Natural Philosophy in the Tokugawa Period

The Early Development of the
Sciences in Japan
The Tokugawa Period: A mixture of
western and eastern science
The social place of intellectuals
•  Japan had a limited local tradition of inquiry
into the fundamentals of the natural world. •  Early intellectual traditions were strongly
influenced by texts brought over from China.
•  In the Tokugawa feudal system (士農工商),
there was no established place for intellectuals
and professionals working in specialist fields
(physicians, teachers, clerks, mathematicians,
etc.)
Scientists
in Tokugawa
•  There was no social role for the researcher in
Tokugawa and those who did research or
publish, did so haphazardly. •  There was no institutional support for the
pursuit of knowledge for its own sake.
•  Few norms for professional behavior.
–  Scholars often kept secrets from colleagues,
refused to publish, presented arguments in bits
and pieces, etc.
•  Most careers were hereditary. A
scientific
career
•  Hereditary routes. –  The official translators of Nagasaki (and later Edo).
–  The physicians. –  The astronomers employed by the shogunate and some
some daimyo for the regulation of the calendar.
•  Other routes.
–  Merchants.
–  Wealthy farmers. (Especially in mathematics.)
–  Samurai. •  Class advancement. Very occasionally,
commoners could advance to the samurai class
based on scientific achievements. Wages
•  During Tokugawa, intellectuals were
chronically underpaid. •  A high ranking samurai might receive 8,000
koku (石) but no Confucian scholar ever
received more than 3,500 k.
•  The average for scholars in official positions
was around 300 k.
•  A physician could earn between 150 k and
5,000 k. Tokugawa mathematics I
•  Mathematics had no official place in society.
Early on, there were some samurai
mathematicians, but later only commoners.
•  Nevertheless, there was a tradition of
Japanese mathematics that was developed
largely independently of Western
mathematics (和算, 算額). Tokugawa Mathematics II
•  Wasan was associated with methods for solving
equations, linear algebra and calculus-like
methods. It was largely a local development based
on using mathematical techniques learned from
the Chinese classics.
•  Sangaku were problem boards that were placed in
temples and shrines.
•  There was no (successful) applied mathematics
and most people regarded advanced mathematics
as useless. Indeed, many mathematicians thought
that mathematics should be useless. Segregation of fields
•  There was a sort of segregation of
mathematics from the other areas of study.
•  In early Tokugawa, samurai dominated in
mathematics and did little other science. In
late Tokugawa, the situation was reversed.
•  The samurai increasingly needed to earn a
living and felt that mathematics was useless
for this. Distain of mathematics
•  Nisimura Tosato (astronomer), 1761:
Mathematics is a childish subject in which
only people wishing to seek fame by
constructing impracticable theories… will
indulge. •  Yamakawa Kenjiro (early Meiji) was unable
to study mathematics at school because
mathematics was despised by the samurai
as something which only the merchants
should study… The same situation existed in
every other region. The influence of China
•  Until the modern period, the most important foreign
influence on Japan was China. (The number of Japanese
scholars who could read Chinese was much greater than
those who could read any other foreign language.)
•  In the late Heian and early Tokugawa, even Western
books were transmitted through their Chinese
translations. •  The main theme of natural inquiry before Meiji was the
accommodation of Western ideas into a Neo-Confucian
framework.
–  The claim that Western ideas had existed in ancient China (or
Japan) but had been subsequently lost. –  The transplantation of Western ideas into the intellectual
framework of the Book of Changes.
Book of Changes (易經)
•  A set of 64 oracular statements based on
hexagrams of six broken or solid lines (26=64),
arranged into sets of 3 lines. •  The interpretation of these describes a system
of cosmology and philosophy based on the
concepts of yin-yang (陰陽) and five
movements or phases (五行).
•  Although not set out systematically, there is an
underlying cosmology and philosophical
system.
Yin-Yang (陰陽)
•  Two primary states of all forces or actions in
the world. •  They always come into being together,
oppose one another, transform from one to
another and are in balance. •  They have certain key associations.
–  Yin: black, female, receptive, night, valleys, etc.
–  Yang: white, male, active, dominating, day, hills.
•  During Heian and Tokugawa, the office of the
astronomers was within Onmyoryo (陰陽寮). Other principles
•  Five movements (五行): Five movements or
phases: wood, fire, earth, metal, water. These
ideas were used to describe change from one
natural state to another. •  Li-Ch i (理氣): Li (ri) denotes the
regularity, pattern, form, etc., while ch’i (ki)
denotes the active force or energy. •  The detailed interpretations of these principles
changed over time and depending on the
scholars who discussed them.
Meteorology
•  Mukai, 1656: In the summer, yin ch i enters
the earth and yang ch i comes out of the earth.
Therefore, the surface is hot, and the earth and
well water are cool. In the winter yang ch i
enters the earth and ying ch i comes out of the
earth. Therefore, the surface is cold, and the
earth and well water are warm. The water in the
sea and the rivers follows the same principle.
Scholars of the Southern barbarians
[Westerners] know nothing of the Book of
Changes and are ignorant of the theory of
chi ien and k un (hexagrams 1 & 2). Western and Eastern approaches
•  Mukai, 1656: Giving up the ideas of lich i, yin-yang, five movements to pursue
other things is not practical learning. They
[SB, Westerners] do not know the right
way. •  Since Westerners do not comprehend the
significance of li-ch i and ying-yang their
theory of material is vulgar and
unrefined. Rangaku (蘭学)
•  Western learning was known as Dutch
learning because during Tokugawa all
western texts came through the Dutch. •  After the country was closed (鎖国), only
around 20 Dutch men were allowed to stay and
trade on the artificial island of Dejima in
Nagasaki. •  The government had a bureaucracy of hundreds
of people to deal with the Dutch, including
~150 translators. [All paid by the Dutch.]
Western
Learning
•  In the early period, books that mentioned
Christianity were banned and hence there was
very little access to western sources.
•  In 1720, Tokugawa Yoshimune relaxed the
regulations. But this was apparently not
announced at the time.
•  Many of the books were translations of
Chinese translations. Many others were
sensational but not very insightful. •  Nevertheless, there were a number of texts
that impressed people with western science. New Anatomy Text, 1759 (解体新書)
Sayings of the Dutch, 1787 (紅毛雑話)
Difficulties with Rangaku
•  Holland was just one European country. In the 17th
and 18th centuries they were scientifically, and
economically, very successful, but Dutch was never a
widely used European language. •  The Dutch at Dejima were merchants and had their
own agendas for their interactions with Japanese
scholars.
•  Japanese scholars could not leave the islands, so it was
difficult to develop language ability and to get access to
original sources. •  For all of these reasons, the interpretation that the
rangaku-sha developed of western science was often
peculiar. Shizuki Tadao 志筑忠雄 (1760-1806)
•  Was trained as an interpreter but lead a reclusive
life dedicated to scholarship.
•  Introduced Newton to the Japanese through a Dutch
translation of some textbooks by John Keill
(1671-1721). Introductio ad veram Physicam
(1701), and Introductio ad veram Astronmiam
(1718). •  Shizuki set out the Newtonian laws and attempted
to apply mathematics to dynamics in his New
Calendrical Phenomena.
•  It is unclear whether or not Shizuki understood all
the mathematics in Keill s works.
Shizuki s work •  New Treatise on Calendrical Phenomena
(暦象新書, 1798-1802).
•  Book I: Heliocentric theory. Astronomical
tables for prediction. Kepler s laws. A
discussion of the relatively of motion.
•  Book II: Neo-Confucian justification of
Newton s laws. Discussion of gravity.
Origin of the solar system. •  Book III: Centripetal force. Properties of
ellipses.
Confucian metaphysics
•  After introducing Newton s laws of motion, Shizuki
gives a justification in terms of Chinese science. •  The expansion of force always implies the
contraction of the material. The contraction of the
material always implies the expansion of force. Because
of expansion and contraction, change is everlasting.
Since force is monistic, everything is one. We dare not
discuss the underlying principle concerning the cause of
movement. If you want to understand the subtle
principle of movement and density, you should study
the Book of Changes. •  He applied yin-yang to explain attraction, gravitation,
action and reaction, and used the five movements to
explain the theory of particles. Mass
• 
The cause of all is change and flux and the
one ki (氣). However, gravity is in objects of
substance. Therefore, although it appears in
myriad forms, there is an aspect of substantive
ki (実氣) that is always comparable to gravity.
The fact that something can remain the same
size and change in weight is a result of change
in substantive ki. If a substance is dense, it has
much substantive ki and is heavy, if a
substance is rarefied, it has little substantive ki
and is light. Heliocentric theory
•  There is a potential problem with the
heliocentric theory: Heaven is yang and
earth is yin. Movement is the attribute of yang
and non-movement is the attribute of yin. If
the earth moves, it goes against the attributes
of yin-yang. However, when I examine the
idea of the Westerners over and over, it is hard
to say that western theory is not solid in its
view of the mathematical principles of
movement. Reconciliation
• 
I have the following idea: the main
objective of the Book of Changes is to praise
the wonder and function of heaven and earth.
When it discusses the force of heaven, or
heaven-as-force and earth-as-material, heaven
is yang and earth is yin. However, when it
refers to the material of heaven and earth, it
undoubtedly treats heaven as soft and light
yin, and earth as tough and solid yang. It is
like the hexagram shih ho in the Book of
Changes. • 
It reads: There is something between
the corners of the mouth. Mouth and the
thing are earth. The space inside the mouth
are heaven. Yang lines represent the mouth
and the things, whereas yin lines represent
the space. Hence, from this explanation, we
come to know clearly that the material of
heaven is yin and the material of the earth
moves around the heaven. Terminology and Technique
•  Shizuki had to coin many new terms for the ideas in
Newtonian science. Some of them are still in use
today (ex. 真空) but many others, based on Buddhist
and Confucian philosophy are no longer relevant (ex.
無量小) for infinitesimal.
•  He struggled most of all with how to handle the
mathematics. He left much of it out. He used different
symbolism in the different editions. Shizuki often
used prose descriptions (in literary Chinese) in place
of Keill’s symbolic expressions. Mathematical difficulties
•  Shizuki, marginal notes: Items such as the
laws of circular motion and the centrifugal
force at the equator may be difficult for
beginners to understand. If you are struggling to
understand… go to a mathematical meeting,
where you can share these problems. If you do
that, you will easily understand. If they try but
… say they do not understand and give up, they
have neither the intelligence to understand
astronomy nor the wisdom to understand
dynamics (動静). Wasan and Science
•  Although wasan would have largely been
technically capable of handling the new
sciences, there were a number of conceptual
and cultural difficulties. •  Wasan-ka felt that practical problems were
below the dignity of the field and they never
developed mathematical models for treating
motion, force, etc. Koide Shuki 小出修喜 (1791-1865)
•  Koide was one of the few wasan-ka who
made any attempt to apply wasan to physical
sciences. •  Ex.: He worked on revising the shogunal
calendar and published a number of treatises
on gunnery.
•  Treatise on Artillery Shells (砲術玉道真法,
1846) Impractical mathematics
•  While pointing out that the actual details of the
trajectory would be determined by the weight of the
ball and the strength of the charge, he says, I entrust
these matters to the gunners as such things are not of
concern to mathematicians. •  Later, when starting with an equation for the overall
trajectory, he calculates the height of the ball at given
distances and the apex of flight. •  These concerns are of purely mathematical interest.
What one really wants to know is: given a particular
set up, where the ball will land. [One needs
expressions for mass and charge.]
•  Koide starts out
with a given
equation for the
parabola. •  He then
calculates the
apex of the flight
and the height at
given intervals. Electricity
•  There were a number of studies of static
electricity in Tokugawa period. Like the
early European studies, they mostly focused
on parlor tricks. •  The first electrostatic generator was made
by Hiraga Gennai (平賀源内), which he
called the erekiteru. He consulted the works
of the rangaku-sha and a broken generator
in Edo. Electrical theory
•  One of the first works on electricity in
Japanese was the Fundamentals of the
Erekiteru of the Dutch (阿蘭陀始制エレキ
テル究理原, 1811), by Hashimoto Sokichi
橋本宗吉 (1763-1836).
•  This work gave examples of experiments
that could be done with the generator and
situated the theory of electricity within the
context Confucian metaphysics.
Electrical theory
•  Fundamentals, 1811: The principles of electricity
reveal that everything from… heaven and earth… to
corn dust is subject to the same principle. Natural
phenomena like wind, rain thunder, lightning,
earthquakes, and shooting stars can be created, and
experimented on by us. We are now able to know the
movement of a mini-universe which represents
heaven and earth… If you investigate the principles
of electricity by looking at the activity of the Book of
Changes through its images from this book, you will
feel like a man who had been awakened from a
billion-year-sleep by the first rays of sunlight shining
through the window. Overview
•  There were a number of factors that made it
difficult for the sciences to develop.
–  Little local support for science. –  Cultural and linguistic barriers. –  Limited social role for intellectuals.
–  No access to research level science.
–  Developing technical and linguistic apparatus. •  Despite this, there was a growing interest in
science and in the technologies that could be
developed through science.