Thinkers Timeline

Guru Nanak (1469-1539) was the founder of Sikhism, whose teaching and poetic hymns established a distinctive religious tradition in the Punjab region of South Asia. He was born on 15 April 1469 at Rai Bhoi ki Talwandi — today Nankana Sahib, in Pakistan — to a Hindu family of the Khatri merchant caste. His father Mehta Kalu was an accountant for a local Muslim landlord; his mother Mata Tripta raised him in a household that was traditionally Hindu but exposed to the Muslim cultural world of early-sixteenth-century Punjab. He showed unusual religious sensitivity from childhood, and traditional accounts describe incidents in which he departed from expected conventions — refusing at eleven to wear the sacred thread (janeu) that marked Hindu caste identity unless it had deeper meaning, using money given for trade to feed hungry holy men rather than make a profit. He worked for several years as a clerk in a Muslim administrator's household in Sultanpur. At around thirty he had a transformative religious experience, which he later described as a direct encounter with the divine: he disappeared into a river for three days, and on emerging declared na koi Hindu, na koi Musalman (there is no Hindu, there is no Muslim). From that point he devoted his life to religious teaching. Over the following two decades he made four long journeys (udasis) — south to Sri Lanka, north to Tibet, west to Mecca and Baghdad, east through much of the Indian subcontinent — conversing with religious teachers of many traditions and composing the hymns that would form the core of Sikh scripture. In his last years he settled at Kartarpur on the Ravi River, where he established a community that combined devotional practice, manual labour, and shared meals crossing caste and religious lines. He named Bhai Lehna — renamed Guru Angad — as his successor rather than his own sons, establishing the principle of spiritual rather than hereditary succession. He died at Kartarpur on 22 September 1539. His followers preserved and expanded his hymns, which became the foundation of the Guru Granth Sahib, the scripture and ultimately the eternal Guru of the Sikh tradition.

Sigmund Freud (1856–1939) was an Austrian neurologist and the founder of psychoanalysis — one of the most influential and contested intellectual movements of the 20th century. Born into a Jewish family in Moravia (now the Czech Republic), he spent most of his life in Vienna, where he developed his theories about the unconscious mind, dream interpretation, and the psychological origins of mental illness. He was forced to flee Vienna in 1938 when the Nazis annexed Austria and died in London the following year. His ideas transformed not only psychiatry and psychology but also literature, art, anthropology, philosophy, and popular culture. Almost every time someone speaks of repression, the unconscious, denial, or a Freudian slip, they are using concepts he introduced.

Émile Durkheim (1858-1917) was a French scholar who is widely regarded as one of the founders of modern sociology. He was born in Épinal, in the Lorraine region of north-eastern France, into a Jewish family. His father, grandfather, and great-grandfather had all been rabbis, and his family expected him to follow this path. As a young man he turned away from religious study but remained deeply interested in why religion mattered to societies. He studied at the prestigious École Normale Supérieure in Paris, where his classmates included the philosopher Henri Bergson and the socialist leader Jean Jaurès. He did not immediately find his direction. Early teachers found him brilliant but hard to place. He taught philosophy at several secondary schools while developing his own approach to studying society. In 1887 he became a professor at the University of Bordeaux, where he taught the first sociology course in a French university. He moved to the Sorbonne in Paris in 1902, where he taught for the rest of his life. He founded one of the first major sociology journals, L'Année Sociologique, which brought together a group of brilliant young scholars — his nephew Marcel Mauss, the philosopher Maurice Halbwachs, and others — who became known as the Durkheimian school. His major books include The Division of Labour in Society (1893), The Rules of Sociological Method (1895), Suicide (1897), and The Elementary Forms of Religious Life (1912). Each became foundational for a different area of sociology. He was a passionate patriot who believed sociology could help France become a more just and integrated society. The First World War devastated him. His son André was killed at the Front in 1915, and many of his brightest students died in the trenches. He never recovered from these losses. He died in Paris in 1917 at the age of fifty-nine, two years after his son's death. His influence on sociology has been enormous. His work has shaped how the field studies religion, education, crime, suicide, work, and the relationships between individuals and the societies they live in.

Mustafa Kemal Atatürk was the founder and first president of the Republic of Turkey. He was born in 1881 in Salonica (now Thessaloniki, Greece), then a thriving Ottoman port. His birth name was simply Mustafa. He earned the additional name Kemal, meaning 'the perfect one', from a mathematics teacher at his secondary school. He was given the surname Atatürk, meaning 'Father of the Turks', by the Turkish parliament in 1934 when surnames became compulsory under his reforms. He was a career military officer in the late Ottoman army. He fought in Libya against Italy in 1911-1912 and in the Balkan Wars in 1912-1913. He became famous internationally for his successful defence of the Gallipoli peninsula against Allied forces in 1915 during the First World War. He was an Ottoman general by the war's end. When the Allies began partitioning the defeated Ottoman Empire, Mustafa Kemal organised an armed nationalist resistance from Anatolia. He won the Turkish War of Independence (1919-1923) against Greek, Armenian, French, and British forces, in a war that also included the ethnic cleansing of Armenians, Greeks, and other minorities from much of Anatolia. He abolished the Ottoman Sultanate in 1922 and proclaimed the Republic of Turkey on 29 October 1923, becoming its first president. From then until his death he led an extraordinary programme of reforms: the abolition of the caliphate, the secularisation of law and education, the replacement of Arabic script with Latin alphabet, women's suffrage, civil marriage and divorce, monogamy, and the comprehensive Westernisation of dress, names, and public life. He governed through a single-party state. He died at Dolmabahçe Palace in Istanbul on 10 November 1938 of cirrhosis of the liver. He was 57.

Chester Irving Barnard (1886-1961) was an American business executive whose book The Functions of the Executive (1938) became one of the foundational works of mid-twentieth-century organisational theory, produced by a practising businessman rather than by an academic. He was born in Malden, Massachusetts, to a family of modest means. His mother died when he was five; he was raised partly by grandparents. He attended Mount Hermon School, working to support himself, then won a scholarship to Harvard University in 1906, where he studied economics and philosophy. He left Harvard in 1909 without completing his degree, having refused to take a required laboratory course, and joined the American Telephone and Telegraph Company as a statistician. He stayed with AT&T or its subsidiaries for most of his working life. He rose to become president of the New Jersey Bell Telephone Company in 1927 and held that position until 1948. He combined his business career with substantial reading in philosophy, sociology, and psychology, drawing on thinkers from Vilfredo Pareto to Alfred North Whitehead. In the 1930s he was invited to give a series of lectures at Harvard, which became The Functions of the Executive. He also served on many public bodies — the United Service Organizations during the Second World War (he was its president from 1942 to 1945), the Rockefeller Foundation (president 1948-1952), the National Science Foundation (chairman 1952-1954), and various advisory committees. He wrote a second book, Organization and Management (1948), and many articles. He was awarded honorary degrees by several universities but never held an academic position. He died in New York in 1961 at seventy-five. His work combined the authority of long practical experience with unusually wide reading, producing a synthesis that academics found intellectually serious and practitioners found grounded in reality.

Ikujiro Nonaka (born 1935) is a Japanese organisational theorist whose work on knowledge creation in organisations has made him one of the most influential management thinkers of the knowledge economy era. He was born in Tokyo in 1935 and grew up through the hardships of wartime and postwar Japan. He graduated from Waseda University with a degree in political science in 1958 and worked for nine years at Fuji Electric, where he saw first-hand how Japanese companies developed new products and managed learning across the organisation. In 1967 he left for California to pursue graduate study, earning an MBA and then a PhD from Berkeley's Haas School of Business in 1972. He joined the faculty of the Nanzan University in Nagoya, then moved to Hitotsubashi University in Tokyo, where he spent most of his academic career and is now Professor Emeritus. He has also held positions at Berkeley, Harvard Business School, and the University of British Columbia. His most influential work is The Knowledge-Creating Company (1995), co-authored with Hirotaka Takeuchi, which introduced the SECI model of knowledge creation and drew extensively on cases from Japanese companies including Honda, Canon, and Matsushita. The book was one of the first major works to treat knowledge creation as a central strategic activity rather than as a by-product of operations. It drew on Japanese philosophical traditions as well as Western organisational theory, producing a synthesis that was distinctively grounded in its cultural context while addressing universal questions. Nonaka has continued publishing on knowledge management, leadership, and organisational learning, including The Wise Leader (with Takeuchi, 2011) and work on phronesis (practical wisdom) as a leadership capacity. He received the Chevalier in the Ordre des Arts et des Lettres from France in 2001 and was the first Japanese inductee into the Thinkers50 Management Hall of Fame in 2017. He has been instrumental in making Japanese organisational thinking accessible to global management thought.

Coimbatore Krishnarao Prahalad (1941-2010) was an Indian-American management scholar whose ideas about corporate strategy, core competence, and the business opportunity at the bottom of the pyramid transformed how companies and development thinkers approached both strategy and poverty. He was born in Coimbatore, in Tamil Nadu, the son of a judge and a civil servant. He studied physics at Loyola College, Madras, and worked for four years in an Indian branch of Union Carbide, the American chemical company, before entering the Indian Institute of Management in Ahmedabad. In 1972 he travelled to the United States for doctoral work at Harvard Business School, completing his thesis in 1975. He joined the faculty of the University of Michigan's Ross School of Business in 1977 and remained there for the rest of his career. His 1990 Harvard Business Review article with Gary Hamel, The Core Competence of the Corporation, became one of the most-cited business articles ever written and reshaped strategic thinking through the 1990s. His later work took him in a different direction. His 2002 article and 2004 book The Fortune at the Bottom of the Pyramid argued that the world's poorest four billion people represented not only a moral claim on international attention but also a significant market that could be served profitably if products and business models were designed appropriately. The book reached business schools, development agencies, and corporations. He continued publishing influential work until his death, wrote regularly for Indian newspapers on the country's development, and mentored a generation of scholars and practitioners. He died in San Diego in 2010 at the age of sixty-eight.

Indra Krishnamurthy Nooyi (born 1955) is an Indian-American businesswoman and former chief executive of PepsiCo, one of the world's largest food and beverage companies. She was born in Madras (now Chennai) to a Tamil Brahmin family and grew up in a middle-class household where education was valued intensely. Her mother regularly asked her daughters at dinner to explain what they would do as president or prime minister, a practice Nooyi later credited with shaping her ambition. She studied physics, chemistry, and mathematics at Madras Christian College, earned an MBA from the Indian Institute of Management in Calcutta, and won a scholarship to Yale School of Management, where she completed a second master's degree in 1980. She worked at the Boston Consulting Group, Motorola, and Asea Brown Boveri before joining PepsiCo in 1994. She rose through corporate strategy and finance roles, led the spin-off of PepsiCo's restaurant businesses (Pizza Hut, KFC, Taco Bell) into Yum Brands, and led the acquisition of Tropicana and Quaker Oats. She became chief financial officer in 2001, president and CFO in 2006, and chief executive officer and chairman in 2006 — the first woman of colour to lead a Fortune 50 company. During her twelve years as CEO, PepsiCo's revenue grew from forty-four to sixty-four billion dollars. She led a strategic reorientation she called Performance with Purpose, shifting the company's portfolio toward healthier products while maintaining profitability. She retired as CEO in 2018 and as chairman in 2019. She has since served on the boards of Amazon, the International Cricket Council, and the World Economic Forum, co-led a New York State commission on reopening during the Covid pandemic, and published her 2021 memoir My Life in Full. She lives in Connecticut with her husband, Raj, and their two daughters.