How solid is the health layer?

Lineage

Where the idea comes from

The four temperaments have a long written history. This timeline shows what each source says and, next to it, what modern science says. Age shows how long an idea has been held. It does not show that it is true.

The case in four links

1. 1

   The idea is old and traceable

   From the Hippocratic texts to Galen, Avicenna, Salerno and Huarte, the four temperaments and their hot, cold, wet and dry qualities appear in written sources.

   Well documented
2. 2

   Spain helped carry it

   The Canon was put into Latin at Toledo, stayed obligatory at some Spanish universities into the early 18th century, and Huarte's 1575 book was licensed by Philip II.

   Well documented
3. 3

   The old physiology does not hold

   Modern medicine does not accept the humours as the cause of personality or disease, and humoral theory was abandoned after the 1850s.

   Not supported
4. 4

   Modern traits and biology: early signs

   Eysenck and Pavlov tried to ground temperament in the nervous system, and small genetic studies point to biological correlates. They are early and none tests the HOS or RGP method.

   Early, small studies

14 sources

1. c. 400 BCE

   Hippocratic Corpus, On the Nature of Man

   Describes four body fluids, blood, phlegm, yellow bile and black bile, and links their balance to health and disease. A summary source lists their qualities as blood hot and wet, phlegm cold and wet, black bile cold and dry, and yellow bile hot and dry, the same grid HOS uses. The work is in the Hippocratic Corpus and is traditionally attributed to Polybus, Hippocrates' son-in-law, an attribution regarded as dubious.

   Modern statusNot supported today

   Not supported. The four fluids are not the basis of personality or disease in modern medicine.

   • On the Nature of Man (encyclopedia summary) (secondary summary)
   • Humorism (encyclopedia summary, to be replaced by primary scholarship) (secondary summary)

2. c. 170 CE

   Galen, De temperamentis

   Galen (129 to about 200 CE) wrote the first typology of temperament. He classified temperaments by hot or cold and dry or wet qualities, and named four after the humours: sanguine, choleric, melancholic and phlegmatic. This is the source of the quality grid HOS uses.

   Modern statusNot supported today

   The quality grid is a historical model. It is not a measured physiological map.

   • Four temperaments (encyclopedia summary, to be replaced by primary scholarship) (secondary summary)
   • Humorism (encyclopedia summary, to be replaced by primary scholarship) (secondary summary)

3. 1025

   Avicenna, Canon of Medicine

   Avicenna (980 to 1037) carried humoral medicine into the Islamic tradition and applied temperament to emotional aspects, mental capacity, moral attitudes, movements and dreams. The Canon was a standard text in many medieval universities. This is the line that leads to Unani mizaj.

   Modern statusDocumented tradition

   Documented tradition. Not tested with modern methods.

   • Four temperaments (encyclopedia summary, to be replaced by primary scholarship) (secondary summary)
   • Humorism (encyclopedia summary, to be replaced by primary scholarship) (secondary summary)

4. Second half of the 12th centurySpain

   Gerard of Cremona, Latin Canon, Toledo

   The Latin version of Avicenna's Canon was made by Gerard of Cremona at Toledo in the second half of the 12th century. Gerard (born c. 1114, died 1187 in Toledo) is credited with about 80 translations from Arabic, though some may be the work of a team and the attribution of individual works is uncertain. This is how Avicenna's temperament medicine reached Latin Europe through Spain.

   Modern statusDocumented tradition

   A documented route of transmission. It shows how the idea spread, not that it is correct.

   • Britannica, Gerard of Cremona
   • Encyclopaedia Iranica, Avicenna xiii, Influence on the West (Canon in Latin)

5. 12th to 13th century

   Regimen Sanitatis Salernitanum

   A health poem in Latin verse tied to the medical school of Salerno. It addresses the humours and the complexions, and was printed in nearly forty editions before 1501 and translated into almost every European language. It was discussed as a serious medical text until the 19th century.

   Modern statusDocumented tradition

   Shows how widely the idea spread. Popularity is not proof.

   • Regimen sanitatis Salernitanum (encyclopedia summary) (secondary summary)

6. 1575Spain

   Juan Huarte de San Juan, Examen de ingenios para las ciencias

   Printed in Baeza in 1575 and dedicated to Philip II of Spain. The text edition records a royal licence from Philip II for Castile (Madrid, 25 April 1574, ten years), an approval by the Council of Aragon (11 August 1574) and a royal licence for Aragon (15 August 1574). Huarte linked the four qualities to Galen's four temperaments and argued that temperament shapes aptitude. The Inquisition later made heavy cuts to the book, and a later privilege refers to it having been seen by the Holy Office and amended.

   In the original

   la que apetece, frialdad; la que retiene, sequedad; la que expele, humidad

   Huarte, chapter 1, original Spanish, on the qualities each faculty needs.

   Modern statusPartly carried forward

   The licences were permissions to print, not an endorsement of the theory. The aptitude-by-temperament claims have no modern support.

   • Article on Juan Huarte de San Juan and the Examen de ingenios, Rev. Asoc. Esp. Neuropsiquiatria
   • Huarte, Examen de ingenios para las ciencias (text edition with the licences and approvals)

7. Late 15th to early 18th centurySpain

   The Canon in Spanish university teaching

   The Canon entered European university teaching from the 14th century and left most syllabi in the second half of the 16th century, but it stayed obligatory at some Spanish universities, and at Padua, into the early 18th century.

   Modern statusDocumented tradition

   Shows the framework was official medical teaching in Spain for centuries. Teaching it is not the same as testing it.

   • Encyclopaedia Iranica, Avicenna xiii, Influence on the West (Canon in Latin)

8. 17th century

   Nicholas Culpeper (1616 to 1654)

   A summary source reports that Culpeper linked the humours to astrology and proposed that a person has a primary and a secondary temperament. This is the oldest precedent we found for the primary plus neighbor idea HOS uses. Verify against a primary source before relying on it.

   Modern statusDocumented tradition

   A historical precedent for the structure, not evidence that it is right.

   • Four temperaments (encyclopedia summary, to be replaced by primary scholarship) (secondary summary)

9. 1798

   Immanuel Kant, Anthropology

   Kant recast the four temperaments as combinations of feeling and activity: energetic and emotional (choleric), weak and balanced (phlegmatic), energetic and balanced (sanguine), weak and emotional (melancholic).

   Modern statusPartly carried forward

   Moves the idea from fluids to psychology, which is how modern research treats it.

   • Four temperaments (encyclopedia summary, to be replaced by primary scholarship) (secondary summary)

10. 1543 to 1858

    The decline of humoral medicine

    Vesalius challenged Galen's anatomy in 1543, and humoral theory fell out of favor as cellular pathology and chemistry advanced. Sources date its definitive abandonment to the 1850s, after the work of Rudolf Virchow.

    Modern statusNot supported today

    This is the honest limit: the humours are not what modern medicine measures.

    • Humorism (encyclopedia summary, to be replaced by primary scholarship) (secondary summary)
    • Four temperaments (encyclopedia summary, to be replaced by primary scholarship) (secondary summary)

11. 1920s

    Ivan Pavlov, types of nervous system

    From work with dogs, Pavlov described properties of the nervous system, strength, mobility and balance between excitation and inhibition, and derived four types that were compared with the classical temperaments.

    Modern statusPartly carried forward

    An early attempt to ground temperament in measurable nervous system traits. Animal work, and the typology is not widely used today.

    • Four temperaments (encyclopedia summary, to be replaced by primary scholarship) (secondary summary)

12. 1947 to 1967

    Hans Eysenck, neuroticism and extraversion

    Using factor analysis, Eysenck identified neuroticism and extraversion and argued that temperament has a biological basis. Combining the two dimensions gives four quadrants that resemble the classical temperaments, although a summary source flags that resemblance as needing a citation.

    Modern statusPartly carried forward

    The most defensible modern link: temperament as continuous traits with biological correlates, not four boxes.

    • Four temperaments (encyclopedia summary, to be replaced by primary scholarship) (secondary summary)

13. 2015

    Govindaraj et al., Ayurveda Prakriti and the genome

    A study of 262 well-classified men found 52 genetic variants that differed between the Ayurvedic constitutional types Vata, Pitta and Kapha. The authors conclude that the classification may have a genetic basis.

    Modern statusPartly carried forward

    A parallel tradition, not Unani and not RGP. One study, men only. Suggestive, not confirmation for HOS.

    • Govindaraj et al., Genome-wide analysis correlates Ayurveda Prakriti, Scientific Reports 5:15786, 2015

14. 2017

    Zendehboodi, mizaj and two detox genes (Iran)

    In 247 healthy male blood donors aged 20 to 40 in Fars, Iran, mizaj was self-reported and genes GSTM1 and GSTT1 were tested. Most comparisons showed no significant difference. Pooling groups, the warm-temperament group had more GSTT1-null people, and one genotype combination had higher odds of a warm temperament (odds ratio 2.94, confidence interval 1.05 to 8.24, p = 0.041). The author calls it preliminary.

    Modern statusPartly carried forward

    Small, men only, self-reported, several borderline results. Suggestive at best, and it does not test the HOS or RGP method.

    • Zendehboodi, GSTM1 and GSTT1 polymorphisms and temperament (mizaj), Iran, 2017

What history can and cannot showMany centuries of use show the idea was influential. They do not test it.Doctors in Hippocratic, Galenic, medieval and Spanish Golden Age traditions held the humours as physiology. Modern medicine does not.What survives is narrower: temperament as continuous traits with some biological correlates. HOS uses the four types as a map for reflection, not as a medical diagnosis.A royal licence from Philip II to print Huarte's book in 1574 is documented, along with church and Council of Aragon approvals. These were permissions to print, and the Inquisition later cut the book. We found no source showing that the Spanish crown endorsed the temperament method itself.