Geosophia is nothing else than the knowledge of the qualities of the earth, and the knowledge of these qualities by those living amongst them.

Such was the synopsis of Johannes Christophorus Homann’s Dissertation entitled Medicinae Cum Geosophia Nexu, quam auspice deo propotio.

Written in Latin around 1720-1724, the title of this work translates to “The medical-geosophia connection, as proposed under the auspices of God”.

Homann is the first to define in writing a popular belief held for the time, which states that theosophy, geography, anthropology, health and medicine are all embraced by a single field known as Geosophia or geosophy.  The roots of this term are ‘Geo’ for ‘earth’, and ‘sophia’ for ‘knowing’ and ‘wisdom’.


This belief was very different from the much older, more traditional teachings of geomancy.  Geomancy essentially was a practice that required the art of predicting specific attributes for a given place or region.  Whereas geosophy involved the practice of observing and then explaining natural features and events based on previous knowledge and experience, geomancy involved the production of lines, points, circles, squares and other forms on a piece of paper or writing surface which are then interpreted and developed into some sort of message with special meaning.  Geosophy was linked to the art of map making, in particular precision map making skills which made use of geometry and mathematics and at times looked at the various unique forms of nature as expressions of divine art.  Geomancy was the search for meaning of the shapes and forms evolved from various clues provided, using mathematics as well, but in a more metaphysical way and often with sacred geometry  underlying its philosophy and ideology.  Geosophy usually adhered to a belief in the classical Christian God.  Geomancy relied more upon the natural God, or G-d, or spirit, or Creator, or Universal Energy.


Definitions of Geosophia, a term primarily of German use and application, in two European Foreign Language Dictionaries.

During its earliest years of use, from about 1729 to 1785, the term geosophy was considered synonymous with theosophy, even though the latter makes a direct reference to theos or God, whereas the former only refers to Earth.  Such a use of the term ‘geosophy’ during this time appeased both religious and non-religious groups, and in New York, or more accurately stated, New Netherlands history, it satisfied the pantheistic nature of the religious and non-religious settlers who believed in this natural philosophy tradition.  The first settlers of this region tended to believe in natural philosophy much the same way–the belief that God was, is and shall always be a part of nature.


The most religiously minded settlers devoted to natural theology considered nature to be a form of Divine Art.  Early New York female botanist Jane Colden, for example, demonstrated her attachment to the natural signs for plants and their uses, features important to her due to her work in plant identification (see Jane’s Plant Numerology).  In a review of the plants discussed by the Jesuit missionaries trying to convert America Indians in Canada, we find writings that demonstrate a fascination with plants and plant parts that bore the signs of trinity–for example a leaf with three lobes, and a plant bearing three kinds of leaves, both considered defining features for the sassafras tree.

Augustine Hermann (1605-1686), Counselor and metaphysician for Elizabeth Philips

The late 17th and early 18th centuries also defined a period of time when mysticism was honored, and the most important mystic of all locally, Jakob Boehme, had developed a popular movement along the Hudson River, involving members of the Filipse family.    The most traditional Boehmites supported his teachings of alchemy as a spiritual philosophy, with the mercury, sulphur and earth of Paracelsus considered representative of the various physical, spiritual and soul related parts of the body.     Another set of followers for this New Paracelsian movement were the Helmontians, Dutch individuals who took to the metaphysical claims in medicine made by the famous Dutch chemist Van Helmont, the famous professor from a Dutch University.


John Dee (1527-1608/9, source: wikipedia)

But there was also the philosophy of the British playing important roles in these social belief changes.  Christian Alchemist John Dee was an English Alchemist who was spreading his version of New Paracelsian philosophy to religious leader John Winthrop, Jr. of Connecticut.  From here it probably spread into the New York region by making its way westward into lower New York, primarily influencing areas east of the Hudson River and well distanced from the more traditionally motivated City of New York located to the south.  This manner of spread for new philosophies would continue to be seen in the years ahead, for example the next new form of medical electricity faith which took the route from Connecticut to New York in 1797.


In addition to Boehme, Van Helmont and Dee, there was the philosophy of a Bermudian scholar who removed to Harvard around 1649 to study Christian Alchemy.  George Starkey’s philosophy came a result of his education in the traditional writings on alchemy accompanied by his own personal communications with God, as he attempted to create the perfect philosopher’s stone, or as he called it “ens veneris”.  He managed to succeed in this venture by 1651, and passed on his discoveries to the most important chemist for the time Robert Boyle, but never got the full support and recognition he had hoped for (perhaps because Starkey  claim to have received many of his ideas from God Himself, at least according to his personal notes that were reviewed and republished 10 years ago; this could have made Boyle feel a little uncertain about Starkey’s once he read these lines in Starkey’s diaries/lab books; nevertheless Boyle took this idea and produced a similar iron based version of ‘ens veneris‘ with it, the most popular outcome of this piece of history for which Starkey gets no credit for . . . c’est la vie/vitre).  So, like other New Paracelsian ways of thinking, his philosophy remained more a part of the local oral and handwritten history of the region, stored in manuscript form in various archives, not as part of any written and officially published history.


John Baptiste Van Helmont (1579-1644, source: wikipedia)

The Ens or Entia, power of being, was an important idea critical to how medicine was practiced during the 17th century.  It became very important to Homann’s philosophical interpretations of the world as a cartographer due to his belief that plants grew in regions where they were needed–a traditional, very pastoral way of interpreting man’s relationship with the wilderness.


Friedrich Hoffman (1660-1742, source: wikipedia)

By the end of the 18th century, several scientists interested in these philosophical principles were also developing their own philosophies about health and disease.  One such writer was Friedrich Hoffman, a religious leader, chemist, mechanist, and new form of alchemist.   His associate and counterpart for the time was once again Van Helmont.  Together their preachings helped promote ideas about another form of the entia of plants–their essence or smell, or essential oil.  Considered the fifth element of plants by neo-Paracelsians, its values were considered alongside those for earth, air, fir and water when it came to healing.    As noted in my research on Dr. Cornelius Osborn, ca. 1745-1783 medical practitioner, both Hoffman and Van Helmont were popular to early American medical practitioners who wrote, taught and practiced their beliefs along the Hudson River Valley of New York during the mid to late 1700s.


Herbalists Nicolas Culpeper (1616-1654), John Gerarde (1545-1611), and John Parkinson (1567-1650)

Some of the most important plant medicine philosophers for the New World and European medicine in general included Christian Astrologer and herbalist Nicolas Culpeper, along with John Gerard and John Parkinson.   An herbal by Matthioli also existed in one of the local Dutch settlers’ libraries of the Hudson Valley.  It was through the work of Culpeper however that many of these latin writings became readable by those only trained in English.  Likewise for author and famed chemist Robert James, an apothecarian favored by Royalty whose translations of the famous Latin books by Sydenham made it possible for early American physicians to make sense of the native plants blooming all around them.

Still, it was Johannes Christophor Homann’s study of the philosophy and materialistic presentation of geosophy that served as one of the most important primers to assisting in the evolution of a Hudson Valley medical philosophy, one that was not only based on the more physiographically based traditions of disease theory and healing practices,but also upon the metaphysical components of nature, and the religious qualities of natures symbols, God’s Signs.  These teachings of the earlier natural philosophers were supported worldwide by the influences the Homann family had on the world as cartographers of place and people.   But it was J.C. Homann’s writings that had the most important influences of all-with this dissertation he enabled nature and the natural forms of God to become an important part of both European and early American medicine.

Johann C. Homann was not a mystic like Jakob Boehme.  His philosophy of health and disease was more focused on the physical world, but he recognized the role of God in creating these natural gifts.   Homann’s philosophy therefore was not at all agnostic or atheistic, or completely Newtonian  and mechanical in nature.  Instead, it had a metaphysical aspect that taught us how God through Nature played a role in defining both our health, our diseases, and our potential for discovering much-needed medicines.  To many colonial physicians, it worked well alongside the writings and teachings of religious leader and physician Friedrich Hoffmann.

Like many believers in God, nature was God’s most important gift to us.  Due to the Homann family history, J.C. Homann was very familiar with the physical make up of the world, and so once he took control of the family business in cartography in 1703, he became very interested in exploring the relationship between place and medicine.  He accomplished this successfully with his dissertation, for which he received a medical degree from the university in Halles along with some much-needed support from the church.  This writing also makes reference to a number of individuals who greatly influenced him, their metaphysical philosophies most important to understanding the underlying wisdom of the book and how the field of medical geography came to be as a by-product of J.C. Homann’s Geosophia.

During his schooling, one of Homann’s mentors and teachers, Rudolph Wilhelm Crausius, who wrote the following in an oration to his students, a few years before Homann received his degree in the study of medicine from the university in Halles:

Hippocrates Medicinae parens optimus in eo, qui fe Aesculapii саstris devovit, requirit naturam, locum studis aptum, industriam, tempus, doctrinam, institutionem a puero.

Physician Hippocrates, the father of the best [physicians], who devoted himself to the camp of Aesculapius, requires that nature be a place of study of industry (work), time, doctrines (ways or laws), and the manner of living for the new and the young.


Homann had limited influence for years to come in early American history.  His influences during the last Colonial years were evident, although never mentioned or referred to as such.  The beliefs were their, but their source soon forgotten.

We also don’t see any direct or indirect clues to The Homann family’s influences on United States in general, minus its medical history, until 1815, when a mid-18th century Homann’s map of Mexico played an important role in defining our rights to own and possess the former New France territory of Louisiana.

From William Darby’s 1817 book A Geographical Description of the State of Louisiana

In the years and decades leading up to this moment in American history, Homann’s work was generally used to describe the various continents and countries of the world, producing several Atlases along the way.  The influences of Johanne Christopher’s dissertation on the study of medicine, geography, health and disease would not be seen or felt for another 75 years.  J.C. Homann’s geosophy teachings remained a topic of religious and spiritualism studies, rather than a study of science and nature.  [Note: a brief mention of the “Geosoph” appears on p. 237 of an 1780s writing published in 1790 as part of Neuer Atlas . . . .  1790 and is mentioned in Allgemeine deutsche Bibliothek, Volume 106, edited by Friedrich Nicolai, page 105.  No links as of yet are made for this use of the term, but probably existed as “fuel for the fire” in the United States medical geography writings just a few years later.]

Geosophie ~ Theosophie

The following entries in two ca. 1900 German lexicons provide us with insight into the cultural limitations that kept J.C. Homann’s term from becoming commonplace.

Geosophie od[er] Theosophie ᵻ: Molenaar, H., Flugschriften 6.

From Vollständiges Bücher-Lexicon by Christian Gottlob Kayser, Alexander Bliedener, Ernest Amandus Zuchold, Gustav Wilhelm Wuttig, Richardt Haupt, Albert Dressel, Oskar Wetzel, Heinrich Dullo, Heinrich Conrad, August Hilbert, Richard Schmidt, Alfred Dultz.  1908.  p. 141.

Geosophie s. Theosophie. 

From Karl Georgs Schlagwort-katalog: Verzeichnis der im deutschen Buchhandel  erschienenen Bucher und Landkarten in sachlicher Anordung. V. Band 1903-1907.  1. Abteilung.  A-K.  p. 635.


Throughout the remaining 18th century, Homann’s influences were seen with the writings on the healthiness of different parts of the world.  The health of New York and the Hudson Valley as detailed by Cadwallader Colden, the metaphysical take on mechanisms responsible for how medications worked on ailing bodies, the notion that air flow patterns and directions, weather, climate and topography could help define the health of a given region, were all based upon beliefs held by J.C. Homann as well as well as the traditional writings they referred to by Riverius.

Between 1730 and 1750, the writings of Riverius, Hoffman and Homann played very prominent roles in how medicine was being practiced and how the causes for disease were redefined.  With the onset of the Revolutionary War, the exchange of similar knowledge occurred internationally as foreign physicians came to support the side of the Patriots.  This solidified the many teachings that related disease to the endemic and epidemic forms of disease taught by Riverius, and the roles of nature and natural philosophy in disease taught by Hoffman.  By 1796, this allowed the practice and study of medical geography to be developed by New York state physicians, a description of which appears in the very first medical journal published in New York City–Medical Repository.

Along with the works of Hoffman, Riverius and Hippocrates, Homann’s work turned medicine into an extension of the natural sciences (or natural history as they called it then).   With his Dissertation, Medicinae Cum Geosophia Nexu, Homann provides us with the term and  definition for the Geosophen, or Geosophers, and Medicinae Geographica, or Geographic Medicine.  The subsequent spread of this philosophy took several distinct routes during the late 19th century.  As a result, Homann helped to develop or greatly influence several major fields of study, namely:

  • phytomedical geography, and research focused on the importance of local herbal medicines for treating local diseases,
  • anthropology, and its subspecialty medical anthropology–a study of disease and culture
  • medical geography, medical climatology, disease ecology, and the value of disease mapping, and
  • modern geosophy, or the study of sacred places.

Today we can state these influences to be mostly related to the knowledge of the following, promoted as a part of Homann’s dissertation writings:

  • the absence or presence of medicinal plants befitting a region
  • the absence or presence of specific cultural and anthropological ways of being and behaving
  • the absence or presence of specific diseases characteristic of the region and therefore defined as being epidemic or endemic to it
  • the existence and cultural definition of special places, human values placed upon these objects which are defined by their location, form and the occurrence of specific, related human and/or natural events

In a more modern sense, Homann’s term Geosophy was rediscovered or perhaps even reinvented from scratch during the 194os (see wikipedia entry on this term.)  His dissertation on geographical medicine however did have an impact on common knowledge, and therefore over the years has led to the development of three of the most important specialities today in medical geography–geoepidemiology, disease ecology, and spatial epidemiology.  Each of these fields of study benefitted from the knowledge base that Homann’s maps produced for geographers and physicians and the geosophical essay Johannes Christopher produced as a result of his own enlightenment process during the 18th century.



Additions to this site over the last months include two new maps on medical or disease geography

My review of the history of disease mapping and epidemiology is focusing much more on the yellow fever.  This is because yellow fever set the stage for the large-scale production of disease maps seen by the mid-18o0s for global epidemic disease patterns like Asiatic cholera.  Aside from Valentine Seaman’s map of this disease–the first of its kind and already reviewed at this site–are two new examples of how the early yellow fever epidemics were first interpreted by medical geographers (but with no maps produced).  These include:

  • 1799 – Samuel Anderson and the Mystery of Yellow Fever in Curaçao and On Board.
  • 1806 – The Next War – Yellow Fever in Upstate New York and Matthew Brown.  This page in particular addresses the geographic definition of disease issue developing in the United States.  This philosophy of assigned place names for particular diseases was less than 10 years old, and was disputed abroad and even by other physicians located in other parts of the U.S.  The politics underlying to identity of a disease was that place-name also indicated place of cause–either locally or by means of import by way of land and water travel.  Each had its repercussions economically, and in the case of New York, certain families had their reputations at stake due to these arguments.  [See also the long four part tale about John W. Watkins and the tale of “Lake Fever“, not Yellow Fever, a disease common to the region in Western New York he just purchased, with plans for settlement–Watkins Glen or “Salubria“.]

Between 1800 and 1850, the medicine of livestock or what later became veterinary science was developed.  Some of the earliest examples of this (with much more to follow) are provided as:

Synopses on the two sets of disease mapping projects I have been engaged in are provided as distinct pages.  These are for comparing maps that demonstrate similar spatial features or represent similar goals and techniques used for disease mapping,  They are:


Also, for those “addicted” to the use of GIS for mapping population health, more of my research on population health analysis has been posted as well.  These appear as icons posted on various pages summarizing my work or discussing the applications of GIS to modern epidemiological research.  Approximately 200 examples of population health analysis locally and regionally have been provided (approximately one fifth of the results of this project), but are not being promoted at this time.   You can see examples of these at

Ï   Α   Τ   Ρ   Ω

Based on 20 years of experience living in the Pacific Northwest as a student, university lecturer, and population health analyst, I am also pulling these “video maps” together to present a single public health topic or theme, for example a Regional Population Health Analysis of the Pacific Northwest.  This project (a work in process related to my National Population Health Grid project) can be reviewed at

REGIONS & HEALTH – the Pacific Northwest as an Example

This represents cutting edge use of GIS and some of my analytic techniques.