Widely regarded as the father of analytical psychology, Carl Jung is one of the most important contributors to symbolization and dream analysis. The concepts of socionics and a popular psychometric instrument called Myers-Briggs Type Indicator (MBTI) were developed from Jung's theory. Apart from working as a psychiatrist and psychoanalyst, Carl Jung was also an artist, craftsman, builder, and prolific writer.
Robert Koch was a German microbiologist and physician. One of the prominent co-founders of modern bacteriology, Koch is credited with creating and improving laboratory techniques and technologies in the field of microbiology. He is also credited with making important discoveries in public health. In 1905, Robert Koch won the Nobel Prize in Physiology or Medicine for his research on tuberculosis.
Almost 2 decades before germ theory was laid down, Ignaz Semmelweis became the first physician to suggest that hand-washing could prevent the spread of puerperal fever and related deaths. Ironically, after being ridiculed for his theory, he died in a mental asylum, due to an infection from a wound.
Best known as the father of modern epidemiology, British doctor John Snow revolutionized medical science with his study of London’s Broad Street cholera outbreak of 1854. His research contributed to the development of London’s sewage and water systems and led to the reduction in cholera cases.
British surgeon Joseph Lister was a pioneer of antiseptic medicine usage and made a huge contribution to the development of preventive medicine for bacterial infection. His achievements have been honored by many, such as the makers of Listerine antiseptic and mouthwash, who named their product after him.
Regarded as the father of psychoanalysis, Sigmund Freud was a neurologist. Despite suffering criticism, psychoanalysis remains influential in the fields of psychology and psychiatry; such is the influence Freud has on humanities. Scholars believe that Freud is one of the most influential personalities of the 20th century and that his impact is comparable to that of Marxism and Darwinism.
German scientist Paul Ehrlich is remembered for his contribution to immunology, which also won him a Nobel Prize. Known as the pioneer of chemotherapy, he also discovered the first-known treatment of syphilis. Born into a business family, he was introduced to the method of studying cells by his pathologist uncle.
Johns Hopkins Hospital co-founder William Osler was also an avid historian. He redefined medical education with his emphasis on clinical experience and his book The Principles and Practice of Medicine. Born to a missionary father in Canada, he was to follow in his father’s footsteps but decided to study medicine instead.
Jose Rizal was a Filipino polymath and nationalist. An ophthalmologist by profession, Rizal turned towards writing and inspired the Philippine Revolution through his writings. The revolution eventually led to Philippine independence and Rizal became a national hero. His life has inspired several biographical films and TV series.

Georgios Papanikolaou was a Greek physician who was a pioneer in early cancer detection. He reported that uterine cancer cells could be detected in vaginal smears as early as 1928, but his work did not receive much attention until the 1940s. He invented the Papanicolaou test, commonly known as the Pap smear or Pap test for cervical screening.
Maria Montessori was an Italian educator and physician best known for developing the Montessori method of education, a student-friendly method, which is being used in several public and private schools around the world. In 2020, she was nominated by Time magazine as one of their Top 100 Women of the year.
Albert Schweitzer was an Alsatian polymath who won the Nobel Peace Prize in 1952 for his philosophical work, Reverence for Life. He is credited with founding the Albert Schweitzer Hospital, which was a direct result of his philosophical expression. Schweitzer is also credited with influencing the Organ reform movement, which began in the mid-20th-century.
Rudolf Virchow was a German physician, pathologist, anthropologist, biologist, prehistorian, editor, writer, and politician. Nicknamed the Pope of medicine by his colleagues, Virchow is credited with founding the field of social medicine. He is also widely regarded as the father of modern pathology. Rudolf Virchow was the first person to name diseases, such as thrombosis, leukemia, ochronosis, embolism, and chordoma.
Scottish surgeon Robert Liston worked in an era when anesthesia wasn’t invented. He could complete amputations within minutes, thus saving the lives of many when the speed of the surgery made the difference between life and death. Later, he became the first European surgeon to operate under anesthesia.

Known as The Father of Modern Gynaecology, J. Marion Sims is remembered for developing a surgical method to deal with vesicovaginal fistula, a childbirth-related complication. However, since his experiments were conducted on Black slave-women, without anesthesia, they were later deemed unethical. He had also headed the American Gynecological Society.
The son of a musician, Emil Kraepelin, remembered as the founder of psychiatry, was the first to differentiate between dementia praecox, now known as schizophrenia, and manic-depressive psychosis. His classification of mental illnesses influenced much of the research on the subject in the 20th century.

A reputed Polish doctor, Henryk Goldszmit was better known by his pseudonym, Janusz Korczak, which he used to write several children’s books. Apart from working as a pediatrician and a military doctor, he also owned a Jewish orphanage and stayed with the children while the Germans deported him and other staff to Treblinka.
Mary Edwards Walker, or Dr. Mary Walker, was the only female surgeon who served injured soldiers during the American Civil War. A dress reform supporter, she believed women should value comfort more than tradition when it came to clothes. She was also the first and only Medal of Honor winner.
Best known for his iconic medical textbook Gray's Anatomy, surgeon Henry Gray, who was a skilled anatomist, was made a Fellow of The Royal Society at the tender age of 25. His untimely death at 34 due to small pox, while treating his nephew, cheated him of an illustrious career.


German psychiatrist and neuropathologist Alois Alzheimer is noted for identifying the first published case of presenile dementia, which his colleague and German psychiatrist Emil Kraepelin later identified as Alzheimer's disease. Alois publicly discussed his findings on brain pathology and symptoms of presenile dementia in late-1906 and penned a larger paper giving details of the disease and his findings in 1907.

William Stewart Halsted was the man behind the first American surgical school at the Johns Hopkins University. The master surgeon made a number of contributions to medical science, including the introduction of mastectomy and aseptic surgical procedures. He often injected cocaine into his body to develop anesthesia.
The founder of homeopathy, Samuel Hahnemann was a qualified physician but disapproved of medical practices such as bloodletting that were used back then. He thus formed his system of alternative medicine. The apathy of his fellow physicians in Leipzig forced him to move first to Köthen and then to Paris.
A descendant of Pennsylvania founder William Penn through his mother, Hermann von Helmholtz studied medicine, pushed by his father, in spite of being interested in the natural sciences. Best known for his law of conservation of energy, he coalesced the fields of medicine, physiology, math, and physics in his studies.

Jewish doctor Eduard Bloch began his career as a physician for the Austrian Army. He had later treated a young Adolf Hitler and his cancer-stricken mother, charging very little fees owing to their poor financial condition. This act that made Hitler grant Bloch special protection during the Nazi attack on Austria.
Nobel Prize-winning British doctor Ronald Ross is best remembered for his pathbreaking work on malaria, which proved that the disease was caused by the Anopheles variant of mosquitoes. After his extensive research in India, he went back to London, where he was knighted. He also wrote poetry and songs.
Canadian thoracic surgeon Norman Bethune served as an army physician for the Canadian Army during World War I. He revolutionized medical science by introducing the concept of mobile blood-transfusion. A Communist Party of Canada member, he later served the Chinese army against Japan, becoming a revered name in China.

Wong Fei-hung was a Chinese physician, martial artist, and folk hero. Wong is the subject of many television series and films. Between the 1940s and 1980s, Wong was portrayed by Hong Kong actor Kwan Tak-hing in over 70 films which earned Kwan the nickname Master Wong. Wong was also played by Jet Li in Once Upon a Time in China.
Though she was married off at age 9 and had had a baby by 14, Anandi Gopal Joshi rose to become one of the first female doctors in India and the first Indian-origin woman to graduate with a medical degree in the US. Unfortunately, she died of tuberculosis shortly before her 22nd birthday.
Cesare Lombroso was an Italian criminologist, phrenologist, and physician. He founded the Italian School of Positivist Criminology at the end of the 19th century. Initially an army surgeon, he later became a professor of forensic medicine and hygiene. His works drew from the concepts of physiognomy, degeneration theory, and psychiatry. Later in life, be became interested in spirituality.
While he apprenticed as a cobbler and a barber in childhood, Santiago Ramón y Cajal later took up medicine inspired by his father, a professor of anatomy. Cajal’s study of the microscopic structure of the human brain later formed the basis of neuroscience and earned him a Nobel Prize.

Walter Reed was a U.S. Army physician best remembered for leading a team which confirmed that yellow fever gets transmitted by a mosquito rather than by direct contact. His work went a long way in the fight against yellow fever.

Best known for his iconic war poems such as In Flanders Fields, Canadian poet John McCrae was also an army physician. He was the first Canadian to serve as a consulting surgeon for the British Army and had earned the rank of Lieutenant Colonel in the Canadian Army.

Neuroscientist Wilder Penfield redefined medical science with his innovative way of treating epilepsy patients through surgery. He would note down his patients’ responses when they would be conscious under local anesthesia. He also founded the Montreal Neurological Institute, but was unable to cure his sister’s brain cancer.

Though a doctor, Franz Mesmer studied the influence of astronomical bodies on the human body and on an invisible fluid inside it. He was a pioneer of animal magnetism, or mesmerism, which paved the path for modern-day hypnotism. Critics slammed his ideas and called him a fraud, too.
Daniel Hale Williams was a general surgeon known for performing the first documented, successful pericardium surgery in the US in 1893. Born to interracial parents, he faced numerous struggles in his journey to become a physician. He later founded the first non-segregated hospital in the United States, Chicago's Provident Hospital. He also founded a nursing school for African Americans.

Hans Christian Gram was a Danish bacteriologist best remembered for developing a technique called Gram stain, which is still used today to classify bacteria. He achieved international recognition after developing the Gram stain technique. Hans Christian Gram also served as a professor at the University of Copenhagen.
The first female doctor and surgeon of Britain, Elizabeth Garrett Anderson was initially denied admission to medical schools because of her gender and had thus started studying privately. Soon after joining the Marylebone Dispensary as an attendant, she contributed to the formation of the New Hospital for Women.

William Chester Minor was an army surgeon and lexicographical researcher. He studied at Yale Medical School and earned a medical degree with a specialization in comparative anatomy. He then became an army surgeon. He was later committed to a London psychiatric hospital for many years as he suffered from paranoid delusions. He became a lexicographical researcher while incarcerated.

French social psychologist Gustave Le Bon is best remembered for his research on crowd psychology. In his iconic work La psychologie des foules, or The Crowd, he stated that people are driven by their emotions and not by their intellect when they act as part of a crowd.

Hudson Taylor was one of the most popular Christian missionaries in China. His 51-year stint in China witnessed him baptizing over 50,000 people. Apart from converting people, he also mingled with the Chinese at a personal level, adopting their clothing habits, contrary to what other missionaries practiced.
Remembered for inventing the inkblot test to uncover the hidden traits of a subject’s personality, known as the Rorschach test, Swiss psychiatrist Hermann Rorschach was born to an art teacher in Zürich and had thus wished to be an artist initially. His Rorschach test was later criticized for its subjectivity.