The enlightenment era-importance & impact in history of medicine

The enlightenment era – Its importance & impact in history of medicine

Dr. Abhijit Chakma* 

What is enlightenment? Enlightenment is man’s emergence from his self-imposed immaturity. Immaturity is the inability to use ones understands without guidance from another. This immaturity is self-imposed when its cause lies not in lack of understanding, but in lack of resolve and courage to use it without guidance from another. Sapere Aude! [Dare to know] “Have courage to use your own understanding!”–that is the motto of enlightenment. -IMMANUEL KANT (1784).

  • Laziness and cowardice are the reasons why so great a proportion of men, long after nature has released them from alien guidance (natura-liter maiorennes), nonetheless gladly remain in lifelong immaturity, and why it is so easy for others to establish themselves as their guardians. It is so easy to be immature.
  • Nothing is required for this enlightenment, however, except freedom; and the freedom in question is the least harmful of all, namely, the freedom to use reason publicly in all matters. 
  • The “Enlightenment” was not a single movement or school of thought or of those philosophers, but its core was a critical questioning of traditional institutions, customs, and morals, and a strong belief in rationality and science. 

Era of Enlightenment: The Age of Enlightenment (or simply the Enlightenment) is the era of Westernphilosophy, intellectual, scientific and cultural life. Basically the era was centred upon the 18th Century, in which reason was advocated as the primary source for legitimacy and authority. Some renowned historians also include the late 17th century, which is typically known as the ‘Age of Reason’ or ‘Age of Rationalism’, as part of the Enlightenment; however, most historians consider the Age of Reason to be a prelude to the ideas of the Enlightenment. This time period is also known for several rememberable incidents which had important influences in the society as a whole starting from development of general awareness (that is the base of reasoning) to important inventions in different fields. If Renaissance can be called as a child in cradle, then enlightenment can be the learning to walk of that child. 


  • Establishment  of Commonwealth in England after War of Naesby (1642-1649)
  • Glorious Revolution in England with establishment of Democracy (1685)
  • Anglo-French War III (1756-1763)
  • Industrialization in Europe (18th century)
  • French Revolution (1789)
  • Rise of Napoleon Bonaparte (1799)

Effect of revolutions in the society: Effect of revolution developed general awareness about rights & choices in the mind of the people at that time. Reasoning & new thoughts give rise to many inventions in different fields. Establishment of various new teaching institutions, universities, libraries made the society much advanced in all fields. Introduction of social science – the earliest concept of social medicine, introduction of concept of anthropology, introduction of social contracts by several authors are also important from sociological point of view. Some of them were Thomas Hobbes [1588-1679 (nascent idea of liberalism)], John Locke [1632-1704 (Easy concerning human understanding- i.e. knowledge begins in introspection)], Jean Jacques Rousseau [1712-1778 (natural independence and political liberty-1762)]

Whenever a lamp is giving light, the dark shadow is also expected just under it. Enlightenment era is not an exception. Different revolutionary or political wars, industrialization of Europe, changes in life style – all give rise to many social and health problems in the population. Some of them are mentioned as follows-

  • Effect of Different Wars: Effect of war gives rise to several Epidemics ($73); several losses, grief, tortures in war caused serious impact on mental health and development of different kind of mental diseases. Increased occurrence of venereal diseases in the society as Hahnemann himself mentioned in his “Chronic Disease” that increased occurrence of gonorrhea during French war (1809-1814).
  • Impact of Industrialization: Industrialization leads to urbanization of the society; creation of slums; congested living environment and poor housing of the workers leads to occurrence of infectious diseases, particularly tuberculosis and other respiratory infections. Development of different occupational diseases was also increasing notably. Not only that, child labor involvement causes serious impact on child health, both physical as well as mental. 

These important discoveries of enlightenment era can be described in following points- 

1. Field of Medicine (Basic anatomy & physiology)


  • Discovery of capillaries by Marcello Malpighi (1628-1694).
    • Intravenous injection of medicaments by Sir Christopher Wren assisted by Boyle and Wilkins (1656), Major (1662), Elsholtz (1665).
    • Transfusion of blood: From animal to animal first done by Richard Lower (1665) and thereafter from animal to a 16 year old lad by Jean Denis (1667).
    • Description of Red Blood Cell was given by Jan Swammerdam (1637- 1680).
    • Experimental work on coagulation of blood was done by William Hewson (1749-1774).


  • Discovery of the component of air which is particularly responsible for life by Robert Boyle (1627-1691).
  • Blowing of air into trachea and lung rather than mechanical movement of chest wall is more important for maintaining life was first described by Robert Hooke (1635-1703).
  • The color of venous and arterial blood is different and it is related to respiration was first mentioned by Richard Lower (1631-1691).


  • Jean Baptiste von Helmonni (1577-1644) was the first person to consider digestion as a series of fermentation and he also identified hydrochloric acid in stomach.
  • Experimentation on pancreas & gall bladder of dogs was done by Regner de Graaf (1641-1673).

Perspiration & body temperature: Sanctorius (1561-1636) introduced the concept of insensible perspiration & metabolism; he also invented clinical thermometer & pulse clock and thereby developing both physiology as well as clinical medicine.

Development of muscle physiology was extensively done by Steno, Borelli, Willis and Glisson.

Discovery of lymphatic system was another excellent step in development of physiology which was done by Aselli (1622), Pecquet (1651), Bartholinus (1652) and Rudbeck (1653). 

2. Field of Clinical Medicine (Integration of pathological anatomy with clinical observations)

  • Baglivi contributed in description of pathology of typhoid.
  • Marvelous description of rickets was given by Glisson.
  • Sylvius gave description of tuberculosis.
  • Description of beriberi was given by Dr Tulp.
  • Richard Morton (1635-1698) differentiated malaria from other fevers by the therapeutic use of quinine.
  • Jacob Wepfer (1620-1695) showed evidences through autopsy that cerebral strokes and apoplexies occur due to brain hemorrhages.
  • Clinico-pathological description of valvular diseases of heart (aortic regurgitation & mitral stenosis) and anatomical configuration of nervous system was given by      Raymond Vieussens (1641-1717).
  • Bernardino Ramazzini (1633-1714) introduced the concept of occupational diseases.
  • Giovani Maria Lancisi (1654-1720) gave descriptions of heart disease; he also had contribution in describing sanitary measures. Discovery of connection between malaria & mosquito was another important contribution of Lancisi.
    • Willem Piso (1563-1636) observed the therapeutic use of Ipecacuanha for amoebic dysentery by Brazilian Indians.
    • Development of measuring technique of blood pressure, velocity of blood current & capacity of heart were done by Stephen Hales (1677-1761).
    • Study of “putrid malignant” (typhus) & “slow nervous” (typhoid) fevers was done by John Huxham (1692-1768).
    • Robert Whytt gave clinical description of tubercular meningitis.
    • J. Fothergill described diphtheria & neuralgia.
    • Sir John Floyer (1707) recommended about timing the pulse rate.
    • Spaniard Casal first described pellagra in the year 1735.
    • Hypothesis about fluid in nervous system as well as clinical description of rubella, chlorosis and diseases of pancreas and liver were given by Friedrich Hoffmann (1660-1742).
    • Johann Platner (1744) stated the tubercular nature of Pott’s disease.
    • Introduction of Digitalis was effectively done in the field of clinical medicine by William Withering in the year 1775.
    • Description of varicella (1767), angina pectoris (1768) and arthritis was given by         William Heberden (1710-1801).

3.Field of Obstetrics

  • This field was under domain of midwives for many years which now become more and more part of domain of male doctors.
  • Description of tubal pregnancy was given by F. Mauriceau (1637-1709).

4.Field of Surgery

  • Well illustrated works on surgical pathology and tumors by Marco Aurelio Severnino (1580-1656).
  • Anal fistula of King Louis IV surgically cured by Royal surgeon Felix (1686) and this incidence cause rehabilitation of Surgery in France by King Louis IV.
  • Foundation of Surgical anatomy laid by Pierre Dionis.
  • Foundation of Royal Academy of Surgery (1731) by Mareschal.
  • Mastoid operation performed & removal of metastatic lymph glands in cancer was first recommended by Jean Louis Petit (1674-1750).

5. Field of Scientific & Legal Medicine

  • Birth of Forensic medicine/ medical jurisprudence occurred in the hands of Paolo Zacchias (1584-1659) and Johan Bohn (1640-1719).
  • Introduction of code of ethics was done by Thomas Percival (1803).

6.Appearance of Medical Statistics

  • Publication of John Grant’s “Natural and political observations upon the bills of mortality” (1662)
  • Some contributions of Sir William Petty (1623-1687) are also important.
  • Works done by Edmund Halley (1656-1742).

7.Field of Psychiatry

  • Consideration of mental disease as a separate disease entity rather than influence of possession, devils, crime, sin etc.
  • Social pressure was to be considered for development of mental diseases.
  • Introduction of new scientific and humane approach for treating the psychiatric patients and removal of chains and physical tortures on insane patients was first came into action under influence of Philippe Pinel (1755- 1826). 

8. Field of Philosophy

  • Philosophy made great contribution in the advancement of 18th century medical sciences.
  • Great clinical work & scientific progress and medical advances in 18th century are mostly directly associated with the philosophy.
  • This philosophy underlay the American Revolution as well as the French.
  • Rapid spread of this new philosophy led to the disappearance of belief in the devil & possessions.
  • This turned the mental diseases again as disease rather than a kind of possession, crime, sin.
  • It also made possible a more humane treatment of insane, which was previously in atrocious condition, often in chains.
  • Social pressures were now considered as causative factors in mental disease.

9. Field of Preventive Medicine & Hygiene

  • Development of Preventive idea in mind of clinicians.
  • Sanitary practices & use of clean cloths & coverings were gradually increasing.
  • Preventive power of citrus fruits against scurvy was established by James Lind (1716-1794).
  • Efforts made to improve the health status of children under influence of Jean Jacques Rousseau.
  • Swaddling discarded and mothers returned to nursing their own babies.
  • Improved child health statistically was manifested by reduction of child death rate.
  • Introduction of effective preventive measures against the most fatal thethen disease – small pox. Vaccination against small pox was introduced in 1796 by Edward Jenner (1749-1823).

10.  Field of Iatrophysics  (Qualitative, Mathematical, Experimental form of Physics)

  • Improvement of microscope done by Anton Von Leeuwenhoek.
  • Development of ophthalmology with the help of physics by Descartes, Mariotte, Scheiner.
  • Law of gravity and idea of gravitational force was introduced by Sir Isaac Newton (1689).

11.  Field of Iatrochemistry

  • Attempt to classify disease according to acidosis & alkalosis by Francosis de la Boe (1614-1672).
  • Interpretation of fever as fermentations by Thomas Willis (1621-1675).

The time period is well advanced and augmented by the contributions of some great personalities. The following few are worthy of mentionable- 

  1. Thomas Willis (1621–1673 AD): Founder of scientific medicine.

The true founder of scientific medicine, whose aim it is to find out the causes of disease and which considers it to be the highest skill, not only to find out causes, but to remove them altogether. For the better understanding of clinical problems he used anatomical and pathological methods. He was known for close, careful clinical observation. Beside these he ceaselessly sought for the natural laws which they exemplified; this is the true philosophic method.

The Circle of Willis (also called Willis’ Circle, cerebral arterial circle, arterial Circle of Willis, and Willis Polygon) is a circle of arteries that supply blood to the brain. It is named after Thomas Willis.

2.  Thomas Sydenham (1624-1689 AD):  The father of clinical observation.

Clinical practice was revolutionized by Thomas Sydenham who developed a treatment procedure that recognized the importance of environmental considerations and included careful, detailed observation and record keeping. Thomas Sydenham matriculated at Oxford University in 1642, but left shortly thereafter to join the Parliamentary troops fighting the civil war. Four years later, he returned, earned a Bachelor of Medicine degree in 1648.

His philosophy and methodology had its origin in Bacon’s Novum Organum and in the Hippocratic maxim, “You must go to the bedside. It is there alone you can learn disease.”

Sydenham incorporated is knowledge of the influence of environment, emotion, stress, diet, season of the year, rest, exercise, inherited constitution, and atmospheric corruption with bedside observation and experience to “work out” the history of diseases and remedies.

Sydenham’s therapy consisted of a carefully regulated diet; fresh air in the sick room, abundant liquids, cooling drinks for fever, iron for anaemia, mercurial inunctions for syphilis until the patient salivates freely, cooling air for smallpox etc.

3.Herman Boerhaave (1668–1738 AD): The founder of clinical teaching

He was a Dutch botanist, humanist and physician of European fame. He is regarded as the founder of clinical teaching and of the modern academic hospital.

Boerhaave first described Boerhaave’s Syndrome, which involves tearing of the esophagus, usually a consequence of vigorous vomiting & haematemesis. This condition was uniformly fatal prior to modern surgical techniques allowing repair of the esophagus.

4.Giovanni Battista Morgagni (1682-1771 AD): Italian Anatomist

One of the great achievements in the field of medicine is due to this man, who described anatomy nicely. He described the appearances met with at the post-mortem examination as well as the symptoms during life in a number of cases of various diseases. He described these things in series of letters De sedibus et causis morborum per anatomen indagatis and published in his 80th year.

Morgagni’s work at once made an epoch in the science. Morbid anatomy now became a recognized branch of medical research, and the movement was started to put more lights on the subject. He putted the most solid basis for studying the natural history of disease.

5.Albrecht von Haller (1708 – 1777 AD):The anatomist, physiologist, naturalist and poet.

As a physician, his best energies, however, were devoted to the botanical and anatomical researches. He also warmly interested himself in most of the religious questions, both ephemeral and permanent, of his day.

Albrecht von Haller is quoted in the footnote to paragraph 108 in the Organon of Medicine, by the founder of Homoeopathy, Samuel Hahnemann. In this paragraph, Hahnemann describes how the curative powers of individual medicines can only be ascertained through accurate observation of their specific effects on healthy persons. “Not one single physician, as far as I know, during the previous two thousand five hundred years……except the great and immortal Albrecht von Haller. He alone, besides myself, saw the necessity of this (vide the Preface to the Pharmacopoeia Helvet., Basil, 1771, fol., p. 12)”.

6.Emmanuel Kant (1724- 1804 AD): The great philosopher

Immanuel Kant was one of the greatest philosophers of all time, and had more influence on other renounced thinkers than any other philosopher of the 18th century. He was inspired by his study of Hume’s writings especially Hume’s psychological analysis of causality. One of his greatest contributions is to philosophy which was the merging of rationalism and empiricism.

Kant argued that the mind brings to experience certain qualities of its own that order it. While the mind has no substance, it is an active process that serves to convert raw sensory data into meaningful, ordered experiences. Things in themselves cannot be known, we perceive the world only the way our mind makes us do it, i.e., through the instrumentality of the innate mental categories.

Kant thus accepted the notion of mental facilities like cognition, feeling, desire, understanding, judgement, and reason.

With the development in different fields of medical science some adverse situations also developed either from over-experimentation, deficient knowledge of the then physicians or from medical malpractice such as mismatched blood transfusions (causing thromboembolism and haemolysis), blood-letting, venesections,  prolonged use of violent drugs ($74) which often leads the patients to  life threatening situations even death. This requires a new and rational therapeutic system to develop, which was ultimately developed in the year 1796 – the axiom of which was similia similibus curanter – the homoeopathic mode of treatment.

Samuel Hahnemann (1755 – 1843 AD): The father of homoeopathy.
Homoeopathy is a form therapeutic system, first proposed by German physician Samuel Hahnemann in 1796, in which practitioners use highlydiluted preparations. Based on an ipse dixit axiom formulated by Hahnemann, which he called the law of similia (similia similibus curanter); preparations which cause certain symptoms in healthy individuals are given in diluted form to patients exhibiting similar symptoms.

Homoeopathic remedies are prepared by serial dilution with shaking by forceful striking, or by grinding in mortar which are termed succession and trituration, after each dilution under the assumption that this increases the effect. This process is called potentization. Dilution often continues until none of the original substance remains.Apart from the symptoms, physicians use aspects of the patient’s physical and psychological state in recommending remedies and therefore treating in a rational, harmless and holistic way for the suffering humanity. 

Enlightenment broke through “the sacred circle,” whose dogma had circumscribed thinking. The sacred circle is a term used to describe the interdependent relationship between the hereditary aristocracy, the leaders of the church and the text of the Bible. This interrelationship manifests itself as kings invoking the doctrine “Divine Right of Kings” to rule. Thus church sanctioned the rule of the king and the king defended the church in return.

The Enlightenment is held to be the source of critical ideas, such as the centrality of freedom, democracy, and reason as primary values of society. This new thoughts and rational ideas gave rise of a new beginning in all fields in the society. Though there were some negative sides, the glory and the importance of this period cannot be ignored in the development of field of medicine. Doctors in the 18th century, enjoyed much high social standing and much high respect, that later generations have looked upon this period as the ‘‘GOLDEN AGE OF THE MEDICAL PROFESSION


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  5. Garrison FH. History of Medicine. 4th edition. Philadelphia. WB Saunders Company. 1929.
  6. Hahnemann S. Organon of Medicine. Sixth Edition. B. Jain Publishers Pvt. Ltd. New Delhi.
  1.  Hahnemann S. The Chronic Diseases; Their Peculiar Nature and Their Homoeopathic Cure. Reprint Edition. B. Jain Publishers Pvt. Ltd. New Delhi; 2005.
  1. Haller AV. from <>
  2. Kant E. from <>
  3. Khan LM. Utility of History of Medicine for the physicians. Asian Homoeopathic Times. April, 1993.
  4. Margotta R. History of Medicine. 1st edition. Octopus Publishing Group. London; 1996.
  5. Morgagni; from <>
  6. Willis T. from <>

Dr. Abhijit Chakma, MD (Hom.)
Senior Research Fellow (H), Clinical Research Unit for Homoeopathy,
¼ Main Road, Colonel Chowmuhani, Krishnanagar, Agartala-799001

1This paper is also presented by the author in a seminar on 16-11-2010 at National Institute of Homoeopathy, Kolkata-700106.


  1. Dr Abhijt, your article on Enlightment should find place for the 1st year Homoeopathic students, it would enlighten, them and pave path to gain confidence in Homoeopathic system of medicine, my Good wishes.

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