The Age of Progress and Modernity

By the end of this lesson, students will be able to:

• Account for how science and other intellectual disciplines developed and changed between 1815 and 1914 (Skill 5.A; LO F).
• Account for KC-3.6.II.A: how positivism (the philosophy that science alone provides knowledge) emphasized rational and scientific analysis of nature and human affairs.
• Account for KC-3.6.III: how the late-century turn to relativism in values and the loss of confidence in the objectivity of knowledge produced modernism in intellectual and cultural life.
• Account for KC-3.6.III.A: how philosophy moved from rational interpretations of nature and human society toward an emphasis on irrationality and impulse (Nietzsche, Bergson, Sorel).
• Account for KC-3.6.III.B: how Freudian psychology offered a new account of human nature that emphasized the irrational and the conscious-subconscious struggle.
• Account for KC-3.6.III.C: how developments in the natural sciences (quantum mechanics, special and general relativity) undermined the primacy of Newtonian physics as an objective description of nature.

Topic 7.5 traces the principal late-nineteenth-century European intellectual transformation. The mid-century positivist confidence in scientific method gave way late in the century to a new relativism: Nietzschean irrationalism in philosophy, Freudian psychology, and the Einstein-Planck physics revolution all challenged the post-Enlightenment European confidence in objective rational knowledge. The intellectual transformation is the principal "Age of Progress and Modernity" arc that Topic 7.5 covers; Topic 7.8 carries the artistic-cultural side forward.

Positivism. KC-3.6.II.A: positivism, the philosophy that science alone provides knowledge, emphasized rational and scientific analysis of nature and human affairs. The doctrine had its principal articulation in Auguste Comte (1798-1857), the French philosopher and former secretary to Henri de Saint-Simon (Topic 6.7). Comte's Course of Positive Philosophy (six volumes, 1830-1842) argued that human thought passes through three stages: theological (in which natural phenomena are explained by reference to gods or spirits), metaphysical (explained by abstract metaphysical principles), and positive (explained by empirical observation of the regularities of nature). The positive stage represents the mature condition of knowledge; the social sciences had reached this stage only with Comte's own work, which he called "sociology." Comte's System of Positive Polity (four volumes, 1851-1854) developed the political and ethical implications of the positivist program; his late-life "Religion of Humanity" attempted to substitute scientific-rational practice for traditional religion.

Comtean positivism had broad late-Victorian and continental influence. John Stuart Mill (Topic 6.7) was the principal British positivist; his System of Logic (1843) provided the systematic methodology for both natural and social science. Mill corresponded extensively with Comte and adopted much of the Comtean program before parting company with him over the late-life Religion of Humanity. Emile Durkheim (1858-1917) extended positivist methods to systematic social investigation: The Rules of the Sociological Method (1895) defended the empirical study of "social facts" as the proper subject of sociology; Suicide (1897) used French statistical records to demonstrate that suicide rates correlate with social-structural variables (religion, marriage, occupation) rather than with individual psychology alone. Durkheim's The Elementary Forms of Religious Life (1912) extended the positivist program to systematic comparative study of religion. Together, the Comte-Mill-Durkheim tradition established positivism as the principal mid-century European philosophical-methodological doctrine.

The late-century turn to relativism. KC-3.6.III: in the later nineteenth century, a new relativism in values and the loss of confidence in the objectivity of knowledge produced modernism in intellectual and cultural life. The relativist turn had three principal components: irrationalist philosophy, Freudian psychology, and the Einstein-Planck physics revolution.

Irrationalist philosophy. KC-3.6.III.A: philosophy moved largely from rational interpretations of nature and human society to an emphasis on irrationality and impulse, contributing to the view that conflict and struggle drive progress. Friedrich Nietzsche (1844-1900) was the principal late-nineteenth-century philosopher of irrationalism. A classical philologist by training, Nietzsche resigned his chair at the University of Basel in 1879 due to deteriorating health and lived in itinerant retirement until his 1889 mental collapse. His major works of the 1880s — The Gay Science (1882, expanded 1887), Thus Spoke Zarathustra (four parts, 1883-1885), Beyond Good and Evil (1886), On the Genealogy of Morality (1887) — challenged the rationalist and Christian foundations of European moral life.

Nietzsche's principal claims developed across the 1880s. The Gay Science announced "God is dead" — not as triumphant atheist proclamation but as recognition that the cultural foundations of European Christian morality had been undermined by the late-nineteenth-century scientific worldview, with consequences (philosophical, ethical, political) yet to be worked out. Beyond Good and Evil challenged the supposed objectivity of moral categories, arguing that traditional European morality (Christian, rationalist) reflects historically contingent power relations rather than universal truths. The Genealogy of Morality developed the historical-anthropological account of how Western moral categories emerged from ancient social-political conditions. The Will to Power (assembled posthumously by his sister Elisabeth from his notebooks; published 1901, expanded 1906) further developed the doctrine of the will to power as the fundamental drive underlying organic life and human culture. Nietzsche's works circulated narrowly in his lifetime; his fame and influence developed after 1890. The early-twentieth-century reception was complicated by Elisabeth's editorial manipulation of his unpublished notes for nationalist-political purposes; the proper scholarly Nietzsche reception developed only after the Second World War.

Henri Bergson (1859-1941) was the principal French parallel. His Time and Free Will (1889), Matter and Memory (1896), and Creative Evolution (1907) developed a philosophy of "duration" (lived time, distinct from the abstract clock-time of physics) and creative biological evolution driven by an "elan vital" (vital impulse). Bergson's phenomenological approach to consciousness and his rejection of mechanistic explanations of life and mind influenced early-twentieth-century European philosophy and (via Charles Peguy and others) shaped late-Third-Republic French Catholic intellectual life. Georges Sorel (1847-1922) applied irrationalist categories to revolutionary politics; his Reflections on Violence (1908) argued that revolutionary politics requires myth (specifically the "myth of the general strike") rather than rational programs.

Freudian psychology. KC-3.6.III.B: Freudian psychology offered a new account of human nature that emphasized the role of the irrational and the struggle between the conscious and subconscious mind. Sigmund Freud (1856-1939) was a Viennese neurologist who developed the systematic theory of the unconscious and the practice of psychoanalysis across the 1890s and 1900s. His principal works span four decades. The Interpretation of Dreams (1900, expanded through eight editions through 1930) argued that dreams represent the disguised fulfillment of repressed unconscious wishes and that systematic interpretation of dream content can recover material from the unconscious. Three Essays on the Theory of Sexuality (1905) outlined the developmental theory of human sexuality, including the controversial claims about infantile sexuality and the "Oedipus complex." The Ego and the Id (1923) presented the structural model of mental life: the id (instinctual unconscious drives), the ego (the conscious self mediating between id and external reality), and the superego (the internalized social-moral standards). Civilization and Its Discontents (1930) developed the cultural implications: civilization requires the suppression of instinctual drives, producing chronic discontent that no level of material progress can fully alleviate.

Freud's work circulated within a narrow Vienna scientific community before 1900 and reached broader European and American audiences gradually through the 1900s and 1910s. The 1909 Clark University lectures in Massachusetts brought Freud to American attention; his collaborator Carl Jung's later break with him (after about 1913) produced the first major schism in the psychoanalytic movement. The early-twentieth-century reception of Freud combined enthusiastic adoption (the British Bloomsbury circle; the early-twentieth-century American intellectual establishment; Modernist novelists like James Joyce and Virginia Woolf who explicitly drew on Freudian themes) with substantial scientific skepticism. The contemporary scientific consensus accepts the central Freudian insights about unconscious mental processes and developmental influences while rejecting much of the specific clinical and theoretical apparatus.

The Einstein-Planck physics revolution. KC-3.6.III.C: developments in the natural sciences, such as quantum mechanics and Einstein's theory of relativity, undermined the primacy of Newtonian physics as an objective description of nature. Two principal revolutions transformed early-twentieth-century physics.

Max Planck (1858-1947) was a German physicist whose 1900 paper on black-body radiation proposed that electromagnetic energy is emitted and absorbed in discrete packets ("quanta") rather than continuously. Planck's quantum hypothesis was developed by Einstein (1905, on the photoelectric effect, for which Einstein received the 1921 Nobel Prize), Niels Bohr (1913, atomic structure), and others into the systematic theory of quantum mechanics during the 1920s (Werner Heisenberg's matrix mechanics 1925; Erwin Schrodinger's wave mechanics 1926; Heisenberg's uncertainty principle 1927). The quantum revolution showed that the Newtonian assumption of continuous, deterministic physical processes does not hold at the atomic scale; physical reality at the atomic level is fundamentally probabilistic.

Albert Einstein (1879-1955) was a German-Swiss-American physicist whose 1905 papers transformed physics in three ways: the special theory of relativity (showing that time and space are not absolute but depend on the motion of the observer); the explanation of Brownian motion (providing decisive evidence for the atomic theory of matter); and the photoelectric effect paper (extending Planck's quantum hypothesis). The 1915 general theory of relativity extended special relativity to gravitation, treating gravity as the curvature of space-time produced by mass. The 1919 confirmation of the general theory's prediction of the bending of starlight by the sun's gravity (during the May 1919 solar eclipse, observed by Arthur Eddington) made Einstein a global celebrity. The Einstein-Planck revolution in physics had both technical implications (the Newtonian mechanics that had dominated European science since 1687 was now seen as a special case of more general theories) and broader cultural implications (the public perception that even physics had become "relative" contributed to the broader late-century relativist mood).

The Continuity and Change argument. Topic 7.5's reasoning process is Continuity and Change, applied to European intellectual life across the long nineteenth century. The principal continuity is the post-Enlightenment European commitment to systematic intellectual inquiry: Comte, Mill, Durkheim, Nietzsche, Freud, Planck, and Einstein were all heirs to the eighteenth-century scientific revolution and Enlightenment philosophical traditions, and all worked within the institutional framework of European universities, scientific societies, and publishing infrastructure that had been established across the early-modern centuries. The principal change is the late-century shift from confident rationalism to skeptical relativism: positivism's confidence that science alone produces objective knowledge gave way to Nietzschean recognition of the historical-cultural contingency of moral categories, Freudian recognition of the unconscious sources of conscious thought, and the Einsteinian recognition that even the foundations of physics are not what nineteenth-century scientists had supposed. The combination produced what historians call "Modernism" — the early-twentieth-century intellectual and cultural sensibility that defines the world Unit 8 will cover.

Three sources framing the late-nineteenth-century intellectual transformation: Comte on positivism, Nietzsche on the death of objective values, and Freud on the unconscious.

1. (Continuity and Change, Skill 5.A) Account for the late-nineteenth-century European intellectual transformation. How did mid-century positivism give way to late-century relativism, and what continuity persisted across the shift?
2. (Continuity and Change) Account for KC-3.6.II.A: how did positivism (Comte, Mill, Durkheim) emphasize rational and scientific analysis of nature and human affairs? Identify the principal claims of the positivist program.
3. (Continuity and Change) Account for KC-3.6.III.A: how did late-century philosophy turn toward an emphasis on irrationality and impulse? Compare Nietzsche, Bergson, and Sorel as principal figures.
4. (Continuity and Change) Account for KC-3.6.III.B: how did Freudian psychology offer a new account of human nature? Identify the principal Freudian works and concepts.
5. (Continuity and Change) Account for KC-3.6.III.C: how did the Einstein-Planck physics revolution undermine the Newtonian worldview? Identify the principal contributions of Planck (1900 quantum hypothesis), Einstein (1905 special relativity, 1915 general relativity), and the broader cultural implications.

Draft alignment — pending educator review. AP European History codes correspond to the official College Board Course and Exam Description (Effective Fall 2023, V.1). Statements below are paraphrased in the CountryReports voice; refer to the College Board's published CED for verbatim wording.