Human molecular hypothesis (1789) “We conclude that there exists a principle of the human body which comes from the great process in which so many millions of atoms of the earth become many millions of human molecules.”
French polymath Jean Sales who in 1789 introduced the basics of human molecular hypothesis, in his conclusion that the "human molecule", or "molécule humaine" in the original french, came about form a "great process" in which the atoms of the earth combined to form the human molecule. [1]

In chemistry, human molecular hypothesis, a precursor to human molecular theory, is the hypothesis that a human is a type of large "molecule", termed a "human molecule", or "atoms fitted together", in the original 1649 coining of the term molecule by 1649 by French thinker Pierre Gassendi, which has been synthesized, over time, from a great process. Dutch-born American mathematician, theoretical physicist, and economist Tjalling Koopmans, in 1947, seems to have been the first, in the 20th century, to state something along the lines of a human molecular hypothesis: [3]

“While it was long possible and sometimes tempting for physicists to deny the usefulness of the molecular hypothesis, we economists have the good luck of being some of the ‘molecules’ of economic life ourselves, and of having the possibility through human contacts to study the behavior of other ‘molecules’.”

The actual term "molecular hypothesis", to note, is a mid 18th century term, generally tracing to the work of Italian chemist Amedeo Avogadro’s and his 1811 “Essay on a Manner of Determining the Relative Masses of the Elementary Molecules of Bodies and the Proportions According to Which they Enter Into These Combinations”.

18th century
The history of the so-called "human molecular theory", the postulate that a human is a molecule, originated in the works of French philosopher Jean Sales who in 1779 published the first volume of his multi-volume opus The Philosophy of Nature: Treatise on Human Moral Nature, which over the years grew and expanded, supposedly going through seven editions, increasing in size to include up to a dozen volumes. In the 1789 edition, Sales outlined the basics of human molecular theory, with his statement:

“We conclude that there exists a principle of the human body which comes from the ‘great process’ in which so many millions of atoms of the earth become many millions of human molecules.”

In pictorial form, from the cover of Judson Herrick's The Evolution of Human Nature (1956):

Sales quote

In summarized form, the conclusion posits, based on Sales natural philosophy theory, that:

(a) a human is molecule.
(b) the name of this type of molecule is ‘human molecule’.
(c) this human molecule was formed through a ‘great process’ over time.
(d) the precursors or reactants to this great process were the atoms of the earth.

This is very advanced even form modern times, many modern-day scientists considering this view to be pseudoscience and crackpottery.

The next big thinker was German polymath Johann Goethe who in 1799, independent of Sales (1789), gleamed the view humans are large types of reactive chemicals whose interpersonal reactions are governed by the laws of affinity reaction, as detailed in Swedish chemist Torbern Bergman's 1775 physical chemistry textbook A Dissertation on Elective Attractions. Goethe published the finalized version of his human molecular theory in his 1809 scientific novella Elective Affinities. [2]

19th century
Thinkers into the nineteenth century to have employed human molecular theory include: Alphonse Esquiros (1840), Hector Berlioz (1854), Hippolyte Taine (1869), Alphonse Esquiros (1840), Henry Adams (1885), and Max Leclere (1894), Vilfredo Pareto (1896), to name a few.

20th century
Thinkers into the nineteenth century to have employed human molecular theory include: Yves Guyot (1903), Thomas Dreier (1910), George Perris (1911), George Carey (1919), Tjalling Koopmans (1947), mentioned above, Gustavus Esselen (1948), C.G. Darwin, (1952), Robert Nisbet (1970), to name a few.

21st century
Thinkers of the twenty-first were the first to expand on human molecular theory by calculating the human molecular formula for the average human, such as: Robert Sterner (2000), James Elser (2000), and Libb Thims (2002), among at least one other.

See also
● HMS pioneers (timeline of the 100+ human molecular theorists)
● Atomic theory

References
1. Sales, Jean. (1789). De la Philosophie de la Nature: ou Traité de morale pour le genre humain, tiré de la philosophie et fondé sur la nature (The Philosophy of Nature: Treatise on Human Moral Nature, from Philosophy and Nature), Volume 4 (molécules humaines, pg. 281). Publisher.
2. (a) Goethe, Johann. (1799). "Comment on Crebillon", October 23, German author Friedrich Schiller. Publisher.
(b) Lynch, Sandra. (2005). Philosophy and Friendship (Crebillon, pg. 37). Edinburgh University Press.
(c) Steer, Alfred G. (1990). Goethe’s Elective Affinities: the Robe of Nessus (Crebillon, pg. 37). Winter.
(d) Prosper Jolyot de Crebillon – Wikipedia.
(e) Goethe, Johann. (1809). Elective Affinities. Publisher.
3. Koopmans, Tjalling C. (1979). Scientific Papers of Tjalling C. Koopmans (“molecules of economic life”, pg. 150), Volume 1. Springer-Verlag.
4. Avogadro, Amedeo. (1811). “Essay on a Manner of Determining the Relative Masses of the Elementary Molecules of Bodies and the Proportions According to Which they Enter Into These Combinations”, Journal de Physiques, 73: 58-76.

External links
● History of molecular theory – Wikipedia.