices in works like Ninety-five Theses (1517). According to Philip Melanchthon (1497–1560), they were posted on the door of All Saint's Church.^[66]

Protestantism and Lutheranism held salvation was achieved by faith alone (sola fide) and through God alone (monergism). While Luther praised reason as "the best and something divine,"^[67] he saw it as inadequate in achieving knowledge of God, calling reason "the Devil's harlot".^[68]

Erasmus argued against Luther in On Free Will (1524), defending free will and synergism. Led by Erasmus's former assistant Œcolampadius (1482–1531), Basel adopted the Reformation in 1529, deposing elected Catholic councilmen.^[69] Erasmus fled to Catholic university town Freiburg im Breisgau, receiving the protection of his former student, Archduke Ferdinand of Austria.^[70] Erasmus influenced German Anabaptists such as Balthasar Hubmaier.^[71]

Ramism

The doctrines of French logician, education reformer, and Protestant convert Petrus Ramus known as Ramism influenced Freigius (1543–1583), Caspar Olevian (1536–1587) and Johannes Piscator (1536–1625).^[72] Ramist and follower of Melanchthon Rudolph Goclenius (1547–1628) taught Otto Casmann (1562–1607), a humanist, Protestant convert who attempted Mosaic physics.^[73]

Hermeticism

Johannes Trithemius (1462–1516) was a humanist and mystic hermeticist who taught Heinrich Cornelius Agrippa von Nettesheim (1486–1535) and Paracelsus (1493–1541).^[74][75]

The Albertists and Erasmus also influenced Nettesheim.^[76] His Three Books of Occult Philosophy (1533) was widely influential among esotericists, and condemned as heretical by the inquisitor of Cologne.^[77] His skepticism also proved influential, found in On the Uncertainty and Vanity of the Arts and Sciences: An Invective Declamation (1530).^[78]

Paracelsus was an alchemist and pioneer of the Medical Renaissance called the "father of toxicology".^[79] In addition to Aristotle's four classical elements (earth, water, air, and fire), Paracelsus added three principles or tria prima (sulphur, mercury, and salt). Paracelsus thought the tria prima contained the poisons contributing to all diseases.^[80] Gerhard Dorn, Oswald Croll, Andreas Libavius, Heinrich Khunrath, and Valentin Weigel helped popularize his work.^[81][82]

Valentin Weigel (1533–1588) also followed religious radicals Thomas Müntzer, Andreas Bodenstein von Karlstadt, Sebastian Franck, and Caspar Schwenckfeldt, who believed Christ could be known internally, without reading.^[83] Pietist predecessor Johann Arndt (1555–1621) and Pietist Gottfried Arnold (1666–1714) helped spread Valentin Weigel's ideas.^[84]

Kepler

Melanchthon taught the Wittenberg interpretation of Copernicus and influenced Protestant mathematicians Philipp Apian and Michael Maestlin, who introduced Copernicus to natural philosopher Johannes Kepler (1571–1630), a key figure in the Scientific Revolution and heliocentrist Copernican Revolution,^[85] known for his laws of planetary motion,^[86] found in such books as Astronomia nova, Harmonice Mundi, and Epitome Astronomiae Copernicanae.

In Mysterium Cosmographicum (1596) Kepler proposed the distance between the planets could be understood by the five Platonic solids, showing the influence of Plato's Timaeus.^[87] Kepler also wrote the Rudolphine Tables (1627), based on the data and measurements of Dane Tycho Brahe.^[88]

Böhme

Influenced by Valentin Weigel, Lutheran mystic Jakob Böhme (1575–1624) founded theosophy and Behmenism, writing The Way to Christ (1624).

A key concept for Böhme is the Ungrund, the un-grounded, primeval abyss prior to the creation of the world, but that is also a will and pure freedom.^[89] Hegel called Böhme "the first German philosopher."^[90][d]

Cartesianism

Piscator's grandson Tobias Andreae, Johannes Clauberg, Johann Eberhard Schweling, and Ehrenfried Walther von Tschirnhaus defended Cartesianism, the views of French "father of modern philosophy" René Descartes (1596–1650).^[92][93] Princess Elizabeth of Bohemia (1618–1680) posed the interaction problem for substance dualism to Descartes.^[94]

Leibniz

Lutheran philosopher and mathematician Gottfried Wilhelm Leibniz (1646–1716) wrote primarily in Latin and French, such as the Discourse on Metaphysics (1686) and Nouveaux Essais (1689). Leibniz, along with Descartes and Baruch Spinoza (1632–1677), was one of the three great advocates of rationalism, the epistemological view that "regards reason as the chief source and test of knowledge,"^[95][96] rather than empirical evidence. Leibniz believed necessary truths were based on the law of non-contradiction, and contingent truths on the principle of sufficient reason, advancing the cosmological argument for God's existence.^[97] He anticipated modern logic and analytic philosophy with his wish for a universal language and logical calculus,^[98] but his philosophy also looks back to the scholastic tradition.^[99]

Leibniz expounded an idealist theory of monads in works like Monadologie (1714). Monads are the ultimate elements composing the universe, and can be compared to the corpuscles of Cartesian mechanical philosophy; except Cartesian objects are merely extended in space, while Leibniz agreed with the scholastics that objects have substantial forms and entelechy.^{[100][101][102]} Monads are centers of force; while space, matter, and motion are merely phenomenal or relational.^[100][103] Monads additionally have the following properties: they are simple (having no parts) substances, eternal, individual, subject to their own laws, un-interacting ("windowless"), and seem to interact causally due to God's pre-established harmony (a historically important example of panpsychism).^[100]

Leibniz is also noted for his optimism – his Théodicée (1710) tries to resolve the problem of evil by claiming this is the best of all possible worlds,^[104] because it was created by an all powerful and all knowing God, who would not choose to create an imperfect world if a better world was possible.^[104]

A heavy influence on the Enlightenment was British natural philosopher (scientist) Sir Isaac Newton (1643–1727) and Newtonianism. Influenced by Kepler, Newton published Philosophiæ Naturalis Principia Mathematica (1686) and his laws of motion, introducing classical mechanics to physics.^[105] Leibniz and Newton disputed who had invented calculus,^[106] and the nature of space.^[103]

Occasionalists think only God causes things. The occasionalists were Leibniz teacher Erhard Weigel (1625–1699), and Descartes and Leibniz critic Johann Sturm (1635–1703).^[107] Erhard Weigel was also a teacher of Samuel von Pufendorf (1632–1694). Pufendorf supported religious tolerance following the Thirty Years War (1618–1648), and authored On the Duty of Man and Citizen (1673).^[108]

Enlightenment

Pufendorf's follower was Christian Thomasius (1655–1728). Thomasius lecturing in German is commonly seen as the start of the German Enlightenment (Aufklärung).^[109] This also spread to the Swiss Enlightenment, such as Johann Kaspar Lavater and Johann Konrad Pfenninger.

Wolff

The most eminent German philosopher between Leibniz and Kant was Christian Wolff (1679–1754), often grouped together with Leibniz as “Leibnizian-Wolffian philosophy”.^[110] Wolff's rationalism was criticized by Pietists at the University of Halle like Philipp Spener (1635–1705) and August Hermann Francke (1663–1727).^[110]

Wolff studied what he called both theoretical and practical philosophy, which includes economics and public administration. His oeuvre studying almost every scholarly subject of his time, displayed according to his logical method, arguably represents the peak of German Enlightenment rationality.^[110] Wolff was a pioneer of German language scholarship, replacing Latin terminology with German, but he also wrote in Latin for an international audience.^[111][112]

Wolff and Tübingen logician Gottfried Ploucquet (1716–1790), were originally occasionalists, but eventually abandoned the view.^[107] Georg Bernhard Bilfinger (1693–1750) and Israel Gottlieb Canz (1690–1753) also followed Wolff at Tübingen.^[113] August Friedrich Bök (1739–1815) was an influential student of Ploucquet.^[114]

Wolff influenced German Enlightenment scientist Tobias Mayer (1723–1762).^[115][116] Alsatian polymath Johann Heinrich Lambert (1728–1777) further developed Leibniz's universal language, Ploucquet's logic, and Mayer's science in Neues Organon (1764), in contrast to Aristotle's old Organon.^[117] After Mayer's death, Abraham Gotthelf Kästner (1719–1800) was director of the Observatory at Göttingen.^[118] Kästner taught philosopher and physicist Georg Christoph Lichtenberg (1742–1799).^[119]

Art theorists Alexander Gottlieb Baumgarten (1714–1762) and Georg Friedrich Meier (1718–1777) were students of Wolff. Baumgarten coined the term aesthetics, and Meier was the teacher of Aufklärer Thomas Abbt (1738–1766).^[120]

Mendelssohn

Moses Mendelssohn (1729–1786) of the Haskalah, or 'Jewish Enlightenment', wrote Phaedon (1767), a defense of immortality, after the death of Thomas Abbt. One scholar describes Mendelssohn as “the last great representative of the Leibniz-Wolffian school”.^{[121][122][e]} Mendelssohn influenced Salomon Maimon (1753–1800).^[123]

Lessing

Abbt admired Gotthold Ephraim Lessing (1729–1781), who embraced the Enlightenment and religious tolerance, for instance in his play Nathan the Wise (1779), written as a tribute Mendelssohn.^[124] Lessing said there was an "ugly, broad ditch" between the "accidental truths of history" and "the necessary truths of reason".^[125]

Lessing published the work of deist and rationalist Hermann Samuel Reimarus (1694–1768) anonymously as the Wolfenbüttel Fragmente.^[126] A friend of Lessing and Mendelssohn was Christoph Friedrich Nicolai (1733–1811), who influenced popular philosopher Johann August Eberhard (1739–1809).^[127][128] As well as Kant, Lambert, Eberhard, and Johannes Nikolaus Tetens (1736–1807) were early phenomenologists.^{[129][130][131]} Tetens has been called the "German Locke" and was influenced by Scottish common sense realism.^[132]

Kant

Königsberg University professor Immanuel Kant (1724–1804) studied under Wolffian Martin Knutzen (1713–1751).^[133] Kant published his elaborate philosophy of transcendental idealism in the Critique of Pure Reason (1781). Since its publication, Kant has been considered one of the greatest influences in all of western philosophy. Kant saw himself engaged in a "Copernican Revolution", shifting one's outlook into the mind rather than out to the world.^[134] Kant was regarded as the "destroyer" of (scholastic) metaphysics ever since he was called the "all-destroying Kant" by Mendelssohn.^[135]

Kant distinguished between analytic truths stipulated by definition, and synthetic truths about the world; as well as between knowledge obtained prior to experience or a priori, and after experience, or a posteriori.^[134]

Kant attempted to determine what can be known about the world, through the use of reason independent of all experience, which Kant called the synthetic a priori. Briefly, he concluded knowledge is had through experience, but what can be known is limited by how the mind can think: if we can only comprehend things in terms of, for example, cause and effect, then we can only know causes and effects. It follows one can know the form of all possible experience in the apparent, phenomenal world; but nothing else, one can never know the noumenal world as it really is, the "thing-in-itself" absent a standpoint, and therefore one can never know the world in its entirety.^[136]

Kant was a Pietist who sought the limits of knowledge “in order to make room for faith”. Kant also published the Prolegomena (1783), the Critique of Practical Reason (1788), and the Critique of Judgment (1790). The Critique of Practical Reason has Kant's deontological ethics, with the categorical imperative; and a moral argument for God, free will, and the immortality of the soul.^[137] There was also Groundwork of the Metaphysics of Morals (1785) and The Metaphysics of Morals (1797). The Critique of Judgment contains Kant's aesthetics, including his views on the beautiful and the sublime. Kant considered disinterest to be a key part of the judgement of taste.^[138]

Knutzen also introduced Kant to Newtonianism.^[133] Kant was a champion of the Enlightenment who wrote Idea for a Universal History with a Cosmopolitan Purpose (1784) and adopted the phrase Sapere aude (Dare to know) in his essay "Answering the Question: What Is Enlightenment?" (1784).

Kant published three separate texts on the 1755 Lisbon earthquake.^{[139][140][141][142]} Kant's theory involved shifts in huge caverns filled with hot gases. While inaccurate, it was one of the first attempts to naturally explain earthquakes. It "probably represents the beginnings of scientific geography in Germany. And certainly the beginnings of seismology".^[143] Kant also wrote on anthropology in Anthropology from a Pragmatic Point of View (1798).

Early critics of Kant's "thing-in-itself" include Eberhard, Friedrich Bouterwek (1766–1828) and rational realist Christoph Gottfried Bardili (1761–1808).^[144]

German idealism

Growing out of Kant's work, German idealism was a late 18th and 19th century movement, linked to both the Enlightenment's revolutionary politics, and Counter-Enlightenment-associated German Romanticism.^[145][146] Besides Kant, the prominent German idealists were Johann Gottlieb Fichte, Friedrich Wilhelm Joseph Schelling, and most notably Georg Wilhelm Friedrich Hegel.^[145][147] Also important were Friedrich Heinrich Jacobi, Karl Leonhard Reinhold, and Arthur Schopenhauer.^[145]

The French Revolution occurred in 1789.^[148] The 19th century in Germany saw the Napoleonic Wars (1803–1815), revolutions of 1830 and 1848, and Unification of Germany and German Empire (proclaimed January 18, 1871) led by Otto von Bismarck following the Franco-Prussian War (1870).^[149]

Hamann and Herder

Johann Georg Hamann

Johann Gottfried Herder

Kant's criticism of rationalism influenced German Romanticism.^[146] Johann Georg Hamann (1730–1788) and Johann Gottfried Herder (1744–1803) were influential both for Romanticism and the proto-Romantic Sturm und Drang movement.^[150][146]

Hamann wrote Socratic Memorabilia (1759), comparing Socratic ignorance with religious faith. His most notable contributions were to philosophy of language. He stated "Reason is language".^[151]

Kant read Hamann's translation of Scottish skeptic philosopher David Hume, whose criticism of causation in Enquiry Concerning Human Understanding (1739) Kant credited for awakening him from his "dogmatic slumber".^[152] Maimon attempted an intermediate position between Hume and Kant.^[123] Hamann also introduced Kant to the work of French philosophe Jean-Jacques Rousseau, whose portrait hung in Kant's home, and whom Kant called "Newton of the moral world".^[153][154]

Hamann's student Herder won a Berlin Academy prize essay contest and subsequently published Treatise on the Origin of Language (1772).^[155][156] Herder was one of the first to argue language shapes thought,^[146] and his vitalism also revived philosophy of mind.^[157] Herder disputed the ruins of Persepolis with Göttingen professor Arnold Hermann Ludwig Heeren (1760–1842), arguing they were of Jamshid origin rather than Achaemenid.^[158]

Wilhelm von Humboldt (1767–1835) similarly saw language as creative rather than merely representative.^[159][160] His younger brother was polymath Alexander von Humboldt.^[161] Both are namesakes of the Humboldt University of Berlin.^[162]

Romanticism

The Early Romantics centered in Jena included poets Friedrich Hölderlin, Novalis, and Ludwig Tieck, brothers Karl Wilhelm Friedrich Schlegel and August Wilhelm Schlegel, theologian Friedrich Schleiermacher, and platonic realist August Ludwig Hülsen.^{[172][173][174]}

Friedrich Hölderlin (1770–1843) wrote the novel Hyperion (1799).^[175] Novalis (1772–1801) was a magical idealist.^[176] Ludwig Tieck (1773–1853) published tragic author Heinrich von Kleist (1777–1811).^[177]

Friedrich Schlegel (1772–1829) coined the term historicism.^[178] According to him, art historian Johann Joachim Winckelmann marked the beginning of a new era in philosophy by recognizing the unique character of antiquity.^[179] The Schlegel brothers founded the journal Athenaeum and influenced conservative Adam Müller (1779–1829).^[180]

Friedrich Schleiemacher (1768–1834) argued the true essence of religion lies not in the active love of one’s neighbor, but in passive contemplation of the infinite. Schleiermacher also contributed to the history of philosophy as "the pioneer of Heraclitus studies" and by challenging the Tübingen notion of Plato's unwritten doctrines. Schleiermacher taught polymath Hermann Grassmann (1809–1877).^[181]

Following the French July Revolution (1830) and German Hambach Festival (1832), Heinrich Heine (1797–1856) criticized romanticism and hoped to inspire revolution, writing On the History of Religion and Philosophy in Germany (1834), an attack on Madame de Staël's book On Germany (1813).^[182][183] The period preceding the 1848 revolutions, the Vormärz and Biedermeier era, saw the end of the Romantic era.^[184]

Fichte

Johann Gottlieb Fichte's (1762–1814) philosophy or "science of knowledge" was a subjective idealism rejecting even the "thing-in-itself" in works like Foundations of the Science of Knowledge (1795) and The Vocation of Man (1799). Fichte states the starting point of his philosophy is the absolute, self-aware, thinking "I", which itself creates the world with all its laws.^{[185][186][187]}

Romanticism also saw the birth of nationalism, inspired by the likes of Rousseau and Herder.^[188] The word Volkstum (nationality) was coined as part of the struggle against French emperor Napoleon and Wars of Liberation. Fichte is regarded as one of the founders of modern German nationalism^[189] when he expressed the unity of language and nation in his Addresses to the German Nation (1808):

Those who speak the same language are joined to each other by a multitude of invisible bonds by nature herself, long before any human art begins; they understand each other and have the power of continuing to make themselves understood more and more clearly; they belong together and are by nature one and an inseparable whole. ...Only when each people, left to itself, develops and forms itself in accordance with its own peculiar quality, and only when in every people each individual develops himself in accordance with that common quality, as well as in accordance with his own peculiar quality—then, and then only, does the manifestation of divinity appear in its true mirror as it ought to be.^[190]

Fichte was of pivotal importance for the Romantics. Friedrich Schlegel identified the "three sources of Romanticism": the French Revolution, Fichte's philosophy, and Wilhelm Meister.^[191] Fichte also influenced On War (1832) author Carl von Clausewitz.^[192] The University of Jena expelled Fichte on the charge of atheism.^[185]

Schelling

Friedrich Wilhelm Joseph Schelling (1775–1854) initially adhered to Fichte, and associated with the Schlegel brothers, but subsequently created his own philosophy, called by one writer "the first manifestation of irrationalism".^[193] Schelling averred "it is a poor objection to a philosopher that he is unintelligible."^[194]

Influenced by Böhme and Kant, Schelling advanced organicism and Naturphilosophie, which sees nature as an expression of spiritual powers, expressed in the System of Transcendental Idealism (1800).^[195] Schelling believed the absolute, or spiritual basis of nature, develops and eventually dissolves distinctions into contradictions, inaugurating idealist dialectics and influencing Schelling's monist "philosophy of identity." The absolute is immersed in the same passive, motionless state as Schleiermacher's God.^[196]

In his early or negative philosophy, such as the posthumously published The Philosophy of Art (1859), Schelling assigns a special role to art, in which freedom and the reality of "higher being" is fully comprehended, as contrasted with nature.^[197] The artist is a kind of mystical creature who creates the world with "revelation", both conscious and unconscious intuition, or "inner contemplation."^{[198][199][f]} In later life, Schelling evolves towards a mythological and mysticist "philosophy of revelation".^[199]

Schelling influenced Karl Christian Friedrich Krause (1781–1832), who founded Krausism, another "philosophy of identity". Krausism was panentheism, and influential in Restoration Spain.^[201]

Hegel

Georg Wilhelm Friedrich Hegel (1770–1831), a protégé of von Abel and influenced by Böhme,^[202] built a system of absolute idealism. Hegel thought the world was always in motion and contradictory;^[g] a dialectic typically presented as a three-stage process of thesis, antithesis, and synthesis.^[204]

The absolute is expressed in self-knowledge, which increasingly presents itself in history. Hegel traces its development in three main stages in The Phenomenology of Spirit (1807). The first stage of the absolute is logical concepts, set forth in The Science of Logic (1812–1816).^[205] The second stage is nature, expounded in the "Philosophy of Nature" entry from the Encyclopedia of the Philosophical Sciences (1817).^[206] The highest, third stage is spirit, presented in art, religion, and philosophy, as revealed in "Philosophy of Spirit" from the Encyclopedia, and his University of Berlin lectures, covering material not found in his published writings.^[207][h]

The Lectures on the Philosophy of History and Elements of the Philosophy of Right (1821) contain Hegel's political philosophy.^[208]

Jacobi

Friedrich Heinrich Jacobi (1743–1819) debated the pantheism controversy with Mendelssohn, a result of Lessing privately avowing Spinozism.^[209] After Fichte was accused of atheism, in the atheism dispute, Jacobi further explicated his view that the Enlightenment and philosophy led to nihilism, popularizing the concept. Jacobi advocated fideism (faith and revelation) instead of speculative reason. Pietist Thomas Wizenmann (1759–1787) was a disciple.^[210]

Danish philosopher Søren Kierkegaard (1813–1855) was influenced by Jacobi and is widely considered to be the first existentialist philosopher.^{[211][212][213]} Kierkegaard believed religion required a leap of faith (salto mortale). According to one writer, Kierkegaard's views on philosophy and aesthetics were also an offshoot of Romanticism.^[214]

Reinhold

Karl Leonhard Reinhold (1757–1823) was one of the best known popularizers of Kant with Letters on the Kantian Philosophy (1787).^[215] Reinhold advanced "elementary philosophy" which held the first principle of philosophy is "the principle of consciousness" that there is a subject, object, and a relation between them.^[216]

Reinhold influenced Friedrich Adolf Trendelenburg (1802–1872), who as well as German idealism defended Aristotelian philosophy and teleology.^[217] His student, ethical activist Rudolf Christoph Eucken (1846–1926), won the 1908 Nobel Prize in Literature.^[218][219]

Hegelianism

Hegel was highly influential throughout the nineteenth century. Two distinct groups of Hegelians can be roughly divided into the more conservative 'right', or 'old', Hegelians, and the politically and religiously radical 'left', or 'young', Hegelians. The groups were not as unified or as self-conscious as the labels 'right' and 'left' make them appear. The term was first used by David Strauss (1808–1874) to describe Bruno Bauer (1809–1882)—who actually was a typically 'Left', or Young, Hegelian.^[220] Schelling was invited by Prussian king Friedrich Wilhelm IV to a University of Berlin professorship to combat the Young Hegelians.^[199]

Right Hegelians

The Right Hegelians were Hegel's successors at the University of Heidelberg and University of Berlin. They included Karl Daub, Hermann Friedrich Wilhelm Hinrichs, Leopold von Henning, and Heinrich Gustav Hotho. Karl Daub (1765–1836), in his book Judas Ischariot (1816), writes Judas Iscariot was "an incarnation of the devil".^[221] Heinrich Gustav Hotho (1802–1873) compiled Hegel's posthumously published Lectures on Aesthetics (1835).^[222]

The Right Hegelians believed the dialectic of history had come to an end—Hegel's Phenomenology of Spirit reveals itself to be the culmination of history.^[223] Hegel's thought that reason and freedom had reached their zenith in the existing Prussian state was viewed as a paradox, at best; the Prussian regime provided extensive civil and social services, good universities, high employment, and some industrialization, but it was considered rather backward compared with the more liberal constitutional monarchies of France and Britain.^[223]

Speculative theism

Speculative theism was an 1830s movement closely related to, but distinguished from, Right Hegelianism.^[224] Its proponents Immanuel Hermann Fichte (1796–1879), Christian Hermann Weisse (1801–1866), and Hermann Ulrici (1806–1884) were united in their demand to recover the "personal God" after panrationalist Hegelianism.^[225][226]

Weisse and panpsychist Gustav Fechner (1801–1887) taught anti-psychologism advocate and logician Hermann Lotze (1817–1881).^[227] Lotze criticized vitalism, proposing teleological idealism and the principle of teleomechanism, that mechanism is compatible with teleology.^[217] Lotze influenced personalists, theologian Albrecht Ritschl, and perspectivist Gustav Teichmuller (1832–1888).^[228]

Young Hegelians

Ludwig Feuerbach

Bruno Bauer

David Strauss

Max Stirner

Members of the Young Hegelians

The Young Hegelians included Ludwig Feuerbach, David Strauss, Bruno Bauer, and Max Stirner among their ranks. They rejected utopian aspects of Hegelianism that "Old Hegelians" had interpreted to mean the world had already essentially reached perfection.^[229]

They drew on Hegel's idea that the purpose and promise of history was the rejection of everything restricting freedom and reason; and they proceeded to mount radical critiques, first of religion and then of the Prussian political system. They felt Hegel's belief in the end of history conflicted with other aspects of his thought. They also felt the dialectic was certainly not complete, given the irrationality of religious beliefs and the apparent lack of political and religious freedom in Prussian society.^[229]

Ludwig Feuerbach (1804–1872) wrote The Essence of Christianity (1841), arguing God is anthropomorphizing.^[230] Strauss was a pioneer in the historical investigation of Jesus and connected to the Tübingen School historical-critical method.^[231] Bauer was another critic of both Judaism and Christianity and a central figure in the intellectual circles of the Vormärz.^[232] Max Stirner (1806–1856) was an anarchist.^[233]

Feuerbach influenced positivist Friedrich Jodl (1849–1914).^[234] The Tübingen School was led by Ferdinand Christian Baur (1792–1860), who taught Jakob Friedrich Reiff (1810–1879), teacher of Edmund Pfleiderer (1842–1902), younger brother of Otto Pfleiderer.^[235]

Materialism

Many post-1848 intellectuals abandoned metaphysics.^[236] The materialism controversy challenged conventions in the 1850s. Zoologist Carl Vogt (1817–1895) argued mental processes were entirely physical, stating "thoughts stand in the same relation to the brain as bile does to the liver or urine to the kidneys."^[237] Vogt was supported by Ludwig Büchner (1824–1899) and opposed by Rudolf Wagner (1805–1864) and Justus von Liebig (1803–1873).^[238]

Marx and Engels

Young Hegelian Karl Marx (1818–1883), influenced by Zionist Moses Hess (1812–1875), incorporated French socialism and British economics.^[239] He wrote Das Kapital, a critical examination of capitalism. Marxism became one of the major forces on twentieth century world history.^[240][241]

Karl Marx

Friedrich Engels

Friedrich Engels (1820–1895), also a Young Hegelian, was a friend and associate of Marx, together with whom he wrote the Communist Manifesto (1848). Marx and Engels developed the criticism of private property, theory of class struggle and scientific socialism (communism), and the doctrines of dialectical and historical materialism rather than German idealism. As they wrote in the posthumously published The German Ideology (1932), "In direct contrast to German philosophy which descends from heaven to Earth, here we ascend from Earth to heaven."^[242] As Marx similarly said in an afterward in Das Kapital, Hegel "is standing on its head. It must be turned right side up again".^[243]

Engels' philosophical works include Ludwig Feuerbach and the End of Classical German Philosophy (1888), which explains how Hegel and Feuerbach led to Marx. There was also The Holy Family (together with Marx, 1844) criticizing the Young Hegelians,^[244] Socialism: Utopian and Scientific (1880) studying the utopian socialists and their differences with scientific socialism,^[245][246] Dialectics of Nature (1883) applying Marxism to science,^[247] and The Origin of the Family (1884) arguing that the family is an ever-changing institution shaped by capitalism.

Dühring

Engels dedicated his entire book Anti-Dühring (1878) to criticizing Dühring's views.^[189] Eugen Dühring (1833–1921) was a German socialist, professor of mechanics, philosopher and economist. In philosophy he was an eclectic who combined positivism, mechanistic materialism and idealism into a "philosophy of the actual". Dühring’s views found support among some Social Democrats, most notably revisionist Eduard Bernstein (1850–1932).^[248]

Schopenhauer

Arthur Schopenhauer (1788 –1860) was an opponent of Hegel, influenced by Eastern and Hindu philosophy.^[j] His teacher was Gottlob Ernst Schulze (1761–1833), who wrote Aenesidemus (1792), a skeptical polemic against Kant and Reinhold.^[256] Leibniz also influenced Schopenhauer, whose dissertation was On the Fourfold Root of the Principle of Sufficient Reason (1813).

Schopenhauer followed Kant but concluded introspection was a way to access the thing-in-itself. Schopenhauer's most influential work, The World as Will and Representation (1818), claimed at the heart of the world and man lies the “will to life.” Schopenhauer is seen as foreshadowing the work of psychologist Sigmund Freud (1856–1939) and the unconscious mind.^[257]

Schopenhauer was a pessimist whose analysis of will led him to believe that desires can never be fulfilled. Consequently, he eloquently described a lifestyle of abandoning desires, similar to the asceticism of Buddhist Nirvana, Vedanta, and the Desert Fathers of early Christianity.^[258] Schopenhauer also thought art could alleviate suffering.^[259]

Post-Schopenhauerian pessimism became a popular trend,^[260] but was viewed with disdain by other popular philosophies at the time, since the typical pessimist was seen as detriment to society in an age of revolution and science. A group of philosophers influenced by Schopenhauer responded to this growing criticism, such as Julius Bahnsen, Karl Robert Eduard von Hartmann, and Philipp Mainländer.^[k]

Mainländer

Philipp Mainländer (1841–1876) similarly sees the will as the first principle. However, with Schopenhauer, the will is singular, unified, and beyond time and space, while Mainländer instead believed in pluralism.^[263] Mainländer also believed in salvation for all of creation. With Schopenhauer, the silencing of the will is a rare event. The artistic genius can achieve this temporarily, but only a few saints have sustained it. For Mainländer, the whole cosmos is slowly but surely moving towards silencing the will-to-live and "redemption".^[264] The appendix to Mainländer's The Philosophy of Redemption contains the "Critique of the Doctrines of Kant and Schopenhauer".^[265]

Haeckel

Ernst Haeckel (1834–1919) introduced to Germany Charles Darwin's theory of evolution, as found in On the Origin of Species (1859).^[266] Haeckel propounded recapitulation theory, or "ontogeny recapitulates phylogeny", and was also a monist.^[267] Haeckel was opposed by neo-vitalist Hans Driesch (1867–1941).^[268]

Neo-Kantianism

Neo-Kantianism was a late 19th century revival of Kant's philosophy, influenced especially by Schopenhauer's criticism, as well as by other philosophers such as Jakob Friedrich Fries (1773–1843) and Johann Friedrich Herbart (1776–1841). Otto Liebmann (1840–1912) urged going "back to Kant".^[269]

The neo-Kantian schools emphasized understanding over sensibility and preferred scientific readings of Kant. The neo-Kantian school also made early use of such philosophical terminology as "epistemology" and upheld its prominence over ontology.^[270] Eduard Zeller (1814–1908) combined Neo-Kantianism with the methods of the Tübingen School.^[271] The Neo-Kantians influenced socialists such as Eduard Bernstein^[272] and the Austromarxists.^[273]

Southwest school

The Southwest School (or Heidelberg School or Baden School) emphasized culture and value theory (notably the fact–value distinction), and included Lotze student Wilhelm Windelband, Alois Riehl, Heinrich Rickert, Ernst Troeltsch, and Emil Lask.^[276] Wilhelm Windelband (1848–1915) influenced sociologist Max Weber (1864–1920), author of The Protestant Ethic and the Spirit of Capitalism (1905).^[277] Max's brother Alfred Weber taught Karl Mannheim.^[278]

Nietzsche

Friedrich Nietzsche (1844–1900) was an influential philosopher and philologist, and initially a proponent of Schopenhauer. Nietzsche was also an irrationalist and perspectivist influenced by Romanticism and Teichmuller.^[l]

Nietzsche soon replaced Schopenhauer's will to life with the will to power.^[285] He disavowed Schopenhauer's pessimism, and sought to provide a life-affirming, positive philosophy. He believed this task to be urgent, as he believed a form of nihilism caused by modernity and Christianity was spreading across Europe, which in works like Thus Spoke Zarathustra (1885) and The Gay Science (1882),^[m] he summed up in the phrase "God is dead".^[288]

He believed he found his solution in the concepts of the Übermensch and Eternal Recurrence.^[289] Nietzsche followed this with the aphoristic Beyond Good and Evil (1886). In On the Genealogy of Morals (1887), Nietzsche gives a genealogical critique of Christian morality and a related theory of master–slave morality. He continues the polemic against Christianity in The Antichrist (1895).^[290]

Dilthey

Trendelenburg student Wilhelm Dilthey (1833–1911) along with Nietzsche, Georg Simmel (1858–1918), and Ludwig Klages (1872–1956), founded the intuitionist and irrationalist school of German Lebensphilosophie.^[291] Dilthey was a historist who initiated a Romantic renaissance with his Schleiermacher biography and works on Novalis and Hölderlin.^[292] His vitalistic interpretations of Hegel and Goethe were influential; the latter led from Simmel and Friedrich Gundolf (1880–1931) to Klages,^[293] who coined the term logocentrism.^[294] Dilthey and Simmel influenced Austrian-Israeli existentialist Martin Buber (1878–1965), author of I and Thou (1923).^[295] Dilthey also influenced Hermann von Keyserling (1880–1946).^[296]

Mach

Austrian physicist Ernst Mach (1838–1916) in works such as Analysis of Sensations (1885) and Cognition and Delusion (1905) propounded neutral monism, affirming everything was physical, but equally considered “complexes of sensations,” rejecting an external world independent of consciousness. Mach and teacher Gustav Kirchoff (1824–1887) believed in the "economy of thought," to eliminate all superfluous metaphysical elements. Following Leibniz, Mach was a relationist about space.^[297] Mach's rival was Ludwig Boltzmann (1844–1906), notable for the Boltzmann brain thought experiment.^[298]

Fritz Mauthner (1849–1923) was Mach's student. Mach's views were widespread among physicists, including theory of relativity pioneer Albert Einstein, electromagnetism pioneer Heinrich Hertz (1857–1894), and Philipp Frank (1884–1966).^[189] They also found support among Marxists such as Friedrich Adler (1879–1960) and Otto Bauer (1881–1938), and in Russia among a part of the Bolshevik intelligentsia.^[n]

Richard Avenarius (1843–1896) was a founder of empirio-criticism. Avenarius similarly denied a world independent of consciousness. According to Avenarius, consciousness and being, subject and object ("I" and "environment") are in constant, obligatory connection ("fundamental coordination").^[299] Joseph Petzoldt (1862–1929) was a disciple.^[299]

Communist Vladimir Lenin (1870–1924) dedicated his entire book Materialism and Empirio-Criticism (1909) to the criticism of Mach, Frank, and Avenarius, writing "this philosophy serves the clergy, serves the same purposes as the philosophy of Berkeley and Hume."^[189]

Austrian realism

A school of thought called Austrian realism formed in the former state of Austria-Hungary,^[300] notable for influencing both analytic and continental philosophy.^[301][o]

In Psychology from an Empirical Standpoint (1874), Trendelenburg student and University of Vienna philosopher and psychologist Franz Brentano (1838–1917) re-introduced the scholastic concept of intentionality, or aboutness.^[303] For Brentano, all mental events or acts of consciousness have a real, non-mental intentional object, which the thinking is directed at or "about".^[304] Intentionality is "the mark of the mental."^[304] Intentionality is to be distinguished from intention or intension.^[305]

The School of Brentano included Edmund Husserl (1859–1938) and Alexius Meinong (1853–1920). Meinong defends his unique ontology of empty names referring to real, nonexistent objects. This view is known as Meinongianism, or pejoratively as Meinong's jungle. According to Meinong, objects like flying pigs or golden mountains have real being, even though they do not exist. Meinong founded the Graz School, which included Ernst Mally (1879–1944).^[306]

Meinong's student Christian von Ehrenfels (1859–1932) is one of the founders of Gestalt psychology, also influenced by Goethe and Mach.^[307] Carl Stumpf (1848–1936), a student of Brentano and Lotze, founded the Berlin School of experimental psychology, which included Max Wertheimer, Wolfgang Köhler, and Kurt Koffka.^[308]

Brentano also influenced the Polish Lwów–Warsaw school, founded by Kazimierz Twardowski, who emphasized "small philosophy", or the detailed, systematic analysis of specific problems.^[309] Husserl, Meinong, and Twardowski were influenced by Bohemian Catholic and logical realist Bernard Bolzano (1781–1848).^[310] Bolzano foreshadowed analytic philosophy with talk of propositions, but in Kantian language, "sentences-in-themselves".^{[310][311][p]}

Neo-Romanticism

Adam Müller influenced Austrian neo-romantic universalist Othmar Spann (1878–1950), who taught Friedrich Hayek (1899–1992), critic of scientism and winner of the 1974 Nobel Prize in economics.^[319]

Neo-Hegelianism

Neo-Hegelianism, also known as Post-Hegelianism, was a trend including Richard Kroner, Siegfried Marck, Arthur Liebert, and Hermann Glöckner.^[189] Richard Kroner (1884–1974) was a Jewish convert to Christianity who dubbed Hegel "the Protestant Aquinas".^[320]

Spengler

German philosopher of history Oswald Spengler (1880–1936) was influenced by Goethe, Nietzsche, and Neo-Kantian scientific fictionalist Hans Vaihinger (1852–1933), author of The Philosophy of 'As if' (1911).^[321] Spengler's main work is The Decline of the West (1918), published shortly after World War I. Spengler predicts the inevitable collapse of European civilization. In Man and Technics (1931), Spengler said "Optimism is cowardice."^[322]

Spengler’s philosophy of history is based on analogy and denies causation, knowledge, and truth, preferring intuition and absolute relativism.^[323] Spengler contrasts the scientific understanding of natural historical development with historical fatalism or “destiny.”^[323]

Spengler rejects historical progress and linear, unified whig history. adopting a cyclical, organic theory of history.^[324] Independent, unique “cultures,” special organisms, guided by a unique idea and destiny, experience periods of early age emergence, middle age flourishing and old age dying. According to Spengler, the philosopher of history comprehends the “morphological structure” of the "soul" of each “culture". He calls Western European culture Faustian, ruled by the idea of infinity, and says its decline started in the 19th century, with the victory of capitalism.^[325]

Spengler was an elitist who praised the era of feudalism and the “Old Prussian spirit” of monarchy, nobility and militarism,^[326] stating war is “an eternal form of higher human existence.”^[327] He disliked democracy, declaring "the mass", the “fourth estate”,^[s] were “outside" of history and culture, a “radical nothing.”.^[326]

He advances “German socialism” against “Marxist socialism” in Prussianism and Socialism (1919).^[328] Englishman Arnold Toynbee advanced similar views.^[189] Historicist Friedrich Meinecke (1862–1954) criticized Spengler.^[329]

Spartacists

The Marxist revolutionaries after World War I such as Rosa Luxembourg and Karl Liebknecht founded the Spartacist League.^[330] The revolutionaries were defeated by the Freikorps.

Nazi philosophy

Nazi Germany was led by Hitler and its combination of anti-semitism, nationalism and socialism, arguably influenced by Spengler.^[328] The Nazi Party included Carl Schmitt (1888–1985), author of The Concept of the Political (1932),^[331] and Martin Heidegger, who took the vow of allegiance.^[332] Ernst Mally joined the National Socialist Teachers League soon after the Anschluss (1938).^[333] Meinecke supported the invasion of Poland (1939).^[334]

The Nazi Party or National Socialist German Worker's Party was an outgrowth of the German Worker's Party founded shortly after World War I by Pan-German folkist Anton Drexler, poet Dietrich Eckart, economist Gottfried Feder, and Karl Harrer.^[335]

The Nazis propounded the Stab-in-the-back myth and opposed the system of the Weimar Republic. They denounced the subsequent revolution and German leaders who signed the Treaty of Versailles and Armistice of 11 November 1918 as "November criminals".^[336]

The best known work of Nazi philosophy was The Myth of the Twentieth Century (1930) by head of the Militant League for German Culture Alfred Rosenberg (1893–1946). It said soul was race seen from within, and was awarded the State Prize for Art and Science for 1937.^[337] Its title was an homage to Houston Stewart Chamberlain's The Foundations of the Nineteenth Century (1899).^[338]

Positive Christianity was a religious movement in Nazi Germany.^[339] The pagan German Faith Movement was founded by Tübingen Indologist Jakob Wilhelm Hauer (1881–1962) and influenced by occultist Guido von List (1848–1919), founder of Wotanism and author of The Secret of the Runes (1908).^[340]

Nazi Germany's most prominent academic philosopher was Alfred Baeumler (1887–1968), director of the Institute for Political Pedagogy in Berlin, who advocated Nietzsche's philosophy.^[341] There was also anti-Kantian Ernst Krieck (1882–1947).^[342]

By 1933, the various neo-Kantian circles in Germany had dispersed.^[270] The Nazis also expelled both the analytic Vienna Circle and the continental Frankfurt School, entrenching them in American philosophy. Emil Fackenheim (1916–2003) was interned at Sachsenhausen concentration camp.^[343]

Analytic philosophy

Early Wittgenstein and the Vienna Circle

Ludwig Wittgenstein of the prominent Wittgenstein family read solipsist and misogynist Otto Weininger (1880–1903) in his youth.^[354] After studying with Russell, Wittgenstein served for the Austro-Hungarian Army in World War I, simultaneously developing a comprehensive system of logical atomism and picture theory of meaning. When Wittgenstein published Tractatus Logico-Philosophicus (German: Logisch-Philosophische Abhandlung, 1921), he thought he solved all the problems of philosophy.^[355][356]

The Tractatus starts, "The world is all that is the case." Wittgenstein claims the universe is the totality of actual states of affairs, which can be expressed and mirrored by the language of first-order predicate logic. Thus, a picture of the universe can be constructed by expressing facts in the form of atomic propositions and linking them using logical operators.^[357][358]

The Tractatus introduced philosophers to the terms tautology, truth conditions, and to the truth table method. Wittgenstein believed tautologies or logical truths say nothing, but show the logical structure of the world,^[359][360] and has been labeled a mystic who believed in the ineffable by some readers.^[361] The Tractatus further ultimately concludes that all of its propositions are meaningless, illustrated with a ladder one must toss away after climbing up it.^[362] The book ends, "Whereof one cannot speak, thereof one must be silent."^[363]

The Vienna Circle (originally the Ernst Mach society) formed to promote scientific thought and combat the influence of Hegelian system-building.^[364] Their philosophy called logical positivism was influenced by Wittgenstein and believed everything meaningful is either an analytic truth or a verifiable synthetic truth. They were led by Moritz Schlick (1882–1936) and included Philipp Frank, Rudolf Carnap (1891–1970), Hans Hahn (1879–1934), and Otto Neurath (1882–1945).^[364] The closely related Berlin Circle was led by Hans Reichenbach (1891–1953) and included Carl Hempel (1905–1997) and mathematician David Hilbert (1862–1943).^[365][v]

Hahn's student Kurt Gödel (1906–1978) published his incompleteness theorems (1931), showing Hilbert's program was impossible.^[367] Schlick was murdered by his former student Johann Nelböck.^[368] Vienna Circle associate Karl Popper (1902–1994) was notable for falsification and The Open Society and Its Enemies (1945).^[369]

Later Wittgenstein

Wittgenstein then had a radical break with his early philosophy, as exemplified by the posthumously published Philosophical Investigations (1953).^[370]

The later Wittgenstein develops a therapeutic approach. He introduces the concept of a "language-game" as a "form of life". By "language-game", he meant a language simpler than an entire language. Wittgenstein argued that a word or sentence has meaning only as a result of the "rule" of the "game" being played. Depending on the context, for example, the utterance "Water!" could be an order, the answer to a question, or some other form of communication. Rather than his prior picture theory of meaning, the later Wittgenstein advocates a theory of meaning as use, according to which words are defined by how they are used within the language-game.^[371]

The notion of family resemblance thinks things thought to be connected by one essential, common feature may in fact be connected by a series of overlapping similarities, where no one feature is common to all of them. Games, which Wittgenstein used to explain the notion, have become the classic example.^[372]

Philosophical Investigations also contains the private language argument. Another point Wittgenstein makes against the possibility of a private language involves the beetle-in-a-box thought experiment. He asks the reader to imagine that each person has a box, inside which is something that everyone intends to refer to with the word beetle. Further, suppose that no one can look inside another's box. Under such a situation, Wittgenstein says the word beetle is meaningless.^[373]

He also uses the duck-rabbit, an ambiguous image, as a means of describing two different ways of seeing: "seeing that" versus "seeing as". Wittgenstein listed his influences as "Boltzmann, Hertz, Schopenhauer, Frege, Russell, Kraus, Loos, Weininger, Spengler, and Sraffa."^[374]

Continental philosophy

Edmund Husserl

Karl Jaspers

Martin Heidegger

Hannah Arendt

Continental philosophers

While some of the seminal philosophers of analytic philosophy wrote in German, 20th-century German philosophy tends to be classified as 'continental' philosophy – as befits Germany's position on the European 'continent' as opposed to the British Isles or Anglosphere.

Existentialism influenced continental philosophy. Phenomenologist Martin Heidegger is often identified as an existentialist, though he rejected this. Karl Jaspers (1883–1969) also rejected the label, despite being a student of Kierkegaard and Nietzsche. Jaspers' early philosophy believed in the authentic self or existenz, found in Philosophy of Existence (1938).^[375]

Phenomenology

Phenomenology is philosophy which emphasizes phenomena as it is given to consciousness, attempting to avoid imposed explanations.^[376] It began with the transcendental phenomenology of Edmund Husserl, and has had a large influence on continental philosophy, particularly existentialism and poststructuralism.^[377]

Edmund Husserl

Influenced by Brentano and Stumpf, Husserl taught at the University of Göttingen. Frege responded to Husserl's psychologism in Philosophy of Arithmetic (1891), and Husserl subsequently changed his mind, refuting psychologism in his Logical Investigations (1901).^[378] Husserl's other best known work is the Cartesian Meditations (1931). Husserl advocates bracketing to focus on experience and achieve eidetic reduction. For Husserl, every mental act has noema or content.^[379]

He influenced the students of Neo-Kantian Theodor Lipps (1851–1914), such as World War I casualty Adolf Reinach (1883–1917), who started Munich phenomenology, which included Max Scheler (1874–1928).^[380] He also influenced philosophers of science like operationalist Hugo Dingler (1881–1954).^[381]

Martin Heidegger

Phenomenology was transformed by Martin Heidegger, whose magnum opus Being and Time (1927) applied phenomenology to ontology and discussed the metaphysics of presence. Heidegger is notable for such concepts as Dasein, the consciousness particular to people of "being there", and "thrownness" the feeling of being thrown into the world. He argued aletheia (usually translated as "truth") is better understood as disclosure.^[382]

Heidegger gave up "philosophy" in his later life, preferring the term "thinking".^[383] According to W. Julian Korab-Karpowicz, Heidegger, in works like his Introduction to Metaphysics (1953), believed "the thinking of Heraclitus and Parmenides, which lies at the origin of philosophy, was falsified and misinterpreted" by Plato and Aristotle, thus tainting all of subsequent Western philosophy.^[384] His later philosophy was much concerned with technology, in works like The Question Concerning Technology (1954).^[385]

Hermeneutics

Originally, hermeneutics referred to the interpretation of texts, especially religious texts. In the 19th century, Schleiermacher, Dilthey, and others expanded the discipline beyond mere exegesis into a general humanistic discipline.^[386] Schleiermacher wondered whether there could be a hermeneutics that was not a collection of ad hoc pieces of advice for the solution of specific problems, but rather a "general hermeneutics," which dealt with the "art of understanding" as such, the structure and function of understanding wherever it occurs. Later in the 19th century, Dilthey saw possibilities for continuing Schleiermacher's project as a "general methodology of the humanities and social sciences".^[387]

In the 20th century, with Martin Heidegger's Being and Time, hermeneutics took an 'ontological turn', the discipline was seen as dealing with the most fundamental questions of being.^[388][389] Heidegger developed the concept of a hermeneutic circle in The Origin of the Work of Art (1950). Heidegger's conception of hermeneutics was further developed by his pupil Hans-Georg Gadamer (1900–2002), in his book Truth and Method (1960).^[390]

Frankfurt School

In 1923, Carl Grünberg founded the Institute for Social Research, drawing from neo-Hegelianism,^[189] anti-Stalinist Marxism, Freud's psychoanalysis, and Max Weber, which came to be known as the "Frankfurt School". The Frankfurt School founded critical theory and was associated with thinkers such as Theodor W. Adorno, Ernst Bloch, Walter Benjamin, Max Horkheimer, Erich Fromm, Herbert Marcuse, and Wilhelm Reich.^[391]

The school reformed again in Frankfurt after World War II, critiquing what they saw as the problems of the Enlightenment and modernity in books like Dialectic of Enlightenment (1947) by Theodor Adorno (1903–1969) and Max Horkheimer (1895–1973) and Negative Dialectics (1966) by Adorno.^[391]

Walter Benjamin (1892–1940) was a colleague of Heidegger and Jaspers student Hannah Arendt (1906–1975), an influential political theorist.^[392] In the 1960s and the 1970s, Herbert Marcuse (1898–1979) became known as the pre-eminent theorist of the New Left.^[393] Since the 1960s, the Frankfurt School has been guided by Jürgen Habermas' (1929–2026) work on communicative reason^[394][395] and linguistic intersubjectivity. Habermas once debated Niklas Luhmann (1927–1998).^[396]